Institute of Food Safety and Food Hygiene, Freie Universität Berlin, Königsweg 69, 14163 Berlin, Germany.
Institute of Food Safety and Food Hygiene, Freie Universität Berlin, Königsweg 69, 14163 Berlin, Germany.
Int J Food Microbiol. 2018 Sep 20;281:82-89. doi: 10.1016/j.ijfoodmicro.2018.05.022. Epub 2018 May 25.
Food producing animals are considered a reservoir for Extended-spectrum beta-lactamase (ESBL) and AmpC beta-lactamase (AmpC) producing Enterobacteriaceae. Therefore, meat is discussed to be a potential source for the transmission of these resistant bacteria to humans. There is only limited information about the quantitative load of ESBL-/AmpC-producing Enterobacteriaceae in different sample matrices during slaughter and their distribution in the slaughterhouse environment. Therefore, the aim of this study was to determine the prevalence as well as quantitative load of ESBL-/AmpC-producing Enterobacteriaceae in caecum, skin and filet samples of different broiler chicken flocks during slaughter in Germany. In addition, environmental samples were taken during slaughter of the respective flocks. To gain insights into possible transmission routes of ESBL-/AmpC-producing Enterobacteriaceae, the corresponding phylogroup and beta-lactamase genes were determined for selected isolates. ESBL-/AmpC-producing Enterobacteriaceae were detected during slaughter of all seven investigated flocks. On average, 47% (83/175) of caecum, 55% (96/175) of skin, 28% (49/175) of filet and 28% (25/89) of environmental samples harboured ESBL-/AmpC-producing Enterobacteriaceae. Prevalence varied widely between the flocks as well as between the different sample matrices. In about half of the caecum (23/40) and skin (19/40) samples as well as 85% (17/20) of the filet samples, the number of putative ESBL-/AmpC-producing Enterobacteriaceae (cefotaxime resistant Enterobacteriaceae) was below quantification limit. The median of cefotaxime resistant Enterobacteriaceae was 2.5 × 10 cfu/g in caecum, 1.5 × 10 cfu/g in skin and 1.5 × 10 cfu/g in filet samples. The median of cefotaxime resistant Enterobacteriaceae was, depending on the sample matrix, 1-4 log units below the median of total Enterobacteriaceae. Using real-time PCR, in 82% (629/767) of the cefotaxime resistant Enterobacteriaceae at least one of the investigated beta-lactamase genes bla, bla, bla, bla was detected. The respective resistance genes of 322 isolates were further sequenced. The predominant bla-gene was bla (48%), followed by bla (23%). A contamination from the broiler chicken to the slaughterhouse environment and vice versa seems probable as isolates of the same species and phylogroup, encoding the same resistance genes were detected in all matrices during slaughter of the respective flock as well as in the slaughterhouse environment.
食用动物被认为是产生超广谱β-内酰胺酶（ESBL）和AmpCβ-内酰胺酶（AmpC）的肠杆菌科的储库。因此，肉类被认为是这些耐药菌传播给人类的潜在来源。关于屠宰过程中不同样本基质中ESBL-/AmpC 产生肠杆菌科的定量负荷及其在屠宰场环境中的分布，只有有限的信息。因此，本研究的目的是确定在德国屠宰期间不同肉鸡群盲肠、皮肤和肉片样本中 ESBL-/AmpC 产生肠杆菌科的流行率和定量负荷。此外，还在屠宰相应鸡群时采集了环境样本。为了深入了解 ESBL-/AmpC 产生肠杆菌科的可能传播途径，我们对选定的分离株进行了相应的系统发育群和β-内酰胺酶基因的测定。在所有 7 个研究鸡群的屠宰过程中均检测到 ESBL-/AmpC 产生肠杆菌科。平均而言，盲肠（83/175）、皮肤（96/175）、肉片（49/175）和环境样本（25/89）分别有 47%、55%、28%和 28%携带 ESBL-/AmpC 产生肠杆菌科。各鸡群之间以及不同样本基质之间的流行率差异很大。在约一半的盲肠（23/40）和皮肤（19/40）样本以及 85%（17/20）的肉片样本中，推定的 ESBL-/AmpC 产生肠杆菌科（头孢噻肟耐药肠杆菌科）的数量低于定量限。盲肠中头孢噻肟耐药肠杆菌科的中位数为 2.5×10cfu/g，皮肤中为 1.5×10cfu/g，肉片中为 1.5×10cfu/g。根据样本基质的不同，头孢噻肟耐药肠杆菌科的中位数比总肠杆菌科的中位数低 1-4 个对数单位。使用实时 PCR，在 767 个头孢噻肟耐药肠杆菌科中，82%（629/767）至少检测到一种研究的β-内酰胺酶基因 bla、bla、bla、bla。对 322 个分离株的相应耐药基因进行了测序。主要的 bla 基因是 bla（48%），其次是 bla（23%）。从肉鸡到屠宰场环境的污染和反之亦然似乎是可能的，因为在各自鸡群屠宰过程中以及屠宰场环境中所有基质中都检测到相同物种和系统发育群的分离株，并且编码相同的耐药基因。
