Survey of Medical Bacteriology Flashcards
What bacteria is this:
gram-positive cocci in chains; beta hemolytic on blood agar. Group-specific carbohydrate (Group A); type-specific protein M protein. Has numerous toxins, adhesins, and antiphagocytic components. Can be identified by its catalase negative, bacitracin sensitive, Group A ag.
streptococcus pyogenes
What are the suppurative infections that streptococcus pyogenes can cause?
pharyngitis cellulitis scarlet fever necrotizing fascitis pyoderm erysipelas streptococcal toxic shock syndrome
What are the non-suppurative infections that streptococcus pyogenes can cause?
rheumatic heart disease
acute glomerulonephritis
What bacteria is this:
gram positive cocci in chains; beta hemolytic
group-specific cell wall carbohydrate (group B- GBS)
type specific antiphagocytic capsular polysaccharide
Identified by: catalase negative, CAMP positive, Group B ag
streptococcus agalactiae
What are the diseases associated with streptococcus agalactiae
MAJOR cause of meningitis in newborns
early onset neonatal disease
late onset neonatal disease
infection in adults-various disseminated infections
What bacteria is this:
gram positive cocci in chains; alpha hemolytic, antigenic typing- no lancefied carbohydrate antigen.
Identification- catalase negative, optochin resistent, must differentiate from alpha hemolytic S. pneumoniae
viridans streptococci
What diseases does Viridans streptococci cause?
endocarditis
bacteremia in neutropenic patients
dental caries
What bacteria is this:
lancet-shaped, gram positive cocci in pairs; alpha hemolytic, antigenic typing-antiphagocytic capsular polysaccharide. Identification- differentiate from viridans streptococci-> catalse negative, optochin sensitive, bile soluble
streptococcus pneumoniae
What are the diseases associated with streptococcus pneumoniae?
pnuemonia meningitis bacteremia sinusitis and otitis media sickle cel disease is a risk factor
How can you prevent streptococcus pneumoniae?
with a vaccine
-> capsular polysaccharide or CPS-protein conjugate
What bacteria is this:
Gram positive cocci
antigenc typing- group D cell wall polysaccharide.
highly resistant to antibiotics
Enterococci
What are the most important species of enterococci?
E. faecalis and E. faecium
What diseases does enterococci cause?
UTI
wound infection, particularly intra-abdominal
bacteremia
endocarditis
What bacteria is this:
gram positive cocci in clusters, catalase positive, coagulase positive, protein A on surface. Virulence-> adhesive and antiphagocytic factors, toxins and enzymes,
Staphylococcus aureus
What makes staphylococcus aureus into MRSA?
altered PBP encoded by mecA gene
What suppurative diseases does staphylococcus aureus cause?
impetigo folliculitis furuncles/boils carbuncles bacteremia endocarditis osteomyelitis septic arthritis pneumonia and empyema brain abscess
What toxin-mediated diseases does staphylococcus aureus cause?
food poisoning
toxic shock syndrome
scalded skin syndrome
What bacteria is this:
gram positive cocci, catalase positive, coagulase-negative, primary species: S. epidermidis, extracellular polysaccharide contributes to biofilm.
coagulase-negative staphylococci
What diseases does coagulase-negative staphylococci?
endocarditis, catheter and shunt infections, UTI, s. saprophyticus (UTI in young, sexually active women)
A 5-day postoperative patient develops a high fever. An IV catheter is removed and culture of the tip reveals gram-positive cocci believed to be Staphylococcus aureus. Which of the following laboratory test results would further support this belief?
Coagulase positivity
What are the aerobic gram-positive cocci?
streptococcus pyogenes streptococcus agalactiae viridans streptococci streptococcus pneumoniae enterococci staphylococcus aureus coagulase-negative staphylococci
What bacteria is this:
gram-negative diplococci
outer surface with multiple virulence factors/antigens
diagnosis by nucleic acid amplification
resistant to most antibiotics; now use ceftriaxone
Neisseria gonorrhoeae
What diseases does neisseria gonorrhoeae cause?
gonorrhea-veneral disease
disseminated infections-spread to skin or joints
opthalmia neonatorum- ocular infection acquired at birth
What bacteria is this:
gram-negative diplococci
antiphagocytic Group-specific capsular polysaccharide
endotoxin (lipooligosaccharide) produces inflammation.
