Microbiology Flashcards by KM Guntayon

G(+) cocci arranged in clusters
colonies are opaque and smooth
grows well on most media
beta-hemolytic on sheep blood agar (SBA)
catalase (+)
coagulase (+)
(-) ability to metabolize pyrrolidonyl-alpha-naphthylamide (PYR) and ornithine
can tolerate high salt concentration of mannitol salt agar
penicillin-resistance

Staphylococcus aureus

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G(+) cocci arranged in clusters
colonies appear white to gray on blood agar
nonhemolytic
catalase (+)
coagulase (-)
most common coagulase (-)
novobiocin (S)

Staphylococcus epidermidis

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G(+) cocci arranged in clusters
colonies appear white to gray on blood agar
nonhemolytic
catalase (+)
coagulase (-)
novobiocin (R)
significant only in UTIs

Staphylococcus saprophyticus

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G(+) cocci arranged in clusters
colonies appear white to gray on blood agar
nonhemolytic
catalase (+)
coagulase (-)
PYR (+)
ferments manitol
clumps in plasma
frequent cause of endocarditis

Staphylococcus lugdunensis

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normal flora of the skin and mucous membranes
GS: arranged in tetrads, larger than Staphylococcus spp
appear yellow and non hemolytic on SBA
acid production from glucose under anaerobic conditions (-)
modified oxidase test (+)
bacitracin (S)

Micrococci spp

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catalase (-)
G(+) cocci arranged in pairs and chains
alpha or beta hemolytic or non hemolytic on SBA
Lancefield grouping is based on a cell wall antigen

Streptococcaceae

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Infections spread by respiratory secretions
cause pharyngitis, impetigo, cellulitis, scarlet fever, otitis media, nectrotizing fasciitis
sequelae include rheumatic fever, post streptococcal glomerulonephritis
bacitracin (S)
PYR positive
colonies pinpoint, translucent, beta hemolysis

group A stretococcus

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pathogenic group A streptococcus

S. pyogenes

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group A strep virulence factors: inhibits phagocytosis and antibodies formed against this are protective

cell wall M protein

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group A strep virulence factors: causes rash seen in scarlet fever; acts as superantigens interacting with macrophages and associated with streptococcal toxic shock syndrome (STSS)

exotoxin (Spe A, B, C, F)

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group A strep virulence factors: dissolves clots

streptokinase

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group A strep virulence factors: inhibits phagocytosis

hyaluronic acid capsule

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group A strep virulence factors: lyse erythrocytes, platelets, neutrophils

streptolysin O & S

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group A strep virulence factors: hydrolyzes hyaluronic acid, an interstitial barrier, facilitating spread of the infection

hyaluronidase

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isolates typically express Lancefield group C or G antigens
clinical spectrum of disease resembles S. pyogenes and include pharyngitis, skin infections, necrotizing fasciitis, STSS, endocarditis, glumerulonephritis, acute rheumatic fever

S. dysagalactiae subspecies equisimilis

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normal flora of GI tranct
cause infection in OB/GYN patients
neonates acquire infections during birth, resulting in sepsis and meningitis
can cause endocarditis, pneumonia, pyelonephritis in immunocompromised patients
colonies are medium-sized (>1mm), flat, creamy and show small zones of beta hemolysis
CAMP test (+)
hippurate hydrolysis (+)
PYR (-)
bacitracin (R)

group B streptococcus

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normal fecal and oral flora
associated with wound infections, UTIs and abdominal abscesses
isolation in blood cultures is an indicator of colon cancer
colonies are gray to white, translucent, round and convex
alpha hemolytic or nonhemolytic, rarely beta
bile esculin (+)
6.5% NaCl (-)
PYR (-)

group D non-enterococcus

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normal flora of the oral cavity, respiratory tract and GI tract mucosa
major cause of bacterial endocarditis; also causes wound infections and brain abscesses
may enter the blood after dental procedures
alpha hemolytic, some strains non hemolytic
optochin (R)
bile (insoluble)
does not grow on bile-esculin medium

viridans streptococci

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normal upper respiratory tract flora but can cause lobar pneumonia, otitis media, meningitis
G (+) diplococci that are lancet or bullet-shaped and alpha hemolytic
grows on SBA with 5-10% CO2 at 48h
mucoid strains produce a large polysaccharide capsules
umbilicated, depressed centers caused by autolytic enzymes

s. pneumoniae

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rust-colored sputum and lobar pneumonia is often associated with ____

s. pneumoniae

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most common encountered sp of enterococcus

e. faecalis
e. faecium

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bile esculin (+)
6.5% NaCl (+)
PYR (+)
lancefield group D antigen
alpha-, beta-, non-hemolytic

enterococcus

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associated with a number of infections including endocarditis, meningitis, lung abscesses and osteomyelitis
PYR (+)
leucine aminopeptidase (+)
bile esculin (-)

gemella

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have been linked osteomyelitis, ventriculitis, postsurgical endophthalmitis, and bacteremia in neonates
vancomycin (R)
PYR (-)
LAP (-)
catalase (-)

leuconostoc

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require vitamin B6 for growth normal flora of the oral cavity and have associated with endocarditis, ophthalmic infections, infections of the CNS

abiotropha granulicatella

causes spontaneous abortion and meningitis in animals found in environment, normal flora of the vagina and intestines in human grows on most media colonies are white and small with a narrow zone of beta hemolysis closely resemble group B strep on SBA umbrella motility in semi-solid media and end-over-end tumbling in a wet mount hippurate hydrolysis (+) CAMP (+) esculin (+) catalase

listeria monocytogenes

pseudomembrane formed by dead cells and exudates at the back of the throat found only in humans gram stain: picket fence or chinese letters methylene blue: metachromatic granules urease (-) pyrazidamidase (-) nitrate (+) catalse (+) non-motile

corynebacterium diphtheria

what test uses antitoxin to detect toxin production of the C. diphtheria

elek test

appearance of corynebacterium spp: cystine-tellurite

black colonies

appearance of corynebacterium spp: tinsdale's agar

brown to black colonies with halos

appearance of corynebacterium spp: loeffler agar

small white to gray colonies

appearance of corynebacterium spp: SBA

small, white, dry colonies non hemolytic

important cause of nosocomial infections and produces infections after prosthetic implants and infections in immunocompromised patients pyrazidamidase (+) antimicrobial agents (R)

corynebacterium jeikeium

cause UTIs rapid urease (+) grows very slowly

corynebacterium urealyticum

6 species but 3 clinically significant natural habitat have not been confirmed small beta hemolytic colonies on SBA catalase (-) non motile

arcanobacterium

associated with pharyngitis and wound and tissue infections small beta hemolytic colonies on SBA catalase (-) non motile can be identified with CAMP inhibition test

arcanobacterium haemolyticum

found on mucous membranes of cattle, sheep, and swine linked to abscess formation, wound and soft tissue infections in cattle and humans small beta hemolytic colonies on SBA catalase (-) non motile

arcanobacterium pyogenes

produced by a. haemolytitcum inhibits the activity of staphylococcus aureus beta-lysin this phenomenon is also exhibited by ___

phospholipase D c. pseudotuberculosis

primarily infects animals human generally become infected through contact with infected animals or by consuming infected meat causes cellulitis, bacteremia or endocarditis non motile pleomorphic G(+) bacilli catalase (-) H2S (+)

erysipelothrix rhusiopathiae

erysipeloid lesions that resembles erysipelas caused Streptococcus pyogenes

cellulitis

generally found in immunocompromised patients with chronic pulmonary disorders most clinically relevant species pleomorphic, branching G (+) bacilli in chains that produce a beading arrangement, appear fungal-like partially acid fast catalase (+) non motile requires up to 6w for growth exudates contain masses of filamentous organism with pus that resemble sulfur granules

nocardia asteroides

bacterial spores contain ____ which makes them resistant to adverse environment

calcium dipicolinate

can survive adverse conditions for prolonged periods of time and are frequent contaminants of laboratory cultures can be centrally or terminally located

bacterial spores

form straight bacilli with square ends (box-car morphology) appearing in chains and singly SBA (+) phenylethyl alcohol (PEA) agar (+) catalase (+) large, flat colonies

bacillus spp

causes anthrax potential bioterrorism agent large non hemolytic agent with filamentous projections (Medusa head) colonies PEA (-) at 24 hr preliminary testing by sentinel lab: typical colony morphology, G(+) bacilli with spores, catalase (+) non motile

bacillus anthracis

3 clinical forms of anthrax

cutaneous anthrax pulmonary anthrax gastrointestinal anthrax

most common form of anthrax

cutaneous anthrax

skin lesions of cutaneous anthrax

black eschar

pulmonary anthrax spread by inhalation of spores from sheep's wool

wool-sorter's disease

important cause of food poisoning and occasionally wounds, may also cause opportunistic eye, bone and brain infections large, flat, beta hemolytic colonies with irregular edges motile penicillin (R)

bacillus cereus

oxidase (+) fastidious and grow best in 5-10% CO2 at 37degC cannot tolerate cold

neisseriaceae

neisseriaceae includes these genera

neisseria eikenella kingella simmonsiella

not a normal flora humans are their only host fastidious doses not survive long outside the host be isolated from the urethra, cervix, anal canal, oropharynx, skin lesions, joins and blood

neisseria gonorrhoeae

gonorrhea in males characterized by pus-containing urethral discharge and dysuria

acute urethritis

gonorrhea in females

UTI cervicitis (cervical discharge, fever, acute pain, dysuria) pelvic inflammatory disease gonococcal arthritis salphingitis endometritis peritonitis

to prevent newborn conjunctivitis, this is being administered to all infants at birth

erythromycin

Gram stain: appears intracellular to neutrophils fastidious, requiring enriched media such as chocolate agar plate, Thayer Martin, Martin-Lewis, New York city and GC Lec Agars SBA (-) require increased CO2 with humidified atmosphere autolysis, cannot be incubated for prolonged times flat, smooth and glistening gray or tan colonies superoxol (+) catalase (+) oxidase (+) glucose (+) maltose (-) lactose (-) sucrose (-) DNAse (-) nitrate (-) beta lactamase (+) most

neisseria gonorrhoeae

spread by respiratory droplets and may be normal flora of the nasopharynx causes meningococcal meningitis, meningococcemia, leading to DIC and waterhouse-friderichsen syndrome csf, sputum, blood and nasopharyngeal swabs falt, smooth and gray-white colonies on chocolate agar SBA with increased CO2: bluish-gray colonies catalase (+) oxidase (+) glucose (+) maltose (+) DNAse (-) nitrate (-)

neisseria meningitidis

colonizes the throat of children predilection for infections of the bones and joints in children generally limited to those who are immunocompromised isolated from joints and bones in blood culture media SBA (+) chocolate agar (+) Thayer Martin agar (+) MCA (-)

