| Affiliation: | 1. Institute of Nutrition and Functional Foods, Université Laval, Québec, Quebec, G1V 0A6 Canada;2. Institute of Integrative Biology and Systems, Université Laval, QC, Québec, G1V 0A6 Canada;3. Institute of Nutrition and Functional Foods, Université Laval, Québec, Quebec, G1V 0A6 Canada Muséum National d'Histoire Naturelle, Centre National de la Recherche Scientifique, Laboratory of Communication Molecules and Adaptation of Micro-organisms, UMR 7245 CNRS-MNHN, Paris, CP 54, 57 rue Cuvier 75005 France;4. Muséum National d'Histoire Naturelle, Centre National de la Recherche Scientifique, Laboratory of Communication Molecules and Adaptation of Micro-organisms, UMR 7245 CNRS-MNHN, Paris, CP 54, 57 rue Cuvier 75005 France;5. Guelph Research and Development Center, Agriculture and Agri-Food Canada, 93 Stone Road West, Guelph, Ontario, N1G 5C9 Canada;6. Department of Food Science and Agriculture, McGill University, Ste Anne de Bellevue, Québec, Quebec, H9X3V9 Canada |
| Abstract: | In livestock production, antibiotics are used to promote animal growth, control infections and thereby increase profitability. This practice has led to the emergence of multiresistant bacteria such as Salmonella, of which some serovars are disseminated in the environment. The objective of this study is to evaluate microcin J25 as an inhibitor of Salmonella enterica serovars of various origins including human, livestock and food. Among the 116 isolates tested, 37 (31.8%) were found resistant to at least one antibiotic, and 28 were multiresistant with 19 expressing the penta-resistant phenotype ACSSuT. Microcin J25 inhibited all isolates, with minimal inhibitory concentration values ranging from 0.06 μg/ml (28.4 nM) to 400 μg/ml (189 μM). Interestingly, no cross-resistance was found between microcin J25 and antibiotics. Multiple sequence alignments of genes encoding for the different proteins involved in the recognition and transport of microcin J25 showed that only ferric-hydroxamate uptake is an essential determinant for susceptibility of S. enterica to microcin J25. Examination of Salmonella strains exposed to microcin J25 by transmission electronic microscopy showed for the first-time involvement of a pore formation mechanism. Microcin J25 was a strong inhibitor of several multiresistant isolates of Salmonella and may have a great potential as an alternative to antibiotics. |
