microbio: enterobacterales

all enterics are oxidase ___, except ___

negative, Plesiomonas

all enterics are ___, except ___

motile, Klebsiella, Shigella, Yersinia

which enterics are mucoid colonies

klebsiella and enterobacter

which antigenic virulence factor is described as somatic, heat stable, and present on the cell wall

O antigen

which antigenic virulence factor is described as flagellar, heat labile, present on flagellar surface

H antigen

which antigenic virulence factor is described as heat labile polysaccharide, that is present only in certain encapsulated species

K antigen

which antibiotic resistance factor is considered a current urgent public health concern

CRE (carbapenem-resistant enterobacteriaceae)

which kind of pathogen is often part of the usual intestinal flora

opportunistic pathogens

which kind of pathogen is acquired from ingesting contaminated food and water

primary pathogen

all of the following are primary pathogens EXCEPT

E. coli

which enteric is the most common cause of UTIs

E. coli

which organism is one of the most common causes of septicemia and meningitis in neonates

e. coli

what does e. coli look like on MAC

rose red/pink colonies

what does e. coli look like on an EMB plate

metallin sheen

IMVC pattern for e. coli

+, +, =, =

the enterotoxigenic strand of e. coli (ETEC) is associated with

traveler’s diarrhea

the enterohemorrhagic strand of e. coli (EHEC/STEC) is associated with

hemorrhagic diarrhea, HUS

the O157:H7 strain of E. coli is associated with

EHEC/STEC

EHEC/STEC is associated with

TTP and HUS

O157:H7 is sorbitol ___

negative

bloody diarrhea is a specific marker of

EHEC, O157:H7

which strand of e. coli is associated with severe diarrhea in young children

enteropathogenic (EPEC)

persistent diarrhea in young children is associated with

enteroaggregative e. coli (EAEC)

which strand of e.coli is able to invade and destroy colonic tissue

enteroinvasive e. coli (EIEC)

which enterics have an IMVC result of -, -, +, +

klebsiella, enterobacter, serratia, hafnia

klebsiella, enterobacter, and serratia are all

lactose fermenters

klebsiella is indole___ , except K. oxytoca

negative

k. pneumoniae is associated with

rhinoscleroma

which enteric produces a yeasty smell

klebsiella pneumoniae

klebsiella is

nonmotile

what differentiates enterobacter from klebsiella

enterobacter is motile, klebsiella is nonmotile

klebsiella pneumoniae is urease

positive

which enteric produces a pink-red pigmented colony

serratia spp.

serratia marcescens is a

late lactose fermenter

what test differentiates serratia spp. from enterobacter and klebsiella

DNAse

serratia spp is DNAse ___, klebsiella and enterobacter are DNAse ___

positive, negative

which enteric produces a human feces odor

hafnia alvei

which enterics are non lactose fermenting

proteus, morganella, providencia

proteus, morganella, and providencia are all

opportunistic pathogens

what test can be used to differentiate proteus, morganella, and providencia from other enterics

PAD test

proteus, morganella, and providencia are PAD ___, all other enterics are PAD ___

positive, negative

p. vulgaris is indole ___

positive

p. mirabilis is indole ___

negative

what test can differentiate proteus from providencia and morganella

H2S

proteus is H2S ___, morganella and providencia are H2S ___

positive, negative

which enteric produces a cheap chocolate cake mix odor

proteus spp.

which organisms can produce swarming colonies

p. mirabilis/vulgaris

which proteus species can ferment sucrose

p. vulgaris

which enteric is a common inhabitant of a snake’s oral flora

morganella morganii

which enteric is a common cause of nosocomial outbreaks in burn units

providencia stuartii

the primary pathogens of the enterobacteriaceae include all of the following EXCEPT

proteus mirabilis

stool samples should be plated within ___ of collection

2 hours

what is a cary-blair media

it is a form of transport media used for delayed deliveries

what does salmonella look like on HE or XLD plate

black center with clear zone around

which enteric can retreat to the gallbladder due to multi drug resistance

salmonella

which enteric involves the Vi antigen

salmonella typhi

which of the three categories of salmonella infections is the most severe form

enteric fever (typhoid fever)

which level of salmonella infection is caused by food poisoning and is mostly self-limiting

gastroenteritis/diarrhea

rose spots after 2 weeks of fever is characteristic of

typhoid fever

what test differentiates salmonella from citrobacter

PYR

salmonella is PYR ___, citrobacter is PYR ___

negative, positive

which enteric is associated with endocarditis in IV drug usuers

citrobacter spp.

