Phenotypic and Genotypic Alterations of Durancin GL-Resistant Enterococcus durans Strains.
The emergence and spread of bacteriocin-resistant bacteria threaten the efficiency of bacteriocin usage as food preservatives. In this experiment, 19 selected Enterococcus durans strains acquired resistance after exposure to durancin GL, and the mutants had similar intermediate levels of resistance. One wild-type E. durans KLDS 6.0603 and its two resistant mutants, E. durans KLDS 6.0603-2 and E. durans KLDS 6.0603-3, were used to characterize phenotypic and genotypic differences. Approximately 100 μg/mL of durancin GL can penetrate the cytoplasmic membrane of E. durans KLDS 6.0603, causing damage to bacterial cells, but cannot penetrate E. durans KLDS 6.0603-2 and KLDS 6.0603-3 membranes. Unsaturated fatty acid content in resistant strains was significantly increased compared with wild-type strains, indicating that the former has more fluidity of cell membrane than the latter. Decreased mannose phosphotransferase system gene expression (mptD) was observed in the two resistant strains. Results showed that the factors, including the increased unsaturated fatty acid and decreased mptD expression, could contribute to durancin GL resistance.
1 College of Food Science and Engineering, Collaborative Innovation Center for Modern Grain Circulation and Safety, Key Laboratory of Grains and Oils Quality Control and Processing, Nanjing University of Finance and Economics , Nanjing, China .
Lihui
L
Du
1 College of Food Science and Engineering, Collaborative Innovation Center for Modern Grain Circulation and Safety, Key Laboratory of Grains and Oils Quality Control and Processing, Nanjing University of Finance and Economics , Nanjing, China .
Lingping
L
Liu
2 Institute of Agricultural Products Processing , Jiangsu Academy of Agricultural Sciences, Nanjing, China .
Fang
F
Liu
1 College of Food Science and Engineering, Collaborative Innovation Center for Modern Grain Circulation and Safety, Key Laboratory of Grains and Oils Quality Control and Processing, Nanjing University of Finance and Economics , Nanjing, China .
Xingrong
X
Ju
1 College of Food Science and Engineering, Collaborative Innovation Center for Modern Grain Circulation and Safety, Key Laboratory of Grains and Oils Quality Control and Processing, Nanjing University of Finance and Economics , Nanjing, China .
Jian
J
Yuan
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001430:Bacteriocins / Q000494:pharmacology* / Q000627:therapeutic use; D002417:Cattle; D002418:Cattle Diseases / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D002681:China / Q000453:epidemiology; D004252:DNA Mutational Analysis; D003612:Dairying; D024881:Drug Resistance, Bacterial; D016983:Enterococcus / Q000145:classification / Q000187:drug effects* / Q000235:genetics; D005260:Female; D005516:Food Microbiology; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D005838:Genotype; D010641:Phenotype; D010770:Phosphotransferases / Q000235:genetics; D016133:Polymerase Chain Reaction / Q000662:veterinary
D000900:Anti-Bacterial Agents; D001430:Bacteriocins; C000604181:durancin GL, Enterococcus durans; D010770:Phosphotransferases