M5 PART 4 Flashcards
- the most common form of enterococcal infections
- frequently associated with indwelling catheters, instrumentation, or structural abnormalities of the genitourinary tract
UTI
Enterobacteriaceae
MOTILITY
motile w/ peritrichous flagella or nonmotile
Enterobacteriaceae
oxygen requirement
facultative anaerobes
Enterobacteriaceae
grow well on what medium
MacConkey agar
Enterobacteriaceae
____ fermenters, often with gas production
glucose
Enterobacteriaceae
reduce ____ to ____
nitrate to nitrite
Enterobacteriaceae
catalase ____
oxidase ____
catalase positive
oxidase negative
- Gram-negative rods
- Either motile with peritrichous flagella or nonmotile
- Grow on peptone or meat extract media without the addition of sodium chloride or other supplements;
- Grow well on MacConkey agar;
- Grow aerobically and anaerobically (are facultative anaerobes);
- Ferment rather than oxidize glucose, often with gas production
- Are catalase positive, oxidase negative
- Reduce nitrate to nitrite
Enterobacteriaceae
Enterobacteriaceae
LACTOSE FERMENTED RAPIDLY
Klebsiella
Escherichia coli
Enterobacter aerogenes & cloacae
KEE
Enterobacteriaceae | ANTIGENIC STRUCTURE
most external part of the CELL WALL lipopolysaccharide and consist of repeating units of polysaccharide, resistant to heat and alcohol and usually are detected by bacterial agglutination
O antigen
Enterobacteriaceae | ANTIGENIC STRUCTURE
- external to O antigens on some but not all Enterobacteriaceae, “Kapsule”
- may be associated with virulencce
K antigens
Enterobacteriaceae | ANTIGENIC STRUCTURE
located on flagella and are denatured or removed by heat or alcohol
H antigens
The most frequent sites of clinically important infection are the urinary tract, biliary tract, and other sites in the abdominal cavity, but any anatomic site (e.g., bloodstream, prostate gland, lung, bone, and meninges) can be the site of disease.
Escherichia coli
Escherichia coli
____ inhibits adhesion of E. coli to the urothelium
cranberry juice
Escherichia coli
Infection in kidney
cystitis
- the most common cause of UTI
- accounts for 90% of first UTI in young women
Escherichia coli
Escherichia coli
____ may be highly susceptible to E. coli sepsis because they lack IgM antibodies
newborns
Escherichia coli
Newborns may be highly susceptible to E. coli sepsis because they lack ____ antibodies
IgM
Escherichia coli
Sepsis may occur ____ to urinary tract infection
secondary
Escherichia coli
E. coli and group B streptococci are the leading causes of ____ in infants.
meningitis
Escherichia coli
Approximately 80% of E. coli from meningitis cases have the ____
K1 antigen
E. COLI ASSOCIATED DIARRHEAL DISEASES
- EPEC adhesion factor (EAF) and chromosomal locus of enterocyte effacement (LEC) promote tight adherence to the intestine
- Severe, watery diarrhea, vomiting and fever in infants
Enteropathogenic
E. coli
E. COLI ASSOCIATED DIARRHEAL DISEASES
- ETEC colonization factors (pili known as colonization factor antigens [CFA]) that allows attachment to small intestine
- Traveler’s disease, diarrhea in children
Enterotoxigenic
E. coli
E. COLI ASSOCIATED DIARRHEAL DISEASES
- Produces two antigenic forms of toxins: Shiga-like toxin 1 and 2
- Mild non-bloody diarrhea, hemorrhagic colitis (bloody diarrhea), severe form of diarrhea, hemolytic uremic syndrome (a disease resulting to acute renal failure, microangiopathic hemolytic anemia and thrombocytopenia)
Shiga toxin-producing
E. coli
E. COLI ASSOCIATED DIARRHEAL DISEASES
- Invades and destroy the mucosal cells of the colon
- Shigellosis-like, occurs in children in developing countries and in travelers to these countries
Enteroinvasive
E. coli
E. COLI ASSOCIATED DIARRHEAL DISEASES
- They are characterized by their specific patterns of adherence to human cells. This group of diarrheagenic E. coli is quite heterogeneous, and the exact pathogenic mechanisms are still not completely elucidated.
