title: Class I/Class IIa bacteriocin cross-resistance phenomenon in Listeria monocytogenes.
abstract: Variants resistant to nisin A (vA), nisin Z (vZ), pediocin PA-1 (vP), divergicin M35 (vD) and to bacteriocin-like compounds produced by Bifidobacterium thermophilum subsp. infantis RBL67 (vB) were developed from Listeria monocytogenes LSD530. Lactic acid production, specific growth rate, potassium ion efflux, susceptibility to 13 antibiotics, cell-envelope fatty acid composition and bacteriocin cross-resistance were evaluated. Lactic acid production decreased to 75% or less of that by strain LSD530 for vP, vD and vB and to 20% or less for vA and vZ. Specific growth rates also decreased for all five variants. Acquired resistance to nisin A or Z increased resistance to pediocin and divergicin while vD showed increased resistance to nisin Z but decreased resistance to nisin A and vP exhibited increased resistance to nisin Z, pediocin and divergicin but decreased resistance to nisin A. Acquired bacteriocin resistance generally decreased antibiotic sensitivity, particularly to ampicillin, chloramphenicol, erythromycin and tetracycline. Palmitic acid (C(16:0)) in the cell wall fraction of all variants was significantly higher than in strain LSD530, accounting for 18%, 43%, 32%, 26%, 53% and 44% of the total fatty acids for LSD530, vP, vD, vB, vA, and vZ, respectively. The relationship between the acquisition of bacteriocin resistance, cross-resistance and pathogenicity of Listeria monocytogenes should be studied.
authors.affiliation: STELA Dairy Research Center, Nutraceuticals and Functional Foods Institute, Université Laval, Québec, QC, Canada.
authors.forename: Karim
authors.initials: K
authors.lastname: Naghmouchi
authors.forename: Ehab
authors.initials: E
authors.lastname: Kheadr
authors.forename: Christophe
authors.initials: C
authors.lastname: Lacroix
authors.forename: Ismaïl
authors.initials: I
authors.lastname: Fliss
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001430:Bacteriocins / Q000494:pharmacology*; D001644:Bifidobacterium; D002473:Cell Wall / Q000737:chemistry; D015169:Colony Count, Microbial; D024881:Drug Resistance, Bacterial; D024901:Drug Resistance, Multiple, Bacterial; D005227:Fatty Acids / Q000032:analysis; D005516:Food Microbiology; D007700:Kinetics; D019344:Lactic Acid / Q000096:biosynthesis*; D008089:Listeria monocytogenes / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D009561:Nisin / Q000494:pharmacology; D010641:Phenotype
chemical_list: D000900:Anti-Bacterial Agents; D001430:Bacteriocins; D005227:Fatty Acids; C514464:divergicin M35, Carnobacterium divergicin M35; D009561:Nisin; D019344:Lactic Acid