Extraintestinal Pathogenic Escherichia coli Infection in Calves and PCR Detection of the Virulence-Associated Genes of the Isolates

Abstract

In this study, we assessed six cases of extraintestinal pathogenic Escherichia coli (ExPEC) infection in Japanese black calves and used PCR analysis to detect the virulence-associated genes of the ExPEC isolates obtained from the internal organs of each calf. The clinical signs in the calves included ananastasia, opacity eyes, and respiratory disorder. Histological analysis confirmed the presence of bronchopneumonia, multifocal necrosis,and centrilobular necrosis in the liver, purulent meningitis, and disseminated intravascular coagulation. The virulence-associated genes of the ExPEC isolates encoded toxins (cnf2 and cdt III ), adhesins (F17A and afa8), and siderophores (iutA, fyuA, irp1, and irp2). These results indicated that the virulence-associated genes of these E. coli strains may cause ExPEC infection in calves.