Department of Microbiology, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.
BML Inc., Kawagoe, Saitama, Japan.
J Glob Antimicrob Resist. 2020 Dec;23:265-268. doi: 10.1016/j.jgar.2020.09.010. Epub 2020 Oct 9.
The aim of this study was to determine the genetic and epidemiological properties of Pseudomonas aeruginosa strains producing VIM-type metallo-β-lactamases isolated from patients in Japan.
A total of 1860 clinical isolates of carbapenem-resistant P. aeruginosa were obtained from patients hospitalised in Japan from 2012-2018. Carbapenem-resistant P. aeruginosa isolates were screened for bla genes by PCR. Antimicrobial susceptibility was determined by the broth microdilution method. The whole genomes of these isolates were sequenced using a next-generation sequencer, and phylogenetic analysis was performed using single nucleotide polymorphism concatemers. Multilocus sequence typing (MLST) was performed and drug resistance genes were identified using whole-genome sequence data.
Of 1860 isolates, 25 bla-positive isolates were screened in nine medical settings in Japan. The population of VIM-producing P. aeruginosa significantly increased between 2012 and 2018. All 25 bla-positive isolates were resistant to imipenem, meropenem and ciprofloxacin but were susceptible to colistin. The isolates harboured bla, bla, bla, bla or the novel variant bla and belonged to four different sequence types (STs), including ST179, ST233, ST235 and ST1816. The 11 isolates harbouring bla, bla or bla were obtained from a single hospital, all belonging to ST1816. VIM-24, VIM-60 and VIM-66 had an amino acid substitution (Arg228Leu) compared with VIM-2.
The number of P. aeruginosa strains producing VIM-type MBLs has increased in medical settings in Japan. Pseudomonas aeruginosa ST1816 producing VIM enzymes with Arg228Leu substitution have emerged and evolved in a medical setting in Japan.
本研究旨在确定从日本患者中分离出的产 VIM 型金属β-内酰胺酶的铜绿假单胞菌菌株的遗传和流行病学特性。
从 2012 年至 2018 年在日本住院的患者中获得了 1860 株碳青霉烯类耐药铜绿假单胞菌的临床分离株。通过 PCR 筛选碳青霉烯类耐药铜绿假单胞菌分离株中的 bla 基因。采用肉汤微量稀释法测定抗菌药物敏感性。使用下一代测序仪对这些分离株的全基因组进行测序，并使用单核苷酸多态性串联进行系统发育分析。采用多位点序列分型（MLST）并使用全基因组序列数据鉴定耐药基因。
在日本的九个医疗机构中，从 1860 株分离株中筛选出 25 株 bla 阳性分离株。产 VIM 型铜绿假单胞菌的流行率在 2012 年至 2018 年间显著增加。所有 25 株 bla 阳性分离株均对亚胺培南、美罗培南和环丙沙星耐药，但对黏菌素敏感。这些分离株携带 bla、bla、bla、bla 或新型 bla 基因，属于四个不同的序列型（ST），包括 ST179、ST233、ST235 和 ST1816。携带 bla、bla 或 bla 的 11 株分离株来自一家医院，均属于 ST1816。与 VIM-2 相比，VIM-24、VIM-60 和 VIM-66 的氨基酸取代（Arg228Leu）。
在日本的医疗机构中，产 VIM 型 MBL 的铜绿假单胞菌菌株数量有所增加。具有 Arg228Leu 取代的产 VIM 酶的铜绿假单胞菌 ST1816 已在日本的医疗机构中出现并演变。
