Fan Jianzhong, Zhang Linghong, He Jintao, Zhao Maoying, Loh Belinda, Leptihn Sebastian, Yu Yunsong, Hua Xiaoting
Department of Laboratory Medicine, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, China.
Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.
Front Microbiol. 2020 Dec 22;11:604710. doi: 10.3389/fmicb.2020.604710. eCollection 2020.
is an important food pathogen that can cause severe gastroenteritis with more than 600,000 deaths globally every year. Colistin (COL), a last-resort antibiotic, is ineffective in bacteria that carry a functional gene, which is often spread by conjugative plasmids. Our work aimed to understand the prevalence of the gene in clinical isolates of , as the frequency of occurrence of the gene is increasing globally. Therefore, we analyzed 689 clinical strains, that were isolated between 2009 and late 2018. The gene was found in six strains, which we analyzed in detail by whole genome sequencing and antibiotic susceptibility testing, while we also provide the clinical information on the patients suffering from an infection. The genomic analysis revealed that five strains had plasmid-encoded gene located in four IncHI2 plasmids and one IncI2 plasmid, while one strain had the chromosomal gene originated from plasmid. Surprisingly, in two strains the genes were inactive due to disruption by insertion sequences (ISs): IS and IS. A detailed analysis of the plasmids revealed a multitude of ISs, most commonly IS. The IS contained genes that meditate broad resistance toward most antibiotics underlining their importance of the mobile elements, also with respect to the spread of the gene. Our study revealed potential reservoirs for the transmission of COL resistance and offers insights into the evolution of the gene in .
是一种重要的食源性病原体，每年可在全球导致超过60万例严重肠胃炎死亡病例。黏菌素（COL）作为一种最后手段的抗生素，对携带功能性 基因的细菌无效，该基因通常通过接合质粒传播。我们的研究旨在了解 基因在临床分离株中的流行情况，因为该基因在全球的出现频率正在增加。因此，我们分析了2009年至2018年末分离的689株临床菌株。在6株菌株中发现了该基因，我们通过全基因组测序和抗生素敏感性测试对其进行了详细分析，同时我们还提供了感染患者的临床信息。基因组分析显示，5株菌株的质粒编码 基因位于4个IncHI2质粒和1个IncI2质粒中，而1株菌株的染色体 基因源自质粒。令人惊讶的是，在2株菌株中， 基因由于插入序列（ISs）的破坏而失活：IS 和IS。对质粒的详细分析揭示了大量的ISs，最常见的是IS。IS包含介导对大多数抗生素广泛耐药的基因，突出了它们作为移动元件的重要性，也涉及到 基因的传播。我们的研究揭示了COL耐药性传播的潜在储存库，并为 基因的进化提供了见解。
