Gram Negative Fermentative (Enterobacteriaciaeae) Flashcards
General Characteristics of Enterobacteriaciaeae
- Facultative Anaerobe
- Catalase Positive, Oxidase Negative
- Glucose Fermenters
- Nitrate Reducers
- Motile with Preitrichous flagella
All enterobacteriaceae are motile except;
mnemonics: SKY
Shigella
Klebsiella
Yersinia
All are normal flora of the Gut except;
Shigella
Salmonella
Yersinia
True Enteric Pathogens
H antigen
Flagellar antigen
Heat labile, Protein
O antigen
Somatic antigen
Heat stable, Lipopolysaccharide
K antigen
Capsular antigen
Masks O antigen
K antigen
When somatic antigen is negative, but the capsular antigen is positive, what should you do next?
Boil for 15 minutes
Capsular antigen is heat labile that wil destroy K antigen
K antigen of S. typhi
Vi antigen
Most common cause of UTI
E. coli
Virulence factor causing 75% of nenonatal meningitis cases
K1 Capsular antigen
Infection cause by E. coli
mnemonics: DUNG
Diarrhea
UTI
Nenonatal meningitis
Gram (-) Sepsis
Identical to shigatoxin by Shigella dysenteriae
Verotoxin I
The most severe form manifestation of EHEC
Hemolytic Uremic Syndrome (HUS)
Transmitted with ingestion of Hamburgers or undercooked meat
Enterohemorragic E. coli (EHEC)/STEC/VTEC
a.k.a Shiga toxin producing (STEC), Verotoxin producing (VTEC)
Most common isolate of EHEC
E. coli O157:H7
SMAC
Medium of isolating E. coli O157:H7
Colonies of E. coli O157:H7 in sMAC
Colorless - Nonfermenter of Sorbitol
Associated to Traveller’s Diarrhea
a.k.a Montezumas’s revenge or Turista
Enterotoxigenic E. coli (ETEC)
Toxin produced by ETEC Diarrhea
Heat Labile Toxin
similar to Cholarogenic toxin
Causes Bloody type of Diarrhea or Dysentery type of Diarrhea
EnterInvasive E. coli (EIEC)
Infective dose of EIEC
> 10^6
Infantile or Pediatric Diarrhea
Diarrhea of Infants
EnteroPathogenic E. coli (EPEC)
Diarrhea in Malnourished children
EnteroAggregative E. coli (EAEC)
EAEC adheres to Hep2 cells packed in a ________________ pattern.
Stacked Brick Pattern
Chronic diarrhea in HIV patients
EAEC
IMVC Reaction of E. coli
++– with Gas
Identification of E. coli
- MAC:
- EMB:
- TSIA:
- IMVC:
- LOA:
- Motility:
- H2S:
- Urease:
- PAD:
- MAC: flat, dry colonies with sorrounding dark pink area precipitated with bile salts
- EMB: Green metallic sheen
- TSIA: A/A
- IMVC: ++00
- LOA: ++0
- Motility: Motile
- H2S: Negative
- Urease: Negative
- PAD: Negative
Klebsiella in MAC
Mucoid Pink colonies that form a string
Sputum associate with Klebsiella pneumoniae
Currant jelly-like sputum
Klebsiella causing Granuloma inguinale
K. granulomatis
Associated pneumonia with K. pnuemoniae
Ventilator associated pneumonia
Associated with Rhinoschleroma
K. rhinoscleromatis
Associated with Atrophic Rhinitis or tissue degeneration disease in Nose
K. ozonae
Klebsiella that is Indole Positive and Ornithine decarbocylase positive
K. ornitholytica
Member of Enterobacteriaciaeae that is Notile and Ornithine positive
Enterobacter spp.
