title: Restoring the selectivity of Bolton broth during enrichment for Campylobacter spp. from raw chicken.
abstract: OBJECTIVE
  When isolating Campylobacter spp. from retail raw chicken using BS EN ISO 10272-1:2006, contaminants frequently cause overgrowth on mCCDA plates. Therefore, these organisms proliferate in the enrichment medium, Bolton broth, indicating a lack of selectivity in this medium. This study sought to characterize the contaminant flora and to devise a modified Bolton broth to inhibit their growth.
  
  
  RESULTS
  Contaminants (n=30) from separate samples were identified and antibiotic resistances determined. Most (93%) were extended spectrum β-lactamase (ESBL) producing Escherichia coli, able to hydrolyse the cefoperazone present in Bolton broth and mCCDA. To inhibit these organisms, original formulation Bolton broth was supplemented with potassium clavulanate, at three concentrations, and recoveries of campylobacters from raw chicken were determined. Using standard Bolton broth, only 49% of samples (n=104) yielded campylobacters, but supplementation with 2 mg l(-1) potassium clavulanate increased this significantly (P<0.05), with 91% of samples positive.
  
  
  CONCLUSIONS
  Potassium clavulanate can restore the selectivity of Bolton broth when isolating Campylobacter spp. from raw chicken.
  
  
  CONCLUSIONS
  Raw chicken is often contaminated with the pathogen Campylobacter, but the ISO methodology for its detection is becoming compromised by the increasing presence of antibiotic-resistant bacteria. A simple modification ensures effective detection of this pathogen.
authors.affiliation: Food Microbiology Branch, Agri-Food and Biosciences Institute, Newforge Lane, Belfast, UK.
authors.forename: L
authors.initials: L
authors.lastname: Moran
authors.forename: C
authors.initials: C
authors.lastname: Kelly
authors.forename: M
authors.initials: M
authors.lastname: Cormican
authors.forename: S
authors.initials: S
authors.lastname: McGettrick
authors.forename: R H
authors.initials: RH
authors.lastname: Madden
mesh_terms: D000818:Animals; D001419:Bacteria / Q000145:classification / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism; D002167:Campylobacter / Q000254:growth & development* / Q000302:isolation & purification*; D002438:Cefoperazone / Q000378:metabolism; D002645:Chickens; D003470:Culture Media / Q000737:chemistry*; D024881:Drug Resistance, Bacterial; D008460:Meat / Q000382:microbiology*
chemical_list: D003470:Culture Media; D002438:Cefoperazone