Enterobacteriacae

Question 1

Enterobacteriacae

Answer 1

Ferments glucose

reduces nitrate to nitrite

Question 2

Shigella/Slamonella typing

Answer 2

O Ag -> cell wall
H Ag -> flagella
K Ag -> capsule

Salmonella Vi Ag = Salmonella enterica spp, typhi

Question 3

Citrobacter

Answer 3

UTI, pneumonia, abscess

Urea +

Question 4

Edwardsiella tarda

Answer 4

gastroenteritis

reptiles are resevoirs

Question 5

Enterobacter

Answer 5

E. cloacae = infections in burn units

Contaminant in IV fluids/hospital equpiment

Question 6

E.coli

Answer 6

MOTILE
Indole+
Methyl Red+
VP -

Question 7

Enterotoxigenic E.coli (ETEC)

Answer 7

enterotoxin

Traveler’s diarrhea

Question 8

Enteroinvasive E.coli (EIEC)

Answer 8

invades epithelium

shigella-like

Question 9

Enteropathogenic E.coli (EPEC)

Answer 9

non-invasive, non-toxic

nosocomial infant diarrhea

Question 10

Enterohemorrhagic E.coli (EHEC)

Answer 10

shinga toxin producing
bloody diahrrea

E.coli 0157:H7 (clear colony on SMAC, sorbitol neg)

Question 11

E.coli enterotoxins

Answer 11

ETEC: toxins cause hypersecretion of electrolytes into intestines -> diarrhea
-LT: heat labile, increases AMP, results in diarrhea
-ST: heat stable, increases cGMP, results in diarhea
EHEC: verotoxins 1 and 2, bloody poop

Question 12

Klebsiella

Answer 12

Contaminated meds, hand cream, IV fluid

Question 13

Proteus mirabilis

Answer 13

UTI, wound, septicemia, AGN

Indole -

Question 14

Proteus vulgaris

Answer 14

nosocomial UTIs

Indole+

Question 15

Proteus virulence

Answer 15

Production of urease:
hydrolyzes urea -> ammonia and CO2
Ammonia damages epis in urinary tract and increased pH, which allows calcium and magnesium phosphate to deposit -> calcified stones

Proteus can live in the calcified stones

Question 16

Serratia marcescens

Answer 16

Hands of healthcare workers

contaminated solutions/medical equipmemt

Question 17

Yersinia enterolitica

Answer 17

diarrhea and abdominal pain in kids/infants

Question 18

Yersinia pestis

Answer 18

rats are hosts
Bubonic Plague: 
     lesions at regional lymph nodes
     septic shock in <1 week
     untreated = 100% mortality
Pneumonic Plague;
     pulmonary (acquired by droplets)

GNB, safety pin

Question 19

Salmonella

Answer 19

Contaminated food (eggs, milk, poultry)
BLACK on HEK

H2S+
Motility +

Salmonella typhi: fever, bacteremia, spread person-to-person, travelers to areas of bad sanitation, can affect gall bladder and Peyer’s Patches

Question 20

Shigella

Answer 20

Human carriers (poor hygiene)
NON MOTILE
green on HEK

Typings:
     S. dysenterica (group A)
     S. flexneri ( Group B)
     S. boydii (Group C)
     S. sonnei (group D)

Question 21

Indole test

Answer 21

Tryptophan reacts with Eldrich’s/Kovac’s producing a red color

Question 22

Methyl Red

Answer 22

detect the ability of an organism to produce and maintain stable acid end products from glucose fermentation
Red at a pH of 4.4 or less

Question 23

VP test

Answer 23

KOH and alpha napthol added

detects butylene glycol producers

Question 24

Citrate

Answer 24

Detects organisms ability to utiulize citrate as carbon and energy.
Citrate ->oxaloacetate and acetate -> Na2CO3 and NH3
The alkaline pH turns the media blue