Roman L. Hruska U.S. Meat Animal Research Center, Agricultural Research Service, U.S. Department of Agriculture, Clay Center , Nebraska.
Foodborne Pathog Dis. 2017 Dec;14(12):687-695. doi: 10.1089/fpd.2017.2319. Epub 2017 Oct 16.
In the beef industry, product contamination by Salmonella enterica is a serious public health concern, which may result in human infection and cause significant financial loss due to product recalls. Currently, the precise mechanism and pathogen source responsible for Salmonella contamination in commercial establishments are not well understood. We characterized 89 S. enterica strains isolated from beef trim with respect to their biofilm-forming ability, antimicrobial resistance, and biofilm cell survival/recovery growth after sanitizer exposure. A total of 28 Salmonella serovars was identified within these strains. The most common serovars identified were Anatum, Dublin, Montevideo, and Typhimurium, with these accounting for nearly half of the total strains. The vast majority (86%) of the strains was able to develop strong biofilms, and the biofilm-forming ability was highly strain dependent and related to cell surface expression of extracellular polymeric structures. These strains also demonstrated strong tolerance to quaternary ammonium chloride (QAC) and chlorine dioxide (ClO), but were more sensitive to chlorine treatment. Sanitizer tolerance and bacterial postsanitization recovery growth were closely associated with strains' biofilm-forming ability. Thirty percent of the examined strains were found resistant to multiple antimicrobial agents and the resistance phenotypes were serovar associated, but not related to strains' biofilm-forming ability. Pulsed-field gel electrophoresis analysis tended to group strains by serovar rather than by biofilm-forming ability. Collectively, these data indicate that the strong biofilm formers of certain S. enterica strains/serovars possess significant potential for causing meat product contamination in meat processing environment.
在牛肉行业，沙门氏菌污染产品是一个严重的公共卫生问题，可能导致人类感染，并因产品召回而造成重大经济损失。目前，商业场所中沙门氏菌污染的确切机制和病原体来源还不是很清楚。我们对从牛肉切块中分离出的 89 株沙门氏菌进行了研究，研究内容包括其生物膜形成能力、抗菌药物耐药性以及消毒剂暴露后的生物膜细胞存活/恢复生长能力。在这些菌株中总共鉴定出 28 种沙门氏菌血清型。最常见的血清型包括安纳托姆、都柏林、蒙得维的亚和肠炎沙门氏菌，这些血清型占总菌株的近一半。绝大多数（86%）的菌株能够形成强生物膜，且生物膜形成能力具有很强的菌株依赖性，并与细胞表面表达的细胞外聚合结构有关。这些菌株对季铵盐（QAC）和二氧化氯（ClO）也表现出很强的耐受性，但对氯处理更为敏感。消毒剂耐受性和细菌消毒后恢复生长与菌株的生物膜形成能力密切相关。30%的受检菌株对多种抗菌药物具有耐药性，耐药表型与血清型有关，但与菌株的生物膜形成能力无关。脉冲场凝胶电泳分析倾向于根据血清型而不是生物膜形成能力对菌株进行分组。总的来说，这些数据表明，某些沙门氏菌血清型/菌株的强生物膜形成能力具有在肉类加工环境中造成肉类产品污染的巨大潜力。
