Detection of rfbO157 and fliCH7 genes in escherichia coli isolated from human and sheep in Basrah province

Abstract EN

This study aimed to detect Escherichia coli O157:H7 in samples from patients with diarrhea, sheep milk, and sheep drinking water by growth on selective media, biochemical tests, latex agglutination test, and PCR technique.

During the period from November 2008 to May 2009, a total of 340 samples were collected; stools diarrhoeic patients (125), healthy sheep feces (125), milk (45), and sheep drinking water samples (45).

Samples were screened for the presence of non-sorbitol fermenting colonies (NSF) on sorbitol MacConkey agar supplemented with cefixime and potassium tellurite (CT-SMAC).

Out of the 340 samples, 58 (46.4%) stool from diarrhea, 98 (78.4%) from sheep feces, 19 (42.2%) milk, and 17 (37.7%) drinking water were nonsorbitol fermenting.

E.

coli isolates were serotyped as E.

coli O157:H7 by latex agglutination test, 3 (5.7%) isolates of stool from diarrhea patients, 7 (7.3%) isolates of sheep feces, 2 (11.1%) isolates of milk, and none of drinking water samples were positive.

All latex agglutination positive isolates were positive to PCR test except one isolate from sheep feces.

PCR positive isolates were produced enterohemolysin on sheep blood agar, and were found resistant to at least 3 antibiotics.

The highest rate of E.

coli O157:H7 isolation was observed in April (7.6%) followed by December (4.7%) , while those of sheep feces showed the highest rate in March (10%) followed by April (8.6%).