kingella kingae

habit unknown most associated with endocarditis SBA (+) chocolate agar (+) Thayer Martin agar (+) MCA (-) can reduce nitrates

kingella dentrificans

resembles neisseria NF of the upper respiratory tract causes otitis media, sinusitis, respiratory tract infections grow on most nutrient agars catalase (+) oxidase (+) DNAse (+) nitrate (+) butyrase esterase (+) assacharolytic carbohydrate test (-)

moraxella catarrhalis

most medically important family of G (-) bacili normal flora of the GI tract major cause of nosocomial infections UTI, gastroenteritis, septicemia, food poisoning, wound infections, peritonitis, pneumonia, meningitis facultative anaerobes glucose (+) nitrate (+) catalase (+) oxidase (-)

enterobacteriaceae

enterobacteriaceae inhibit four serological characteristics

O, K, H, Vi Ag

somatic Ag cell wall antigen heat stable

O Ag

envelope Ag capsular Ag heat labile

K Ag

flagellar Ag heat labile

H Ag

capsular antigen of salmonella typhi heath labile

Vi Ag

all enterobacteriaceae are oxidase negative except

plesiomonas

MAC agar: lactose (+) ______ lactose (-) ______

pink-red colorless

eosin-methylene blue (EMB) agar: lactose (+) ______ lactose (-) ______

dark center colorless

hektoen enteric (HE) agar: lactose/sucrose (+) ______ salmonella ______ shigella ______

yellow/orange colonies green with black centers clear colonies

salmonella-shigella (SS) agar lactose/sucrose (+) ______ salmonella ______ shigella ______

red colonies colorless with black centers colorless

bismuth sulfite agar lactose/sucrose (+) ______ salmonella ______ shigella ______

yellow/orange colonies black colonies black colonies

brilliant green agar: proteus and salmonella _____ shigella _____ lactose (+) ____

red/pink colonies will not grow will not grow

selenite broth: salmonella _____ gram (+) and coliform (NF of GI) _____

enhanced inhibited

normal GI flora very common clinical isolate causes UTI, appendicitis, peritonitis, gall bladder infections, endocarditis, meningitis, gastroenteritis, food poisoning triple sugar iron (TSI): A/A, H2S (-) MAC: pink-red colonies SBA: shiny, opaque, off-white, 2-4 mm beta hemolytic EMB: green metallic sheen colonies with dark centers indole methyl red (IMB) (+) motility (+) o-nitrophenyl-beta-D-galactopyranoside (ONPG) (+) voges-proskauer (VP) (-) citrate (-) urease (-)

escherichia coli

causes hemorrhagic colitis and hemolytic uremic syndrome leading to kidney failure in young children eating undercooked hamburger, contaminated food eg apple cider, basil, sprouts sorbitol-MAC agar (+)

EHEC

principal virulence factor of EHEC

shiga toxin (Stx) 1 and 2

produces severe epidemic diarrhea, mainly from drinking contaminated water

ETEC (enterotoxigenic)

causes bloody diarrhea by invading intestinal epithelium

EIEC (enteroinvasive)

causes watery diarrhea

EPEC (enteropathogenic)

highly pathogenic (less than 50 bacteria can cause disease) direct fecal contamination from infected humans TSI: K/A H2S (-) VP (-) motility (-) urease (-) citrate (-) lactose (-) MR (+)

shigella

produces an enterotoxin, which affects the large intestines, and a neurotoxin that may result in paralysis mannitol (-) ONPG (-) TSI: K/A H2S (-) VP (-) motility (-) urease (-) citrate (-) lactose (-) MR (+)

S. dysenteriae (serogroup A)

produces a mild diarrhea mannitol (+) ONPG (-) TSI: K/A H2S (-) VP (-) motility (-) urease (-) citrate (-) lactose (-) MR (+)

S. flexneri (serogroup B) S. boydii (serogroup C)

produces a mild diarrhea mannitol (+) ONPG (+) TSI: K/A H2S (-) VP (-) motility (-) urease (-) citrate (-) lactose (-) MR (+)

S. sonnei (serogroup D)

cause UTIs and pneumonia nosocomial, diabetics and alcoholics are prone to infections TSI: A/A with gas MCA: pink colonies are very mucoid H2S (-) MR (-) nonmotile indole (-) VP (+) citrate (+) lactose (+)

klebsiella

most common isolated species of klebsiella

K. pneumoniae

causative agent of granuloma inguinale does not Gram stain or grow on laboratory media Wright's or Giemsa stained Donovan bodies may be seen

K. (Calymmatobacterium) granulomatis

intracellular pleomorphic bipolar staining cells

Donovan bodies

includes 12 species, found in soil, water, and dairy products linked to respiratory tract infections and wounds, and isolated from blood H2S (-) MR (-) indole (-) VP (+) citrate (+)

enterobacter

most common species of enterobacter H2S (-) MR (-) indole (-) VP (+) citrate (+) lactose (+) arginine (+) lysine (-)

E. cloacae

second most common species of enterobacter H2S (-) MR (-) indole (-) VP (+) citrate (+) lactose (+) arginine (-) lysine (+)

E. aerogenes

H2S (-) MR (-) indole (-) VP (+) citrate (+) lactose (+) produces a yellow pigment

E. sakazakii

H2S (-) MR (-) indole (-) VP (+) citrate (+) lactose (-)

E. taylorae

causes opportunistic infection in patients undergoing chemotherapy and immunosuppressed patients DNAse (+) gelatinase (+) lipase (+) VP (+) citrate (+) ONPG (+) lactose (delayed)

serratia

most common clinical isolate DNAse (+) gelatinase (+) lipase (+) VP (+) citrate (+) ONPG (+) lactose (delayed)

S. marcescens

cause moderate to severe gastroenteritis has many animal reservoirs transmitted through contaminated water and undercooked foods especially chicken characterized by a septicemia followed by a GI tract infection lactose (-) H2S (+) citrate (+) indole (-) urease (-) colonies on HE agar are green with black centers

salmonella

majority of human causes of salmonellosis are due to serotypes belonging to this species

S. enterica (S. typhi)

H2S (+) urease (+) tryptophan deaminase (TDA) (+) phenylalanine deaminase (+) ONPG (-) lactose (-) indole (-)

Proteus mirabilis

H2S (+) urease (+) tryptophan deaminase (TDA) (+) phenylalanine deaminase (+) ONPG (-) lactose (-) indole (+)

P. vulgaris

phenylalanine deaminase positive

proteus providencia morganella

selective and differential medium for isolation of Y. enterocolitica, colonies of which will ferment mannitol and absorb the dye neutral red, producing a clear colonies with a pink center

cetsulodin-irgasan-novobiocin medium

endemic to the southwestern US small animals (e.g. rodents) are natural reservoirs, and the bacteria are transmitted by fleas potential bioterrorism agent nonmotile pinpoint colonies on SBA after 24h incubation G (-) bacilli oxidase (-) urease (-) catalase (+)

Yersinia pestis

causes enterocolitis in humans acquired by drinking contaminated water or by eating contaminated meat ONPG (+) delayed lactose fermenter sucrose (+) colorless on MAC at 18 hours but A/A on TSI non motile at 37 deg C but motile at 25deg C

Y. enterocolitica

rare cause of lymphadenitis in children non motile at 37 deg C but motile at 25deg C

Y. pseudotuberculosis

resembles salmonella H2S (+) ONPG (-) indole (+) citrate (-)

Edwardsiella

most common isolate of Edwardsiella

E. tarda

most common species isolated of Citrobacter resembles E. coli on MCA but can be differentiated because of being H2S (+) indole (-)

C. freundii

indole (+) VP (-) citrate (-) PDA (+) TDA (+)

Morganella morganii

PDA (+) TDA (+) indole (+) citrate (+) VP (-) most common isolate of Providencia

P. rettgeri

HACEK fastidious (require complex nutrients for growth) important causes of endocarditis

Haemophilus Actinobacillus Cardiobacterium hominis Eikenella Kingella

pleomorphic gram (-) coccobacilli ranging from very small to filamentous growth requirements include X and V factor do not grow on SBA but will grow on horse or rabbit blood agar, which contains no NADase chocolate agar is routinely used for cultures grows at 35-37 deg C with 5-10% CO2 and is susceptible to drying and temperature changes colony morphology: smooth, round, flat, opaque and tan on chocolate agar non motile catalase (+) oxidase (+)

haemophilus

X factor released from hemoglobin

hemin

V factor heat-labile compound

NAD

haemophilus spp can grow around colonies of S. aureus growing on an SBA plat since the colonies of the latter release NAD, forming a tiny clear pinpoint colonies

satellitism

x factor (+) v factor (+) hemolysis on horse blood agar (-) ALA (-)

H. influenzae H. aegyptius

x factor (+) v factor (-) hemolysis on horse blood agar (-) ALA (-)

H. ducreyi

x factor (-) v factor (-) hemolysis on horse blood agar (-) ALA (+)

H. aprophilus

x factor (+) v factor (+) hemolysis on horse blood agar (+) ALA (-)

H. haemolyticus

x factor (-) v factor (+) hemolysis on horse blood agar (-) ALA (+)

H. parainfluenzae H. paraprophilus

has 6 capsular serotypes and 8 biotypes I-VII should be tested for beta lactamase can be isolated from a variety of specimens including blood, sputum, CSF, eye swabs specific detection of Hib capsular antigen by latex agglutination

H. influenzae

major cause of meningitis in children vaccine had greatly reduced childhood meningitis and other invasive disease caused by this serotype

H. influenzae type b

causes pink eye, a very contagious conjunctivitis similar to H. influenzae except sucrose (+)

H. aegyptius

causes conjunctivitis followed by an invasive disease known as Brazilian purpuric fever resembles H. influenzae biotype III in that it is indole (-), urease (+), and ornithine decarboxylase (-)

H. influenzae biogroup aegyptius

causes genital ulcers produces chancroids and buboes (swollen lymph nodes) chocolate agar with vancomycin is used to inhibit normal flora and contaminants

H. ducreyi

found in the water, soil, food, plants and a few are normal flora of humans approximately 20% of all gram (-) bacilli isolates most are obligate anaerobes do not form spores and do not metabolize carbohydrates under anaerobic conditions most are oxidase (+) TSI: K/K grow on SBA but varied growth in MCA

Non fermentative Gram (-) bacilli (NFB)

most important NFB common clinical isolate that can infect humans, animals, plants and fish causes eye (lens wearer) and ear infections (swimmer's ear, external otitis) lower respiratory tract infection in patients with cystic fibrosis important pathogen in immunocompromised individuals

P. aeruginosa

only organism in the pseudomonas family that is capable of producing the pigment pyocyanin only ones capable of growing both at 35 and 42 deg C