Neisseria meningitidis
What vaccine can be used against neiseria meningitidis?
capsular polysaccharide or CPS-protein conjugate
What diseases can Neisseria meningitidis cause?
meningitis- young adults
meningococcemia-disseminated infection with petechia and purpura
(repeated attacks in patients with deficiencies in terminal complement proteins)
What bacteria is this:
aerobic, large gram-positive, spore-forming rod
capsular polypeptide-poly-glutamic acid; antiphagocytic
three exotoxins-> protective antigen (PA), edema factor (EF), lethal factor (LF)
bacillus anthracis
How do you treat Bacillus anthracis?
ciproflaxin
What diseases can Bacillus anthracis cause?
cutaneous anthrax, Gi anthrax, inhilation anthrax
What causes this:
eschar formation, black
cutaneous anthrax
What causes this:
ulcers at site of invasion
GI anthrax
What causes this:
biothreat; non-specific signs followed by severe sepsis
Inhalation anthrax
What bacteria is this:
aerobic, large gram-positive spore-forming rod
ubiquitous in soil worldwide
two enterotoxins
Bacillus cereus
What diseases does bacillus cereus cause?
food poisoning- vomiting and diarrheal forms
ocular infection- traumatic penetrating injury
severe pulmonary disease-severe anthrax-like pulmonary disease in immunocompetent patients
What bacteria is this:
aerobic, gram positive, motile coccobaccilli, facultative intracellular pathogen, grows at 4 degrees celcius (i.e contaminated food)
listeria monocytogenes
How do you treat listeria monocytogenes?
penicilin alone or with gentamycin
What diseases does listeria monocytogenes cause?
- contaminated food or transplacental spread
- neonatal disease (early onset vs. late onset (meningitis))
- disease in healthy adults (asymptomatic or influenzae-like)
- Pregnant women- usually during third trimester; source of in utero infection (early onset) or shortly after birth (late onset)
What bacteria is this:
aerobic, thin, pleomorphic, gram-positive rods in filaments
zoonotic-colonizes swine, turkeys, fish- occupational disease in humans
Erysipelothrix rhusiopathiae
How do you treat Erysipelothrix rhusiopathiae?
penicillin
What are the diseases that Erysipelothrix rhusiopathiae cause?
- erysipeloid
- generalized cutaneous disease
- septicemia leading to endocarditis
What disease is this:
painful, pruritic inflammatory skin lesion at site of trauma
erysipeloid
What bacteria is this:
aerobic, pleomorphic gram positive rods
diptheria toxin (A-B toxin inactivates EF-2)
special media
Corynebacterium diptheriae
What is the vaccine for corynebacterium diptheriae?
diptheria toxoid
What disease does corynebacterium diptheriae cause?
respiratory diptheria
cutaneous diptheria
What are the symptoms of respiratory diptheria?
- exudative pharyngitis evolving to pseudomembrane
- release of toxin to produce myocarditis and neurotoxicity
What is cutaneous diptheria?
chronic, non-healing ulcer following contact with infected person
What are the Aerobic gram-positive rods?
Bacillus anthracis Bacillus cereus Listeria monocytogenes (gram + coccobacilli) Erysipelothrix rhusiopathiae Corynebacerium diptheriae
What bacteria is this:
gram negative, fermentative rod, normal flora of GI tract, five different pathogenic groups with distinct toxins
Escherichia coli
What diseases does Escherichia coli cause?
gastroenteritis
UTI
neonatal meningitis
septicemia
WHat is this:
there are five major groups with distinct sites of action, symptoms and viruence factors
gastroenteritis
What is the most common cause of UTI?
Escherichia coli
What is the exotoxin, pathogenic lesion and disease type of the common strain of E. coli?
alpha-hemolysin, inflammation, opportunistic
What is the exotoxin, pathogenic lesion and disease type of the uropathogenic strain of E. coli (UPEC)?
alpha-hemolysin
inflammation
UTI
What is the exotoxin, pathogenic lesion and disease type of the enterotoxigenic strain of E. coli (ETEC)?
LT (labile toxin), ST (stabile toxin)
hypersecretion
watery diarrhea
What is the exotoxin, pathogenic lesion and disease type of the enteropathogenic strain of E. coli (EPEC)?
