Detection and Quantification of and spp. in Poultry Dust Using Real-Time PCR Under Experimental and Field Conditions.

Infection of poultry with spp., the causative agent of coccidiosis, can predispose birds to necrotic enteritis (NE) caused by gene-positive strains of . The detection of spp., and were examined in settled dust from broiler flocks under experimental and field conditions. Dust samples were collected from settle plates twice weekly from two experimental flocks inoculated with three species of pathogenic in 9-day-old chicks, followed by gene-positive 5 days later to produce subclinical and clinical NE. A noninoculated 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 wk of age; one scraped dust sample per flock). In the NE-subclinical and NE-clinical flocks, high levels of spp. and were detected after inoculation followed by a gradual decline over time. In the control flock, and were detected at low levels. No significant effect of sampling location was evident on spp, and load within poultry houses. These results provide evidence that spp., , and 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.