P. aeruginosa

oxidase (+) motile lactose (-) large irregular colonies with grape-like odor and metallic sheen on SBA beta hemolytic colonies with a feathery edge on SBA mucoid colonies when isolated from patients with CF very resistant to antimicrobial agents

P. aeruginosa

this test determines if glucose is broken down oxidatively or fermentatively two tubes are used: one is overlayed with mineral oil to produce anaerobic conditions the other tube contains no mineral oil (aerobic) oxidative bacteria produce acid (yellow color) ie the open tube; whereas the closed tube is green

oxidative-fermentative glucose test

acquired as transient flora from hospitals causes pneumonia, UTIs, wound infections oxidase (-) the only non fermentative, gram (-) bacillus that is oxidative (-) maltose (+) one of two clinically encountered NFB that is lysine decarboxylase (+) resistant to most antimicrobials

stenotrophomonas maltophilia

causes nosocomial infections important respiratory tract pathogen in patients with CF (second to P. aeruginosa) enhanced growth on P. cepacia (PC) agar that inhibits P. aeruginosa colony morphology: colorless or yellow on nutrient agar oxidase (+) lactose (+) lysine decarboxylase (+)

burkholderia cepacia

causes glanders grows on MCA oxidative (variable) non motile reduces nitrate to nitrite without gas glucose (+)

burkholderia mallei

highly contagious disease of livestock, particularly among horses, mules and donkey can be transmitted to human by animal contact

glanders

disease of humans and animals endemic to SEA and northern Australia has a wide range of signs and symptoms can be mistaken for other diseases, such as tuberculosis or more common forms of pneumonia.

melioidosis

causes melioidosis found in soil and infections are acquired through the skin or by inhalation grows on MCA oxidase (+) motile reduces nitrate to nitrite with gas oxidizes several sugars including glucose and lactose

burkholderia pseudomallei

obligate aerobic coccobacillus found as normal flora of the GI and respiratory tracts important cause of nosocomial infections and UTIs isolates tend to be multidrug resistant grow on most media and may resemble enterics on MCA and EMB agars produce acid from glucose but others don't non motile oxidase (-) nitrate (-) catalase (+)

acinetobacter

causes tularemia potential agent of bioterrorism carried by wild animals, including deer, rabbits, beavers and squirrels intracellular bacteria that resist phagocytosis causes skin ulcers at the site of inoculation and can cause of infections of the lymph nodes, eyes, lungs and GI system biosafety level 3 is required when handling the organism or suspect specimens faintly straining coccobacilli medium of choice: glucose-cyseine blood agar color morphology: small and grayish agglutination and direct fluorescent antibody test are used to confirm the identification

francisella tularensis

also known as undulant fever symptoms may show up anytime from a few days to a few months after you've been infected, which include fever, chills, loss of appetite, sweats, weakness, fatigue, joint, muscle and back pain, headache humans acquire the infection by drinking contaminated milk or from slaughter house incubation period is 1-3 weeks

brucellosis

causes brucellosis normal GI flora of animals facultative intracellular parasite biosafety level 3 organism isolated from blood and bone marrow fastidious organism that will grow on special media like Thayer Martin agars and require 10% CO2 in humidified air and 3-4 weeks for growth strict aerobe oxidase (+) catalase (+)

brucella

4 species of brucella that infect humans

B. melitensis B. abortus B. suis B. canis

inhabits the mucous membranes of the respiratory tract of humans grows on Bordet-Gengou (potato infusion) and Regan-Lowe agars (charcoal-horse-blood agar) with cephalexin colonies are small and smooth, appear like mercury droplets and are beta hemolytic gram (slow minute), poorly stained coccobacilli, single or in pairs causes pertussis urease (-) does not grow on MCA

bordetella pertussis

other species of bordetella causes mild respiratory infections in humans grows on MCA urease (+)

B. parapertussis

other species of bordetella causes kennel cough in dogs and is an infrequent cause of respiratory infections in humans grows on MCA urease (+)

B. bronchiseptica

found mostly as oral flora of animals infections are caused by animal bites, which can result in cellulitis grows well on SBA and chocolate agar but will grow on MCA produce colonies that show star-like centers most are catalase (+) glucose (+)

actinobacillus spp.

associated with endocarditis, gum disease

A. actinomyecetemcomitans

normal respiratory/GI flora of animals causes cellulitis but can progress into osteomyelitis, meningitis, joint infections and pneumonia grows well on non selective agars but no MAC oxidase (+) catalase (+) indole (+) nitrate (+) non motile, pleomorphic, G (-) coccobacilli that may show bipolar staining penicillin (S)

pasteurella

normal flora of the mouth and upper respiratory tract causes abscesses of oral cavity and human bite wound infectious approximately 50% of the strains corrode or pit the agar surface produces bleach-like odor

eikenella corrodens

what does eikenella corrodens require for growth

hemin (factor X)

first discovered in 1976 as the cause of pneumonia in people attending an American Legion Convention in Philadelphia aquatic organisms that may be found in various water systems, including humidifiers, whirlpools and air conditioning chillers resistant to commonly used concentrations of chlorine

legionella

primary pneumonia severe form of legionellosis

Legionnaires disease

mild form of Legionellosis characterized by flu-like symptoms

Pontiac fever

most common laboratory assay used for the diagnosis of legionellosis

urine antigen test

gram stain: thin, poorly staining G(-) bacilli; better use 0.1% basic fuchsin as the counter stain instead of safranin require L-csyteine for growth grow on BCYE aga but not on SBA asaccharolytic, most biochemical tests are negative autofluoresce when exposed to UV light

legionella

found in water and soil produces a purple or violet pigment on nutrient agar causes wound infections acquired from contaminated soil or water

chromobacterium

very small Gram variable coccobacilli considered normal vaginal flora associated with bacterial vaginosis, UTIs, PID and postpartum sepsis and may infect the newborn catalase (-)

gardnerella vaginalis

presence of clue cells, epithelial cells with numerous bacteria attached

bacterial vaginosis

scoring system used to diagnose BV cultures alone are too sensitive but 50-60% of women who do not meet the criteria for BV are positive for G. vaginalis

Amsel and Nugent

oxidase (-) G (-), curved bacilli

bartonella

agent of trench fever also causes growth of neoplastic blood vessels in various parts of the body (bacillary angiomatosis) and other infections such as endocarditis

bartonella quintana

causes cat-scratch disease and also bacillary peliosis hepatitis and bacillary angiomatosis

bartonella henselae

found as normal flora in humans in the upper respiratory tract and possibly the GI and genital tract mainly associated with endocarditis gram stain: short chains or rosettes of irregularly staining bacilli with bulbous ends requires CO2 for initial isolation and can be recovered on SBA although growth is enhanced in media containing yeast extract oxidase (+) catalase (-) indole (+, weakly)

cardiobacterium hominis

found as normal oral flora in rats and other rodents best isolated from blood, synovial fluid and abscess material non motile facultative G (-) pleomorphic bacillus grows on media enriched with SBA (15% is optimal) incubated in a CO2 incubator

streptobacillus moniliformis

infections following animal bites carrying S. moniliformis

rat-bite fever

ingestion of contaminated food or water with S. moniliformis results in ___

haverhill fever

genus contains about 12 species that are inhabitants of marine water halophilic except for two species

Vibrio

selective and differential (based on sucrose fermentation) medium that supports the growth of most species and is particularly useful for isolating V. cholerae and V. parahaemolyticus

thiosulfate citrate bile salt sucrose agar (TCBS)

characterized by severe watery diarrhea with flecks of mucus sometimes referred to as "rice-water stool"

cholera

causes a cholera acquired by ingestion of undercooked seafood or contaminated drinking water has enterotoxin that alters ion transport of intestinal mucosa, resulting in massive release of water sucrose (+) and will produce yellow colonies on TCBS agar

vibrio cholerae O1

3 serotypes of of V. cholerae O1

Inaba Ogawa Hikojima

2 biotypes of V. cholerae O1

classical El Tor

important virulence mechanisms of V. cholerae

choleragen motility pili mucinase

causes mild to moderate cholera like diarrhea disease acquired by eating raw shellfish important cause of food poisoning in Asia, particularly in Japan and Taiwan sucrose (-)

V. parahaemolyticus

highly virulent, causing septicemia after ingestion of undercooked seafood, notably raw oysters causes rapidly progressive wound infection after exposure to marine water

V. vulnificus

very common in marine environment suspected causes of otitis media and wound infections

V. alginolyticus

found in fresh and salt water infects humans and fish causes cellulitis and diarrhea generally cause a self-limiting infection not usually requiring treatment; however, wound infections may require antimicrobial therapy

aeromonas

beta-hemolytic oxidase (+) citrate (+) indole (+) VP (+) ONPG (+)

A. hydrophila

acquired by eating undercooked seafood primarily associated with a self-limiting gastroenteritis oxidase (+)

plesiomonas shigelloides

major cause of food poisoning causing gastroenteritis, diarrhea and septic arthritis acquired by eating undercooked contaminated poultry or other meat products curved bacilli that may appear S-shaped or spiral on Gram stain microaerophilic do not oxidize or ferment carbohydrates and most human isolates are catalase (+) and oxidase (+) wet mount: darting motility

campylobacter

causes peptic and and duodenal ulcers and has been linked to stomach cancer microorganisms can be isolated from gastric biopsy on SBA, Brucella, and Skirrow's incubated microaerophilically fecal antigen detection, urea breath test and demonstration of urease activity in stomach biopsy material

helicobacter pylori

slender, non motile, non-spore forming, obligate aeorobes resist gram staining because of lipids in their cell wall that prevent penetration of crystal violet and safranin acid fast bacilli (AFB)

mycobacteria

primary stain in the acid fast stain

carbolfuchsin

Ziehl Neelsen stain requires ___ during the staining step whereas the Kinyoun's stain does not

heating

used in decontamination of sputum samples

2% NaOH with N-acetyl-L-cysteine (NALC)

mucolytic agent that liquefies mucus in respiratory specimens, releasing mycobacteria

NALC

increases the pH to a level that is antibacterial

NaOH

solid media for growing mycobacteria: contains egg components for growth and malachite green to inhibit the growth of normal flora

lowenstein-jensen

solid media for growing mycobacteria: made selective by the addition of penicillin and nalidixic acid, and supplemented with RNA

lowenstein-jensen gruft

solid media for growing mycobacteria: agar based and contains 2% glycerol to support the growth of mycobacterium avium complex

middlebrook medium

often used to maintain stock cultures and prepare isolates for biochemical tests

middlebrook 7H9 broth

made by Becton Dickinson contains modified 7H( broth large amount of oxygen in the broth quenches the fluorescence of a fluorochrome

mycobacterium growth index tube (MGIT)

contains a radioactively labeled substrate that can be metabolized by mycobacteria growth of mycobacteria releases radioactive CO2 that is detected by the instrument

