Identification of shiga toxin and intimin genes in Escherichia coli detected from canary (Serinus canaria domestica)

Abstract

The pathogenicity of enterohemorrhagic Escherichia coli (EHEC) strains is, in large part, due to shiga toxin (Stx) genes (Stx1 and Stx2) and/or intimin (eae) gene. The purpose of this study was to analyze the role of domestic canaries (Serinus canaria domestica) as a reservoir of Stx and intimin producing strains of E. coli. For this study, a total of 50 cloacal swabs were collected from 50 healthy domestic canaries. Cloacal swabs were cultured and tested using standard methods of microbiology. After primary identification of E. coli, DNA was extracted and polymerase chain reaction was performed using specific primers for Stx1, Stx2 and eae genes. In this study, three of 50 samples were found to be Stx2 positive. In the present study, nine (18%) of 50 canaries tested were positive for eae gene. Only 2% of total canaries tested were positive for simultaneous Stx and eae genes. By considering the presence of Stx genes in E. coli isolated from cloacal contents of canary, this hypothesis expressed that the canaries may be the carriers of virulence genes that can risk human health. Canary was considered to be a reservoir of Stx and intimin genes and make these birds important vehicles for the spread of zoonosis infection.

Keywords: Canary; Escherichia coli; PCR; intimin; shiga toxin.