Nüesch-Inderbinen Magdalena, Biggel Michael, Haussmann Adrian, Treier Andrea, Heyvaert Lore, Cernela Nicole, Stephan Roger
Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
Department of Veterinary and Biosciences, Faculty of Veterinary Medicine, University of Ghent, Ghent, Belgium.
Front Microbiol. 2023 Jun 14;14:1150070. doi: 10.3389/fmicb.2023.1150070. eCollection 2023.
Linezolid is a critically important oxazolidinone antibiotic used in human medicine. Although linezolid is not licensed for use in food-producing animals, the use of florfenicol in veterinary medicine co-selects for oxazolidinone resistance genes.
This study aimed to assess the occurrence of , and in florfenicol-resistant isolates from beef cattle and veal calves from different herds in Switzerland.
A total of 618 cecal samples taken from beef cattle and veal calves at slaughter originating from 199 herds were cultured after an enrichment step on a selective medium containing 10 mg/L florfenicol. Isolates were screened by PCR for , and which are genes known to confer resistance to oxazolidinones and phenicols. One isolate per PCR-positive species and herd was selected for antimicrobial susceptibility testing (AST) and whole-genome sequencing (WGS).
Overall, 105 florfenicol-resistant isolates were obtained from 99 (16%) of the samples, corresponding to 4% of the beef cattle herds and 24% of the veal calf herds. Screening by PCR revealed the presence of in 95 (90%) and in 22 (21%) of the isolates. None of the isolates contained . Isolates included for AST and WGS analysis were (.) ( = 14), ( = 12), ( = 1), ( = 2), ( = 1), (.) ( = 2), (.) ( = 1), and (.) ( = 1). Thirteen isolates exhibited phenotypic linezolid resistance. Three novel OptrA variants were identified. Multilocus sequence typing identified four ST18 belonging to hospital-associated clade A1. There was a difference in the replicon profile among and -harboring plasmids, with rep9 (RepA_) plasmids dominating in -harboring and rep2 (Inc18) and rep29 (Rep_3) plasmids in -carrying .
Beef cattle and veal calves are reservoirs for enterococci with acquired linezolid resistance genes and . The presence of ST18 highlights the zoonotic potential of some bovine isolates. The dispersal of clinically relevant oxazolidinone resistance genes throughout a wide variety of species including spp., , and the probiotic in food-producing animals is a public health concern.
利奈唑胺是一种在人类医学中使用的极其重要的恶唑烷酮类抗生素。尽管利奈唑胺未被批准用于食用动物，但兽用氟苯尼考的使用会共同选择恶唑烷酮耐药基因。
本研究旨在评估瑞士不同牛群的肉牛和犊牛中耐氟苯尼考分离株中[具体基因名称缺失]的发生情况。
从199个牛群的肉牛和犊牛屠宰时采集的618份盲肠样本，在含有10mg/L氟苯尼考的选择性培养基上进行富集培养后进行培养。通过PCR对分离株进行筛选，以检测[具体基因名称缺失]，这些基因已知可赋予对恶唑烷酮类和酚类的耐药性。每个PCR阳性物种和牛群选择一个分离株进行药敏试验（AST）和全基因组测序（WGS）。
总体而言，从99个（16%）样本中获得了105株耐氟苯尼考分离株，分别对应4%的肉牛群和24%的犊牛群。PCR筛选显示95株（90%）分离株中存在[具体基因名称缺失]，22株（21%）中存在[具体基因名称缺失]。所有分离株均未含有[具体基因名称缺失]。纳入AST和WGS分析的分离株有[具体菌种名称及数量缺失]。13株分离株表现出对利奈唑胺的表型耐药性。鉴定出三种新型OptrA变体。多位点序列分型鉴定出四个属于医院相关进化枝A1的屎肠球菌ST18。携带[具体基因名称缺失]和[具体基因名称缺失]的质粒在复制子图谱上存在差异，携带[具体基因名称缺失]的质粒中rep9（RepA_）质粒占主导，携带[具体基因名称缺失]的质粒中rep2（Inc18）和rep29（Rep_3）质粒占主导。
肉牛和犊牛是获得利奈唑胺耐药基因[具体基因名称缺失]和[具体基因名称缺失]的肠球菌的储存宿主。屎肠球菌ST18的存在凸显了一些牛分离株的人畜共患病潜力。临床相关的恶唑烷酮耐药基因在包括[具体菌种名称缺失]、[具体菌种名称缺失]和食用动物中的益生菌[具体菌种名称缺失]等多种物种中的传播是一个公共卫生问题。
