Frequency of Bacteriocin Resistance Development and Associated Fitness Costs in Listeria monocytogenes
| Autor: | Anne Gravesen, A.-M. Jydegaard Axelsen, J. Mendes da Silva, Tina Beck Hansen, Susanne Knøchel |
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| Rok vydání: | 2002 |
| Předmět: |
Preservative
Pediocins Swine Mutant Microbial Sensitivity Tests medicine.disease_cause Applied Microbiology and Biotechnology Microbiology chemistry.chemical_compound Bacteriocins Bacteriocin Listeria monocytogenes Drug Resistance Bacterial medicine Animals Humans Growth rate Nisin Ecology biology Strain (chemistry) food and beverages biology.organism_classification Anti-Bacterial Agents Culture Media Meat Products chemistry Mutation Food Microbiology Cattle Bacteria Food Science Biotechnology |
| Zdroj: | Applied and Environmental Microbiology. 68:756-764 |
| ISSN: | 1098-5336 0099-2240 |
| Popis: | Bacteriocin-producing starter cultures have been suggested as natural food preservatives; however, development of resistance in the target organism is a major concern. We investigated the development of resistance in Listeria monocytogenes to the two major bacteriocins pediocin PA-1 and nisin A, with a focus on the variations between strains and the influence of environmental conditions. While considerable strain-specific variations in the frequency of resistance development and associated fitness costs were observed, the influence of environmental stress seemed to be bacteriocin specific. Pediocin resistance frequencies were determined for 20 strains and were in most cases ca. 10 −6 . However, two strains with intermediate pediocin sensitivity had 100-fold-higher pediocin resistance frequencies. Nisin resistance frequencies (14 strains) were in the range of 10 −7 to 10 −2 . Strains with intermediate nisin sensitivity were among those with the highest frequencies. Environmental stress in the form of low temperature (10°C), reduced pH (5.5), or the presence of NaCl (6.5%) did not influence the frequency of pediocin resistance development; in contrast, the nisin resistance frequency was considerably reduced (−8 ). Pediocin resistance in all spontaneous mutants was very stable, but the stability of nisin resistance varied. Pediocin-resistant mutants had fitness costs in the form of reduction down to 44% of the maximum specific growth rate of the wild-type strain. Nisin-resistant mutants had fewer and less-pronounced growth rate reductions. The fitness costs were not increased upon applying environmental stress (5°C, 6.5% NaCl, or pH 5.5), indicating that the bacteriocin-resistant mutants were not more stress sensitive than the wild-type strains. In a saveloy-type meat model at 5°C, however, the growth differences seemed to be negligible. The applicational perspectives of the results are discussed. |
| Databáze: | OpenAIRE |
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