Detection and quantification of Clostridium perfringens and Eimeria spp. in poultry dust using real-time PCR under experimental and field conditions

SUMMARY Infection of poultry with Eimeria spp., the causative agent of coccidiosis, can predispose birds to necrotic enteritis (NE), caused by netB gene-positive strains of Clostridium perfringens . The detection of Eimeria spp., C. perfringens and netB were examined in settled dust from broiler flocks under experimental and field conditions. Dust samples were collected using settle plates twice-weekly from two experimental flocks inoculated with three species of pathogenic Eimeria in 9 day old chicks, followed by netB gene positive C. perfringens 5 days later to produce subclinical and clinical NE. A non-inoculated flock was sampled weekly from day 0 and served as a control flock. An additional 227 dust samples from commercial broiler flocks were collected at the end-of-batch (6-7 weeks of age; 1 scraped dust sample/flock). In the NE-subclinical and NE-clinical flocks, high levels of Eimeria spp. and C. perfringens were detected after inoculation followed by a gradual decline over time. In the control flock, C. perfringens and netB were detected at low levels.. There was no significant effect of sampling location on Eimeria spp ., C. perfringens and netB load within poultry houses. These results provide evidence that Eimeria spp., C. perfringens and netB gene copies can be readily measured in poultry dust samples collected in settle plates and may provide an alternative sampling method for monitoring flock coccidiosis and NE status. Further studies are required to assess the utility for such a test in commercial flocks.