title: Phenotypic expression, molecular characterization and transferability of erythromycin resistance genes in Enterococcus spp. isolated from naturally fermented food.
abstract: OBJECTIVE
  To evaluate phenotypic resistance to macrolides-lincosamides and streptogramin B (MLSB ) antibiotics and to determine their localization as well as transferability of erythromycin resistance genes in enterococcal isolates of naturally fermented food-Idli batter.
  
  
  RESULTS
  Diverse MLSB phenotypes observed among the enterococcal spp. (n = 32) were analysed through double disc and triple disc test. Standard minimum inhibitory concentration tests along with induction studies displayed synergistic or cross-resistance among MLSB antibiotics. Plasmid profiling and Southern hybridization revealed that erm(B) and msr(C) genes were localized either on chromosome or on high molecular weight plasmids and showed co-localization of these genes with lnu(B), tet(L) and tet(W) in one of the isolate. In vitro conjugation experiments demonstrated plasmid-mediated transfer of erm(B) gene from three Enterococcus durans strains to Enterococcus faecalis JH2-2.
  
  
  CONCLUSIONS
  The study illustrated diverse MLSB phenotypes, multiple resistance genes and transferable plasmids among enterococci isolated from naturally fermented foods.
  
  
  CONCLUSIONS
  From a public health point of view, the study identified that naturally fermented foods could represent a source of antibiotic resistance enterococci that can spread through foods. These results also suggest that vigilance may be exercised with the use of combination or novel MLSB antibiotics in treating enterococcal infections.
authors.affiliation: Food Microbiology Department, CSIR-Central Food Technological Research Institute, Mysore, India.
authors.forename: S C R
authors.initials: SC
authors.lastname: Thumu
authors.forename: P M
authors.initials: PM
authors.lastname: Halami
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002981:Clindamycin / Q000494:pharmacology; D003227:Conjugation, Genetic; D024881:Drug Resistance, Bacterial / Q000235:genetics; D016983:Enterococcus / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D004917:Erythromycin / Q000494:pharmacology*; D005285:Fermentation; D005516:Food Microbiology; D005798:Genes, Bacterial; D055231:Lincosamides / Q000494:pharmacology; D018942:Macrolides / Q000494:pharmacology; D010641:Phenotype; D010957:Plasmids / Q000235:genetics; D025382:Streptogramin Group B / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D055231:Lincosamides; D018942:Macrolides; D025382:Streptogramin Group B; D002981:Clindamycin; D004917:Erythromycin
keywords: Enterococcus; Erythromycin; MLSB phenotypes; conjugation; fermented foods; tetracycline resistance