Detecting the frequency of Yersinia enterocolitica infection in companion dogs in Ahvaz

Yersinia enterocolitica is one of the most important pathogens transmitted through the digestive tract of pets (dogs and cats) to human. This bacterium is the causative agent of enterocolitis in human. The present study was performed on one hundred dogs (fifty clinically healthy and fifty affected to diarrhea) referred to Veterinary Hospital of Shahid Chamran University of Ahvaz. All characteristics of dogs such as age, gender, breed, gastrointestinal status for diarrhea and characteristic of diarrhea (heamorrhagic), history of raw meat consumption and dog origin were recorded. Then, two stool specimens were taken using sterile glove and swab of the rectum area. The samples were also examined for direct culture and enriched culture (in the buffered peptone water at temperature of 4° C). In cases that the grown colonies were suspected to Yersinia, initial tests (catalase, oxidase and gram staining) were performed and identified with biochemical tests. The probable isolates of Yersinia enterocolitica were recognized by PCR technique and then foxA gene was used to identify bacterium and determine the virulence with ail gene (pathogenicity). Three suspected isolates from one hundred samples (one case of healthy dogs and two cases of diarrheic animals) were included in the results of direct culture. Results of enriched culture were composed of six suspected isolates from one hundred cases (three out of healthy dogs and three other cases of diarrheic animals). Finally, out of the nine suspected isolates to Yersinia, only one sample was confirmed for Yersinia enterocolitica that was negative for ail virulence gene. The positive sample was belonged to a healthy, male and ten-months-old Pit bull terrier imported dog that was fed with raw meat. The results of this study showed that the dogs of this area cannot be considered as a potential reservoir for transmission of Yersinia enterocolitica. Further studies are necessary to determine the status of the disease, with more emphasis on the imported and rural dogs.