Amplified fragment length polymorphism (AFLP) analysis of Listeria monocytogenes

AFLP analysis using four selective primers was performed on a set of 33 Lis teria monocytogenes including strains from patients and foods implicated in outbreaks, human sporadic cases or foods. Strains were tested belonging to serovars 1/2a, 1/2b, 1/2c, 3b, and Ib. Using one of the primers, the AFLP technique generated 20 different sized DNA fragments. The 33 cultures segre gated into 14 different patterns, each comprising 7-12 different fragments. Although the method was not sufficiently discriminatory for epidemiologica l typing, AFLP analysis reconfirmed the observation that L. monocytogenes c omprises two major genetic groups: group 1 includes strains of serovars 1/2 a and 1/2c, while group 2 serovars 1/2b, 3b and 4b.