Ahmed Marwa Fawzy El Metwaly, Schulz Jochen, Hartung Joerg
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(®)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 C. jejuni 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 C. jejuni specific DNA to assess the possible occurrence of non-culturable C. jejuni in the hen house air. The numbers of mesophilic airborne bacteria ranged from 8 × 10(4) - 2 × 10(6) CFU/m(-3) when sampled using AGI-30 Impingers, and from 2 × 10(5) - 4 × 10(6) CFU/m -3 when sampled using a Coriolis(®)µ air Sampler. The concentrations detected simultaneously by both devices correlated well (rPearson = 0.755), but the Coriolis(®)µ air Sampler showed a significantly higher sampling efficiency (p<0.001). Although, the within flock prevalence of C. jejuni was high during the experiments (between 70-93%), neither of the air sampling methods could detect culturable C. jejuni from the air. However, C. jejuni 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 C. jejuni 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 C. jejuni seems negligible. Also, the transmission of culturable C. jejuni to neighboring farms by the airborne route is unlikely. Otherwise, the detection of airborne C. jejuni 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.
蛋鸡舍空气中含有高浓度的空气传播细菌。这些细菌的数量会受到所选采样方法效率的影响。在本研究中，对AGI - 30冲击式采样器和科里奥利（®）µ空气采样器在蛋鸡舍中对需氧嗜温细菌的采样效率进行了比较。在空肠弯曲菌高流行率的蛋鸡群中进行了测量，以调查应用这些方法是否也能检测到该生物体的可培养细胞。还对空气传播的灰尘进行了空肠弯曲菌特异性DNA检测，以评估蛋鸡舍空气中可能存在的不可培养空肠弯曲菌。使用AGI - 30冲击式采样器采样时，嗜温空气传播细菌的数量范围为8×10⁴ - 2×10⁶CFU/m⁻³，使用科里奥利（®）µ空气采样器采样时，数量范围为2×10⁵ - 4×10⁶CFU/m⁻³。两种设备同时检测到的浓度相关性良好（皮尔逊r = 0.755），但科里奥利（®）µ空气采样器显示出显著更高的采样效率（p<0.001）。尽管在实验期间鸡群中空肠弯曲菌的流行率很高（70 - 93%），但两种空气采样方法均未从空气中检测到可培养的空肠弯曲菌。然而，通过mapA PCR在18个空气传播灰尘样本中的15个中检测到了空肠弯曲菌特异性DNA。根据结果可以得出结论，由于空肠弯曲菌浓度低，即使使用高效空气采样器也无法检测到空气传播的可培养空肠弯曲菌。因此，家禽工人吸入空气传播的空肠弯曲菌而导致空气传播感染的风险似乎可以忽略不计。此外，可培养的空肠弯曲菌通过空气传播途径传播到邻近农场的可能性也不大。否则，空气传播的空肠弯曲菌特异性DNA的检测表明，不可培养的细胞可能出现在蛋鸡舍空气中，未来应验证空气采样方法的采样压力是否会诱导出不可培养状态。
