Pathogenic bacteria and the prevalence of virulence genes in E. coli isolated from passerine birds of Iran

Wild birds as source of pathogenic microorganisms infecting livestock and humans are an interesting topic that has received increased attention in recent years. Here we study occurrence of pathogenic bacteria in birds in north-east Iran with focus on to identifying virulence gene in wild and domestic birds. Wild birds were trapped and sampled in different localities in north-east Iran from April to September in ۲۰۱۸ and ۲۰۱۹. From ۱۸۴ birds representing ۳۲ species of wild passerine birds, potentially pathogenic bacteria were isolated from ۱۷۱ samples (۹۲.۹). Escherichia coli was the most frequently isolated bacterium with a prevalence of ۷۰.۱%, followed by Enterobacter spp. (۵۳.۸%) and Salmonella spp (۳.۲%) isolated from ۱۲۹, ۹۹ and ۶ wild birds, respectively. In total ۷۹.۶% of the isolates carried virulence factors. A higher frequency of virulence genes was detected in domestic birds (۸۸.۶%) than in wild birds (۷۶%). The results showed that birds in north-east Iran can serve as a potential source of bacterial pathogens and virulence factors that may cause disease in both humans and birds. Furthermore, our results introduce new host birds as source of pathogenic microorganisms that can carry and disseminate them in the environment.

Keywords:

Cloacal swabs , Pathogen , E. coli , virulence gene , Wild bird