Molecular detection of rfbO157, shiga toxins and hemolysin genes for Escherichia coli O157: H7 from canine feces in Tikrit and Mosul cities, Iraq

Abstract

Escherichia coli O157:H7 is considered as an important pathogen of diarrhea in adult dogs and puppies because it contains virulence genes. The study objective was to the molecular detection of the rfbO157 encoding the O-antigen specific for E. coli O157: H7,shiga toxins and hemolysin genes of E.coli O157:H7 in feces of dogs that collected from different regions in Tikrit and Mosul cities, Iraq. One hundred fecal swabs were collected from pet and K9 dogs including (72 dogs with diarrhea, and 28 without diarrhea). All the Collected swabs were cultured in the nutrient and MacConkey agars, Then the suspected colonies were cultured in the EMB agar. Metallic sheen colonies were cultured by using the chrome agar. All bacteriological identified isolates were enrolled by using the polymerase chain reaction (PCR) technique. The results of this study showed that 7(9.7%) of 72 dogs suffered from diarrhea were positive for E. coli O157:H7 that contained the rfbO157 gene (n= 6), carry stx1 gene (n= 3), carry stx2 gene (n= 3), and hlyA gene (n= 1). On the other hand, 2 (7.1%) of 28 dogs without diarrhea were positive for E. coli O157:H7 that contained the rfbO157 gene (n= 1), stx2 gene (n= 1), and hlyA gene (n= 1). In conclusion, dogs can be a significant reservoir for pathogenic E. coli O157:H7, particularly dogs with diarrhea.