呼吸重症患者及环境中铜绿假单胞菌分子流行病学调查

Molecular epidemiological investigation of Pseudomonas aeruginosa in patientswith severe respiratory disease and environment

目的 探讨呼吸重症患者及环境中铜绿假单胞菌的耐药性情况,并对其进行分子流行病学调查。方法 收集2020—2022年西安市某医院分离的呼吸重症患者及环境中铜绿假单胞菌菌株进行药敏检测实验、耐药基因检测,并利用多位点序列分型技术(MLST)和脉冲场凝胶电泳(PFGE)技术对铜绿假单胞菌菌株进行同源性分析。结果 共收集994株铜绿假单胞菌菌株,其中668株样本来源于患者,占67.20%,环境样本为326株(32.80%)。药敏试验显示氨曲南和哌拉西林耐药率最高,超过30%;其次为亚胺培南(28.37%)和美罗培南(29.18%),哌拉西林/他唑巴坦、环丙沙星、左氧氟沙星、头孢他啶、头孢吡肟和头孢哌酮/舒巴坦耐药率为20%~30%,氨基糖苷类抗菌药物和脂肽类耐药率低于20%,其中以多粘菌素B(1.51%)最低。耐药基因测序结果显示,OprD2基因阳性率最高,为33.60%;其次为氨基糖苷类修饰酶aac(6’)-Ib(28.97%)和ant(3″)-I(27.16%)以及碳青霉烯酶基因blaIMP(22.64%)和ESBLs基因blaTEM(19.52%)。MLST分型分出31个STs分型,主要为ST235(38.53%)、ST244(31.09%)和ST298(12.68%)。PFGE分型分出A~Q共16个亚型,其中以A型(34.21%)和C型(21.33%)为主。结论 呼吸重症患者感染的铜绿假单胞菌菌株耐药情况较普遍,ST235和ST244为本地区主要流行克隆,针对性加强呼吸重症患者院感监测以及重症监护病房清洁,有利于控制铜绿假单胞菌的传播和流行。

Objective To explore the drug resistance of Pseudomonas aeruginosa in patients with severe respiratory disease and environment,and to conduct molecular epidemiological investigations on it.Methods The strains of Pseu⁃domonas aeruginosa isolated from patients with severe respiratory disease and the environment in a hospital in Xi'an from 2020 to 2022 were collected for drug sensitivity test and drug resistance gene detection,and the homology of Pseudomonas aeruginosa strains was analyzed by using multiple site sequence typing(MLST)and pulsed field gel electrophoresis(PFGE).Results A total of 994 strains of Pseudomonas aeruginosa were collected,of which 668 strains were from patients,accounting for 67.20%,and 326 strains(32.80%)were from environmental samples.The drug sensitivity test showed that the resistance rates to amitriptyline and piperacillin were the highest,exceeding 30%;Next were imipenem(28.37%)and meropenem(29.18%),with resistance rates to piperacillin/tazobactam,ciprofloxacin,levofloxacin,ceftazidime,cefepime,and cefoperazone/sulbactam all ranging from 20%to 30%.The resistance rates to aminoglycoside antibiotics and lipopeptides were below 20%,with polymyxin B(1.51%)being the lowest.The sequencing results of resistance genes showed that the positive rate of OprD2 gene was the highest,at 33.60%;Next were aminoglycoside modifying enzymes aac(6’)-Ib(28.97%)and ant(3")-I(27.16%),as well as the carbapenem enzyme gene blaIMP(22.64%)and ESBLs gene blaTEM(19.52%).Thirty‐one STs types were classified by MLST,mainly ST235(38.53%),ST244(31.09%),and ST298(12.68%).The PFGE typing result identified a total of 16 subtypes from A to Q,with type A(34.21%)and type C(21.33%)being the main subtypes. Conclusions Drug resistance of Pseudomonas aeruginosastrains is common in patients with severe respiratory disease,with ST235 and ST244 being the main prevalent clones in thelocal area. Targeted strengthening of hospital infection monitoring for patients with severe respiratory disease and cleaningof the intensive care unit is beneficial for controlling the spread and prevalence of Pseudomonas aeruginosa.