PCR products of the amplified hlyA, inlA and inB genes in L.monocytogenes were electrophoresed on an agarose gel.(a)amplified prodcut of hlyA gene at 174bp, lane1: Gel Pilot 100 bp ladder, lane2:postive control, laneL:3negative control, lane:4-11postive isolates. (b) amplified prodcut of inlA gene at 800bp,lane1: Gel Pilot 100 bp ladder, lane2: postive control, lane3:negative control, lane (5,9,10 and 11) postive isolates. (c) amplified prodcut of inB gene at 343 bp,lane1: Gel Pilot 100 bpladder, lane 2: postive control, lane 3: negative control, lane: 4-11postive isolates.