- Acute and chronic diarrhea (>14 days in duration) in persons in developing countries, cause of foodborne illnesses in industrialized countries and have been associated with traveler’s diarrhea and persistent diarrhea in patients with HIV
Enteroaggregative
E. coli
Escherichia coli | TREATMENT
CYSTITIS
TMP-SMZ or nitrofurantoin
Escherichia coli | TREATMENT
PYELONEPHRITIS
ciprofloxacin or ceftriaxone
Escherichia coli | TREATMENT
SEPSIS
3rd gen cephalosporins with or without aminoglycosides
Escherichia coli | TREATMENT
NEONATAL MENINGITIS
ampicillin and cefotaxime
Klebsiella pneumoniae
Has a very large polysaccharide ____
capsule
Klebsiella pneumoniae
Produce a lobar ____ with thick, mucoid, blood sputum
pneumonia
Klebsiella pneumoniae
mucoid sputum is also called
currant jelly
- found outside the enetric rod
- has K1 antigen (K - kapsular antigen)
- rapid lactose former
- produce lobar pneumonia
- produce mucoid sputum (currant jelly)
KLEBSIELLA PNEUMONIAE
ENTEROBACTER
may cause ____ infections
nosocomial
- E. cloacae complex and E. aerogenes
- found in soil, water, sewage system
- common cause of nosocomial infections (hospital acquired infections)
- known to be resistance because of the** β-lactamase** called ampC
- rapid lactose former
ENTEROBACTER
ENTEROBACTER
known to be resistant to ampicillin first- and 2nd gen cephalosporins because of the ____
β-lactamase called ampC
Serratia marcescens
produce a red pigment called
PRODIGIOSIN
Serratia marcescens
site of infection
urinary tract
Serratia marcescens
drug resistant because of
ampC β-lactamase
- produce a characteristic red pigment (prodigiosin)
- Most common sites of infection include the urinary tract
- resistant to penicillin, ampicillin, and first-generation cephalosporins because it harbors an inducible, chromosomal AmpC ß-lactamase
SERRATIA MARCESCENS
Proteus
motility
swarming motility
- Exhibit swarming motility
- Urease positive → stone formation (struvite)
- P. mirabilis & P. vulgaris
PROTEUS
Proteus
- urinary tract infections
- bloodstream infection (frequently secondary due to a UTI)
- respiratory tract infections
P. mirabilis
Proteus
urease ____
positive
Proteus
- wound and soft tissue infections
P. vulgaris
Morganella morganii
typically resistant to ____
penicillin
- Cause of UTI and wound infections in the hospital
- Drug-resistant (penicillin, cephalosporins)
Morganella morganii
Providencia
associated with ____
UTI
- can cause urinary tract infections, sepsis, respiratory tract infections, intraabdominal infections, and wound infections, principally among immunocompromised and/or debilitated hospitalized patients
- Citrate test: Citrate positive
CITROBACTER
CITROBACTER
can cause urinary tract infections, sepsis, respiratory tract infections, intraabdominal infections, and wound infections, principally among ____ and/or debilitated hospitalized patients
immunocompromised
Enterobacteriaceae species TREATMENT
No single therapy is available
Sulfonamides, ampicillin, cephalosporins, fluroquinolones, and aminoglycosides
Shigellae
antigen present
somatic O antigen
Shigellae
can cause the most severe human infection
Shigella dysenteriae
Shigellae
have a very low ____
infective dose
highly communicable
Shigellae
incubation period
1 - 4 days
Shigellae
infections are almost always limited to ____
gastrointestinal tract
Shigellae
