ENTEROBACTERALES Flashcards
largest and most medically important family of gram-negative bacilli
Enterobacteriaceae/ Gram (-) Enteric Bacilli
common cause of nosocomial infection and part of NF of animals
Enterobacteriaceae/ Gram (-) Enteric Bacilli
ferments glucose and facultative anaerobes
Enterobacteriaceae/ Gram (-) Enteric Bacilli
all Enterobacteriaceae are motile except
Shigella and Klebsiella
motile at RT but NM at 37C
Yersinia
Enterobacterales:
all reduce nitrates to nitrite except
Pantoea and Erwinia
Enterobacterales:
oxidase negative except
Plesiomonas shigelloides
formerly Vibrionaceae
Plesiomonas shigellodies
Enterobacterales:
often with gas production except
Shigella
Enterobacterales:
all are catalase positive except
S. dystenteriae
Antigen:
cell wall
lipopolysaccharide
heat stable
O antigen/ Somatic
Antigen:
heat labile
flagellar
protein
H antigen
Antigen:
heat-labile
capsular
polysaccharide
mask O antigen
K antigen
antigen of S. typhi
Vi antigen
can also be used but cannot differentiate Shigella from E. coli
MALDITOF
General Culture Media:
Brilliant green inhibitor
BSA
General Culture Media:
glucose fermentation
BSA
General Culture Media:
selective for Salmonella and produces black colonies
BSA
General Culture Media:
Mannitol Fermentation and neutral red as pH indicator
CIN
General Culture Media:
selective and differential
isolation of Y. enterolitica
CIN
General Culture Media:
can also isolate Plesiomonas and Aeromonas
CIN
General Culture Media:
eosin y and methylene blue are the inhibitor
EMB
General Culture Media:
Lactose and Sucrose Fermentation
EMB
General Culture Media:
sucrose is an alternate energy source for slow lactose fermenters
EMB
General Culture Media:
selective and differential for lactose and non lactose fermenters
EMB
General Culture Media:
pink/ red colonies for lactose fermenters
amber/ translucent/ colorless for non lactose fermenters
EMB
General Culture Media:
blue-black with greenish metallic sheen on EMB
E. coli
General Culture Media:
Deoxycholate citrate salts inhibitor and Mannitol Fermentation
GN Gram - broth
General Culture Media:
enrichment broth that enhances the recovery of enteric pathogens from fecal spx like Salmonella and Shigella
GN
General Culture Media:
bile salts inhibitors
lactose, salicin, and sucrose with pH indicator of bromthymol blue
HEK
General Culture Media:
detection of enterics from stool or enrichment broth
lactose fermenters: bright orange or salmon pink
HEK
General Culture Media:
lactose fermenterss are bright orange or salmon pink
non lactose are green to blue
HEK
General Culture Media:
bile salts and crystal violet as inhibitors
lactose fermentation with neutral red pH indicator
MAC
E. coli O157:H7
negative in Sorbitol MUG
General Culture Media:
lactose + are pink or red that may be surrounded by bile salts
non lactose are colorless or transparent
MAC
General Culture Media:
bile salts, sodium citrate, and Brilliant green inhibitors
lactose fermentation and neutral red is the pH indicator
SSA
General Culture Media:
lactose + are pink to red
Salmonella are H2S + hence colorless with black center
SSA
General Culture Media:
Na deoxycholate less bile salts inhibitor
sucrose and lactose in excess and xylose in lower amounts
phenol red is the indicator
XLD
General Culture Media:
yellow: fermentation of the excess carbohydrates to produce acid and absence of lysine decarboxylase
colorless or red: lactose -
XLD
General Culture Media:
yellow to red: fermentation of xylose
XLD
colony characteristic of lactose fermenters:
K. pneumoniae in MAC
encapsulated and mucoid colonies
colony characteristic of lactose fermenters:
greenish metallic sheen
E. coli in EMB
laboratory identification of Enterobacerales
gram staining
laboratory identification:
