Occurrence of shiga toxin-producing Escherichia coli (STEC) in bovine feces, feed, water, raw milk, pasteurized milk, Minas Frescal cheese and ground beef samples collected in Minas Gerais, Brazil.

This study aimed to evaluate the occurrence of Shiga toxin-producing Escherichia coli (STEC) in feces samples, water, feed, raw milk, pasteurized milk, Minas Frescal cheese, and ground beef. Seventy samples (40 of feces, 10 of raw milk, 5 of pasteurized milk, 5 of ground beef, 4 of Minas Frescal cheese, 4 of water, and 2 of feed) were collected in two farms of dairy cattle and two farms of beef cattle and in commercial establishments. The samples were processed according to standard methodologies using biochemical methods and molecular and biological assays. Among 209 identified bacterial isolates as E. coli, 120, 70, 7, 7, 3, 2, and zero were obtained from samples of feces, water, feed, ground beef, pasteurized milk, Minas Frescal cheese, and raw milk, respectively. An isolate from water sample coming from a beef cattle farm was identified as E. coli STEC. This isolate showed cytotoxic effect in Vero cells and the EhlyA gene encoding entero-hemolysin. Therefore it is justified to develop studies to limit the spread of this pathogen.