toxin produced
shiga toxin
Shigellae
mode of transmission
food, fingers, feces, flies
person - person
Shigellae
reservoir
humans
only reservoir
Shigellae
can only ferment
glucose
non lactose fermenter
Shigellae
bloody diarrhea
Shigellosis / Bacillary dysentery
Shigellae
only lactose fermenter but SLOW lactose fermenter
Shigella sonnei
Shigellae
positive result in TSI
whole agar is yellow
Shigellae
type 1 hemolytic uremic syndrome
S. dysenteriae
Shigellae
Reiter’s chronic arthritis syndrome
S. flexneri
Shigellae
disease
Shigellosis or Bacillary dysentry
Shigellae
treatment for severe infections
ciprofloxacin
SALMONELLA
antigens
cell wall O, flagellar H, capsular Vi
SALMONELLA
TYPHOIDAL
S. Typhi
S. Parathypi A
SALMONELLA
- severe, systemic illness, caused by Salmonella Typhi (most common) or Salmonella Paratyphi
- The fever rises to a high plateau (39°C to 40°C)
- from food or water
- fever, malaise, headache, constipation, bradycardia, and myalgia
ENTERIC FEVER / TYPHOID FEVER
SALMONELLA
ENTERIC / THYPOID FEVER:
incubation period
10 - 14 days
SALMONELLA
enlargement of ____
spleen & liver
SALMONELLA
spots observed on the chest and abdomen
ROSE SPOTS
SALMONELLA | TREATMENT
uncomplicated
oral azithromycin
SALMONELLA | TREATMENT
complicated
parenteral
3rd gen cephalosporion or fluoroquinolone
SALMONELLA | PREVENTION
oral
live attenuated vaccine
SALMONELLA | PREVENTION
intramascular
Vi capsular polysaccharide vaccine (Typbar)
Bacteriologic Methods for Isolation of Salmonellae
- The specimen (usually stool) can also be placed into selenite F or tetrathionate broth, both of which inhibit replication of normal intestinal bacteria and permit multiplication of salmonellae.
- After incubation for 1-2 days, an aliquot from this broth is plated on differential and selective media.
ENRICHMENT CULTURE
SALMONELLA
- most common manifestation of Salmonella infection
- severe diarrhea
ENTEROCOLITIS
SALMONELLA
complicating Salmonella bacteremia usually involves the aorta, often associated with atherosclerotic plaques or aneurysms; people older than 50 years have a higher risk of developing such complications
endovascular infection
Bacteriologic Methods for Isolation of Salmonellae
- EMB, MacConkey, or deoxycholate medium permits rapid detection of lactose nonfermenters (not only salmonellae and shigellae but also Proteus, Pseudomonas, etc.).
- Gram-positive organisms are somewhat inhibited.
- Bismuth sulfite medium permits rapid detection of salmonellae, which form black colonies because of HS production.
- Most salmonellae produce H2S.
DIFFERENTIAL MEDIUM
SALMONELLA | Serologic Methods
known sera + unknown culture
AGGLITINATION TEST
SALMONELLA
more common among patients with comorbidities (e.g., immunosuppression), as well as infants and the elderly
esp those kids with sickle cell anema
BACTEREMIA
Bacteriologic Methods for Isolation of Salmonellae
- The specimen may also be plated on salmonella-shigella (SS) agar, Hektoen enteric (HE) agar, xylose-lysine desoxycholate (XLD) agar, or desoxycholate-citrate agar, all of which favor growth of salmonellae and shigellae over other Enterobacteriaceae.
- Chromogenic agars specifically for salmonella recovery are also available.
SELECTIVE MEDIUM
SALMONELLA | Serologic Methods
serum agglutinins rise sharply during the second and third weeks of S serotype Typhi infection.
