Detection of Campylobacter species in different types of samples from dairy farms.

BACKGROUND: Livestock, domestic pets and wildlife can be intestinal carriers of thermotolerant Campylobacter species. These reservoirs can in turn contaminate the environment and food products, thus creating pathways to campylobacteriosis in human beings. The purposes of this study were to investigate sampling strategies applied for surveillance of Campylobacter on dairy cattle farms and to identify the presence and species of Campylobacter in different age groups. METHODS: Boot sock and faecal samples were collected from five dairy herds from three age groups-cows, heifers and calves younger than 12 months-and from milk filters. RESULTS: Campylobacter species were isolated in 152 of 250 samples, of which 93 isolates were identified as C jejuni, 51 as C hyointestinalis, two as C lari and one as C coli, whereas five isolates could not be identified to species level. Campylobacter species were isolated from 86 of 110 faecal samples, 60 of 97 sock samples and six of 43 milk filter samples. CONCLUSION: Faecal samples were the optimal sample type for detection of Campylobacter on dairy farms. However, taking multiple types of samples could be recommended in order to optimise the recovery rate and variety of Campylobacter species detected when investigating the presence of Campylobacter on dairy farms.

Within-flock variations of Campylobacter loads in caeca and on carcasses from broilers.

The proportions of broiler caeca and carcass rinse samples positive for Campylobacter spp. within broiler flocks were determined. Twenty intact caeca per flock from 27 flocks were analyzed individually. Rinse samples were obtained from 5 to 25 carcasses from 27 other flocks. In total, 540 caecum samples and 445 carcass rinse samples were analyzed. The proportion of positive caeca within flocks ranged from 10 to 100%, and the proportion of positive carcasses ranged from 85 to 100%. The highest and lowest numbers of Campylobacter spp. found in positive caecum samples were 8.6 and 1.7log cfu/g caecal contents, respectively. The number of Campylobacter spp. in the caeca from individual broilers within a flock varied by up to 6.3log cfu/g caecal contents. The highest number found on one carcass was 4.2log cfu/ml carcass rinse sample, and the within-flock variation in Campylobacter spp. was up to 3.2log cfu/ml rinse sample. There was thus great variation in the load of Campylobacter spp. in individual caecum and carcass samples obtained from each positive broiler flock. This large variation in the numbers of Campylobacter spp. carried by individual birds should be considered when only one or a few samples are collected from a flock and the results are used for risk assessments.