ENTEROBACTERIACEAE Flashcards
A K/A reaction on a TSI slant indicates that the organism is a:
E. coli
Shigella
Klebsiella
EIEC
Shigella
A K/A reaction on a TSI slant indicates that the organism is a:
Yellow/yellow
Red/red
Yellow/red
Red/yellow
Red/yellow
Organisms that typically produce clear colonies (green without black centers) on Hektoen agar are:
Shigella
Salmonella
E. coli
Klebsiella
Shigella
he gram stain characteristic of Enterobacteriaceae should be:
Gram negative rod without spores
Gram negative rods with spores
Gram negative cocci with spores
Gram negative rods without spores
Gram negative rods without spores
Which organism species does not exhibit Phenylalanine deaminase (PD) production:
Morganella
Proteus
Providencia
Klebsiella
Klebsiella
Which species of Enterobacteriaceae has this unique characteristic- VP negative:
Shigella
Proteus
Salmonella
E. coli
E. coli
Resistant to heat and alcohol and detected by bacterial antigen:
H Ag
O Ag
K Ag
Vi Ag
O Ag
An organism gives the following reactions: TSI A/A, no H2S, gas produced. The most likely identification is:
Klebsiella pneumoniae
Salmonella typhi
Shigella dysenteria
Salmonella enteritidis
Klebsiella pneumoniae
The following are characteristics of Citrobacter, EXCEPT:
Citrate (-)
Slow lactose fermenter
Do not decarboxylate lysine compared to salmonella
None of the above
Citrate (-)
What is the treatment for cystitis caused by E. coli?
Ceftriaxone
Piperacillin
Amoxicillin
Nitrofurantoin
Nitrofurantoin
Which species of Enterobacteriaceae has this unique characteristic mucoid colonies?
Shigella
Klebsiella
Proteus
E. coli
Klebsiella
LT of ETEC is antigenic and cross-reacts with the enterotoxin of:
Vibrio cholera
Shigella
Salmonella
Proteus
Vibrio cholera
The enteric media XLD uses which pH indicator?
Methyl red
Phenol red
Both
Neither
Phenol red
A TSI tube is inoculated and incubated for 18-24 hours. After incubation, the TSI is completely yellow. The technologist should report the TSI reaction as:
K/A H2S (+)
A/A (-) H2S
A/K (-) H2S
A/A (+) H2S
A/A (-) H2S
Which species of Enterobacteriaceae has this unique characteristic- Green metallic sheen on EMB?
E. coli
Citrobacter
Morganella
Proteus
E. coli
- The common mode of transmission for Enterobacteriaceae.
a) blood-borne
b) fecal-oral
c) droplet
d) all are correct
b) fecal-oral
These species are normal human microbiota of the GI tract.
a) E. coli
b) Yersinia pestis
c) Klebsiella
d) options 1 and 3
d) options 1 and 3
E.coli
Klebsiella
This organism must be handled in BSL-3 because it produces a
highly fatal bacteremia.
a) Yersinia pestis
b) Yersinia enterolitica
c) Yersinia pseudotuberculosis
d) none are correct
a) Yersinia pestis
Transport media used in the specimen collection of
Enterobacteriaceae are the following, except:
a) Cary-Blair
b) Aimes
c) buffered glycerol saline
d) Stuart
c) buffered glycerol saline
Components of the CIN agar.
a) Ceftazidime
b) Irgasan
c) Nitrofurantoin
d) Cefsulodin
e) Indomethacin
f) Nalidixic acid
g) Cefoxitin
h) Iodine
i) Novobiocin
d) Cefsulodin
b) Irgasan
i) Novobiocin
An indole-negative, slow lactose-fermenting bacteria that is
known to cause infections from infected medical devices.
a) Citrobacter
b) Serratia marcescens
c) Klebsiella pneumoniae
d) E. coli
a) Citrobacter
These are facultative anaerobic, motile,gram-negative rods commonly isolated from the intestines of humans and animals.
