MICRO - Bacteria Associated with CVS and Lymphatic Infections 2

Enterobacteriaceae

What family of bacteria includes Escherichia, Shigella, Salmonella, Enterobacter, Klebsiella, Serratia, and Proteus?

Intestinal tract

What is the natural habitat of Enterobacteriaceae?

Salmonella and shigella

Which two genera in Enterobacteriaceae are NOT normal flora and are regularly pathogenic?

Gram-negative

What is the Gram reaction of Enterobacteriaceae?

Rod-shaped

What is the shape of Enterobacteriaceae?

Peritrichous flagella

What type of motility do many Enterobacteriaceae have?

Yes

Do Enterobacteriaceae ferment glucose?

Catalase

What enzyme is always positive in Enterobacteriaceae?

Oxidase-negative

What oxidase test result characterizes Enterobacteriaceae?

Nitrate

What nitrogen compound do Enterobacteriaceae reduce?

MacConkey agar

What agar is commonly used to grow Enterobacteriaceae?

39-59%

What is the GC content range of Enterobacteriaceae DNA?

TSI agar

What medium differentiates glucose, lactose, and sucrose fermentation?

Yellow

What color indicates acid reaction on TSI?

Red

What color indicates alkaline reaction on TSI?

Blackening

What indicates H₂S production on TSI?

Cracks in agar

What indicates gas production in TSI?

Indole, MR, VP, Citrate

What are the four components of the IMViC test?

Kovacs’ reagent

What reagent is used in the indole test?

Red

What color indicates positive indole test?

Mixed acis

What end products are detected by the methyl red test?

pH 4

What pH gives a positive methyl red reaction?

Barritt’s reagents

What reagents are used for the Voges–Proskauer test?

Red

What color indicates positive VP test?

Blue

What color indicates positive citrate test?

O antigen

What antigen corresponds to heat-stable somatic antigen?

K antigen

What antigen corresponds to capsular structure?

H antigen

What antigen corresponds to flagellar structure?

IgM

What antibody type mostly reacts with O antigens?

IgG

What antibody type mostly reacts with H antigens?

K antigen

Which antigen interferes with agglutination by anti-O antisera?

Vi antigen

What is the capsular antigen of Salmonella Typhi?

Escherichia coli

What is the most common cause of urinary tract infections?

O antigen

What specific antigen helps uropathogenic E. coli colonize?

Hemolysin

What toxin helps E. coli invade during UTI?

Enteropathogenic E. coli

What diarrheal E. coli causes infantile diarrhea?

Enterotoxigenic E. coli

What diarrheal E. coli causes traveler’s diarrhea?

Shiga toxin-producing E. coli

What diarrheal E. coli causes hemorrhagic colitis?

Enteroinvasive E. coli

What diarrheal E. coli mimics Shigella dysentery?

Enteroaggregative E. coli

What diarrheal E. coli causes persistent diarrhea in HIV patients?

K1 antigen

What antigen is associated with neonatal meningitis from E. coli?

IgM

What immunoglobulin is lacking in newborns making them prone to E. coli sepsis?

Gram-negative rods

What is the Gram stain morphology of E. coli?

Pink

What colony color does E. coli produce on MacConkey agar?

Metallic green

What sheen does E. coli show on EMB agar?

A/A

What is the typical TSI reaction of E. coli?

Gas positive

What gas reaction is typical for E. coli on TSI?

Yes

Is E. coli indole positive?

Yes

Is E. coli methyl red positive?

No

Is E. coli Voges–Proskauer positive?

No

Is E. coli citrate positive?

Fluoroquinolones

What drug class is first-line for E. coli infections?

Azithromycin

What macrolide is used for invasive E. coli?

Handwashing

What is the most basic method to prevent E. coli infection?

Gram-negative

What is the Gram stain of Salmonella?

H2S

What gas does Salmonella commonly produce in TSI?

Negative

Is Salmonella oxidase positive or negative?

10^5 - 10^8

What is the infectious dose of Salmonella enterica in humans?

Less than or equal to 10³ organisms

What is the infectious dose of Salmonella Typhi?

Brilliant green agar

What agar inhibits non-Salmonella organisms using brilliant green?

S. enterica and S. bongori

What are the two species of Salmonella?

Typhoidal Salmonella

What serotype group causes typhoid fever?

Non-typhoidal Salmonella

What serotype group causes foodborne disease?

Salmonella Typhi

What organism most commonly causes enteric fever?

Peyer’s patches

Where does Salmonella multiply before causing bacteremia?

Rose spots

What skin manifestation consists of pink blanching macules?

10-14 days

What is the typical incubation period for enteric fever?

8-48 hours

What is the incubation period of Salmonella enterocolitis?

Enterocolitis

What is the most common manifestation of Salmonella infection?

Positive

What is the typical stool culture result in enterocolitis?

Sickle cell patients

What population is prone to Salmonella osteomyelitis?

Aorta

What vascular site is commonly infected in Salmonella bacteremia?

Bone marrow

What specimen has highest sensitivity in typhoid diagnosis?

Week 1

When is blood culture positive in typhoid fever?

Week 2

When is urine culture positive in typhoid fever?

K/A with H2S

What TSI pattern is typical of Salmonella?

Black

What color do Salmonella colonies appear on HE agar?

Selenite F

What broth enriches Salmonella growth?

Widal test

What test detects O and H antibody titers in typhoid fever?

>1:320

What titer of O antigen suggests typhoid fever?

IgA

What antibody prevents Salmonella attachment to gut epithelium?

Azithromycin

What macrolide is used for uncomplicated typhoid fever?

Ceftriaxone

What drug is recommended for Salmonella endovascular infection?

Live attenuated vaccine

What type of typhoid vaccine is given orally?

Vi polysaccharide vaccine

What injectable typhoid vaccine is available?

Swarming

What appearance does Proteus produce on agar due to motility?

Urease

What enzyme produced by Proteus leads to kidney stones?

Proteus mirabilis

Which species of Proteus commonly causes UTI?

Proteus vulgaris

Which Proteus species is more antibiotic resistant?

K/A with H2S

What TSI reaction is typical for Proteus?

Negative

What is the indole reaction of P. mirabilis?

Positive

What is the indole reaction of P. vulgaris?

Nitrofurantoin

What drug is Proteus mirabilis resistant to?

Aminoglycosides

What antibiotic class is most effective for P. vulgaris?

Short catheterization

What measure reduces catheter-associated Proteus infection?

Prodigiosin

What pigment may be produced by Serratia marcescens?

Urinary tract

What is the most common clinical site of Serratia infection?

Serratia marcescens

What Serratia species is most frequently isolated?

Clear zone

What color does a positive DNAse test show for Serratia?

A/A or K/A

What is the typical TSI reaction of Serratia?