title: Characterization and transfer of antibiotic resistance in lactic acid bacteria from fermented food products.
abstract: The study provides phenotypic and molecular analyses of the antibiotic resistance in lactic acid bacteria (LAB) from fermented foods in Xi'an, China. LAB strains (n = 84) belonging to 16 species of Lactobacillus (n = 73), and Streptococcus thermophilus (n = 11) were isolated and identified by sequencing their 16S rRNA gene. All strains were susceptible to ampicillin, bacitracin, and cefsulodin, and intrinsically resistant to nalidixic acid, kanamycin, and vancomycin (except L. bulgaricus, L. acidophilus, and S. thermophilus, which were susceptible to vancomycin). Some strains had acquired resistance for penicillin (n = 2), erythromycin (n = 9), clindamycin (n = 5), and tetracycline (n = 14), while resistance to gentamycin, ciprofloxacin, streptomycin, and chloramphenicol was species dependent. Minimum inhibitory concentrations presented in this study will help to review microbiological breakpoints for some of the species of Lactobacillus. The erm(B) gene was detected from two strains of each of L. fermentum and L. vaginalis, and one strain of each of L. plantarum, L. salivarius, L. acidophilus, L. animalis, and S. thermophilus. The tet genes were identified from 12 strains of lactobacilli from traditional foods. This is the first time, the authors identified tet(S) gene from L. brevis and L. kefiri. The erm(B) gene from L. fermentum NWL24 and L. salivarius NWL33, and tet(M) gene from L. plantarum NWL22 and L. brevis NWL59 were successfully transferred to Enterococcus faecalis 181 by filter mating. It was concluded that acquired antibiotic resistance is well dispersed in fermented food products in Xi'an, China and its transferability to other genera should be monitored closely.
authors.affiliation: Department of Immunology and Pathogenic Biology, School of Medicine, Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, People's Republic of China.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Nawaz
authors.forename: Juan
authors.initials: J
authors.lastname: Wang
authors.forename: Aiping
authors.initials: A
authors.lastname: Zhou
authors.forename: Chaofeng
authors.initials: C
authors.lastname: Ma
authors.forename: Xiaokang
authors.initials: X
authors.lastname: Wu
authors.forename: John E
authors.initials: JE
authors.lastname: Moore
authors.forename: B Cherie
authors.initials: BC
authors.lastname: Millar
authors.forename: Jiru
authors.initials: J
authors.lastname: Xu
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002681:China; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D024881:Drug Resistance, Bacterial; D013293:Enterococcus faecalis / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D005516:Food Microbiology; D022761:Gene Transfer, Horizontal; D005798:Genes, Bacterial; D007778:Lactobacillus / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D048249:Streptococcus thermophilus / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S