Abstract:

Four pairs of primers were designed according to Shiga-like toxin gene (slt) and adhesion factor gene (eaeA) from Escherichia coli O157, hemolysis O encoding gene (hlyA) and virulence gene (plcA) from Listeria monocytohenes, as slt-F/slt-R, eaeA-F/eaeA-R, hlyA-F/hlyA-R and plcA-F/plcA-R, respectively. The corresponding PCR products were 780, 450, 708 and 600 bp, respectively. A multiplex PCR (MPCR) method was developed to detect E. coli O157 and Listeria monocytohenes. The optimal conditions including Mg2+ concentration, dNTPs and anneal temperature for MPCR were investigated. Along with this, the specificity and sensitivity of the method were monitored. Under optimized conditions, the detection limit for DNA template was 0.50 ng for both E. coli O157 and Listeria monocytohenes. The specific and sensitive detection for E. coli O157 and Listeria monocytohenes in food industry can be achieved by using this method.

Key words: multiplex polymerase chain reaction (MPCR), Escherichia coli O157, Listeria monocytohenes