BACTEC 460TB

except for members of the M. tuberculosis complex, the mycobacteria are placed into these groupings according to their growth rate and photoreactivity but due

runyon group

runyon group 1

slow growers and photochromogen

runyon group 2

slow growers and scotochromogen

runyon group 3

slow growers and non chromogen

runyon group 4

rapidly growing mycobacteria

produce yellow to orange pigment only when exposed to light

photochromogen

produce yellow to orange pigment in the light and in the dark

scotochromogen

do not produce pigment

non chromogen

biochemical test for identification of mycobacteria: a suspension of a mycobacterium spp is heated at 68 deg C for 20 minutes then a 1:1 mixture of 30% hydrogen peroxide and 10% Tween 80 is added. after 5 minutes, the suspension is observed for bubbles M. tuberculosis complex are negative

heat-sensitive catalase

biochemical test for identification of mycobacteria: a 1ml aliquot of a mixture of hydrogen peroxide and Tween 80 is added to a 2-week-old culture deep of mycobacteria and after 5 minutes, the height of the column of bubbles is measured M. tuberculosis complex produces columns of bubbles <45mm

semiquantitative catalase

biochemical test for identification of mycobacteria: NaNO3 is added to a heavy suspension of mycobacteria, which is then incubated for 2 hours at 35degC and then this is added ___ color is positive reaction

nitrate pink

M. tuberculosis is one of the few species positive for the accumulation of ____

niacin

because of their slowly growing nature, these are becoming more common in clinical laboratories for the identification for the mycobacteria

nucleic acid assays

causes tuberculosis, chronic primarily lower respiratory tract disease spread by person-to-person contact via infected droplets, dust only a few bacteria are necessary to cause disease

mycobacterium tuberculosis

infection begins in the middle or lower areas of the lungs bacteria can spread in the lymphatic system, CNS and heart macrophages phagocytize the bacteria and form multinucleated cells, which are eventually surrounded by fibroid cells and later on can calcify

primary tuberculosis

granulomatous lesions in primary tuberculosis which can be seen on CXR

tubercles

calcified granulomatous lesions

ghon-complexes

bacteria are contained within the granulomas and the patient is typically asymptomatic

latent infection

occurs in people with who have had latent TB alteration in the cell-mediated immune response triggered by poor nutrition, alcoholism or hormonal factors associated with pregnancy and diabetes

reactivation or secondary TB

first line drugs for treating secondary TB

isoniazid rifampin ethambutal pyrazinamide

resistance to any fluoroquinolone, and at least one of three injectable second-line drugs in addition to isoniazid and rifampicin

extremely-drug-resistant M. tuberculosis

skin test that determines exposure to M. tuberculosis Ag is composed of heat-killed, filtered, ammonium sulfate precipitated protein injected intradermally and is examined at 48 hours for swelling positive test indicates previous exposure

purified protein derivative (PPD)

agent of Hansen disease cannot be grown on artificial media diagnosis is based on characteristic skin lesions and visualizing AFB in lesion

mycobacterium leprae

may cause disseminated disease in immunosuppressed patients such as patients with human immunodeficiency virus infection, producing lung infection, lymphadenitis and intestinal infection slowly growing non chromogen

mycobacterium avium complex (MAC)

causes pulmonary infection and is the most commonly isolated photochromogen in US causes a lung disease that resembles classic TB and rarely disseminates, except in patients with severe immunosuppression slow grower nitrate (+) catalase (+)

mycobacterium kansasii

causes cervical lymphadenitis and other types of infectious predominantly in children slowing growing scotochromogen

mycobacterium scrofulaceum

implicated in skin infections predilection for surface areas and extremities of the body is related to their optimal growth temperature range of 30-32 deg celsius

M. ulcerancs M. marinum M. haemophilum

responsible for a zoonosis, producing pulmonary infections primarily in cattle and occasionally in humans non chromogen like M. tuberculosis nitrate (-) niacin (-) T2H (S)

M. bovis

may cause abscesses, osteomyelitis, wound and lung infection weakly virulent rapidly growing mycobacteria

M. fortuitum M. chelonae M. abscessus

found in fresh water, including tap water rarely pathogenic slow growing scotochromogen often isolated as a contaminant

M. gordonae

comprise most normal flora of the mucous membranes foul odor (from gas production) and necrotic tissue anaerobic body sites, abscesses and wound surgical specimens

anaerobic bacteria

bacterium that cannot use oxygen for metabolism and oxygen is lethal to the microorganism

obligate anaerobe

bacterium that cannot use oxygen but can grow in its presence

aerotolerant anaerobe

bacterium that will use oxygen if its present and can grow, albeit more slowly, without oxygen

facultative anaerobe

bacterium that requires oxygen at a concentration found in room air, about 20%

obligate aerobe

bacterium that requires oxygen at a concentrations of 5-10%

microaerophile

bacterium that requires increased concentrations of CO2

capnophile

being added to the anaerobic media to enhance the growth of Prevotella and Porphyromonas

vitamin K

being added to the anaerobic media as enrichment for Bacteroides and Prevotella

hemin

anaerobic media: for general growth of all anaerobes

centers for disease control and prevention (CDC) anaerobic blood agar

anaerobic media: selective and differential medium used to culture and presumptively identify Bacteroides fragilis

bacteroides bile esculin (BBE) agar

anaerobic media: enriched selective medium for isolation of slowing growing anaerobes such as Prevotella and Bacteroides, which contains component that enhances pigment formation

kanamycin-vancomycin laked sheep blood (KVLB) agar

anaerobic media: enriched and selective medium used for growth of facultative, anaerobic, gram negative bacilli

phenylethyl alcohol (PEA) agar

tapwater bacillus

mycobacterium gordonae

anaerobic media: inhibits gram neg organism and is used to grow most gram positive anaerobes and facultative anaerobes

columbia-colistin-naladixic agar with 5% sheep blood

anaerobic media: used to detect proteolytic enzyme produced by clostridium lecithinase activity produces an opaque zone for the cleavage of lecithin, releasing insoluble fats lipase cleaves lipids, releasing glycerol, which floats to the top of the medium producing a blue-green sheen on the agar surgace

egg yolk agar

must be used to determine if anaerobic conditions have been met

oxidation-reduction indicator

most commonly used oxidation-reduction indicator will turn from blue (oxidized) to white indicating reduction

methylene blue

before attempting to identify a possible anaerobic bacterium, it fist must be demonstrated to be an obligate anaerobe a colony is inoculated to an anaerobic blood agar plate, which is incubated anaerobically, and to a chocolate agar plate incubated under conditions of increased CO2

aerotolerance testing

pale pleomorphic gram (-) coccobacilli with bipolar staining

bacteroides prevotella

long, thin, filamentous, gram (-) bacilli with tapered ends arranged end to end

fusobacterium

branching gram (+) bacilli

actinomyces

large gram (+) bacilli, spore location is important for identification

clostridium

non pigmented bacillus responsible for most anaerobic infections, and many isolates are becoming more resistant to antimicrobial agents major normal flora of the colon causes infections by gaining entry into normally sterile body sties, especially after surgery, trauma or disease non motile, gram (-) bacilli with rounded ends and may be pleomorphic non hemolytic on anaerobic blood agar growth in 20% bile catalase (+) lipase (-) bile-esculin (+) lecithinase (-) geletinase (-)

bacteroides fragilis

important virulence mechanism of bacteroides fragilis

polysaccharide capsule

pigmented saccharolytic gram (-) bacilli normal flora of the oropharynx, nose and GI and urogenital tracts causes head, neck and lower respiratory tract infection young colonies appear tan and exhibit brick-red fluorescence under UV light (older colonies are brown and black) ferments glucose and many other carbohydrates and is inhibited by 20% bile

prevotella melaninogenica

what antibiotics B. fragilis is resistant to

penicillin kanamycin vancomycin

what antibiotics B. fragilis is susceptible to

rifampin

asaccharolytic or weak fermenters, pigmented colonies, gram negative bacilli normal flora of the oropharynx, nose and GI and urogenital tracts causes infections of the head, neck, oral cavity and urogenital tracts brick red fluorescence under UV light

porphyromonas spp

asaccharolytic or weak fermenters, non pigmented colonies, gram negative bacilli normal flora of the upper respiratory and GI tracts cause pulmonary, blood, sinus and dental infections in addition to brain abscesses associated with metastatic conditions colony morphology; opalescent with speckles indole (+) lipase (+) nitrate (-) catalase (-) relatively biochemically inactive

fusobacterium

growth of porphyromonas is inhibited by ____ but they are resistant to ___

bile, vancomycin, penicillin and rifamipin kanamycin

inhibit growth of fusobacterium

kanamycin colistin

fusobacterium is resistant to ___

vancomycin

causes serious pulmonary infections more common isolate asaccharolytic or weak fermenters, non pigmented colonies, gram negative bacilli colony morphology; opalescent with speckles indole (+) lipase (+) nitrate (-) catalase (-) relatively biochemically inactive

fusobacterium nucleatum

causes lung and liver abscesses and arthritis more serious infection asaccharolytic or weak fermenters, non pigmented colonies, gram negative bacilli colony morphology; opalescent with speckles indole (+) lipase (+) nitrate (-) catalase (-) relatively biochemically inactive

fusobacterium necrophorum

causes gas gangrene, post-abortion sepsis, abdominal infections and enterocolitis major cause of food poisoning resulting in mild to moderate diarrhea without vomiting acquired through puncture wound or by ingestion normal flora of the GI tract and can spread from this site following trauma normal flora of the female genital tract and can cause post-abortion infections

clostridium perfringens

produces a double zone of beta hemolysis on SBA incubated anaerobically positive reverse CAMP test lecithinase (+) glucose (+) lactose (+) maltose fructose (+) subterminal spores non motile

clostridium perfringens

anti-lecithincase antibody is swabbed onto half of an egg yolk agar plate isolate is inoculated onto both halves of the plate

nagler test

neurotoxin that affects the anterior horn cells of the spinal cord, resulting in involuntary muscle contractions that begin with the neck and jaw and progress to a backward arching of the back muscles

tetanospasmin

gains entry into the host by puncture wounds contaminated with soil, or by wounds and this bacteria produce little necrosis gram (+I) bacilli with round/terminal spores that resemble drumsticks gelatinase (+) indole (+) motility (+) lecithinase (-) lipase (-)

clostridium tetani

neurotoxin that binds to the synapse of nerve fibers resulting in flaccid paralysis and death acquired by ingestion of spoiled, home-canned foods in which spores are not destroyed lipase (+) lecithinase (+) glucose (+) motility (+) spores: oval/subterminal and resemble tennis rackets

clostridium botulinum

antibiotic-associated pseudomembranous colitis and diarrhea normal GI flora in a small percentage of the population, and as many as 30% of hospitalized patients may carry the bacteria produces exotoxin A and/or B

clostridium difficile

cultures can be performed on watery or unformed stools colonies are yellow fructose (+) glucose (+) lecithinase (-) lipase (-) indole (-) motility (+) spores: oval and subterminal

clostridium difficile

normal flora of animal and human mucous membranes exudates contains sulfur granules - dense clumps of bacteria gram (+) bacilli with a beaded appearance

anaerobic actinomyces

causes abdomen and chest infections and pelvic actinomyces in women with intrauterine devices