No exotoxin
attaching and effacing small intestine
watery diarrhea
What is the exotoxin, pathogenic lesion and disease type of the enteroinvasive strain of E. coli (EIEC)?
No exotoxin
invasion, inflammation, ulcers
dysentery
What is the exotoxin, pathogenic lesion and disease type of the enterhemorrhagic strain of E. coli (EHEC)?
Shiga toxin
attaching and effacing colon, hemorrhage
bloody diarrhea, hemolytic uremic syndrome
What is the exotoxin, pathogenic lesion and disease type of the enteroaggregative strain of E. coli (EAEC)?
shiga toxin
adherent biofilm
watery or bloody diarrhea, hemolytic uremic syndrome
What bacteria is this:
gram-negative, non-fermenting rod
most infections via contaminated food (poultry or eggs)
over 2500 O serotypes
Serovars Typhi and Paratyphi highly adapted to humans
Salmonella enterica
What are the diseases caused by salmonella enterica?
gastroenteritis
septicemia
enteric fever (typhoid fever produced by S. Typhi)
asymptomatic colonization in the gallbladder
carrier for S. Typhi and S. Paratyphi
If you have reduced gastric acidity what are you more susceptible to?
gastroenteritis caused by salmonella enterica
What bacteria is this
Gram-negative, non-fermenting rod, four species (sonnei, flexneri, dysenteriae, and boydii), releases shiga toxin that damages intestinal epithelium (A-B toxin) blocks protein synthesis. Only messes with humans.
Shigella spp.
What diseases does Shigella cause?
shigellosis
asymptomatic carriers
What is shigellosis?
gastroenteritis; 450,000 cases/yr in U.S.
watery diarrhea caused by enterotoxin
abdominal cramps, fever, and bloody stools caused by invasion of colonic mucosa
What bacteria is this:
gram-negative rod, zoonotic (rats, squirrels, rabbits and domestic animals)
Y. pestis-flea vector
enormous historical importance; 3 major pandemics
Yersinia spp.
What diseases does Yersinia cause?
Y. pestis (highly virulent- plague)
Y. entercolitica and Y. pseudotuberculosis
What are the 2 subtypes of Y. pestis and how are they spread?
bubonic plague- spread via fleas
pneumonic plague - spread via aerosal
What is this:
enterocolitis following ingestion of infected meat, milk or water
Y. enterocolitica
What bacteria is this:
gram-negative, fermentative rod
encapsulated-antiphagocytic
carbapenem-resistant K. pneumoniae (CRKP) carbapenemase
Klebsiella pneumoniae
What diseases does Klebsiella pneumoniae cause?
pneumonia
UTI
sepsis
How do people usually get pneumonia when they have Klebsiella pneumoniae?
What do you see in this disease?
if they have impaired pulmonary defense (i.e diabetes, alcholism, malignancy, COPD)
Blood, mucoid sputum
What bacteria is this:
gram-negative rod; urease positive
motile-> swarmer on bacteriological plates
Urease hydrolyzes urea to ammonia, making urine alkaline (leads to struvite crystals in kidney (kidney stones))
Proteus mirabilis
What disease does Proteus mirabilis cause?
UTI with crystal formation
What bacteris is this:
gram-negative rod, red pigament, ubiquitous in damp areas of environment.
Serratia marcesens
What diseases does Serratia marcesens cause?
nosocomial infection in neonates and compromised patients
UTI
respiratory tract infection
wound infection
What bacteria is this:
gram-negative rod, >20 species, ubiquitous to fresh and brackish water
Aeromonas spp.
What diseases does Aeromonas spp. cause
Diarrheal disease in otherwise heatlhy people-contaminated food or water.
wound infection
Opportunistic system disease
When do opportunistic systemic diseases happen with Aeromonas spp.?
hepatobiliary disease or malignancy
What bacteria is this:
curved gram-negative; requires salt for growth. Cholera toxin - A-B toxin.
Vibrio cholera
What is this
similiar to heat-labile enterotoxin of E. coli (LT)
Cholera toxin A-B toxin
What is this:
Interacts with G protein that regulates adenylate cyclase leading to secretion of water and electrolytes.
produced by O1 (major pandemics) and O139 serogroups.
