In Australia, cases of shigellosis usually occur in returned travelers from regions of shigellosis endemicity or in men who have sex with men. Resistance to multiple antibiotics has significantly increased in Shigella sonnei isolates and represents a significant public health concern. We investigate an outbreak of multidrug-resistant S. sonnei in Victoria, Australia. We undertook whole-genome sequencing of 54 extended-spectrum-beta-lactamase (ESBL)-producing S. sonnei isolates received at the Microbiological Diagnostic Unit Public Health Laboratory between January 2019 and March 2020. The population structure and antimicrobial resistance profiles were identified by genomic analyses, with 73 previously characterized Australian S. sonnei isolates providing context. Epidemiological data, including age and sex of the shigellosis cases, were also collected. There was a significant increase in cases of ESBL S. sonnei from July 2019. Most of the ESBL S. sonnei isolates (65%) fell within a single cluster that was predominantly comprised of male cases that were characterized by the presence of the bla_CTX-M-27 gene conferring resistance to extended-spectrum cephalosporins. These isolates were also multidrug resistant, including resistance to azithromycin and co-trimoxazole and reduced susceptibility to ciprofloxacin. Our data uncovered a prolonged clonal outbreak of ESBL S. sonnei infection that was likely first introduced by returned travelers and has subsequently been circulating locally in Australia. The emergence of a local outbreak of ESBL S. sonnei with a multidrug-resistant profile, including reduced susceptibility to ciprofloxacin, represents a significant public health threat.

中文翻译：

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在澳大利亚维多利亚州携带blaCTX-M-27的耐多药志贺氏菌长时间爆发

在澳大利亚，患有志贺菌病的病例通常发生在来自志贺菌病流行地区的返回旅行者中或与男性发生性关系的男性中。猪痢疾志贺氏菌分离物中对多种抗生素的耐药性显着提高，这代表了重大的公共卫生问题。我们调查了澳大利亚维多利亚州多药耐药的S. sonnei疫情。我们对微生物诊断单位公共卫生实验室于2019年1月至2020年3月间收到的54株广谱β-内酰胺酶（ESBL）产的S. sonnei菌株进行了全基因组测序。通过以下方法鉴定了种群结构和抗菌素耐药性基因组分析，其中73种以前表征为澳大利亚S. sonnei隔离提供上下文。还收集了流行病学数据，包括志贺菌病病例的年龄和性别。自2019年7月起，ESBL S. sonnei病例显着增加。大多数ESBL s。onnene分离株（65％）属于单个簇，主要由以bla _CTX为特征的男性病例组成_-M-27基因赋予对广谱头孢菌素的抗性。这些分离株也具有多药耐药性，包括对阿奇霉素和复方新诺明的耐药性以及对环丙沙星的敏感性降低。我们的数据揭示了ESBL S. sonnei的长期克隆爆发感染很可能最初是由返回的旅行者引入的，随后在澳大利亚本地传播。具有多药耐药性的当地ESBL S. sonnei暴发的出现，包括对环丙沙星的敏感性降低，对公众健康构成重大威胁。