Enterotoxigenic Escherichia coli (VTEC) – verotoxins (‘Shiga’-like toxins): VT1, VT2, VTe (SLT1, SLT2, SLT2v); also causes oedema
disease in swine.
Enterohemorrhagic Escherichia coli ( (EHEC) causes hemorrhagic colitis and hemolytic-uremic syndrome.
Enteropathogenic Escherichia coli (EPEC) – bacteria adheres to intestinal epithelial cells, causing diarrhoea.
Presents the EAE, EAF & BFP factors.
It is an important cause of infant mortality.
E. coli on Mac Conkey medium
Genus Escherichia
Taxonomy
Morphology
Cultural characteristics
Biochemical characters
Ecology
Pathogenicity
References
Proteobacteria => Gammaproteobacteria => Enterobacteriales => Enterobacteriaceae => Escherichia =>
- Escherichia adecarboxylata Leclerc 1962 - transfered to genus Leclercia as Leclercia adecarboxylata  Tamura et al. 1987
- Escherichia albertii Huys et al. 2003
- Escherichia blattae Burgess et al. 1973 - transfered to genus Shimwellia as Shimwellia blattae  Priest and Barker 2010
- Escherichia coli – type species of the genus (Bacterium coli commune,  Escherich 1885), Castellani and Chalmers 1919
- Escherichia fergusonii  Farmer et al. 1985
- Escherichia hermannii  Brenner et al. 1983
- Escherichia vulneris  Brenner et al. 1983
Gram negative, straight, facultatively anaerobic bacilli, motile (peritrichous flagella) or
non-motile, non-spore forming, 1.1–1.5 x 2.0–6.0 μm. Colonies on nutrient agar may
be smooth (S type), low convex, shiny surface, entire edge, gray. R type or mucoid
forms may occur. Colonies of
E. hermanii are yellow-pigmented.
Aerobic, facultatively anaerobic. Optimum growth temperature 37°C.
Grow readily on simple nutrient media.
  1. Nutrient agar or nutrient broth
  2. Trypticase Soy Agar ± 5% sheep blood
  3. GEAM / Levine – black colonies with metallic aspect
  4. Mac Conkey – red colonies
  5. Rambach agar – blue-green colonies
  6. Luria-Bertani
  7. Leifson – red colonies
  8. Istrati-Meitert – yellow colonies
Widely distributed in nature. Isolated from water, soil, foods and clinical samples (feces,  blood, urine, spinal fluid, milk, wound
infections) from humans & animals.
E. blattae was isolated from the cockroach intestine and do not seem to have been isolated from other sources.
-Escherichia (Leclercia) adecarboxylata is an opportunistic human pathogen,
isolated from peritonitis in a child (1 report).
-Escherichia albertii -  isolated from diarrhoeal stools.
-Escherichia fergusonii - isolated from human & animal feces, blood, and urine
-E. hermanii, are yellow-pigmented, and while most have been isolated from wounds
and feces, there have also been a few isolations from spinal fluid and blood.
-Escherichia vulneris – wounds contaminant.

-Escherichia coli pathogenicity: nonpathogenic E. coli  is generally located in the
intestinal lumen (colon), but some strains can cause a variety of infections (enteritis,
septicaemia, peritonitis, urinary infections, meningitis etc.) in humans and animals.
Large number of O, K, F and H antigens. F4 (K88), F5 (K99) – fimbriae – causes
enteritis in piglets & calves. Serotype O157:H7 – pathogen for humans & animals. E.
coli is a toxins producer and invasive germ. Enterotoxigenic Escherichia coli (ETEC) –
LT  & ST toxins
  1. J. G.Holt et al., 1994. Begey’s manual of Determinative Bacteriology, 9th-edition, Williams & Wilkins.
  2. Don J. Brenner and J.J. Farmer III, 2001. Family I. Enterobacteriaceae. In:  Bergey’s Manual of Systematic Bacteriology, Second
    edition,Vol two, part B, George M. Garrity (Editor-in-Chief), pp 587-897.
  3. Leclerc (H.): Étude biochimique d'Enterobacteriaceae pigmentées. Annales de l'Institut Pasteur (Paris), 1962, 102, 726-741.
  4. Huys (G.) et al. Escherichia albertii sp. nov., a diarrhoeagenic species isolated from stool specimens of Bangladeshi children.
    Int. J. Syst. Evol. Microbiol., 2003, 53, 807-810.
  5. Sharon L. Abbott, Jennifer O'Connor, Tom Robin,Barbara L. Zimmer and J. Michael Janda: Biochemical Properties of a Newly
    Described Escherichia Species, Escherichia albertii. Journal of Clinical Microbiology, October 2003, p. 4852-4854, Vol. 41, No.
    10.
  6. Burgess (N.R.H.) et al.: Aerobic bacteria occurring in the hind-gut of the cockroach, Blatta orientalis. Journal of Hygiene
    (Cambridge), 1973, 71, 1-7.
  7. Farmer III (J.J.) et al.: Escherichia fergusonii and Enterobacter taylorae, two new species of Enterobacteriaceae isolated from
    clinical specimens. J. Clin. Microbiol., 1985, 21, 77-81.
  8. Brenner (D.J.) et al.: Atypical biogroups of Escherichia coli found in clinical specimens and description of Escherichia
    hermannii sp. nov. J. Clin. Microbiol., 1982, 15, 703-713.
  9. Brenner (D.J) et al.: Escherichia vulneris: a new species of Enterobacteriaceae associated with human wounds. J. Clin.
    Microbiol., 1982, 15, 1133-1140.
Glucose and other carbohydrates are fermented with the production of pyruvate, which
is converted into lactic, acetic and formic acids. Part of the formic acid is split into CO
2
and H
2.
Positive results for catalase, nitrate reduction, acid production from: L-arabinose,
D-mannitol, D-mannose & trehalose.

Negative results for oxidase, H
2S production, urease, Voges-Proskauer reaction,
DN-ase, lipase, gelatinase, citrate utilization, phenilalanine & acid production from
inositol
(c) Costin Stoica
Antibiogram
Encyclopedia
Culture media
Biochemical tests
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R E G N U M
PROKARYOTAE
 
Arginine
dihydrolase
Lysine
decarboxylase
Ornithine
decarboxylase
Indole
production
Growth on
KCN
Esculin
hydrolysis
Motility
E. albertii
-
+
+
-
-
-
-
E. coli
[-]
+
d
+
-
d
+
E. coli inactive
-
d
[-]
[+]
-
-
-
E. fergusonii
-
+
+
+
-
d
+
E. hermanii
-
-
+
+
+
d
+
E. vulneris
d
[+]
-
-
[-]
[-]
+
Differential characters of the species:
Legend: +  positive 90-100%, - negative 90-100%, [+] positive 75-89%, [-] negative 75-89%, d positive 25-74% of strains
Acid production
Adonitol
Cellobiose
Raffinose
Salicin
D-Xylose
Mucate
Lactose
E. albertii
-
-
-
-
-
-
-
E. coli
-
-
d
d
+
+
+
E. coli inactive
-
-
[-]
-
d
d
[-]
E. fergusonii
+
+
-
d
+
-
-
E. hermanii
-
+
d
d
+
+
d
E. vulneris
-
+
+
d
+
[+]
[-]
More Escherichia coli  bibliography