Cholera toxin A-B toxin
What are the diseases associated with Vibrio cholerae?
often asymptomatic or self-limited diarrhea
cholera- watery diarrhea with “rice water” stool (speckled with mucu)
What is this
curved gram-negative rod; requires salt for growth
epidemiology: estuarine and marine environments worldwide
most common cause of gastroenteritis in Japan and SE asia. Most COMMON cause of seafood-associated gastroenteritis in US (raw shellfish).
Vibrio parahaemolyticus
Vibrios require (blank) so they are marine acquired and they are (blank)
salt
curved
What are the diseases associated with Vibrio parahaemolyticus?
gastroenteritis
wound infection
What is this:
curved gram-negative rod; requires salt for growth. Infection via exposures to contaminted salt water or ingestion of contaminated shellfish. Responsible fo 90% of Vibrio-related deaths in U.S.
vibrio vulnificus
What diseases are associated with Vibrio vulnificus?
Septicemia after consumption of raw oysters; high mortality 25% wound infection (after exposure to contaminated water)
What is this:
curved, gram-negative rods
zoonotic- poultry, contaminated food, unpasteurized milk, contaminated water.
Several species: C. jejuni, C. coli, C. fetus, C. upsaliensis
Campylobacter jejuni et al.
What diseases does Campylobacter jejuni cause?
gastrointestinal disease (very common)
Septicemia
Guillain-Barre syndrome
What is the most common cause of gastrointestinal disease in the US?
campylobacter jejuni
How do you kill campylobacter jejuni?
gastric acidity (disease associated with decreased gastric acidity)
Is septicemia common in campylobacter jejuni?
NOOO!
What is this:
cross reactivity between surface LPS and peripheral nerve gangliosides?
Guillain-Barre syndrome
What is this:
spiral, highly motile, gram-negative rods
human primary reservoir, infection common, life-long colonization
copious urease production-non invasive breath test
difficult to culture; requires complex medium
Helicobacter pylori
What diseases does Helicobacter pylori cause?
- life-long colonization if untreated
- gastritis
- gastric ulcers (10-20% lifetime risk if colonized)
- gastric cancer (1-2% lifetime risk of colonized)
What is this:
gram-negative rod; oxidase-postive; green pigment. Mucoid polysaccharide capsule, Ubiquitous in naturel nosocomial infection, highly resistant; requires use of antibiotic combinations
pseudomonas aeruginosa
What diseases does pseudomonas aeruginosa cause?
pulmonary infection infection of burn wounds urinary tract infection external otitis bacteremia
What kind of pulmonary infections does pseudomonas aeruginosa cause?
cytstic fibrosis; mucoid strains
Why can you get UTIs from pseudomonas aeruginosa?
long-term indwelling catheters
What is this:
gram-negative rod
multiple species
burkholderia spp.
What diseases does burkholderia spp cause?
B. Cepacia complex
B. pseudomallei-meliodosis
B. mallei
What is B cepacia complex?
pulmonary infection in patients with undelrying lung disease e.g. cystic fibrosis
What is B. pseudomallei?
pulmonary infection and sepsis
biothreat
What is B. mallei?
glanders in horses; biothreat
What is this: gram-negative coccobacillus ubiquitous saprophytes in many environments emerging nosocomial infection highy resistant to multiple antibiotics
acinetobacter baumanii
What diseases does acinetobacter baumanii cause?
opportunistic pathogen
nosocomial infection in intensive care units e.g. ventiator-associated pneumonia
wound infection- nosocomial infection of battlefield wounds
A pediatric patient with a persistent cough is evaluated for sinopulmonary disease. History and physical examination determines that the child suffers from nasal polyps and possibly, chronic airway obstruction. A sputum sample produces several bacterial species, including a non-typable Haemophilus influenzae and a mucoid variety of Pseudomonas aeruginosa. Which of the following is the most likely diagnosis?
cystic fibrosis
What is this:
small, gram negative coccobacilli
nutrional requirements- X (hemin) and V (NAD) factors
encapsulated - type b most important (Hib)
Haemophilus influenzae
What can you use to protect yourself against haemophilus influenzae?
vaccine- protein conjugate of type b polysaccharide
What are the diseases associated with Haemophilus influenzae?
meningitis
epiglottitis
acute and chronic otitis media and sinusitis
Is epiglottitis life threatening?
yes
What is the most common cause of actue and chronic otitis media and sinusitis other than streptococcus pneumonia?
