Antimicrobial resistance (AMR) developed by Salmonella within animals used for food products is a major global issue. Monitoring AMR in animals destined for slaughter is, therefore, critical. Abattoirs may serve as potential candidate checkpoints for monitoring resistance patterns on farms. A complicating factor, however, is the impact of lairage on Salmonella detected in pigs at slaughter. This study sought to compare AMR patterns in Salmonella spp. in swine collected upon arrival (fecal samples) at the abattoir with those at postslaughter (cecal samples) and evaluate the feasibility of using slaughterhouse samples for surveillance of prevailing AMR Salmonella on farms. Eighty-four Salmonella isolates were recovered from a large, midwestern U.S. abattoir between September and November 2013. Isolates were tested for phenotypic AMR to 12 antimicrobials using the broth microdilution assay. Whole-genome sequencing identified the AMR genes harbored by the strains. Significant differences were observed in the isolate phenotypes and genotypes; however, no significant difference was observed in genotypic resistance patterns. Hence, the AMR profiles of Salmonella spp. postslaughter cannot be predicted from preslaughter samples. Further research considering the genetic diversity of isolates and statistical power of the genotypic analysis is warranted to improve the performance of WGS-inferred antimicrobial susceptibility.

中文翻译：

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沙门氏菌中抗菌素耐药性的比较。来自到达屠宰场的猪和屠宰后的猪

沙门氏菌在用于食品的动物体内产生的抗菌素耐药性 (AMR)是一个主要的全球问题。因此，监测拟屠宰的动物的 AMR 至关重要。屠宰场可以作为潜在的候选检查站，用于监测农场的耐药性模式。然而，一个复杂的因素是围栏对屠宰猪中检测到的沙门氏菌的影响。本研究旨在比较沙门氏菌属中的AMR 模式。在到达屠宰场时收集的猪（粪便样本）与屠宰后收集的猪（盲肠样本）进行分析，并评估使用屠宰场样本监测农场流行的 AMR沙门氏菌的可行性。八十四沙门氏菌2013 年 9 月至 11 月期间，从美国中西部的一家大型屠宰场回收了分离株。使用肉汤微量稀释法测试了分离株对 12 种抗菌剂的表型 AMR。全基因组测序鉴定了菌株携带的 AMR 基因。在分离物表型和基因型中观察到显着差异；然而，在基因型抗性模式中没有观察到显着差异。因此，沙门氏菌属的 AMR 配置文件。不能从屠宰前样本预测屠宰后的情况。考虑到分离株的遗传多样性和基因型分析的统计功效，有必要进行进一步研究，以提高 WGS 推断的抗菌药物敏感性的性能。