Identification of K. pneumoniae
- MAC:
- TSIA:
- IMVC:
- Motility:
- LOA:
- H2S:
- PAD:
- Urease:
- MAC: Mucoid colonies
- TSIA: A/A
- IMVC: –++
- Motility: Nonmotile
- LOA: +00
- H2S: Negative
- PAD: Negative
- Urease: Positive
Test that differentiate K. pnuemoniae from K. oxytoca
Indole
Test that differentiate Klebsiella from Enterobacter
Motility
Ornithine Decarboxylation
Yellow pigmented Coliform found in Milk infant formula
Chronobacterium sakazaki
Differentiation of E. aerogenes vs. E. cloacea
LOA Test
* E. aerogenes: ++0 - Lysine decarboxlation
* E. cloaceae: 0++ - Arginine decarboxylation
Identification of Enterobacter spp.
- MAC:
- TSIA:
- IMVC:
- Motility:
- LOA:
- H2S:
- Urease:
- PAD:
- MAC: Pink colonies
- TSIA: A/A with gas
- IMVC: 00++ (same with Klebsiella)
- Motility: Negative
- LOA: Ornithine Decarboxylase Positive
- H2S: Negative
- Urease: Negative
- PAD: Negative
Identification of E. aerogenes
- MAC:
- TSIA:
- IMVC:
- Motility:
- LOA:
- H2S:
- Urease:
- PAD:
- MAC: Pink Colonies
- TSIA: A/A
- IMVC: 00++
- Motility: Motile
- LOA: ++0
- H2S: Negative
- Urease: Negative
- PAD: Negative
Identification of E. cloacea
- MAC:
- TSIA:
- IMVC:
- Motility:
- LOA:
- H2S:
- Urease:
- PAD:
- MAC: Pink Colonies
- TSIA: A/A
- IMVC: 00++
- Motility: Motile
- LOA: 0++
- H2S: Negative
- Urease: Negative
- PAD: Negative
Test that differentiate K. ozoenae from K. rhinoscleromatis
Lysine Decarboxylation
* Positive: K. ozaenae
* Negative: K. rhinoscleromatis
Malonate Utilization
* Positive: K. rhinocleromatis
* Negative: K. ozoenae
Red pigment produced by S. marcesens
Prodigosin
Causative agent of Red Milk
Serratia marscecens
Causes Nursery outbreak neonatal meningitis
C. freundii
Test that differentiate C. freundii from C. diversus (koseri)
H2S
* Positive: C. freundii
* Begative: C. diversus
Indole
* Positive: C. diversus
* Negative: C. freundii
Resembles Salmonella
Citrobacter
Test that differentiate Citrobacter from Salmonella
ONPG
* Positive: Citrobacter
* Negative: Salmonella
LDC
* Positive: Salmonella
* Negative: Citrobacter
Carrier of S. typhi
Mary Mallon
Appearance of Salmonella in XLD
Red with black centers
Appearance of Salmonella in HEA
Green with black centers
Serologic Test for S. typhi causing Typhoid fever
Widal Test
Mode of Transmission of Salmonella
Ingestion of undercooked poultry and raw eggs
Salmonella that ONLY INFECT HUMANS
S. typhi
S. paratyphi
Causative agent of Typhoid fever
S. typhi
Causative agent of Paratyphoid fever
S. paratyphi A & B
Causative agent of Gastroenteritis
S. entritidis
Biologically inert type of bacteria
Shigella
Characterized by a Blood type of diarrhea
also with mucos, and pus in the stool
Bacillary dysentery/Shigellosis
Causative agent of the most severe type of bacillary dysentery
Shigella dysentery
Test that differentiate Shigella from E. coli
Acetate Utilization Test
Related to E. coli
Shigella
Test that differentiate S. sonnie from other Shigella spp.
