We evaluated the combination of immunomagnetic separation (IMS), multiple displacement amplification (MDA), and real-time PCR to detect Salmonella from poultry environmental samples. The limits of detection (LODs) of IMS-MDA real-time PCR with different culture enrichment hours (0, 4, 6, and 8 h) were determined in artificially inoculated litter samples from a specific pathogen-free (SPF) poultry farm. In addition, Salmonella detection rate of IMS-MDA real-time PCR with 8-h culture enrichment was compared with that of conventional real-time PCR and culture-based detection by analyzing 174 poultry environmental samples (boot swabs, drag swabs, and litter), and the levels of Salmonella in the samples were quantified using the most probably number method. The LODs of IMS-MDA real-time PCR with 0, 4 to 6, and 8-h enrichment were 10, 1, and 0.1 CFU/g, respectively. Salmonella was detected in 25 of the 174 environmental samples (14.4%) by IMS-MDA real-time PCR, compared with 24 (13.8%) by conventional real-time PCR and 19 (10.9%) by culturing. Cohen's kappa index indicated strong concordance (0.79) between IMS-MDA real-time PCR and culture detection. We demonstrated the potential of the IMS-MDA real-time PCR assay as a faster and more sensitive alternative to culture-based Salmonella detection from poultry environmental samples.

中文翻译：

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使用实时 PCR 结合免疫磁性分离和全基因组扩增快速检测家禽环境样品中的沙门氏菌。

我们评估了免疫磁分离 (IMS)、多重置换扩增 (MDA) 和实时 PCR 的组合，以检测家禽环境样品中的沙门氏菌。在来自特定无病原体 (SPF) 家禽场的人工接种垫料样品中确定了不同培养富集时间（0、4、6 和 8 小时）的 IMS-MDA 实时 PCR 的检测限 (LOD)。此外，通过分析 174 份家禽环境样本（靴拭子、拖曳拭子和垫料），比较了 IMS-MDA 实时 PCR 和 8 小时培养富集的沙门氏菌检测率与传统实时 PCR 和基于培养的检测的检测率。 )，并使用最可能数字法对样品中的沙门氏菌水平进行量化。富集 0、4 到 6 和 8 小时的 IMS-MDA 实时 PCR 的 LOD 分别为 10、1 和 0.1 CFU/g，分别。IMS-MDA 实时荧光定量 PCR 在 174 个环境样品中的 25 个（14.4%）中检测到沙门氏菌，而传统实时荧光定量 PCR 为 24 个（13.8%），培养为 19 个（10.9%）。Cohen 的 kappa 指数表明 IMS-MDA 实时 PCR 和培养物检测之间的高度一致性 (0.79)。我们证明了 IMS-MDA 实时 PCR 检测作为一种更快、更灵敏的替代方法来替代家禽环境样本中基于培养的沙门氏菌检测的潜力。