A. israelii

often called anaerobic diphtheroids normal flora of the skin, mouth and GI tract rarely pathogenic catalase (+) indole (+)

propionibacterium

associated with bacterial vaginosis, pelvic inflammatory disease, and abdominal infections curved bacilli motile catalase (-) indole (-) inhibited by vancomycin

mobiluncus

normal flora of the GI and female genitalia this organism helps to maintain an acidic environment in the vagina aerotolerant anaerobes that will form small alpha hemolytic colonies on SBA catalase (-) non motile bacilli

lactobacillus

anaerobic non spore-forming gram (+) bacilli: mostly non pathogenic normal oral and intestinal flora

bifidobacterium eubacterium

anaerobic gram (+) cocci normal flora of the intestines, female genital tract, oral cavity and respiratory tract associated with polymicrobial liver and brain abscesses and wound infections catalase (+) produces olive-green colonies that become black

peptococcus niger

peptostreptococcus

anaerobic small gram (-) cocci reduces nitrate to nitrite does not ferment any carbohydrates inhibited by kanamycin and colistin but resistant to vancomycin

veillonella

obligate intracellular parasites cannot produce ATP contains both dna and rna and are susceptible to antimicrobial agents inclusions in epithelial cells

chlamydia

most common diagnostic method for chlamydia and chlamydophila

nucleic acid amplification tests

serological tests for chlamydia and chlamydophila

Ab to lipopolysaccharide and outer membrane protein Ags

causes lymphogranuloma venereum, trachoma, urethritis, conjunctivitis and infant pneumonia no animal vectors, it is spread by human-to-human contact diagnosis: cell cultures, direct fluorescent Ab tests, enzyme immunoassays, NAATs, and serological procedures

chlamydia trachomatis

leading cause of blindness in the world

trachoma

mild respiratory tract infections producing flu-like symptoms may also cause Guillain-Barre syndrome no animal vectors, it is spread by human-to-human contact diagnosis: fluorescence-labeled Abs

chlamydophila pneumoniae

causes psittacosis or parrot fever humans get infections by the inhalation of bird fecal dust incubation period 1-2 weeks: chills, fever, malaise, can progress to pneumonia

chalamydophila psittaci

obligate intracellular parasites requiring nucleotides and other metabolic building blocks from host cells spread by insect vectors

rickettsia ehrlichia

causes rocky mountain spotted fever

rickettsia rickettssi

causes typhus, also called epidemic or louse-borne typhus carried by human lice

rickettsia prowazekii

reactivation of typhus (louse-borne typhus)

brill-zinsser disease

causes endemic or murine typhus transmitted by fleas

rickettsia typhi

causes O fever transmitted by inhalation, contact with fomites, and ingestion of contaminated milk

coxiella buruetti

causes ehrlichiosis or human monocytic ehrlichiosis transmitted by ticks and is endemic to the US

ehrlichia chaffeensis

causes human granulocytic anaplasmosis

anaplasma phagocytophilum

lack cell wall, making them pleomorphic and resistant to all antibiotics that inhibit cell wall synthesis contain both rna and dna and can self-replicate

mycoplasma ureaplasma

causes tracheobronchitis and community acquired primary atypical pneumonia resulting a dry non productive cough spread by direct respiratory contact produces hydrogen peroxide, which causes lysis of RBCs in vitro

mycoplasma pneumoniae

opportunistic pathogen linked to pelvic inflammatory disease in sexually active adults may cause infant meningitis and post partum fever

mycoplasma hominis

causes non gonococcal urethritis and may cause other genital tract infections requires urea

ureaplasma urealyticum

long, slender, helically curved bacilli that cannot usually be seen on Gram stain requires silver, and Giemsa stain can be observed by darkfield or phase-contrast microscopy

spirochetes

treponema leptospira borrelia

causes syphilis transmitted by sexual contact, direct blood transmission or transplacentally exhibit corkscrew motility seen by darkfield microscopy on material taken from lesion generally diagnosed by serology

treponema pallidum subsp. pallidum

stages of syphilis: chancre at the site of inoculation

primary

stages of syphilis: skin rash and lesion on oral mucosa

secondary

stages of syphilis: absence of clinical symptoms

latent

stages of syphilis: CNS disorders, aneurysms, and skin, liver, bone disorders

tertiary

causes yaws

treponema pallidum subsp. pertenue

causes endemic syphilis

treponema pallidum subsp. endemicum

causes pinta

treponema carateum

causes epidemic relapsing fever, which is characterized by recurrent high fever, chills, muscle pain and headache humans are only known reservoir and transmitted by body lice diagnosis is based on observing bacteria in the peripheral blood stream via the Giemsa or silver stains

borrelia recurrentis

causes leptospirosis zoonosis of rodents, dogs and cattle infection can produce fever, kidney, liver and CNS involvement

leptospira interrogans

diagnosis of leptospirosis: ___ is the most sensitive specimen during early infections but ____ can be cultured after the second week

blood urine

when two or more antimicrobials are used and the combined effect is greater than what would be expected for the simple additive effect of the agents

synergy

inhibit cell wall synthesis

beta-lactam antibiotics

can be given with a beta-lactam antibiotic to provide effective treatment

beta-lactamase inhibitors

class of antimicrobial agents: cephalosporins

beta-lactam antibiotics

class of antimicrobial agents: clavulanic acid

beta-lactamase inhibitors

class of antimicrobial agents: sulbactam

beta-lactamase inhibitors

class of antimicrobial agents: tazobactam

beta-lactamase inhibitors

inhibit protein synthesis at the 30s ribosomal subunit and are active against gram (-) and gram (+) bacteria no activity against obligate anaerobes potential toxicity

aminoglycosides

class of antimicrobial agents: gentamicin

aminoglycosides

class of antimicrobial agents: tobramycin

aminoglycosides

class of antimicrobial agents: netilmicil

aminoglycosides

aminoglycosides: bactericidal

tobramycin

inhibit protein synthesis at the 30s ribosomal subunit active against gram (+) and gram (-) bacteria and mycoplasma and chlamydia

tetracycline

class of antimicrobial agents: doxycycline

tetracycline

class of antimicrobial agents: minocycline

tetracycline

inhibits protein synthesis by binding to the 50S ribosomal unit broad spectrum against gram (-) bacteria e.g. meningitis risk of bone marrow toxicity, aplastic anemia

chloramphenicol

mode of action of macrolides

inhibit protein synthesis

class of antimicrobial agents: erythromycin

macrolides

class of antimicrobial agents: clarithromycin

macrolides

inhibit folic acid synthesis by forming non functional analogs of folic acid

sulfonamides

inhibit cell wall formation by inhibiting peptidoglycan synthesis

glycopeptides

class of antimicrobial agents: vancomycin

glycopeptides

inhibit dna activity by inactivating dna gyrase

quinolones

disrupts plasma membranes used to treat infections caused by gram (-) bacteria

polymyxins

class of antimicrobial agents: polymixin B and polymixin E

polymyxins

bacteria are exposed to different concentrations of antimicrobial agents in the assays

dilution tests

smallest concentration that inhibits the growth of the bacteria is recorded

minimal inhibitory concentration

lowest concentration of an antimicrobial agent that kills at least 99.99% of the bacteria in the original inoculum

minimum bactericidal concentration

inoculation of the bacteria then the diameters of the zones of inhibition are measured

disk diffusion Kirby-Bauer sensitivity test

used for standardization in the disk diffusion test

mueller-hinton agar

provides quantitative antimicrobial susceptibility testing results after incubation, the bacteria produce an elliptical zone of inhibition around the strip MIC is read from the scale on the strip where the zone of inhibition crosses the strip

gradient diffusion

enzyme that confers resistance to penicillin and some of the semi-synthetic penicillin

beta-lactamase

used to detect the presence of inducible clindamycin resistance by erythromycin after incubation, the plate is examined for a flattening of the zone of inhibition around the clindamycin disk, indicating the presence of inducible resistance to clindamycin

d-zone test

bacteria increasing in numbers in the blood causing harm to the patient

septicemia

blood culture bottles often contain this an an anticoagulant inhibits complement and inactivates neutrophils

sodium polyanethol sulfonate

inflammation of the brain

encephalitis

most common isolates found in CSF

neisseria meningitidis streptococcus pneumoniae streptococcus agalactiae e. coli straphylococcus auerus listeria moncytogenes

most important pathogen isolated in throat

s. pyogenes

used to diagnose lower respiratory tract infections normally sterile

sputum

acceptable sputum specimen

<10 squamous epithelial cells >PMNs/low per field

important cause of community-acquired pneumonia most common cause of pneumonia in geriatric patients

streptococcus pneumoniae

associated with nosocomial pneumonia and pneumonia in alcoholics

klebsiella pneumoniae

causes community-acquired and nosocomial pneumonia, usually secondary to infection or predisposing factor

staphylococcus aureus

causes infection in infants, children and the immunosuppressed incidence of infections has decreased dramatically since routine use of vaccination

haemophilus influenzae

causes atypical pneumonia, which is mostly seen in young adults won't grow on routinely used media

mycoplasma pneumoniae

normally sterile may contain bacteria sometimes but does not indicate an infection

urine

bacteria causing gastroenteritis

shigella spp campylobacter jejuni e coli yersinia enterocolitica clostridium difficile vibrio spp

cervicitis and urethritis are usually caused by:

N. gonorrhoeae C. trachomatis

due to overgrowth of some species of normal vaginal flora, most likely mobiluncus

bacterial vaginosis

considered normal vaginal flora and may only be an indicator of bacterial vaginosis

gardnerella vaginalis

complication of infection caused by N. gonorrhea or C. trachomatis involving the endometrium or fallopian tubes

pelvic inflammatory disease

usually caused by enterics

prostatitis

most common bacteria causing superficial skin infections

s. aureus p. aeruginosa

most common bacteria causing folliculitis

s. aureus p. aeruginosa

most common bacteria causing boils, bedsores, etc

s. aureus

most common bacteria causing impetigo

s. pyogenes s. aureus

most common bacteria causing erysipelas

s. pyogenes erysiphelothrix rhusiopathiae

enzyme that produces water and oxygen from hydrogen peroxide

catalase

catalase test: staphylococci

postitive

catalase test: streptococci

negative

clumping factor identification of s. aureus

coagulase test

detects the enzyme l-pyrrolidonly arylamidase red color after the addition of p-dimethylaminocinnamaldehyde is positive indicator s. pyogenes and enterococcus are typically positive used to differentiate s. aureus from s. lugdunensis and s. scheleiferi