c. koseri is indole ___

positive

c. freundii is urease ___, s. enterica is urease ___

positive, negative

which is the only enteric that is oxidase positive

plesiomonas

what organism possesses the Vi antigen

salmonella typhi

a microbiologist is reading stool culture plates. she is looking for enteric pathogens on the MAC plate. what do they look like?

clear, colorless colonies

most enteric pathogens are lactose

nonfermenters

what is the name of the organism that has been a documented cause of nursery outbreaks of neonatal meningitis and brain abscesses

c. koseri

a microbiologist is reading stool culture plates. she sees an organism that has a large, mucoid pink colony on MAC. what is a strong suggested identification of this organism

klebsiella/enterobacter-like organism

what disease produced by a salmonella spp. is a severe form of enteric fever

typhoid fever

all of the following are biochemical features of salmonella EXCEPT

lactose positive

what genus has the following characteristics: urea negative, positive for lysine decarboxylase, hydrogen sulfide, and indole, and does no grow on simmon’s citrate

edwardsiella

a DNAse-positive member of the family enterobacteriaceae is suggestive of

serratia

what organism in the genus providencia is incriminated in nosocomial outbreaks in burn units and has been isolated from urine cultures

providencia stuartii

the e. coli serotype O157:H7 is associated with all of the following EXCEPT

liver damage

all of the following are categories of diarrhea-causing e. coli EXCEPT

EMEC

what are the primary antigens used in serologic grouping of salmonellae

flagellar H antigen and somatic O antigen

in the carrier state, where are pathogenic salmonella carried

gallbladder

a microbiologist is reading a stool culture and notices a mucoid pink colony on MAC agar. what is the most likely organism

klebsiella pneumoniae

what organism presents as a pink colony with a halo on MAC agar and a green metallic sheen on EMB agar

e. coli

what substance produced by the salmonella spp., which cause gastroenteritis, has been implicated as a significant virulence factor

enterotoxin

all of the following are symptoms of salmonellosis that may appear 8 to 36 hours after ingestion of contaminated food, except

headache

why is it that most cases of salmonella food poisoning are not treated with antibiotic

the disease is self limiting and will subside on its own

bacillary dysentery caused by this organism is marked by penetration of intestinal epi cells following attachment of the organisms to mucosal surfaces, local inflammation, shedding of the intestinal lining, and formation of ulcers that follow the epithelial penetration. what is this organism

shigella

most cases of plesiomonas are

self-limiting

what test differentiates plesiomonas spp. from other enterics

oxidase

plesiomonas is oxidase ___, other enterics are oxidase ___

positive, negative

which shigella subgroup is most commonly isolated in the US

D (s. sonnei)

which serogroup of shigella is mannitol positive

s. sonnei

the capsule must be removed to serotype the O antigen for which organism

shigella

bacillary dysentery is also known as

shigellosis

which shigella serotype is ONPG positive

s. sonnei

which organism is primarily found in freshwater fish

edwarsiella tarda

which organism is the common cause of the plague (black death)

y. pestis

which yersinia species is able to survive refrigerator temperatures

y. enterolitica

which yersinia species is transmitted by the consumption of incompletely prepared food products (especially pork)

y. enterocolitica

which yersinia species infects humans rarely

y. pseudotuberculosis

which specimen has a characteristic ‘safety pin’ staining in giemsa/wright stain

y. pestis

CIN is selective for

yersinia and aeromonas