<strong>Air samplings in a <em>Campylobacter jejuni</em> positive laying hen flock</strong>

Jochen Schulz 2,  
Institute for Animal Hygiene, Animal Welfare and Farm Animal Behaviour, University of Veterinary Medicine Hannover, Foundation, Germany; Department of Animal Hygiene and Zoonoses, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt
Institute for Animal Hygiene, Animal Welfare and Farm Animal Behaviour, University of Veterinary Medicine Hannover, Foundation, Germany
Ann Agric Environ Med 2013;20(1):16–20
The air in laying hen houses contains high concentrations of airborne bacteria. The numbers of these bacteria can be influenced by the efficiency of the chosen sampling method. In the presented study, AGI-30 Impingers and the Coriolis[sup]®[/sup]µ air Sampler were compared in terms of their efficiency in sampling aerobic mesophilic bacteria in a laying hen house. Measurements were conducted in a laying hen flock with high prevalences of [i]C. jejuni[/i] in order to investigate if culturable cells of this organism can also be detected by the applied methods. Airborne dust was also analyzed for the presence of [i]C. jejuni[/i] specific DNA to assess the possible occurrence of non-culturable [i]C. jejuni[/i] in the hen house air. The numbers of mesophilic airborne bacteria ranged from 8 × 10[sup]4[/sup] – 2 × 10[sup]6 [/sup] CFU/m[sup]-3[/sup] when sampled using AGI-30 Impingers, and from 2 × 10[sup]5[/sup] – 4 × 10[sup]6[/sup] CFU/m -3 when sampled using a Coriolis[sup]®[/sup]µ air Sampler. The concentrations detected simultaneously by both devices correlated well (r[sub]Pearson[/sub] = 0.755), but the Coriolis[sup]®[/sup]µ air Sampler showed a significantly higher sampling efficiency (p&amp;lt;0.001). Although, the within flock prevalence of [i]C. jejuni[/i] was high during the experiments (between 70-93%), neither of the air sampling methods could detect culturable [i]C. jejuni[/i] from the air. However,[i] C. jejuni [/i]specific DNA was detected in 15 out of 18 airborne dust samples by mapA PCR. Based on the results, it can be concluded that airborne culturable [i]C. jejuni[/i] were not detectable, even with an efficient air sampler, because of their low concentration. Therefore, the risk of airborne infection to poultry workers on inhaling airborne [i]C. jejuni[/i] seems negligible. Also, the transmission of culturable [i]C. jejuni[/i] to neighboring farms by the airborne route is unlikely. Otherwise, the detection of airborne [i]C. jejuni[/i] specific DNA suggests that non-culturable cells could appear in the hen house air, and in future it should be verified whether sampling stress of the air sampling methods could induce the non-culturable state.