| The relationship between the acquisition of bacteriocin resistance in strains of Listeria monocytogenes was studied and the resistance of these strains to preservation factors such as temperature, acidity and high salt concentration. Resistant strains were obtained by exposure of test organisms to three different bacteriocins. Bacteriocin-resistant strains that were stable for 100 generations were obtained. Leucocin-resistant strains of L. monocytogenes ATCC 15313 were more thermo-, salt- and acid-tolerant (p < 0.05) than the wild-type strain. Acid tolerance of brochocin-C resistant strains of L. monocytogenes Scott A and the brochocin-C/nisin-resistant strains was significantly (p < 0.05) greater than the wild-type strains; whereas, acid tolerance of leucocin A-resistant strains was not significantly different than the wild-type (ATCC 15313) strain. The study demonstrated that acquisition of resistance to bacteriocins in strains of L. monocytogenes could alter the resistance to other preservation factors. |