test position for cytochrome C to produce a dark-blue end product when reacted with Microdase reagent
Oxidase Negative
laboratory identification:
ability of an organism to reduce nitrate to nitrite
Nitrate reduction positive
laboratory identification:
differentiate gram - by their ability to ferment glucose, lactose, and sucrose and to produce H2S
TSI: Carbohydrate Fermentation Test
laboratory identification:
1:10:10
read at 18-24 hrs
TSI
laboratory identification:
pH indicator is phenol red
H2S indicator is ferrous sulfate
TSI
laboratory identification:
alkaline slant and alkaline deep
no change in color
K/K: non fermenters
laboratory identification:
alkaline slant (red) and acid deep (yellow)
K/A: non lactose fermenters (Glucose fermenters)
laboratory identification:
acid slant and butt
yellow/ yellow
A/A: lactose and sucrose fermenters
laboratory identification:
black precipitate in the medium/ butt is acidic
H2S production
laboratory identification:
similar medium to TSI but only 2 sugars; glucose and lactose
Kliger’s Iron Agar
laboratory identification:
A/A on TSI but only K/A on KIA
P. vulgaris, S. marsescens. Y. enterolitica
Enterobacteriaceae on TSI:
Lactose Fermenters
Klebsiella
Escherichia
Enterolitica
Enterobacteriaceae on TSI:
Late Lactose Fermenters
S. arizonae
Citrobacter
Serratia
Enterobacteriaceae on TSI:
Non-Lactose Fermenter
Salmonella
Shigela
Edwardsiella
Morganella
Providencia
Proteus
Yersinia
Hafnia
laboratory identification:
reading time must be within 24 hrs
used to differentiate lactose fermenters
IMViC
laboratory identification:
detects organism’s ability to produce the enzyme tryptophanase and deaminase tryptophan to indole, pyruvic acid, and ammonia
Indole
laboratory identification:
it is detected by the addition of Ehrlich’s Reagent AKA
paradimethylaminobenzaldehyde or Kovac’s Reagent
laboratory identification:
positive color is red or pink color
SIM is also used
Indole
laboratory identification: Indole
used for colonies from SBA or CAP and + is blue color
Spot Indole (Kovac’s Reagent)
laboratory identification: indole
added for visualization in which colorless turns red with growth
Triphenyl Tetrazolium Chloride
laboratory identification:
based on either the mixed acid fermentation pathway or the butylene glycol pathway
MRVP
laboratory identification:
detects the end of glucose fermentation
MRVP
laboratory identification:
produce acid that will convert the methyl red to red color under what pH
<4.5
laboratory identification:
____ is the MRVP conclusive color, if conclusive after _____. Continue up to addition three days
orange, 48 hours
laboratory identification:
VP measures
acetoin or acetylmethylcarbinol
laboratory identification: VP
addition of 40% KOH followed by a-napthol will produce ________ which indicated + test
red complex (neutral pH)
laboratory identification: VP
method also used using alpha napthol and KOH + creatine
Coblentz
laboratory identification:
ability of an organism to utilize sodium citrate as carbon source from pyruvate
Citrate utilization test
laboratory identification: Citrate
are the N source and use of these will liberate ammonia producing alkaline pH
Ammonium salts
laboratory identification: Citrate
indicator that turns the medium from green to prussian blue which is the positive reaction
Bromthymol blue
laboratory identification:
false - if cap not loose
Citrate
laboratory identification: Citrate
if this medium is used, phenol red is the indicator and organic nitrogen
at alkaline pH, it changes yellow to pink
Christensen citrate medium
laboratory identification:
organisms that produce urease will hydrolyze urea to ammonia
Urease Test
laboratory identification: Urease
Ammonia reacts to form ______ which increases pH
ammonium carbonate
