PCR MULTIPLEX PARA DETERMINAÇÃO DE MARCADORES DE VIRULÊNCIA EM Escherichia coli ISOLADAS DE BOVINOS COM DIARRÉIA EM MINAS GERAIS

Abstract

Diarrhea is one of the most common diseases in calves and leads to substantial economic loss due to treatment costs, increased mortality and morbidity rates, and growth constraints. Enterotoxigenic Escherichia coli (ETEC), attaching and effacing E. coli (AEEC) and Shiga toxin-producing E. coli (STEC) have been identified as causes of diarrhea and dysentery in calves. This study investigates virulence factors of E. coli strains isolated from calves by multiplex PCR. The animals were up to 60 days old and were raised in Minas Gerais State, Brazil. Samples were obtained from semi-intensive dairy farms in the center-west and Alto Paranaiba regions of Minas Gerais. Feces were collected and processed routinely. The DNA templates of E. coli strains were subjected to multiplex PCR for the detection of the genes encoding the virulence factors Stx1, Stx2, Int, F41, K99, and STa. Out of 156 isolates, 51 (32,7%) were positive, whereas 105 (67,3%) did not present any of the virulence factors investigated. Results show that E. coli is an important cause of diarrhea in calves in Minas Gerais and that multiplex PCR test is a useful tool for the identification and characterization of pathogenic E. coli strains.