title: Development and stability of bacteriocin resistance in Campylobacter spp.
abstract: OBJECTIVE
  Several bacteriocins (BCNs) that were identified from chicken commensal bacteria dramatically reduced Campylobacter colonization in poultry and are being directed toward on-farm control of this important foodborne human pathogen. A recent study has shown that BCN resistance in Campylobacter jejuni is very difficult to develop in vitro. In this study, in vivo development and stability of BCN resistance in Campylobacter was examined.
  
  
  RESULTS
  Chickens infected with Camp. jejuni NCTC 11168 were treated with BCN E-760 at the dose of 5 mg kg(-1) body weight day(-1) via oral gavages for three consecutive days, which selected BCN-resistant (BCN(r)) mutants in the treated birds. However, all the in vivo-selected mutants only displayed low levels of resistance to BCN (MIC = 2-8 mg l(-1)) when compared to parent strain (MIC = 0.5 mg l(-1)). Inactivation of CmeABC efflux pump of the BCN(r) mutants led to increased susceptibility to BCN (8-32 fold MIC reduction). Three different BCN(r) Campylobacter strains (in vitro- or in vivo-derived) were examined for the stability of BCN resistance using both in vitro and in vivo systems. The low level of BCN resistance in these strains was not stable in vitro or in vivo in the absence of BCN selection pressure.
  
  
  CONCLUSIONS
  Usage of BCN E-760 only selected low-level BCN(r) Camp. jejuni mutants in vivo, and the low-level BCN resistance was not stable in vitro and in vivo.
  
  
  CONCLUSIONS
  The study provides helpful information for risk assessment of the future practical application of the anti-Campylobacter BCNs in animals.
authors.affiliation: Department of Animal Science, The University of Tennessee, Knoxville, TN 37996-4574, USA.
authors.forename: K V
authors.initials: KV
authors.lastname: Hoang
authors.forename: N J
authors.initials: NJ
authors.lastname: Stern
authors.forename: J
authors.initials: J
authors.lastname: Lin
mesh_terms: D000818:Animals; D001430:Bacteriocins / Q000494:pharmacology*; D001693:Biological Transport, Active; D002169:Campylobacter Infections / Q000382:microbiology / Q000662:veterinary*; D016123:Campylobacter jejuni / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development; D002645:Chickens / Q000382:microbiology*; D024881:Drug Resistance, Bacterial; D008826:Microbial Sensitivity Tests; D011201:Poultry Diseases / Q000382:microbiology*
chemical_list: D001430:Bacteriocins