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Abstract
A total of 468 samples (cattle faeces, water, milk and feed) were collected from three dairy farms at different localities of Sharkia governorate during a period from June 2003 to May 2004. The samples were examined for Enterohaemorrhagic E.coli (EHEC) serogroups O157:H7, O26:K60 and O111:K58 using enrichment-HCI treatment method and the isolates were confirmed biochemically and serologically. Shiga toxin 2 and attaching & effacing genes were detected in twenty isolates of EHEC. The DNA fingerprints and the antibiogram patterns for certain E.coli O157:H7 isolates were determined. Also, the survival of STEC O157:H7 in cattle faeces and water was studied. Moreover, the effect of some chemical disinfectants on STEC O157:H7 and pathogenic effects on experimental animals were assessed.
The obtained results were summarized as follows:
1- Examination of 360 faecal samples collected from cattle of different ages and localities at Sharkia governorate (Table 6) revealed that Enterohaemorrhagic E.coli was recovered from 60 samples with overall prevalence 16.7%. Moreover, the overall percentage of the three serogroups of EHEC O157:H7, O26:K60 and O111:K58 in cattle faeces was 5%, 8.9% and 2.8%, respectively.
Regarding EHEC in cattle faeces in relation to investigated farms, it was found that E.coli O157:H7, O26:K60 and O111:K58 were highest in farm 1, followed by farm 2 and finally farm 3.