A comparison analysis of Listeria monocytogenes isolates recovered from chicken carcasses and human by using RAPD PCR.

Abstract

Chicken meat is a valuable source of protein and consumption of it continues to rise day to day. The aim of the present study was to evaluate the genetic homogeneity of Listeria monocytogenes (L. monocytogenes) isolates obtained from chicken carcasses and human. Random Amplification of Polymorphic DNA (RAPD) PCR with three different primers were used to analyze the 31 L. monocytogenes isolates recovered from human and chicken carcasses. Primers were D8635, HLWL74, and OPM01. Scanned images of RAPD-PCR products were analyzed using Photocap software. The data were analyzed by SPSS software using Jaccard distance matrix and Ward's hierarchical cluster technique, isolates were clustered and displayed in dendrogram form. Molecular serotyping of the isolate was done. Most of the isolates were grouped into two serogroup IIb and IIa. However some of them were serotyped as IVb serogroup. In the RAPD assay, all of the primers gave amplified bands. Among these three primers, OPM01 had the most discriminatory power due to producing polymorph bands. Totally, 75 different bands with sizes ranging from 150 bp to 3300 bp, were produced. The dendrogram for Listeria monocytogenes isolates from chicken and human showed five different clusters (designed as A to E). In this study, there wasn't any association between food and human isolates of L. monocytogenes. RAPD has more discriminatory power than serotyping. On the other hand, there were different RAPD profiles among isolates of the same serotype and also, similar RAPD profile among different serotypes were observed.