E. Coli

1. INTRODUCTION
Introduction
Group of Enterobacteriaceae in human includes several that cause
primary infections of the human gastrointestinal tract. Bacteria that
affect the gastrointestinal tract include certain strains of E. coli and
Salmonella, Shigella, and Yersinia entercolitica. Members of this
family are major causes of opportunistic infection (including
septicemia, pneumonia, meningitis and urinary tract infections).
Examples of genera that cause opportunistic infections are:
Citrobacter, Enterobactcr, Escherichia, Hafnia, Morganella,
Providencia and Serratia. Selection of antibiotic therapy is complex
due to the diversity of organisms. The mortality and morbidity are
much higher for the ages less than two years than in older one, fever,
sever loss of electrolyte and dehydration accompanied with watery to
bloody diarrhea (Forfor and Arneil, 1978).
Many species are intestinal pathogens or commensals in the
intestine of man and animal, few are saprophytes in soil and water.
Some species are also transmitted between man and animals (WHO,
2000).
The most common serotypes are E. coli O157:H7 and E. coli
O26:H11. These are unique from the enteropathogenic E. coli (EPEC)
organisms that are the main causes of infantile diarrhea (Shebib et al.,
2003).
Avian pathogenic E.coli (APEC) cause aerosacculitis, poly-
serositis, septicemia in chicken. APEC isolates commonly belong to
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