PYR test

positive for bile solubility test

streptococcus pneumoniae

will give a purple color after the addition of ninhydrine group B streptococci are positive, whereas most other beta-hemolytic streptococci are negative can be used to differentiate C. jejuni from most other campylobacter spp.

hippurate hydrolysis test

detects enxyme that is used in the electron transports system several drops of reagents (tetramethyl-p-phenylenediamine dihydrochloride) are placed on filter paper containing bacterial colonies or or directly on plate colonies colonies should be taken from nonselective non differential media indicated by a purple color within 10-15 seconds

oxidase

detects the bacterial enzyme tryptophanase detected by an aldehyde indicator (Ehrlich's reagent) yield a red color or Kovac's reagent, yielding a bright pink color

indole test

detects the enzyme which forms ammonia indicated by a bright pink color

urease test

triple sugar iron agar will show the pattern of:

glucose lactose sucrose sulfide gas production

indicator used in TSI

phenol red

TSI result for nonfermenter, non enterobacteriaceae

K/K

TSI result for non lactose, non sucrose fermenter, glucose fermenter

K/A

TSI result for lactose and/or sucrose fermenter, glucose fermenter

A/A

more sensitive method to detect H2S gas in TSI agar

lead acetate

what are being tested in IMViC

indole methyl red voges-proskauer citrate

IMViC: pink

indole (presence of tryptophanase, which breaks down tryptophan to pyruvic acid, ammonia, and indole)

IMViC: methyl red

glucose fermentation: (+) yellow, (-) red

IMViC: VP

glucose metabolism: (+) red, (-) yellow

IMViC: citrate

citrate: (+) blue, (-) green

amino acid degradation test: detects the ability of an organism to remove amino group from specific amino acids

deaminase reaction

amino acid degradation test: detects the ability of bacteria to remove the carboxyl group a specific amino acid

decarboxylation reaction

all purpose preservative to preserve stool specimens for concentration procedures

5% or 10% formalin

mercury-containing preservative for preparing stained smears for stool specimens

polyvinyl alcohol

mercury-free preservative that can be used to preserve stool sample for both concentration and permanent stained smears

sodium acetate formalin

fecal concentration methods

formalin ethyl acetate sedimentations zinc sulfate flotation sheather sugar flotation

generally recommended for cryptosporidium and some ova

sheather sugar floration procedure

this method entails suspension of 3-4g of stool in 5-10% formalin and being filtered through gauze before centrifugation. after washing the sediment is resuspended in about 3ml of 33% aqueous solution of zinc sulfate

zinc sulfate flotation

uses low-speed centrifugation to concentrate blood samples suspected of containing minimal numbers of parasites

knott method

used for Leishmania or Trypanosoma detection in blood samples

buffy coat slides

stains for microscopic detection of stool, tissue and blood parasites: quick and easy to perform and will allow trophozoite motility and helminth ova and larvae to be seen

saline wet mount

stains for microscopic detection of stool, tissue and blood parasites: useful for the detection of larvae, ova and protozoan cysts in stool samples

iodine wet mounts

stains for microscopic detection of stool, tissue and blood parasites: used in fecal smears when enhanced detail is needed

iron hematoxylin stain

stains for microscopic detection of stool, tissue and blood parasites: most commonly used stain for fecal parasite study

trichrome stain (wheatley or gomori)

stains for microscopic detection of stool, tissue and blood parasites: used to detect crytosporidium and isospora

modified acid fast stain

stains for microscopic detection of stool, tissue and blood parasites: microsporidia are not easily stained, therefore the concentration of the stain and the staining time is increased

modified trichrome stains

stains for microscopic detection of stool, tissue and blood parasites: microsporidia stain pink (oval, 1-3 micrometer) and the background is green

weber green stain

stains for microscopic detection of stool, tissue and blood parasites: microsporidia stain pink but the background is blue

ryan blue stain

collection methods: used to collect enterobius vermicularis (pinworms) eggs for the perirectal area

cellophane (scotch) tape

collection methods: used to obtain duodenal contents for parasitic examination

enterotest (string test)

collection methods: used to collect colon material

sigmoidoscopy

sample types and associated parasites: feces

giardia cryptosporidium entamoeba ascaris enterobius

sample types and associated parasites: blood

plasmodium leishmania trypanosoma microfiliriae

sample types and associated parasites: skin

onchocerca

sample types and associated parasites: vaginal or urethral

trichomonas

sample types and associated parasites: eye scraping

acanthamoeba

sample types and associated parasites: tissues

naegleria acanthamoeba leishmania

sample types and associated parasites: urine

schistosoma trichomonas

sample types and associated parasites: sputum

ascaris strongyloides paragonimus

diagnostic tests: used to identify giardia lamblia, cryptosporidium, trichomonas vaginalis

direct flourescent antibody

diagnostic tests: used to diagnose leishmaniasis and chaga's disease

direct agglutination test

diagnostic tests: used to identify giardia lamblia, cryptosporidium, toxoplasma gondii

ELISA

an asymptomatic host that harbors a parasite and is capable of transmitting it to others

carrier

tapeworm

symbiotic relationship beneficial to one member and harmless to another

commensalism

thick-walled stage of protozoa resistant to adverse conditions

cyst

host supporting the adult or sexual phase of a parasitic life cycle

definitive host

parasite found on the surface of a host

ectoparasite

parasite found inside a host

endoparasite

blood or tissue roundworms

filariae

laval stage of echinococcus granulosis

hydatid cyst

host containing the asexual phase of a parasite

intermediate host

early stage of asexual sporozoa trophozoites

immature schizont

symbiotic relationship beneficial to both species

mutualism

encysted form of an egg

oocyst

symbiotic relationship in which one member benefits at the expense of another member

parasitism

an association between two or more organisms of different species

symbiosis

fluke or flat work

trematode

developmental stage of protozoa

trophozoites

extensions of cytoplasm providing motility unique to amoebae

pseudopods

stages of amoeba life cycle

trophozoites cyst stage

infective stage of intestinal protozoa

cyst

active reproduction stage of intestinal protozoa and can be destroyed of stomach acid

trophozoites

how to identify or diagnose intestinal protozoa in laboratory

microscopic identification of cysts and trophozoites

area chromatin within the nucleus

karyosome

nucleic combined with protein found along the nuclear membrane

peripheral chromatin

development of a cyst into a trophozoite

excystation

development of a trophozoite into a cyst

encystation

rod-shaped, RNA-containing structure found in the cytoplasm

chromatoid bar

only amoeba pathogenic for the GI tract

entamoeba histolytica

characterized by abdominal cramping, anorexia, fatigue, and diarrhea can also cause ulcers and dysentery

amoebic colitis

extraintestinal amoebiasis primarily involves infections of __

liver spleen, brain and lungs

entamoeba histolytica cysts can range from ___ and spherical nuclei: peripheral chromatin: karyosome: cytoplasm:

8-22 micrometers 1-4 nuclei fine and uniformly distributed centrally located finely granular with chromatid bars with round ends

entamoeba histolytica tropozoites size: motility: nucleus: cytoplasm:

5-70 micrometers pseudopods 1 finely granular, may contain RBCs

diagnosis of E. histolytica

presence of intracellular RBCs in amoeba

E. histolytica is identical to this non-pathogenic protozoa and can only be differentiated by immunologic assays detecting surface antigens

E. dispar

generally non pathogenic but may cause intestinal problems in immunosuppressed patients, and if found in stool specimen, it can indicate the presence of pathogenic organisms needs to be differentiated from E. histolytica for purposes of treatment

entamoeba coli

entamoeba coli cyst size: shape: nuclei: peripheral chromatin: karyosome: cytoplasm:

8-40 micrometers spherical 1-8 coarse and unevenly distributed, glycogen mass eccentric and large coarse with thin chromatoidal bars with pointed ends

entamoeba coli trophozoites size: motility: nuclei: peripheral chromatin: cytoplasm:

10-60 micrometers short/blunt pseudopods 1 unevenly distributed coarse and vacuolated with bacterial inclusions

currently classified as amoeba but rRNA analysis indicates it is related to algae and water molds associated with diarrhea and abdominal pain

blastocystis hominis

blastocystis hominis size: morphology:

4-60 micrometers large central body (90%), outer ring of cytoplasm with several nuclei around the central body

other intestinal amoebae: causes asymptomatic mouth and genital tract infections

entamoeba gingivalis

other intestinal amoebae: non pathogenic intestinal parasite

Iodamoeba butschlii endolimax nana entamoeba hartmanni

only pathogenic flagellate causes mild to moderate diarrhea severe infections can lead to malabsorption

giardia lamlia

rod like structure that functions in cellular support

axostyle

intracellular portion of the flageullum

axoneme

flagellum finlike structure that generates a wavelike motion

undulating membrane

rudimentary oral cavity

cytostome

giardia lamblia trophozoites attach themselves to ____

duodenum mucosa

giardia lamblia cyst size: shape: nuclei: peripheral chromatin: cytoplasm:

12 micrometers long and 8 micrometers wide oval shaped; coffee been 4 nuclei none retracted from cyst wall , 2-4 comma-shaped median bodies

giardia lamblia trophozoites size: shape: motility: nuclei: peripheral chromatin: other features:

15 micrometers long to 10micrometers wide pear-shaped, teardrop shaped with bilateral symmetry 4 pairs of flagella 2 none 2 median bodies, 2 axonemes, sucking disk

chilomastix mesnili cyst size: shape: nuclei: peripheral chromatin: karyosome: cytostome:

5-10 micrometers oval 1 none large and centrally located well defined

chilomastix mesnili trophozoites size: shape: motility: nuclei: peripheral chromatin: other features:

5-25 long, 5-10 wide pear shaped flagella: 3 anterior, 1 posterior 1 none large cytostome, spinal groove

flagellated protozoa: causes diarrhea, abdominal pain, anal pruritis infection occur in individuals living in close quarters infects the mucosal lining of the large intestines no cyst stage

dientamoeba fragilis

dientamoeba fragilis trophozoites size: shape: motility: nuclei: peripheral chromatin: other features:

5-19 round hyaline pseudopods 2 none; nuclear chromatin vacuolated cytoplasm with bacterial inclusion

only ciliated protozoa species pathogenic for humans causes balantidiasis, characterized by diarrhea to dysentery MOT: infective cyst through contaminated water or food

balantidium coli

balantidium coli cyst size: shape: nuclei: motility: other features:

43-65 round 2: macronucleus (kidney shaped and large) and micronucleus (round) cilia double cyst cell wall

balantidium coli trophozoites size: nuclei: motility: other features:

