Purpose: The aim of this study was to explore safety aspects of bacteriocinogenic P. acidilactici ET34 based on presence and expression of genes related to the virulence factors, production of biogenic amines and antibiotic resistance.
Methods: P. acidilactici ET34 were isolated from smoked salmon, identified based on their biochemical and genetic characteristics including PCR with species-specific primers, and characterized as bacteriocin producers against some food spoilage microorganisms and foodborne pathogens. The strain was subjected to molecular and phenotypical tests to assess the presence of more than 50 genes related to virulence factors, production of biogenic amines and antibiotic resistance.
Results: P. acidilactici ET34 produced class IIa bacteriocin with 3.5 kDa, with bactericidal activity against Staphylococcus spp., Enterococcus spp. and Listeria spp., including L. monocytogenes from various serological groups. P. acidilactici ET34 presented low virulence profile, indicated by the presence of few genes related to antibiotic resistance and surface proteins, based on genetic and physiological tests.
Significance: Besides the beneficial properties studied for various LAB, most considered as safe, special attention needs to be paid to the possible presence of virulence factors, production of biogenic amines and antibiotic resistance. Horizontal gene transfer of virulence factors between pathogenic and LAB, including probiotics, is a highly possible scenario in the case of uncontrolled application of probiotics or starter cultures.