Department of Pharmacy, Southwest Hospital, Third Military Medical University, Chongqing 400038, China.
Department of Pulmonology, Southwest Hospital, Third Military Medical University, Chongqing 400038, China.
J Glob Antimicrob Resist. 2017 Mar;8:142-147. doi: 10.1016/j.jgar.2016.11.012. Epub 2017 Feb 12.
Pseudomonas aeruginosa is one of the most common pathogens causing nosocomial pneumonia. The aim of this study was to investigate the epidemiology and resistance of P. aeruginosa isolated from hospitalised patients in the respiratory department of a hospital in China.
Clinical isolates were collected from the respiratory department of Southwest Hospital (Chongqing, China) from January 2013 to December 2014. Patients' social and demographic information was obtained from the hospital's information system. Antimicrobial susceptibility was assessed using the agar dilution method. Screening for carbapenemase production among carbapenem-resistant P. aeruginosa was performed using the modified Hodge test and MBL Etest, and carbapenemase-encoding genes were amplified by PCR. Amplification and sequencing of the oprD gene were performed for carbapenem-resistant P. aeruginosa. Sequence types were determined by multilocus sequence typing (MLST).
A total of 92 P. aeruginosa isolates were collected from patients in the respiratory department, and piperacillin/tazobactam was the most effective antibiotic against these isolates. Multivariate analysis revealed that antibiotic use prior to admission was an independent risk factor for P. aeruginosa infection. The isolates comprised 25 genotypes, the most common of which were ST235 and ST111. The bla gene was present in 4 isolates and bla in 1 isolate among the 24 carbapenem-resistant isolates. Most of the carbapenem-resistant isolates contained mutational inactivation of the oprD gene.
These results suggested that patients and the hospital environment were sources of P. aeruginosa in nosocomial infections. Mutational inactivation of the oprD gene might be the main mechanism of carbapenem resistance.
铜绿假单胞菌是引起医院获得性肺炎的最常见病原体之一。本研究旨在调查中国某医院呼吸科住院患者分离的铜绿假单胞菌的流行病学和耐药情况。
临床分离株于 2013 年 1 月至 2014 年 12 月从重庆西南医院呼吸科采集。从医院信息系统获取患者的社会人口统计学信息。采用琼脂稀释法评估抗菌药物敏感性。采用改良 Hodge 试验和 MBL Etest 检测耐碳青霉烯类铜绿假单胞菌产碳青霉烯酶情况，PCR 扩增碳青霉烯酶基因。对耐碳青霉烯类铜绿假单胞菌进行 oprD 基因扩增和测序。采用多位点序列分型（MLST）确定序列型。
共从呼吸科住院患者中分离出 92 株铜绿假单胞菌，哌拉西林/他唑巴坦对这些分离株最有效。多变量分析显示，入院前使用抗生素是铜绿假单胞菌感染的独立危险因素。这些分离株包含 25 种基因型，最常见的是 ST235 和 ST111。24 株耐碳青霉烯类铜绿假单胞菌中有 4 株携带 bla 基因，1 株携带 bla 基因。大多数耐碳青霉烯类铜绿假单胞菌含有 oprD 基因突变失活。
这些结果表明，患者和医院环境是医院感染铜绿假单胞菌的来源。 oprD 基因突变失活可能是碳青霉烯类耐药的主要机制。
