Prevalence and characteristics of Escherichia albertii and Escherichia fergusonii isolates from healthy farm animals in Japan

Abstract

Escherichia albertii and Escherichia fergusonii have recently been recognized as emerging pathogens in humans and animals. E. albertii is a causative agent of foodborne infections in humans, but many aspects of its transmission routes and its prevalence in farm animals remain unclear. E. fergusonii has been isolated mainly from extraintestinal infections in humans and various animal species, but no large-scale surveys of its prevalence in farm animals have been reported. In this study, we isolated E. albertii and E. fergusonii from 3,975 fecal samples collected from farm animals throughout Japan. The prevalence of E. albertii was 3.1% (57/1,838) in swine, 2.2% (12/548) in poultry, and 0.4% (7/1,589) in cattle, while that of E. fergusonii was 37.4% (688/1,838) in swine, 46.2% (253/548) in poultry, and 17.1% (272/1,589) in cattle. We also isolated E. coli from fecal samples from which E. albertii or E. fergusonii was isolated and compared the antimicrobial resistance profiles of the E. albertii/E. fergusonii strains with those of the E. coli strains that were presumed to have experienced the same antimicrobial selection pressure in the farm animals. The antimicrobial resistance profiles of the E. fergusonii and E. coli strains isolated from the same swine fecal samples were similar, but those of the E. albertii and E. coli strains differed significantly (the former strains were highly susceptible). This suggests that E. albertii has not coexisted with E. coli for as long as E. fergusonii.