Emerg Infect Dis. 2022 Jul;28(7):1410-1420. doi: 10.3201/eid2807.211528.
Extended-spectrum β-lactamases (ESBLs) confer resistance to extended-spectrum cephalosporins, a major class of clinical antimicrobial drugs. We used genomic analysis to investigate whether domestic food animals, retail meat, and pets were reservoirs of ESBL-producing Salmonella for human infection in Canada. Of 30,303 Salmonella isolates tested during 2012-2016, we detected 95 ESBL producers. ESBL serotypes and alleles were mostly different between humans (n = 54) and animals/meat (n = 41). Two exceptions were bla and bla IncI1 plasmids which were found in both sources. A subclade of S. enterica serovar Heidelberg isolates carrying the same IncI1-bla plasmid differed by only 1-7 single nucleotide variants. The most common ESBL producer in humans was Salmonella Infantis carrying bla, which has since emerged in poultry in other countries. There were few instances of similar isolates and plasmids, suggesting that domestic animals and retail meat might have been minor reservoirs of ESBL-producing Salmonella for human infection.
扩展谱β-内酰胺酶（ESBLs）使细菌对头孢菌素类广谱抗生素产生耐药性，而头孢菌素类抗生素是临床应用的主要抗菌药物之一。本研究运用基因组分析方法，探究在加拿大，食源性动物、零售肉品和宠物是否为人类感染 ESBL 耐药性沙门氏菌的储主。在 2012 年至 2016 年期间检测了 30303 株沙门氏菌，其中发现了 95 株 ESBL 耐药性沙门氏菌。人类（n=54）和动物/肉品（n=41）来源的 ESBL 血清型和耐药基因存在明显差异。有两个例外，即 bla 和 bla IncI1 质粒，这两种物质在两个来源中均有发现。携带相同 IncI1-bla 质粒的肠炎沙门氏菌亚群的单核苷酸变异仅为 1-7 个。人类中最常见的 ESBL 耐药性沙门氏菌是携带 bla 的肠炎沙门氏菌，该菌已在其他国家的家禽中出现。相似的分离株和质粒较为少见，这表明食源性动物和零售肉品可能是人类感染 ESBL 耐药性沙门氏菌的次要储主。