Haemophilus influenzae
What is this:
gram-negative coccobacilli
commensals of oropharynx of healthy animals (e.g bites, scratches, shared foods)
pasteurella multocida
What diseases does pasteurella multocida cause?
cellulitis and lymphadenitis after animal bite
respiratory infection in patients with underlying pulmonary dysfunction
systemic infection in immunocompromised patient
What is this:
gram negative coccobacillus
pertussis toxin
bordetella pertussis
What does pertussis toxin do?
inhibits protein that regulates adenylate cyclase activity, results in increased cAMP levels
What diseases does bordetela pertussis cause?
pertussis (whooping cough) in unimmunized infants chronic cough (in partially immunized patients)
What are the three stages of pertussis (whooping cough)?
catarrhal stage
paroxysmal stage
convalescent stage
What is this:
gram negative coccobacillus; requires cysteine for growth- alert laboratory-> special media and dangerous.
facultative intracellular pathogen
zoonotic (primarily rabbits)
insect vectors (hard ticks and biting flies)
Franciscella tularensis
What diseases does Franciscella tularensis cause?
ulceroglandular
oculoglandular
pneumonic
What is the most common form of disease cause by Franciscella tularensis that follows insect bite or direct inoculation?
ulceroglandular
What disease will you get if you get franiscella tularensis in your eye?
oculoglandular
A 10-month-old male child presents with episodes of repetitive coughing with intermittent large gasps of air as well as some vomiting. Parents indicate that the child has been suffering from this condition for about 1 week. Incidentally, the previous week he was reported to have a cold-like illness with fever and sneezing. A white count shows 65% lymphocytes and 30% neutrophils. A gram-negative coccobacillus was grown from a nasopharyngeal swab plated on Regan-Lowe charcoal agar. Which of the following is the most likely cause.
Bordetella pertussis
What disease is this:
very small, gram-negative coccobacilli
infects issue rich in erythritol (i.e uterus, placenta)
zoonotic (B. melitensis, B. abortus, B. Suis, B canis)
Brucella spp.
What diseases are caused by Brucella spp.
Undulant fever
Disease spectrum varies with infecting species
Biothreat
How do you know if someone has undulant fever?
if they are infected with brucella and are showing multiple symptoms with intermittent fever
What is this:
slender, pleomorphic gram-negative rods
nutritionally fastidious; requires cysteine-> special media
replicates inside macrophages and amoebae
common in natural bodies of water, cooling towers, etc.
Legionella pneumophila
What are the diseases caused by Legionella pneumophila?
asymptomatic infection (relativey common)
Legionnaire’s disease
Pontiac fever
What is this:
severe form of pneumonia in setting of underlying pulmonary disease
Legionnaire’s disease
What is this:
self-limiting influenza-like illness; several Legionella spp.
Pontiac fever
What is this:
Gram-negative rod
Many transmitted by blood-sucking arthropods
Bartonella spp.
What are the diseases caused by Bartonella spp.?
B. quintana
B. henselae
What is this:
Trench fever of WWI; severe headache, fever, pain in long bones
Vector – human body louse
B. quintana caused by Bartonella spp.
What is this:
Reservoir – cats and their fleas
Bacillary angiomatosis – vascular proliferative disease
Cat-scratch disease – chronic regional lymphadenopathy associated with inoculation of flea excreta via a cat scratch
B. henselae caused by Bartonella spp.
What is this:
long, thin, gram-negative rod
reservoir is rat and other small rodents
Streptobacillus monoiliformis
What diseases are caused by Streptobacillus moniliformis?
- rat-bite fever
- normal flora of nasopharynx of rats
- human infections follow rat bites
- irregular fever, headached, chills, migratory polyarthralgia
- macuopapular or petechial rash
What is this:
small gram-negative rods
normal flora of human mouth and upper respiratory tract
Eikenella corrodens
What diseases are caused by Eikenella corrodens?
opportunistic infection in immunocompromised patients
commonly isolated in human bite wound or fistfight
A 12-year-old girl develops a low-grade fever, malaise, and tender lymphadenopathy in her right axial area. On her right hand are the scratches she received 10 days previously from her kitten. What is the most likely cause of this lymphadenopathy?
Bartonella henselae
What are the aerobic gram-negative rods?
