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20 Cards in this Set
- Front
- Back
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Discovered by
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Dr. Theodor Escherich in 1885, a Germanphysician who Demonstratedthat particular strains were responsible for infant diarrhea andgastroenteritis
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Morphology
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Gram Negative Rods (bacilli) |
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Family it belongs to |
It belongs to the Family Enterobacteriaceae. From Greek word enterikos (intestines)
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Habitat |
These organisms happily inhabit theintestinal tract of most warm blooded animals.
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Physiology |
Facultative anaerobe, Fermenter, Oxidase negative Lipopolysaccharide consists of O polysaccharide, core polysaccharide (Ag) and A lipid (endotoxins) |
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Physical requirement |
Temperature - 25- 37 °C Mesophilic pH- Neutral environment oxygen- Facultative anaerobe |
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Virulence |
Endotoxin, Exotoxins (shiga toxins), Adhesins, H (flagella) and K (capsule) antigens , Permeability barrier of outer membrane invasive capacity Fimbriae (pili) |
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Epidemiology |
Most infection are endogenous by patient's normal flora. Exogenousely cause gastroenteritis manily cause infection in hospitalized patients and travelers. |
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Disease |
Bacteremia, Urinary tract infection(UTI) Neonatal meningitis, Intra-abdominal infection |
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Signs and symptoms
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i) Cystitis- dysuria, urgency, increased frequency, incomplete voiding
ii) pyelonephritis- same as cystitis but more severe and with fever, join pain iii) Septicemia- E. coli causes 45% of enterobacterial septicemia |
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pathogenic groups of E.Coli |
Six different groups ie EPEC, ETEC, EIEC, EHEC, EAEC, DAEC |
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Diagnosis |
Grows on most culture Medias common medias include MacConkey's agar, VRBA , Mannitol salt agar, Endo agar, EMB agar common test include pyuria, hematuria, bacteriuria |
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Biochemical Tests |
Glucose fermentation with gas urea and H2S negative, Motility , methyl red +ve, citrate , VP -ve, TSI A/A, gas +ve, |
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Prevention Methods
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1.Wash hands before and after cooking (At least 30 seconds)
2.Avoid cross contamination of foods 3.Keep food refrigerated or frozen 4.Make sure food is kept at appropriate temperature 5.Avoid raw meat and poultry 6.Do not let food defrost on counter Refrigerate left overs 7.good personal hygiene- cook ground beef 8.Avoid unnecessary use of Chetheters |
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Treatment
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Antibiotic therapy is NOT indicated
Replacement of fluid and Electrolyte Currently, the antibiotics of choice are fluoroquinolones or azithromycin, with an emerging role for rifaximin. Oral rifaximin, a semisynthetic rifamycin derivative, is an effective and well-tolerated antibacterial for the management of adults with non-invasive traveller’s diarrhoea. Rifaximin was significantly more effective than placebo and no less effective than ciprofloxacin in reducing the duration of diarrhoea. While rifaximin is effective in patients with E. coli-predominant traveller’s diarrhoea, it appears ineffective in patients infected with inflammatory or invasive enteropathogens . |
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Uses of Ecoli |
Protects the intestinal tract from bacterial infections, Aids in digestion, Produces vitamins B12 and K ,Lives symbiotically with us 1)Non-poathogenic form of E.Coli named Mutaflor and E. coli O83:K24:H31 are used as Probiotic . 2)Model organism in life science research |
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Bad E.Coli |
Produces a powerful toxin,
Damages the intestines, causes bloody diarrhea, and other complications, Common cause of diarrhea in tourists |
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Cultural Charecteristics |
growth on MacConkey's agar plate - pink lac fermenter |
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Cultural Charecteristics
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growth on EMB agar plate - Metallic sheen
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for more information
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microamaze.blogspot.com
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