Tube Dilution Agglutination Test (Widal Test)
SALMONELLA | Epiemiology
sources of infection
poultry products, food & drinks
SALMONELLA | Epiemiology
Three percent of survivors of typhoid fever become ____
gallbladder, biliary tract, or rarely, the intestine or urinary tract
permanent carriers
PSEUDOMONAS AERUGINOSA
oxygen requirement
obligate aerobe
PSEUDOMONAS AERUGINOSA
Produces a non-fluorescent bluish pigment, ____, which diffuses into the agar
pyocyanin
PSEUDOMONAS AERUGINOSA
Produces the fluorescent pigment ____, which gives a greenish color to the agar when combined with pyocyanin
pyoverdine
PSEUDOMONAS AERUGINOSA
dark red pigment
pyorubin
PSEUDOMONAS AERUGINOSA
brown-black pigment
pyomelanin
- gram negative
- obligate aerobe
- motile & rod shaped
- produces a blue pigment called pyocyanin
- commonly present in moist environments in hospitals
PSEUDOMONAS AERUGINOSA
PSEUDOMONAS AERUGINOSA | ANTIGENIC STRUCTURES
extend from the cell surface and promote attachment to host epithelial cells
PILI (FIMBRIAE)
PSEUDOMONAS AERUGINOSA | ANTIGENIC STRUCTURES
an exopolysaccharide is responsible for the mucoid colonies seen in cultures from patients with CF
ALGINATE
PSEUDOMONAS AERUGINOSA | ANTIGENIC STRUCTURES
responsible for many of the endotoxic properties of the organism
LIPOPOLYSACCHARIDE
PSEUDOMONAS AERUGINOSA | ANTIGENIC STRUCTURES
elastases, proteases, and two hemolysins (a heat-labile phospholipase C and a heat-stable glycolipid)
EXTRACELLULAR ENZYMES
PSEUDOMONAS AERUGINOSA | ANTIGENIC STRUCTURES
responsible for the production of hydrogen peroxide and superoxide, and stimulates the release of interleukin (IL)-8
PYOCYANIN
PSEUDOMONAS AERUGINOSA | ANTIGENIC STRUCTURES
serves as a siderophore, that is, binds iron
PYOVERDINE
PSEUDOMONAS AERUGINOSA | ANTIGENIC STRUCTURES
blocks protein synthesis, causes tissue necrosis and is lethal for animals when injected in purified form.
EXOTOXIN
PSEUDOMONAS AERUGINOSA
bifunctional enzymes with GTPase and ADP-ribosyl transferase activity
EXOENZYME S & T
PSEUDOMONAS AERUGINOSA
phospholipase
EXOENZYME U
PSEUDOMONAS AERUGINOSA
an adenylyl cyclase
EXOENZYME Y
PSEUDOMONAS AERUGINOSA
produces what type of odor
grape-like or corn taco-like
- not part of normal human microbiota but is capable of colonization of various body sites
- known to cause disease in humans, especially in people with altered and decreased host defenses
PSEUDOMONAS AERUGINOSA
PSEUDOMONAS AERUGINOSA
acquisition of the organism can be either ____ or ____
endogenous or exogenous
PSEUDOMONAS AERUGINOSA
occurs after colonization
endogenous infection
PSEUDOMONAS AERUGINOSA
occurs from an environmental reservoir via susceptible portal of entry
exogenous infection
PSEUDOMONAS AERUGINOSA
grows well at what temp
37C - 42C
- Comma-shaped, curved, and sometimes straight
- facultatively anaerobe
- catalase and oxidase-positive
- Motile (monotrichous or multitrichous polar flagella)
- Halophilic
VIBRIOS
VIBRIOS
shape
comma-shaped, curved
VIBRIOS
catalase & oxidase
positive
VIBRIO CHOLERAE
transmission
contaminated water & food
VIBRIO CHOLERAE
Many vibrios share a single heat-labile ____ antigen
flagellar H
VIBRIO CHOLERAE
has ____ found on the cell wall
O lipopolysaccharides
VIBRIO CHOLERAE
can cause epidemic and pandemic cholera
O1 and O139
VIBRIO CHOLERAE
associated with cholera-like diarrheal diseases
non-O1 and non-O139
VIBRIO CHOLERAE
50% of the infections with classic vibrio Cholera are ____
ASYMPTOMATIC
VIBRIO CHOLERAE
75% of the infections are associated with ____
El Tor biotype
VIBRIO CHOLERAE
medium
thiosulfate-citrate-bile salts-sucrose (TCBS) agar
VIBRIO CHOLERAE
secretes an enterotoxin called ____ (cholera toxin)
choleragen
VIBRIO CHOLERAE | ENTEROTOXIN