laboratory identification:
detected by phenol which turns to bright pink and Christensen media is generally the preferred medium
Urease
laboratory identification:
slow urease after 4 hours
KEY- SC: Klebsiella, Enterobacter, Yersinia, Serratia, Citrobacter
laboratory identification:
rapid urease <4 hours
PPM
laboratory identification:
test to detect the ability to produce gelatinase that breakdown gelatin to AA at RT
Gelatin Hydrolysis Test
laboratory identification:
incubation at 35C and should be chilled in a refrigerator before reading
liquefaction is the positive result
Gelatin hydrolysis
laboratory identification:
utilizes sodium thiosulfate as sulphur source to form black or a colorless gas
combines to indicator ferrous sulfate to form black color
use to differentiate Salmonella from Shigella
H2S
laboratory identification:
can be found in certain agar such as SIM, HEA, TSI, and LIA
H2S
laboratory identification:
removal of amine group yielding in the production of phenylpyruvic acid
Phenylalanine deaminase
laboratory identification:
overnight incubation of a 10% ferric chloride to an inoculated slant
Phenylalanine deaminase
laboratory identification:
green is + rx
produces brown if tryptophan is used
deaminase
laboratory identification:
test used for PPM
Phenylalanine deaminase
laboratory identification:
removal of carboxyl-COOH group of lysine, ornithine, and arginine (dihydrolase)
decarboxylase (Moeller) and Dihydrolase
laboratory identification:
semisolid agar tubes are innoculated by stabbing and an acid pH and anaerobic environment must be present hence it is important to add mineral oil
decarboxylase
laboratory identification:
_____ color indicates glucose fermentation and results to acid pH indicates decarboxylase enzyme
yellow
laboratory identification:
alkaline positive produces _____ due to amines
purple
laboratory identification:
presence of decarboxylase is purpule (pH indicator is _________)
bromcresol blue
laboratory identification:
decarboxylase and dihydrolase
lysine - cadaverine and CO2
ornithine - putrescine
arginine - citrulline
laboratory identification:
for late or slow lactose fermenters
appear as non fermenter on primary media
detects the presence of B-galactosidase
ONPG
laboratory identification:
produces yellow compound as +
used to differentiate Citrobacter + from Salmonella -
ONPG
laboratory identification:
streaked in a medium with 0.2% DNA and incubated for 24 hours at 35C
after incubation, 1N HCL is added to the surface
DNase
laboratory identification:
unhrydolyzed is insoluble in
HCL
laboratory identification:
+ is formation of clear zone halo around the inoculum
use to differentiate Serratia + to E. coli
DNase
laboratory identification:
movement away from the stab or a hazy appearance means a motile bacterium
uses SIM
motility
laboratory identification:
uses acetate as a soul source of carbon
Sodium acetate resulting to an alkaline pH in which green to blue
used to differentiate E.coli + from Shigella -
Acetate Utilization Test
Triple Enzyme Positive: Dnase, Gelatinase, Lipase
Serratia
Fermentation Medium:
based on fermentation of carbohydrate into basal medium
Fermentation Medium:
to differentiate enteric from corynebacterium
Peptone medium with _______
Andrade formula
Fermentation Medium:
to differentiate enterococcus from streptococcus
bromcresol blue
Fermentation Medium:
for gas production
durham tube
Fermentation Medium: Durham Tube
pink w/ or w/o gas
+
Fermentation Medium: Durham Tube
growth no color (straw)
-
Fermentation Medium: Durham Tube
BHI + BCP
Strep to Entero
Fermentation Medium: Durham Tube BHI + BCP
growth of yellow color
+
Fermentation Medium: Durham Tube BHI + BCP
growth of purple color
-
laboratory identification:
sodium malonate as source of carbon