E. coli Salmonella enterica Shigella spp. Yersinia spp. Klebsiella pneumoniae Proteus mirabilis Serratia marcesens Aeromonas spp. Vibrio cholerae Vibrio parahaemolyticus Vibri vulnificus Campylobacter jejuni Helicobacter pylori Pseudomonas aeruginosa Burkholderia spp. Legionella pneumophila Bartonella spp. streptobacillys moniliformis Eikenella corrodens bacterioides fagilis
What are the gram-negative coccobacilli?
- Acinetobacter baumanii
- Haemophilus influenzae
- Pasteurella multocida
- Bordetella pertussis
- Franciscella tularensis
- Brucella spp.
What is this:
spore-forming, anerobic, gram positive rod. Ubiquitous in soil, water and GI tract of humans and animals. Numerous toxins and enzymes; alpha toxin (lecithinase)
C. perfringens enterotoxin
Clostridium perfringens
What diseases are caused by Clostridium perfringens?
- cellulitis
- fasciiitis or suppurative myositis
- Myonecrosis or gas gangrene
- Clostridial food poisoning (intoxication; meat produts)
What is this:
spore-forming, anaerobic, gram-positive rod
spores in most soils and GI tract of humans and animals
Tetanospasmin
Clostridium tetani
What is this:
neurotoxin that blocks release of neutrotransmitters for inhibitory synapses (spastic paralysis)
tetanospasmin
What vaccine do you use for clostriudium tetani?
tetanus toxoid
What are the diseases caused by Clostridium tetani?
generalized tetanus
localize tetanus
neonatal tetanus
What kind of tetnus is this:
spread of toxin from local site
generalized tetanus
What kind of tetanus is this:
toxic effects at local site
localized tetanus
What kind of tetanus is this:
toxemia after infection of umbilical stump
neonatal tetanus
What is this:
spore-forming, anaerobic, gram-positive rod, spores in soil worldwide. Has botulinum toxin. Can see this toxin in patient serum or feces
Clostridium botulinum
What diseases are caused by clostridium botulinum?
foodborne botulism, infant botulism, wound botulism
What is this:
prevents release of neurotransmitter acetylchline (flacid paralysis)
botulinum toxin
What is this:
intoxication via contaminatd food
foodborne botulism
What is this:
neurotoxin produced in vivo following colonization of infant GI tract-honey
infant botulism
What is this:
toxemia following wound infection
wound botulism
Infected pressure sores were observed on the buttock of an elderly, bedridden patient recently treated for malignancy of the rectum. Some of the lesions are conspicuously necrotic, exceptionally painful to the touch and give off a musty sweet odor. A gram stain of the watery discharge from one of the lesions reveals an abundance of bacteria (see below). What is the most likely diagnosis?
clostridial gas gangrene
What is this:
spore-forming, anaerobic, gram-positive rod. Colonized human GI tract; spores common in hospital rooms and other health care settings
two toxins: enterotoxin and cytotoxin.
Diagnosed by detection of toxins in patient feces
Clostridium difficile
What diseases are cause by Clostridium difficile?
Pseudomembranous colitis
WHen do you get pseudomembranous colitis with colistridium difficile?
you get it after use of broad spectrium antibiotics. Relapse is common cuz antibiotics dont kill spores
What is this:
anaeroic, gram positive branching rod
infection endogenous (poor oral hygiene, dental work)
sulfar granules (large yellow or orange masses of filamentous organisms at sites of infection)
Actinomyces israelli
What diseases does Actinomyces israelli cause?
oral-cervicofacial infection
other sites too, thoracic, abdominal, pelvic, CNS
What is this:
small, anaerobic, gram positive rods, common on skin, sebaceous glands, sweat glands, produces many products that stimulate local inflammation
Proprionibacterium acnes
What diseases are caused by Propionibacterium acnes?
acne vulgaris-stimulates inflammatory response
AND
opportunistic infections in patients with prosthetic devices or IV devices
What is this:
anaerobic, pleomorphic, gram-negative rods. Colonize human upper respiratory tract, GI tract and genitourinary tract
Bacterioides fragilis
What diseases does bacterioides fragilis cause?
head and neck infection intra-abdominal infection gynecologic infection skin and soft tissue infection bacteremia
What are all the anaerobic bacteria?