enters, closed in an endosome, reaching the cytoplasm; catalyze the addition of ADP ribose to the G protein; G protein will cause the persistent stimulation of this enzyme called the adenylate cyclase and the adenylate cyclase will result to the increase of cyclic AMP – prolonged hypersecretion of water and electrolytes
subunit A
VIBRIO CHOLERAE | ENTEROTOXIN
binding to the GM1 receptor (ganglioside receptor)
subunit B
VIBRIO CHOLERAE | CLINICAL FINDINGS
spectrum of disease
asymptomatic to mild, moderate, or severe diarrhea
VIBRIO CHOLERAE | CLINICAL FINDINGS
incubation period
12 hrs - 3 days
VIBRIO CHOLERAE | CLINICAL FINDINGS
stools resemble
rice water
VIBRIO CHOLERAE | TREATMENT
most important treatment
water & electrolyte replacement
VIBRIO CHOLERAE | TREATMENT
DOC
tetracycline
VIBRIO CHOLERAE | TREATMENT
children and in pregnant women
erythromycin / azithromycin
- Transmitted by contaminated seafood (raw fish or shellfish)
- The enteritis ranges from mild watery diarrhea to a dysentery-like syndrome (bloody)
Vibrio parahaemolyticus
Vibrio parahaemolyticus | TREATMENT
DOC
doxycycline / fluoroquinolone
- Severe wound and soft tissue infections - Can lead to necrosis
- Bacteremia/sepsis (rather than gastroenteritis)
- Chronic liver diseases, such as liver cirrhosis
- Can invade the bloodstream even without causing GI symptoms
Vibrio vulnificus
Vibrio vulnificus | TREATMENT
DOC
fluoroquinolones, doxycycline, 3rd gen cephalosporins
CAMPYLOBACTER JEJUNI
shape
curved, comma, S-shaped, SEA GULL WING shaped
CAMPYLOBACTER JEJUNI
oxygen requirement
macroaerophilic
CAMPYLOBACTER JEJUNI
selective media
camply blood agar, skirrow’s media
CAMPYLOBACTER JEJUNI
grows better at ____C than 37C
42C
CAMPYLOBACTER JEJUNI
catalase & oxidase
positive
- A small motile, Gram-negative rod that appears as curved, comma-, or S-shaped organisms
- “Sea gull wing” shape
- Microaerophilic (5-7% O2, 10% CO₂)
- Selective media – Campy blood agar, Skirrow’s media
- Grows better at 42°C than 37°C
- Catalase and oxidase-positive
CAMPYLOBACTER JEJUNI
CAMPYLOBACTER JEJUNI
transmission
contaminated food & water
contact w infected animals / animal products
CAMPYLOBACTER JEJUNI | ANTIGENIC STRUCTURE
have ____ with endotoxic activity
lipopolysaccharide
CAMPYLOBACTER JEJUNI | CLINICAL FINDINGS
- Characterized by abdominal cramps, diarrhea (bloody), HA, malaise, and fever.
- Self-limiting
- The organism can occasionally invade the bloodstream.
- May resemble enteric fever
- Susceptible in macrolides (e.g., erythromycin)
GASTROENTERITIS
CAMPYLOBACTER JEJUNI | CLINICAL FINDINGS
A form of ascending paralytic disease.
Guillain-Barré syndrome
- A Gram-negative curved rod
- spiral, curved, or fusiform rod-shaped
- Motile (single and/or multiple monopolar flagella)
- Catalase and oxidase-positive; urease-positive
- Microaerophile
HELICOBACTER PYLORI
HELICOBACTER PYLORI
catalase & oxidase
positive
HELICOBACTER PYLORI
urease
positive
HELICOBACTER PYLORI
oxygen requirement
microaerophile
HELICOBACTER PYLORI
transmission
person - person
via fecal-oral route
- survives in the acidic environment of the stomach and ultimately establish lifelong colonization of the gastric mucosa through urease activity.
- does not appear to invade the gastric mucosa, but rather release various toxins
- infection is a known independent risk factor for the development of:
o Atrophic gastritis
o Gastric ulcer disease
o Gastric adenocarcinomas
o Gastric mucosa associated lymphoid tissue
(MALT) lymphomas
HELICOBACTER PYLORI
HELICOBACTER PYLORI
reservoir
humans
HELICOBACTER PYLORI
grows optimally at pH of
6 - 7
HELICOBACTER PYLORI | CLINICAL FINDINGS
Acute infection typically yields an upper gastrointestinal illness called
food poisoning
HELICOBACTER PYLORI | CLINICAL FINDINGS
colonization with H. pylori
chronic gastritis
HELICOBACTER PYLORI | TREATMENT
triple therapy
7 - 14 days
HELICOBACTER PYLORI | TREATMENT
quadruple therapy
10 - 14 days