100 (L), 70 (W) 2 cilia 1-2 contractile vacuoles

intestinal sporozoa

cryptosporidium parvum cyclospora cayetanensis isospora belli

causes cryptosporidiosis, moderate to severe diarrhea in patients with AIDS, important cause of death due to dehydration

cryptosporidium parvum

MOT of cryptosporidium parvum

contaminated food or water through oocyst human-to-human transmission

diagnosis of cryptosporidium parvum

acid fast oocysts in stool or small bowel mucosal epithelial cells

cryptosporidium parvum oocyst size: sporozoites: cytosplasm:

4-6 4 enclosed within a thick cell wall may contain several dark granules

host of cyclospora cayetansesis

humans

causes nonbloody diarrhea diagnosis is made by examination of stained fecal smears: oocysts will stain with the modified Kinyoun's acid-fast stain, 8-10 micrometers

cyclospora cayetanensis

causes isosporiasis, characterized by mild diarrhea to severe dysentery transmission is by ingestion of the infective oocyst in contaminated food and water diagnosis: oocysts in wet mounts and/or acid fast or auramine-rhodamine stains

isospora belli

isospora belli cyst size: cytoplasm:

25-40 granular and contains 2 sporoblasts that contain 4 sporozoites

4 causative agents of malaria

plasmodium vivax plasmodium falciparum plasmodium malariae plasmodium ovale

plasmodium spp have 2 life cycles phases: sexual phase that occurs within the intestinal tract of mosquito

sporogony

plasmodium spp have 2 life cycles phases: asexual phase that occurs in the human host

schizogony

MOT of plasmodium spp.

bite of a female anopheles mosquito

microscopic examination of blood smears for plasmodium: blood collection

finger stick and blood smears made immediately EDTA used as an anticoagulant

this cannot be used in blood collection for plasmodium diagnosis as it can cause distortion of the parasite

heparin

microscopic examination of blood smears for plasmodium: thick smears

drop of blood on a slide, air dried, stained with giemsa

microscopic examination of blood smears for plasmodium: thin smears

drop of blood on a slide, blood is spread out, fixed in methanol, then is stained

3 morphologies of plasmodium

trophozoites schizonts gametocytes

plasmodium morphology: erythrocytic intracellular ring-like appearance

trophozoites or ring-forms

using these stains, blue cytosplasmic ring connected to a red chromatin dot is demonstrated in the presence of trophozoites

giemsa or wright's stain

plasmodium morphology: active chromatin activity causes the parasite to increase in size pigmented granules are numerous and reddish brown in color contain merozoites, the number and arrangement depend on the species

schizonts

plasmodium morphology: characterized by a chromatin mass staining pink to purple round to oval in shape (most) varied pigmentation

gametocytes

banana shaped gametocytes

plasmodium falciparum

infective stage of plasmodium spp being transmitted to humans by anopheles mosquitoes infect hepatic cells and bein the exo-erythrocyte cycle

sporozoite

dormant form of plasmodium vivax and plasmodium ovale that can remain in the liver reactivation results in a recurrence (true relapse)

hypnozoites

life cycle of plasmodium spp: infect RBCs and initiate the erythrocyte cycle may develop into ring forms and reproduce by schizogony, or into microgametocytes or macrogametocytes which are transmitted to the mosquito during human blood meal

merozoites

life cycle of plasmodium spp: RBC form of the parasites can be nearly eliminated by treatment or an immune response, and the patient may become asymptomatic. after several weeks, the parasites can increase in number and the symptoms will return

recrudescence

plasmodium vivax RBC appearance: trophozoites: schizont: gametocytes: fever cycle:

enlarged, pale with prominent Schuffner's dots (only reticulocytes) 1/3 size of an RBC 12-24 merozoites round to oval with a large chromatin mass 48 hours

causes benign tertian malaria following a 10- to 17-day inoculation period most common cause of malaria

plasmodium vivax

plasmodium falciparum RBC appearance: trophozoites: schizont: gametocytes: fever cycle:

normal in size, all are infected 1/5 size of an RBC, multiple rings, some have 2 chromatin dots rarely seen crescent- or banana-shaped interval between paroxysms (intense fever and chills) is 24 hours

causes malignant tertian malaria (black water fever) following a 7-10 day incubation period

plasmodium falciparum

plasmodium malariae RBC appearance: trophozoites: schizont: gametocytes: fever cycle:

normal in size without dots, older RBCs similar to P. vivax but stain more intense blue, mature produce band forms 8-12 merozoites arranged in rosettes resemble P. vivax 72 hours

causes quartan malaria following an 18-40 day incubation period

plasmodium malariae

plasmodium ovale RBC appearance: trophozoites: schizont: gametocytes: fever cycle:

enlarged, with thicker forms contain Schuffner's dots, often oval-shaped and have irregularly shaped membranes with projections (only reticulocytes) maintain ring appearance as they develop averages 4-8 merozoites arranged in rosettes resemble P. vivax but smaller

causes benign tertian following a 10-20 day incubation period

plasmodium ovale

persistence of exo-erythrocytic cycle p. vivax: p. falciparum: p. malariae: p. ovale:

yes no no yes

length of replication cycle (hours) p. vivax: p. falciparum: p. malariae: p. ovale:

44-48 36-48 72 48

number of merozoites in mature schizonts p. vivax: p. falciparum: p. malariae: p. ovale:

16 (12-24) 8-24 (not usually seen in peripheral blood) 8 (6-12) 8 (8-12)

important criteria for identification p. vivax: p. falciparum: p. malariae: p. ovale:

infected RBCs enlarged, tropozoites irregularly shaped, Schuffner's dots multiple ring forms seen in a single RBC, crescent shaped gametocytes, and ring shaped young trophozoites are only forms seen normal size and color, trophozoites compact and band forms may be seen enlarged and oval shaped with fimbriated edges, trophozoites irregular shaped Schuffner's dots

causes babesiosis, which can affect spleen, kidneys, liver erythrocytic intracellular parasite that can cause hemolytic anemia transmitted through a tick bite

babesia microti

infective sporozoite of the babesia microti is transmitted by this

ixodes scapularis

babesia microti ring form can have a size between 3-5 micrometers and can be identified through blood smear examination with what appearance

2-4 rings per RBC appearing like a maltese cross

characterized by a broad spectrum of symptoms and has a predilection for cns infections: in healthy individuals, this resembles infectious mononucleosis and produces fatigue, swollen lymph glands, fever and myalgia and can affect the heart and the liver; in premature or antibody-deficient infants, symptoms can include splenomegaly, jaundice and fever and the cns infection can lead to developmental complications including vision and hearing problems, hydrocephalus, mental mental retardation; in immunosuppressed individuals, the parasite becomes localized in the cns with symptoms of encephalitiss and brain lesions

toxoplasmosis

sexual reproduction of toxoplasma gondii occurs in the ___ and can be transmitted through ____

intestinal tract of house cats ingestion of cat feces-contaminated food and water, ingestion of undercooked meat (lamb and pork), transplacental

toxoplasma gondii trophozoites can range in size from 1-3 micrometers are crescent to round in shape

tachyzoites

toxoplasma gondii cysts contain many

bradyzoites

naegleria fowleri can cause this which is often fatal within 3-6 days

amoebic meningoencephalitis

infective stage of naegleria folweri

trophozoites

naegleria fowleri cyst size: shape: nucleus: peripheral chromatin: karyosome:

10-13 round 1 nucleus none centrally located, large

naegleria fowleri trophozoites size: motility: nucleus: peripheral chromatin: cytoplasm:

10-23 blunt pseudopods 1 none granular, vacuolated

naegleria fowleri flagellate size: shape: motility: nucleus: karyosome: cytoplasm:

7-15 pear-shaped 2 flagella 1, indented centrally located, large granular, vacuolated

causes ameobic encephalitis and amoebic keratitis (cornea infection) through direct invasion by the trophozoites

acanthamoeba

acanthamoeba cyst size: shape: nucleus: peripheral chromatin: karyosome: cytoplasm:

8-25 round shape, with jagged edge 1 none centrally located and large granular and vacuolated

acanthamoeba trophozoites size: motility: nucleus: peripheral chromatin: karyosome: cytoplasm:

15-45 spine-like pseudopods 1 none centrally located and large granular and vacuolated

causes vaginitis in women whereas men are generally asymptomatic carriers sexually transmitted disease and can infect neonates (aspiration pneumonia)

trichomonas vaginalis

trichomonas vaginalis trophozoites are the infective stage and infect the _____

epithelial or mucosal lining of the vagina, urethra, prostrate gland

(T or F) trichomonas vaginas does not have a cyst stage

true

trichomonas vaginalis trophozoites size: shape: motility: nucleus:

30 pear shaped undulating mechanism (flagella 3-5 anterior and 1 posterior and large axostyle with cytoplasmic granules) 1 prominent

hemoflagellates inhabit the ___ of humans and can be transmitted to humans by ___

blood and tissue of humans arthropod bites

4 stages of development of hemoflagellates

amastigote promastigote epimastigote trypomastigote

developmental stage of hemoflagellates: non flagellated ova form, found in tissue

amastigote

developmental stage of hemoflagellates: flagellated stage found in the vector, rarely seen in the blood

promastigote

developmental stage of hemoflagellates: long, slender, flagellated from found in arthropod vectors

epimastigote

infection occurs mainly in Africa and South America diagnosis is made by microscopic examination of blood and CSF and serologic testing

trypanosoma

causes sleeping sickness and infection affects the lymphatic system and CNS

trypanosoma brucei

african trypaosomiasis can cause this swollen lymph nodes at the posterior base of the neck called ___

winterbottom's signs

causes Chagas disease characterized by lesion formation (chagoma), conjunctivitis, edema of the face and legs, and heart muscle involvement leading to myocarditis mostly found in south america

trypanosoma cruzi

mianly a disease of africa, eastern europe and south/central america diagnosis is through identification of amastigote in the blood or tissue and serologic testing has 2 forms: cutaneous and disseminated (liver, spleen and reticuloendothelial involvements)

leishmania

flat, hermaphroditic and have at least 2 suckers (one opens into the digestive tract and one is for attachment)

trematodes

final stage of development of trematodes occurring in snails, motile by means of a tail

cercaria

encysted form of trematodes occurring in the second intermediate host (fish or crayfish)

metacercaria

first larval stage of trematodes that emerges from the egg in fresh water

miracidium

emerges from the miracidium as a sac-like structure containing the larvae

sporocyst

intermediate larval stage occurring in the sporocyst

redia

schistosoma species pathogenic for human

s. mansoni s. haematobium s. japonicum s. mekongi s. intercalatum

characterized by abdominal pain, bloody diarrhea and hepotosplenomegaly can cause intestinal lesions and blockage, and eggs penetrate the bladder and are passed into the urine