bromthymol blue as pH indicator
ammonium sulfate as N source
Malonate Utilization Test
laboratory identification:
+ is increase alkalinity from green to blue
to differentiate Salmonella + from Citrobacter -
Malonate
laboratory identification:
based on deC and deA of lysine and formation of H2S
Bromcresol purple as pH indicator
LIA
laboratory identification:
lysine + Glucose + Fe ammonium citrate + sodium thiosulfate
aerobic slant and anaerobic butt
LIA
laboratory identification: LIA
if lysine occurs with a compound due to fe ammonium citrate and flavin mononucleotide, it produces ___________
burgundy slant
Organisms under Enterobacteriaceae:
most common cause of UTI
E. coli
Organisms under Enterobacteriaceae:
2nd cause of neonatal meningitis
E. coli
Organisms under Enterobacteriaceae:
NF of GIT and + for B-glucuronidase using MUG under long wavelength of UV light
do not isolate from media with dyes
E. coli
Organisms under Enterobacteriaceae:
Sorbitol - MUG
O157:H7 E. coli
Organisms under Enterobacteriaceae:
K/A + gas + H2S Heavy
resembles E. coli IMViC ++–
assoc. with wound infection and bacteremia
Edwardsiella
Organisms under Enterobacteriaceae:
NM
K/A with no gas
do not hydrolzed urea
H2S -
+ KCN broth
Shigella
Organisms under Enterobacteriaceae:
bacterial diarrhea dysentery
closely resembles E. coli
Shigella
Organisms under Enterobacteriaceae:
bloody diarrhea due to exotoxin or Shiga toxin
Shigella
Organisms under Enterobacteriaceae:
may lead to HUD
Shigella
Organisms under Enterobacteriaceae:
- +- - IMViC
- PAD
H2S major producer and LDC + except ________
Salmonella, S. paratyphi A
Organisms under Enterobacteriaceae:
All salmonella are motile excpt __________ and ______
S. pullorum and S. gallinarum
Organisms under Enterobacteriaceae:
TSI: K/A + gas
K/K: LIA
no growth in KCN
Salmonella
Albert’s Bacillus
serogroup D and Vi
S. typhi
Specimen for Entero
blood, urine, and stool
Spx:
first week of dse
blood
Spx:
+ after second week
urine
Spx:
second or third week of enteric fever but first week in enterocolitis
Stool
Organisms under Enterobacteriaceae:
Citro bacter is formerly known as
Bethesda-Ballerup Group
Organisms under Enterobacteriaceae:
resembles salmonella but ONPG + and LDC -
resembles E. coli on plates
Citrobacter
can be isolated in diarrheal stool known to cause extraintestinal which is acquired in hospital setting
V - - Indole ODC Malonate
C. freundii
formerly _______, case of nursery outbreaks of neonatal meningitis and brain abscesses
+++ Indole ODC Malonate
C. diversus/ C. koseri
Usually Indole (-)
MR (-), VP (+)
Large amount of gas on TSI
Most grow on Citrate and Potassium Cyanide
None produce H2S
Few hydrolyzes urea
KEP CHS
Kelbsiella that is indole +
K. oxytoca
Enterobacter that is K/A + gas
E. taylorae
Enterobacter that produces yellow pigment at RT
E. sakazakii
produces rodigiosin
assoc. with pneumonia and septicemia
resist cephalotin and colistin
Serratia marsescens
ferment arabinose
S. liquifanciens
produce red pigment
S. rubidea
Rancid potato like odor
S. odorifera
Rapid Urease + and PAD +
PPM
source of wei felix for diagnosis of ricketssia
#2 cause of UTI
swarm on BAP
Proteus
associated with stone formation
purtid odor in UTI
choco cake burnt cake odor/ burnt gun
powder/ fishy smell
proteus
proteus that is indole + and R to ampicilin, Cephalosphorin and Chloramphenicol
P. vulgaris
burned patient and pungent odor
citrate +
Providencia
Providencia that is urease +
P. rettgeri
providencia that is variable to urease
P. stuartii
_____ assoc. with UTI
PPM that is citrate - and LDC -
M. morganii, Moragnella
CIN is best for isolation but BAP is routinely used
Yersinia
from pet feces
waterborne gastroenteritis, contaminated milk or pork
bull’s eye appearance
Y. enterolitica
