SUMMARYLogistic regression, supported by other statistical analyses was used to explore the possible association of risk factors with the fluoroquinolone (FQ)-resistance status of 108 pig finisher farms in Great Britain. The farms were classified as 'affected' or 'not affected' by FQ-resistant E. coli or Campylobacter spp. on the basis of isolation of organisms from faecal samples on media containing 1 mg.l -1 FQ. The use of FQ was the most important factor associated with finding resistant E. coli and/or Campylobacter, which were found on 79% (FQ-resistant E. coli) and 86% (FQ-resistant Campylobacter) of farms with a history of FQ use. However, resistant bacteria were also found on 19% (FQ-resistant E. coli) and 54% (FQ-resistant Campylobacter) of farms with no history of FQ use. For FQ-resistant E.

Aims:  To estimate the proportions of farms on which broilers, turkeys and pigs were shedding fluoroquinolone (FQ)‐resistant Escherichia coli or Campylobacter spp. near to slaughter. Methods and Results:  Freshly voided faeces were collected on 89 poultry and 108 pig farms and cultured with media containing 1·0 mg l−1 ciprofloxacin. Studies demonstrated the specificity of this sensitive method, and both poultry and pig sampling yielded FQ‐resistant E. coli on 60% of farms. FQ‐resistant Campylobacter spp. were found on around 22% of poultry and 75% of pig farms. The majority of resistant isolates of Campylobacter (89%) and E. coli (96%) tested had minimum inhibitory concentrations for ciprofloxacin of ≥8 mg l−1. The proportion of resistant E. coli and Campylobacter organisms within samples varied widely. Conclusions:  FQ resistance is commonly present among two enteric bacterial genera prevalent on pig and poultry farms, although the low proportion of resistant organisms in many cases requires a sensitive detection technique. Significance and Impact of the Study:  FQ‐resistant bacteria with zoonotic potential appear to be present on a high proportion of UK pig and poultry farms. The risk this poses to consumers relative to other causes of FQ‐resistant human infections remains to be clarified.

Data on husbandry practices, performance, disease and drug use were collected during a cross-sectional survey of 89 poultry meat farms in England and Wales to provide information on possible risk factors for the occurrence of fluoroquinolone (FQ)-resistant bacteria. Faeces samples were used to classify farms as "affected" or "not affected" by FQ-resistant (FQr) Escherichia coli or Campylobacter spp. Risk factor analysis identified the use of FQ on the farms as having by far the strongest association, among the factors considered, with the occurrence of FQr bacteria. Resistant E. coli and/or Campylobacter spp. were found on 86% of the farms with a history of FQ use. However, a substantial proportion of farms with no history of FQ use also yielded FQr organisms, suggesting that resistant bacteria may transfer between farms. Further analysis suggested that for Campylobacter spp., on-farm hygiene, cleaning and disinfection between batches of birds and wildlife control were of most significance. By contrast, for E. coli biosecurity from external contamination was of particular importance, although the modelling indicated that other factors were likely to be involved. Detailed studies on a small number of sites showed that FQr E. coli can survive routine cleaning and disinfection. It appears difficult to avoid the occurrence of resistant bacteria when FQ are used on a farm, but the present findings provide evidence to support recommendations to reduce the substantial risk of the incidental acquisition of such resistance by farms where FQ are not used.

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008

No abstract