schistosomiasis

egg morphology: large terminal spine

s. haematobium

egg morphology: large lateral spine

s. mansoni

egg morphology: s. japonicum

small inconspicuous lateral spine

causes pulmonary infections characterized by chest pain, cough, bronchitis, and sputum with blood acquire infection by ingesting metacercariae in undercooked crabs and crayfish adult forms develop in human lung tissue

paragonimus westermani (lung fluke)

egg morphology: range in size from 72-130 in length with a prominent operculum

paragonimus westermani

causes liver problems characterized fever, abdominal pain and diarrhea found mainly in china humans acquire the disease by eating undercooked fish containing encysted metacercariae

clonorchis sinensis

egg morphology: egg contains miracidium with a small knob opposite the direction the operculum

clonorchis sinesis

causes intestinal problems, including diarrhea and ulceration of the intestines and possibly the stomach acquire infections by ingesting metacercariae on water plants (water chestnuts and bamboo)

fasciolopsis buski

egg morphology: large oblong (130-140 by 80-85) and contain an operculum

fasciolopsis buski

primarily a zoonosis of sheep affecting the liver found in south america and mediterranean area human acquire infections by ingesting metacercariae on water plants (watercress)

fasciola hepatica

egg morphology: large, oblong (130-150 by 63-90) and contain an operculum

fasciola hepatica

lung fluke

paragonimus westermani

chinese or oriental fluke

clonorchis sinensis

inttestinal fluke

fasciolopsis buski

liver fluke

fasciola hepatica

subclass of helminths compromising true tapeworms

cestodes

anterior portion of the body containing suckers and sometimes hooklets responsible for attachment to the host

scolex

crown of the scolex

rostellum

make up the major portion of the tapeworm and contain the male and female reproductive structures

proglottids

entire length of the tapeworm except for the scolex and neck

strobila

infection is by the ingestion of undercooked beef that contains the cysticercus larva

taenia saginata

infection is by the ingestion of undercooked pork that contains the cysticercus larva

taenia solium

how to differentiate taenia saginata from taenia solium for diagnosis

proglottids or scolex analysis

egg morphology: range in size 30-40, 3 pairs of hooklets, have radial striations

taenia spp.

infection is acquired by eating raw or undercooked fish containing th plerocercoid causes intestinal pain, diarrhea and sometimes vitamin b12 deficiency (causes pernicious anemia)

diphyllobothrium latum

fish tapeworm

diphyllobothrium latum

egg morphology: size range in 50-80 in length, oblong in shape, shell is smooth, and color is yellow to brown, terminal knob is located at one end opposite the operculum

diphyllobothrium latum

causes abdominal pain and diarrhea humans usually acquire the infection by ingestion of ova found in mice or human feces most common tapeworm in the US

hymenolepsis nana

dwarf tapeworm

hymenolepsis nana

egg morphology: average size in 40, round ova, contains three pairs of hooklet, polar thickening of the sell is common

hymenolepsis nana

causes abdominal pain and diarrhea humans acquire the infection from the ingestion of insects containing the cystecercoids=

hymenolepsis diminuta

mouse and rat tapeworm

hymenolepsis diminuta

egg morphology: average size of the round egg is 40, contains three pairs of hooklets

hymenolepsis diminuta

human infection results in the development of a hydatid cyst in many body sites as the cyst grows, surrounding tissue is destroyed intermediate host is sheep acquired infection through ingesting ova in dog feces cyst contains fluid, daughter cysts, brood capsules and hydatid sand

echinococcus granulosis

tapered, cylindrical body with an esophagus and longitudinal muscles based on adult, larvae or egg morphology can cause disease associated with the intestines, skin, including diarrhea, vomiting and skin lesions

nematodes

intestinal nematodes

enterobius vermicularis trichuris trichiura ascaris lumbricoides strongyloides stercoralis necator americanus acylostoma duodenadale

intestinal-tissue nematodes

trichinella spiralis dracunculus medinensis

pinworm

enterobius vermicularis

causes infections that are usually self-limiting and characterized by itching and inflammation of the anus common in US especially in school-aged children

enterobius vermicularis

enterobius vermicularis life cycle

1. infective eggs are ingested and larvae are released in the small intestines 2. larvae develop into adult worms in the colon 3. gravid females migrate to the perianal region, where eggs are laid 4. eggs are infective following a 6-hour incubation period 5. itching results from the irritation caused by the deposition of eggs and spread from the perianal region by scratching 6. eggs will be infective for several weeks and can be found in dust, clothing

enterobius vermicularis diagnosis

identification of ova from a tape preparation collection of specimen is done in the morning

egg morphology: range in size from 50-60 in length and 30 in width, oval in shape and one side is flat, shell is thick and double walled, contains a developing embryo

enterobius vermicularis

whipworm

trichuris trichiura

causes infection in that in children presents as colitis and dysentery, in adults symptoms include abdominal pain and bloody diarrhea most infectious occur in africa and south america eggs from human feces are infective

trichuris trichiura

egg morphology: 50-60 in length and 25 in width, lemon or football shaped, with clear plugs at each end, shell is smooth and yellow to brown, egg contains a developing embyro

trichuris trichiura

giant intestinal round worm causes intestinal tissue destruction and bowel obstruction that can be fatal, worms can also migrate to the lungs

ascaris lumbricoides

egg morphology: decorticated, unfertilized ova are oval and measure up to 90, fertilized ova are round, has thick shell and contains a developing embryo

ascaris lumbricoides

(male or female) adult ascaris lumbricoides has curved posterior end

male

causes threadworm infections, characterize by diarrhea and abdominal pain

strongyloides stercoralis

strongyloides stercoralis: repeated exposure to larvae can produce this allergic reaction

larval migrans

strongyloides stercoralis diagnosis

stool examination for rhabditiform larvae

strongyloides stercoralis rhabditiform larvae morphology

700 micrometers in length tail is notched

can cause human hookworm infections symptoms can include coughing and headaches

necator americanus ancylostoma duodenale

strongyloides stercoralis MOT

skin contact with contaminated soil (filariform larvae)

hookworms MOT

skin penetration of the filariform larvae

hookworms diagnosis

identification of larvae (filariform) in sputum or ova from stool specimens

egg morphology: oval, measures 56-75 micrometers long by 36-40 micrometers wide, thin shelled, developing embryo can sometimes be seen inside

necator americanus ancylostoma duodenale

difference between the adult hookworm morphology

necator americanus: smaller, has a pair of cutting plates ancylostoma duodenale: larger, has teeth

causes trichinosis with symptoms including diarrhea, blurred vision, muscle edema and coughing

trichinella spiralis

trichinella spiralis reservoir

pigs

trichinella spiralis MOT

eating contaminated undercooked pork

trichinella spiralis diagnosis

examining muscle tissues for encysted larvae lab tests reveal: eosinophilia, leukocytosis, increased creatine kinase and lactate dehydrogenase

trichinella spiralis larvae morphology

125 micrometers in length, 7 micrometers wide encysted forms are found in striated muscle tissue

trichinella spiralis adult morphology

can range up to 1mm in length and reside in the intestinal tract

causes guinea worm infection, symptoms include allergic reactions and painful ulcers most infections occur in Africa, India and Asia

dracunculus medinensis

dracunculus medinensis MOT

ingestion of infected copepods (water fleas) carrying the larvae

dracunculus medinensis diagnosis

observing worms emerging from ulcerated areas of the body

order of nematodes consisting of adult thread like worms inhabit the circulatory and lymphatic system, also found in muscle, connective tissue and serous cavities

filarial parasites

four primary species of filarial parasites that cause diseases in humans

wuchereria bancrofti brugia malayi loa loa onchocerca volvulus

causes malayan filariasis, a condition that produces lesions in lymphatics, and elephantiasis may result east asia

brugia malayi

brugia malayi is being transmitted by ___

mosquitos

brugia malayi diagnosis

microscopic examination of blood smears for mcirofilariae samples collected at night

brugia malayi microfilariae morphology size: nuclei: sheath: habitat: cephalic space:

200-300 micrometers in length 2, located in the tail present upper lymphatic twice as long as broad

causes bancroftian filariasis, a condition that produces lesions in the lymphatics, elephantiasis may occur tropics and subtropics

wuchereria bancrofti

wuchereria bancrofti vectors

culex aedes anopheles

wuchereria bancrofti microfilariae morphology size: nuclei: sheath: habitat: cephalic space:

250-300 micrometers in length none present lower lymphatic long as broad

causes river blindness most infections occur in africa, south america and mexico

onchocerca volvulus

onchocerca volvulus MOT

bite of the simulium (black fly)

onchocerca volvulus microfilariae morphology size: nuclei: sheath: habitat:

150-360 micrometers none present subcutaneous tissue

loa loa microfilariae morphology size: nuclei: sheath: habitat:

250-300 micrometers continuous up to the tip of the tail none subcutaneous tissue

causes subcutaneous tissue infections and infections of the conjunctival lining of the eye most infections occur in africa

loa loa

loa loa MOT

bite of the Chrysops (deer) fly

onchocerca volvulus diagnosis

tissue or ophthalmic analysis for microfilariae skin snips or skin shavings (urine)

loa loa diagnosis

blood smear examination of microfilariae

mansonella perstans / dipetalonema perstans: common name

persistent filaria

mansonella perstans / dipetalonema perstans: intermediate host/vector

cullicoides spp biting midges

mansonella perstans / dipetalonema perstans: periodicity

non periodic (present both day and night)

mansonella perstans / dipetalonema perstans: specimen

blood

mansonella perstans / dipetalonema perstans: appearance

non sheathed

mansonella perstans / dipetalonema perstans: tail end

nuclei continuous to the tip of the blunt tail

mansonella perstans / dipetalonema perstans: habitat

body cavities (usually peritoneal and pleural cavity)

mansonella ozzardi: common name disease

ozzard's filaria

mansonella ozzardi: diseases

mansoneliasis ozzard's filariasis

mansonella perstans / dipetalonem perstans: disease

dipetalonemiasis

mansonella ozzardi: intermediate host/vector

cullicoides spp biting midges

mansonella ozzardi: periodicity

non periodic (present both day and night)

mansonella ozzardi: specimen

blood and skin biopsis

mansonella ozzardi: appearance

non sheathed

mansonella ozzardi: tail end

no nuclei on tail tail is tapering into thin filament

mansonella ozzardi: habitat

body cavities

mansonella streptocerca: disease

streptocerca filariasis dermatitis

mansonella streptocerca: intermediate host/vector

cullicoides spp biting midges

mansonella streptocerca: periodicity

non periodic (present both day and night)

mansonella streptocerca: specimen

skin snips

mansonella streptocerca: appearance

non sheathed

mansonella streptocerca: tail end

nuclei continuous to the tip relatively straight but strongly bent in "shepherd's crook curve)

mansonella streptocerca: habitat

skin and subcutaneous tissues