Abstract

The consumption of fresh produce has led to increase in antibiotic-resistant (AR) Salmonella outbreaks. In this study, indigenous Salmonella was isolated from a total of two hundred-two samples including fresh produce and agricultural environmental samples in Korea. After biochemical confirmation using the Indole, Methyl Red, Voges-Proskauer, Citrate tests, presumable Salmonella isolates were identified by 16S rRNA sequencing. Identified Salmonella isolates were evaluated for antibiotic susceptibility against twenty-two antibiotics. The specificity and the efficiency of plating (EOP) of vB_SalS_KFSSM were evaluated against fifty-three bacterial strains. Twenty-five suspected Salmonella were isolated and confirmed by the positive result for methyl red and citrate, of which ten were identified as Salmonella spp. through 16S rRNA gene sequencing. Eight Salmonella isolates (4.0%, n = 8/202) were resistant to at least one antibiotic, among which five were multi-drug resistant. As a lytic phage against Salmonella spp. CMGS-1, vB_SalS_KFSSM was isolated from cow manure. The phage was observed as a tailed phage belonging to the class Caudoviricetes. It exhibited an intra-broad specificity against four indigenous AR Salmonella isolates, two indigenous Salmonella isolates, and five other Salmonella serotypes with great efficiencies (EOP ≥ 0.75). Thus, this study suggested the potential of vB_SalS_KFSSM to combat indigenous AR Salmonella.

中文翻译：

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本土抗生素耐药沙门氏菌分离株的流行及其在探索具有广泛特异性的裂解噬菌体 vB_SalS_KFSSM 中的应用

摘要

新鲜农产品的消费导致耐抗生素（AR）沙门氏菌爆发的增加。在这项研究中，从韩国总共 202 个样本中分离出了本土沙门氏菌，其中包括新鲜农产品和农业环境样本。使用吲哚、甲基红、Voges-Proskauer、柠檬酸盐测试进行生化确认后，通过 16S rRNA 测序鉴定出可能的沙门氏菌分离株。评估了鉴定的沙门氏菌分离株对 22 种抗生素的抗生素敏感性。针对 53 种细菌菌株评估了 vB_SalS_KFSSM 的特异性和铺板效率 (EOP)。经甲基红和柠檬酸盐阳性结果分离并证实了25 株疑似沙门氏菌，其中 10 株被鉴定为沙门氏菌属。通过16S rRNA基因测序。8 株沙门氏菌分离株（4.0%，n = 8/202）对至少一种抗生素具有耐药性，其中 5 株具有多重耐药性。作为针对沙门氏菌的裂解噬菌体。CMGS-1，vB_SalS_KFSSM 是从牛粪中分离出来的。观察到该噬菌体是属于Caudoviricetes纲的有尾噬菌体。它对四种本土 AR沙门氏菌分离株、两种本土沙门氏菌分离株和其他五种沙门氏菌血清型表现出广泛的特异性，且效率很高 (EOP ≥ 0.75)。因此，本研究表明 vB_SalS_KFSSM 对抗本土 AR沙门氏菌的潜力。