Rapid detection of food-borne pathogens by using molecular techniques

Department of Genetics, Bhagwan Mahavir Hospital and Research Centre, Masab tank, Hyderabad, Andhra Pradesh, India-500 004 Correspondence Kaiser Jamil kaiser_jamil{at}yahoo.co.in Received March 29, 2004 Accepted October 5, 2004 Traditional methods of identification of food-borne pathogens, which cause disease in humans, are time-consuming and laborious, so there is a need for the development of innovative methods for the rapid identification of food-borne pathogens. Recent advances in molecular cloning and recombinant DNA techniques have revolutionized the detection of pathogens in foods. In this study the development of a PCR-based technique for the rapid identification of the food-borne pathogens Salmonella and Escherichia coli was undertaken. Suitable primers were designed based on specific gene fimA of Salmonella and gene afa of pathogenic E. coli for amplification. Agarose gel electrophoresis and subsequent staining with ethidium bromide were used for the identification of PCR products. The size of the amplified product was 120 bp as shown by comparison with marker DNA. These studies have established that fimA and afa primers were specific for detecting Salmonella and pathogenic E. coli , respectively, in the environmental samples. Thus a rapid, sensitive and reliable technique for the detection of Salmonella and pathogenic E. coli was developed.