Detection of mobile genetic elements in pediocin PA-1 like producing lactic acid bacteria.

To evaluate the presence of mobile genetic elements in intergeneric and interspecific pediocin
producing lactic acid bacteria (LAB) the flanking regions of the pediocin PA-1/AcH (pediocin
PA-1) operon was characterized. In Enterococcus faecium Acr4 and Lactobacillus plantarum Acr2 a
variation in the amplicon size in the downstream region of the operon was identified,
suggesting a deletion in this region. Beyond that, in pediocin PA-1 encoding plasmids mobile
genetic elements such as ISLpl1 and mobilization regions were detected by Southern hybridization
analysis. Phylogenetic analyses of the E. faecium Acr4 ISLpl1 gene sequence suggested
the gene transfer from lactobacilli in the environment. The tyrosine recombinase detected in
pediocin plasmids of P. acidilactici H and K7 indicate a possible transfer of the entire operon
among LAB. Since these elements are known to be associated with transfer of genes linked to
the bacteriocin production, antibiotic resistance and sugar utilization, we suggest similar
mechanism for natural spread of pediocin PA-1 operon among different bacterial species.