Clostridium perfringens Clostridium tetani Clostridium botulinum Clostridium difficile Actinomyces israelii Propionibacterium acnes Bacterioides fragilis
What is this:
acid-fast, aerobic rods, cell wall rich in lipids, slow growth -16-20 h doubling time. Intracellular pathogen-grows in un-activated macrophage. Disease due to host response. MDR-TB multiple drug resistance.
Mycobacterium tuberculosis
What disease does Mycobacterium tuberculosis cause?
tuberculosis
most infections asymtpomatic and latent (skin test)
pulmonary
extrapulmonary (pleura, CNS, genitourinary system)
What is this:
acid-fast, aeroic rods; cell wall rich in lipids
obligate intracellular pathogen; no culture
disease due to host response
Mycobacterium leprae
What diseases are caused by mycobacterium leprae?
Tuberculoid leprosy
Lepromatou leprosy
What kind of leprosy is this:
strong cellular immune response
relatively few bacteria
tuberculoid leprosy
What kind of leprosy is this:
-strong antibody response but defect in cellular response
abundant bacteria-most infectious form
Lepromatous leprosy
What is this:
acid-fast, aerobic rods; cell wall rich in lipids
two species, M. avium and M. intracellulare
common in soil and water; acquired via ingestion of contaminated water or food
Mycobacterium avium complex
What diseases are caused by Mycobacterium avium complex?
- asymptomatic colonization
- chronic localization pulmonary disease
- disseminated disease- AIDS patients
What is this:
gram-positive rods with filamentous forms that resemble hyphae; weakly acid fast
ubiquitous in soil rich with organic matter
serious disease in immunocompromised patients
Nocardia spp.
What diseases are caused by Nocardia spp.?
bronchopulmonary disease lymphocutaneous disease (may progress to mycetoma) brain abscess (in immunocompromised patients)
A homeless man who is known to be HIV positive presents with a productive cough, periods of shaking chills, fever and night sweats. An acid-fast stain of sputum is shown in the photograph. A tuberculin skin test was negative. What is the most likely etiologic agent?
Mycobacterium tuberculosis
What are the acid fast bacteria?
Mycobacterium tuberculosis
Mycobacterium leprae
Mycobacterium avium complex
Nocardia spp.
What is this:
- spirochete with gram-negative like cell wall
- humans only natural host
- cannot be cultured; darkfield microscopy of primary lesion
- serology used fro diagnosis in secondary and late stages
Treponema pallidum
What diseases can Treponema pallidum cause?
primary syphilis secondary syphilis latent tertiary (late) syphilis congenital syphilis
What kind of syphilis is this:
painless chancre at site of inoculation
primary syphilis
What kind of syphilis is this:
disseminated disease; rash
secondary syphilis
What kind of syphilis is this:
asymptomatic; serological evidence of infection
latent syphilis
What kind of syphilis is this:
destruction of multiple organs
tertiary (late) syphilis
What is this:
spirochete with gram-negative-like cell wall; stain poorly. Zoonotic; leading vector-borne disease in U.S.
Reservoir- mice (larval form of vector) and deer (adult form)
Vector- Hard-shelled ticks; larval/nymph form (mouse host) accounts for 90% of human disease
Borrelia burgdorferi
What diseases are caused by Borrelia burgdorferi?
Lyme disease
What are the signs of Lyme disease?
initial circular “bull’s eye” skin lesion-erythema migrans
systemic signs-arthritis, neurologic, cardiac
What is this:
spirochete with gram-negative like cell wall
relapses because bacterium varies expression of lipoprotein coat to escape immune surveillance
Borrelia- relapsing fever
What diseases are caused by Borrelia?
endemic relapsing fever
epidemic relapsing fever
What is this: worldwide and western U.S. several borrelia sp. Resevoir- rodents and small mammals vector-soft ticks
Endemic relapsing fever
What is this:
regions of Africa - B. recurrentis
resevoir-man
vector–human body louse
Epidemic relapsing fever
What is this:
spirochete with gram-negative like cell wall
zoonotic-rodents, dogs, farm animals, wild animals
infection via contact with water, food, or soil contaminated with urine from infected animal
Leptospira interrogans
What diseases does leptospira interrogans cause?
leptospirosis
What is this:
most disease is mild, influenzae-like syndrome
systemic disease presents as aseptic meningitis
Leptospirosis
What syndrome is this and what is it caused by:
overwhelming disease; vascular collapse, hepatic disease with jaundice and renal dysfunction
Weil syndrome caused by leptospira interrogans
What are the spirochete bacteria?
