Optimising recovery of Campylobacter spp. from the lower porcine gastrointestinal tract.

To determine the incidence of campylobacters in Northern Ireland pigs, ileal contents and anal swabs were taken shortly after death. Direct streaking onto Preston agar, and modified charcoal cefoperazone desoxycholate agar (mCCDA), were compared, as was enrichment in selective broths prior to streaking onto the corresponding solid medium. For anal swabs direct plating on mCCDA was most efficient, with 100% of samples positive, whilst for ileal contents enrichment in mCCD broth was best with 86% of samples positive. Although only 34% of ileal samples enriched in Preston broths were positive they yielded three species not isolated from mCCD broth, and hence indicated that some pigs were infected by at least two species of Campylobacter. Overall, the number of samples found to contain campylobacters, and the range of species isolated, was seen to be markedly affected by both the choice of selective medium and the isolation procedures.