RAPD PCR and actA based molecular typing of L. monocytogenes isolated from human, food and domestic animals in northwest of Iran

Abstract

Twenty-one Listeria monocytogenes isolates originated from food, animal, and clinical sources were evaluated by RAPD-PCR typing using four random primers (OPM-01, HLWL-74, HLWL-82, and HLWL85), both individually and in combination. The actA gene-typing and PCR-based serotyping were also used for the characterization of the isolates. Data were analyzed using the related software, and clusters were displayed in dendrogram. Among four primers, OPM-01 showed the highest discriminatory power. The dendrogram for human, food, and livestock isolates showed four different clusters (A-D) and two singletons. Using RAPD-PCR, lineages I, II, and the serogroups were discriminated. In actA gene-typing, 95% of isolates (all except one) belonged to actA type I. Results of PCR-serotyping and RAPD-PCR showed that animal isolates differed from food and clinical isolates. RAPD-PCR showed higher discriminatory power compared to other typing methods used in this study as isolates belonging to the same serotypes in PCR-based serotyping indicated different RAPD profiles.