RT Journal Article SR Electronic(1) A1 Sakayori, Youko A1 Muramatsu, Mizuho A1 Hanada, Satoshi A1 Kamagata, Yoichi A1 Kawamoto, Shinichi A1 Shima, JunYR 2003 T1 Characterization of Enterococcus faecium mutants resistant to mundticin KS, a class IIa bacteriocin JF Microbiology, VO 149 IS 10 SP 2901 OP 2908 DO https://doi.org/10.1099/mic.0.26435-0 PB Microbiology Society, SN 1465-2080, AB The emergence and spread of mutants resistant to bacteriocins would threaten the safety of using bacteriocins as food preservatives. To determine the physiological characteristics of resistant mutants, mutants of Enterococcus faecium resistant to mundticin KS, a class IIa bacteriocin, were isolated. Two types of mutant were found that had different sensitivities to other antimicrobial agents such as nisin (class I) and kanamycin. Both mutants were resistant to mundticin KS even in the absence of Mg2+ ions. The composition of unsaturated fatty acids in the resistant mutants was significantly increased in the presence of mundticin KS. The composition of the phospholipids in the two resistant mutants also differed from those in the wild-type strain. The putative zwitterionic amino-containing phospholipid in both mutants significantly increased, whereas amounts of phosphatidylglycerol and cardiolipin decreased. These changes in membrane structure may influence resistance of enterococci to class IIa and class I bacteriocins., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.26435-0