Isolation and Detection of Four Major Virulence Genes in O157:H7 and Non-O157 E. Coli from Beef at Yogyakarta Special Province, Indonesia

Abstract

E scherichia coli O157:H7 is a subset of enterohemorrhagic E. coli (EHEC) that can cause diarrhea in human. Escherichia coli O157:H7 differ from normal flora found in the intestine and are categorized into specific group based on virulence factors, such as exotoxin (Fernandez, 2008). The EHEC produces Shiga-like toxin, it is also called Shiga toxin (stx)-producing E. coli (STEC). Stx consists of two subgroups, namely stx1 and stx2. Other virulence factors found in EHEC are eae (intimin), rfbE (O157 antigen), and fliC (flagellar antigen). EHEC lives research Article Abstract | Food products of animal origin, especially beef, are at risk of Escherichia coli (E. coli) contamination during slaughtering and/or processing that poses serious threat to consumers. E. coli contamination affects food quality because the pathogen contains toxins that can cause disease and even death. This study aimed to detect virulence genes in E. coli O157:H7 and non-O157 isolates of beef sold in the traditional markets of the Yogyakarta Special Province, Indonesia, using the multiplex polymerase chain reaction (multiplex PCR). A total of 98 raw beef samples were collected aseptically from different markets of study area and cultured on various selective media followed by the analysis by multiplex PCR amplification. The results exhibited that out of 98 beef samples, 83 (84,69%) were positive for E. coli. The main virulence genes detected were eae, fliC, rfbE, and stx2A. All of these virulence genes of E. coli O157:H7 were detected in all beef samples. The 28 isolates were identified as non-O157 E. coli that exhibited the eae gene, however they were not exhibited the rfbE and fliC genes. This study concluded the presence of significant contamination of virulent E. coli strains in beef meat sold in the Yogyakarta Special Province, Indonesia. Moreover, multiplex PCR assay was shown to be effective for the detection of E. coli O157:H7 and non-O157 strains from beef and may be applied for other food matrices as well.