Frequency and combination patterns of virulence genes
The targeted virulence genes were found in 97.89% (n =93)
isolates, while two isolates were found negative for the virulent genes.
Majority of the isolates belong to group A, B1, B2, C, D, and E showed
the presence of virulence factors. Of these 95 isolates the most
predominant gene was ompC , detected in 97.89% (n =93)
isolates followed by fimH in 61.05% (n =58),ECs3703 57.89% (n =55), ompF 50.52% (n =48),irp2 31.57% (n =30), fyuA 21.05% (n =20),iucD 15.78% (n =15), and 2.10% (n =2) isolates were
positive for colV . Two virulence genes eaeA and lerwere not detected in any of these isolates. The incidence of virulence
genes among E. coli isolated from bovine clinical mastitis is
shown in Table 3.
Sixteen different gene patterns were observed in ninety-five E.
coli isolates which are shown in Table 4. The most prevalent pattern of
four different virulence genes ompC, ompF , fimH , andECs3703 was detected in thirteen different isolates, followed by
the combination of six different virulent factors ompC ,ompF , ECs3703 , fimH , irp2 , fyuA which
was detected in eight isolates.