Identification is primarily based on the ability of the organism to use citrate as the sole carbon source and lysine as a nitrogen source in combination with hydrogen sulfide (H2S) production *
a) Salmonella
b) Proteus
c) Providencia
d) Serratia
a) Salmonella
Groups of organisms that are seen in mononuclear endothelial
cells of infected penile lesions are caused by which organism?
a) Klebsiella granulomatis
b) Neisseria gonorrhea
c) Klebsiella pneumoniae
d) Treponema pallidum
a) Klebsiella granulomatis
This medium contains glucose, sucrose, and lactose and differentiates glucose fermenters from non–glucose fermenters.
a) MacConkey
b) Triple sugar iron
c) Selenite broth
d) Salmonella-Shigella agar
b) Triple sugar iron
This bacterium is a lactose fermenter, forms blue black with a
metallic green sheen colonies and is the most common cause of
gram-negative health care–associated infections.
a) E. coli
b) Salmonella typhi
c) Citrobacter
d) Yersinia enterolitica
a) E. coli
Enterobacteriaceae is the most common group of [?] cultured in clinical laboratories both as normal flora and as agents of disease.
gram-negative rods
The taxonomy of the Enterobacteriaceae is complex and rapidly changing since the introduction of techniques that measure evolutionary distance, such as [?] and [?]
nucleic acid hybridization and nucleic acid sequencing.
GENERAL CHARACTERISTICS OF ENTEROBACTERIACEAE
Gram reaction and shape
spore
motility
capsule
oxygen requirement
oxidase
carbohydrate fermentation
nitrate reduction enzyme, which to what
Gram-negative bacilli
Non-spore forming
Motile (peritrichous)
capsule
oxygen requirement
oxidase
carbohydrate fermentation
nitrate reduction enzyme, which to what
Non-motile Enterobacters
[SKY]
Shigella
Klebsiella
Yersinia
Yersinia are nonmotile at [?]
35-37 degree Celsius
Yersinia are motile at [?]
room temperature
(somatic antigen or cell wall antigen)
O antigens
(capsular antigen or fimbrial antigen)
K antigen
(flagellar antigen)
H antigen
most external part of the cell wall lipopolysaccharide
O antigens
consisting of repeating units of polysaccharide
O antigens
usually are detected by bacterial agglutination
O antigens
HA-S
O antigens
H-L
K antigen
HA-L
H antigen
external to the O antigens on some but not all Enterobacteriaceae
K antigen
found on the surface of flagella.
H antigen
within a single serotype, flagellar antigens may be present in either or both of two forms, called phase 1 (designated by lower-case letters) and phase 2 (designated by Arabic numerals).
H antigen
organism tends to change from one phase to the
other; this is called phase variation
H antigen
aerobic and facultative anaerobic
non-sporeforming
gram-negative rods
cytochrome-oxidase negative
capable of growth in the presence of bile salts
COLIFORMS
ferment lactose at either 35 or 37 oC
include the normal enteric flora
COLIFORMS
COLIFORMS spp
[EKEC]
o Escherichia
o Klebsiella
o Enterobacter
o Citrobacter
differ from coliforms by their inability to ferment lactose; NLF
NONCOLIFORMS
Fecal coliforms
o most common facultative bacterium in feces of man and warm-blooded animals
o indicator organism of choice for fecal contamination
Escherichia coli
ferments lactose at 44.5 oC
FECAL COLIFORMS
Non fecal coliforms
[KEC]
Klebsiella
Enterobacter
Citrobacter
Opportunistic, normal gut flora spp
[SHE PPM]
Serratia
Hafnia
Edwardsiella
Proteus
Providencia
Morganella
Pathogenic enterics (true enteropathogens) spp
Salmonella
Shigella
Yersinia enterocolitica
Y. pseudotuberculosis
Pathogenic, non-enteric spp
Yersinia pestis
Escherichia coli was first described by [?] in 1885
Theodor Escherich
Escherichia coli common name
“colon bacillus”
accounts for approximately 90% of first urinary tract infections in young women
Uropathogenic E. coli
Strains of E. coli that cause UTIs usually originate in the large intestine as resident biota.
Infection is more common in women because of their relatively short urethras that promote ascending infection to the bladder (cystitis) and occasionally, the kidneys.
Uropathogenic E. coli
Uropathogenic strains possess ____ that have specifically elaborated virulence factors that facilitate colonization and subsequent clinical infections
O antigen types
most common cause of UTIs;
E. coli