Identification of virulence genes in isolated Escherichia coli from diarrheic calves and lambs by multiplex polymerase chain reaction

Abstract

The purpose of this study was to determine the presence of selected virulence genes in Escherichia coli isolated from diarrheic calves (Tehran province) and lambs (Ghume provinces) of Iran. We examined 40 isolates (29 from calves and 11 from lambs). All 40 isolates were tested for the presence of stx1, stx2, eae, espB and hly genes by multiplex polymerase chain reaction in two protocols. In the first protocol the isolates were tested with EC and hly primers and in the second protocol the isolates were examined with eae, stx1, stx2 and espB primers. Multiplex PCR showed that from 29 strains isolated from diarrheic calves, 4 of isolates (13.7%) were stx1 positive, 16 isolates (55.17%) carried stx2 and 2 isolates (6.89%) had espB gene. 1 isolate (3.44%) possessed eae. Among 11 strains isolated from diarrheic sheep, 9 isolates (81.81%) carried stx2 and 2 isolates (18.18%) had espB gene. Six isolates (54.54%) possessed eae and none of them was stx1 positive. The hly gene was not detected in any of the isolates. The findings of this study indicated that the stx2 may be widespread among pathogenic Escherichia coli in Iran. © 2006 Asian Network for Scientific Information.