Positive: Ornithine Decarboxylation & ONPG
Only Shigella that is Mannitol fermentation negative
S. sonnei
Identification of Shigella
- Motility:
- TSIA:
- IMVC:
- H2S:
- LOA:
- PAD:
- Urease:
- Motility: Nonmotile
- TSIA: K/A
- IMVC: -+–
- H2S: Negative
- LOA: —
- PAD: Negative
- Urease: Negative
Identification of Shigella dysenteriae
- Mannitol
- ODC:
- ONPG:
- Mannitol Negative
- ODC: Negative
- ONPG: Negative
Identification of Shigella dysenteriae
- Mannitol
- ODC:
- ONPG:
- Mannitol: Positive
- ODC: Positive
- ONPG: Positive
Serratia spp. that causes contamination of blood bag
Serratia liqueficans
PAD (+)
Proteus
Providencia
Morganella
Test that will differentiate Proteus from Providencia & Morganella
H2S
* Positive: Proteus
* Negative: Providencia & Morganella
Identification of Proteus
- Culture:
- Odor:
- TSIA:
- H2S:
- Motility:
- Methy Red:
- Decarboxylation Test:
- Urease:
- Culture: Swarming
- Odor: Burnt Gun powder/Burnt chocolate odor
- TSIA: K/A with Gas
- H2S: Positive
- Motility: Positive
- Methy Red: Positive
- Decarboxylation Test: Lysine & Arginine Negative
- Urease: Positive
Crystal found in urine from Proteus Infection
Struvite
Differentiates P. mirabilis from P. Vulgaris
Indole & LOA Decarboxylation test
Indole: Positive - P. vulgaris; Negative - P. mirabilis
LOA: 000 - P. vulgaris; 0+0 - P. mirabilis
Only specie of Morganella
Morganella Morganii
Identification of Morganella morganii
- IMVC:
- MAC:
- TSIA:
- PAD:
- Urease:
- H2S:
- Citrate
- IMVC: ++–
- MAC: NLF
- TSIA: K/A with Gas
- PAD: Positive
- Urease: Positive
- H2S: Negative
- Citrate: Negative
Two major species of Providencia
P. rettgeri
P. stuartii
identification of Providencia
- IMVC:
- TSIA:
- PAD:
- Urease:
- H2S:
- Motility:
- IMVC: ++-+
- TSIA: K/A without Gas
- Citrate: Positive
- PAD: Positive
- Urease: Positive
- H2S: Negative
- Ferments Mannose
Differetiates P. rettgeri from P. stuartii
Urease
Fermentation of Adonitol
Fermentation of Arabinose
Urease to mainly differentiate
Infective stage to cause Shigellosis
<200 bacilli
Y. pestis transmission
Rat flea bite
Scientific name for Rat flea
Xenosyplla cheopis
Causative agent of Plaque
Yersinia pestis
Forms of Plaque
Bubonic
Pneumonic
Septicemic
Culture appearance of Y. pestis in Broth
Stalactite Pattern
Stain that demonstrate Y. pestis
Wayson stain
Microscopic appearance of Y. pestis demonstrated by Wayson stain
Safety pin appearance with Bipolar bodies
Medium for isolation of Yersinia enterocolitica
CIN medium
Colony appearance of Y. enterocolitica in CIN
Bull’s eye appearance
Most common Yersinia isolated
Yersinia enterocolitica
Y. eneterocolitica is motile at ____________________ but not at _______.
Motile at 22C (RT) but not at 35C
Associated disease of Y. eneterocolitica
Appendicitis
Mimic Chron’s disease
Disease of Rodents
Yersinia pestis
Disease of Guine Pigs
Yersinia pseudotubercolosis
Infection caused by Yersinia psedotubercolosis
Mesenteric lymphadenitis
Malonate test is most useful in differentiating of which members
Salmonella subgroups 2, 3 (the former Arizona)
Species of Shigella is most commonly associated with diarrheal disease in the United States
S. sonnie
Enterobacter sakazakii can best be differentiated from Enterobacter cloacae by which of the following characteristics
Yellow Pigmented
Sorbitol Fermentation
E. cloacae is positive sorbitol fermentation