Treponem pallidum
Borrelia burgdorefi
Borrelia (relapsing fever)
Leptospira interrogans
What is this:
smalles free-living bacterium; lacks cell wall; membrane contains sterols from host serum
strictly human pathogen; transmission via aerosol droplet
Mycoplasma pneumoniae
How do you treat Mycoplasma pneumoniae?
macrolides (azithromycin) r quinolones
What diseases does Mycoplasma pneumoniae cause?
- Tracheobronchitis and pharyngitis
- Atypical (walking) pneumonia
- Other species may produce disease (M. genitalium, M. hominis, Ureaplasma urealyticum)
What is this:
small forms similiar to gram-negative rods
obligate intracellular parasites-endothelial cells-> vasculitis
hard ticks are both reservoir and vector
Weil-Felix agglutination-test for Ab, low sensitivity and specificity
Rickettsia rickettsii
What diseases does rickettsia rickettsii cause?
Rock mountain spotted fever
Endemic typhus
What is this:
fever, headache, malise, myalgias, nause; macuar rash with centripetal spread (hands and feet, spreading to trunk)
rock mountain spotted fever caused by Rickettsia rickettsii
How is R. prowazekki caused by Rickettsia rickettssi transmitted?
via lice and causes epidemic typhus
How is R. typhi caused by Rickettsia rickettssi transmitted?
via fleas and causes endemic typhus
How is Orientia tsutsugamushi caused by Rickettsia rickettssi transmitted?
via fleas and causes scrub typhus
What is this:
small forms with cell wall similiar to gram-negative bacteria. Obligate intracellular parasite-cytoplasmic vacuoles of hematopoietic ces
zoonotic-reservoirs include deer, mice, voles, and canines
Vector-ticks
Ehrlicha and anaplasma spp.
What diseases does Ehrlichia and Anaplasma spp cause?
human monocytic ehrlichiosis (E. chaffeensis)
human granulocytic ehrlichiosis (A. phagocytophilum)
A 40-year-old man presented with a rubeola-like rash on the extremities, chills, fever, myalgia, and malaise 5 days after returning from a June fishing trip in Arkansas. A history of tick bites is noted and Rocky Mountain spotted fever (RMSF) is suspected. What is the etiologic agent?
Rickettsia rickettsii
What is this:
small gram-negative, “spore”-forming bacterium; obligate intracellular growth
zoonotic-cattle, sheep, goats, dogs and cats
Infection due to inhalation or unpasteurized milk
extreme environmental stability
Coxiell burnetii
What diseases are caused by Coxiella burnetii?
acute disease-pneumonia, hepatitis, fever
chronic disease- inflammation of heart (endocarditis)
biothreat
What is this:
small gram-negative rods with no peptidoglycan layer
obligate intracellular parasites
two forms: infectious elementary bodies and non-infectious reticulate bodies
Chlamydia trachomatis
How do you treat Chlamydia trachomatis?
azithromycin or doxycycline
What diseases are caused by Chlamydia trachomatis?
urogenital (urethritis, PID, most common STD in U.S)
Trachoma
Lymphogranuloma venereum
What is the most common STD in US?
chlamydia trachomatis
What is the most important global infectious cause of blindness?
trachoma caused by chlamydia trachomatis
What is an STD that is a primary lesion extending to lymphatics and lymph nodes?
lymphogranuloma Venereum caused by Chlamydia trachomatis
What is this:
general properites of C. trachomatis
chlamydophilia
What diseases does chlamydphila spp. cause?
Chlamydophila pneumoniae
Chlamydophila psittaci
What is this:
respiratory infection-sinusitis, pharyngitis, pneumonia
possibe role in atherosclerosis
Chlamydophila pneumoniae caused by chlamydophila spp.
What is this:
Psittacosis (parrot fever)
respiratory infection with spread to RES cells of liver and spleen
Ornithosis-birds are natural reservoir
Chlmydophila psittaci caused by chlamydophila sp.
A 47-year-old woman in India is becoming blind due to repeated infection with Chlamydia trachomatis. What is seen in the pus draining from her eyes when stained by immunofluorescence?
Elementary bodies
