Investigation of the molecular epidemiology of Acinetobacter baumannii isolated from patients and environmental contamination
Investigation of the molecular epidemiology of Acinetobacter baumannii isolated from patients and environmental contamination
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患者分离鲍曼不动杆菌及环境污染的分子流行病学调查
DOI：
10.1038/ja.2015.30
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发表时间：
2015-09-01
影响因子：
3.3
通讯作者：
Yang, Chengde
中科院分区：
文献类型：
--
作者：
Ying, Chunmei;Li, Yongli;Yang, Chengde
本研究的目的是探讨神经外科重症监护病房患者分离的鲍曼不动杆菌与其环境之间的相关性。这是一项前瞻性、观察性研究。采用琼脂稀释法测定了27株临床分离菌和28株环境分离菌的最低抑菌浓度。采用肠杆菌重复基因间共有序列PCR（ERIC-PCR）、脉冲场凝胶电泳（PFGE）和多位点序列分型（MLST）进行基因分型。通过特异性PCR和DNA测序分析碳青霉烯酶和金属-β-内酰胺酶基因的存在。从临床A.鲍曼不动杆菌对米诺环素耐药率为25.9%，对头孢哌酮-舒巴坦耐药率为51.9%，对亚胺培南耐药率为59.3%，对其他抗菌药物耐药率为70%。环境分离株的敏感性高于临床分离株（P< 0.05）。27株临床分离株包括3种ERIC-PCR基因型、4种主要PFGE脉冲型和5种不同MLST序列型（ST 208、ST 368、ST 191、ST 195、ST 540），均属于CC 92，只有1个位点（gpi）不同。28株环境分离株的基因型比临床分离株的基因型更为多样，包括6个ERIC-PCR群、9个PFGE群和2个主要ST（ST 208、ST 229）。4个临床和15个环境分离株无法通过MLST鉴定，并被分配到非克隆ST。我们在大多数临床分离株（21/27）中发现了bla OXA-23碳青霉烯酶编码基因的存在，但在环境分离株中发现的较少（3/28）。助理从患者分离的鲍曼不动杆菌菌株与环境菌株在遗传上相似，以CC 92成员为主要部分，但具有不同的抗生素敏感性。
The objective of this work was to investigate correlations between Acinetobacter baumannii isolates from neurosurgical intensive care unit patients and its environment. This is a prospective, observational study. The minimal inhibitory concentrations of antimicrobial agents against 27 clinical and 28 environmental isolates were determined by the agar dilution method. Molecular genotyping was performed by enterobacterial repetitive intergenic consensus PCR (ERIC-PCR), pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). The presence of carbapenemase and metallo-β-lactamase genes were analyzed by specific PCRs and DNA sequencing. From the clinical A. baumannii isolates, 25.9% were found resistant to minocycline, 51.9% to cefoperazone-sulbactam, 59.3% to imipenem and 70% resistant to other antimicrobial agents. Environmental isolates were more sensitive compared with clinical isolates (P< 0.05). Twenty-seven clinical isolates comprised three ERIC-PCR genotypes, four major PFGE pulsotypes and five distinct MLST sequence types (STs)(ST208, ST368, ST191, ST195, ST540), all belonging to CC92 with only one locus (gpi) difference among them. Twenty-eight environmental isolates showed more diverse genetic types than clinical isolates and comprised six ERIC-PCR groups, nine PFGE groups and two main STs (ST208, ST229). Four clinical and 15 environmental isolates could not be identified by MLST and were assigned to non-clonal STs. We identified the presence of the bla OXA-23 carbapenemase encoding gene in most of the clinical (21/27) but fewer in the environmental isolates (3/28). The A. baumannii strains isolated from patients were genetically similar to the environmental strains, with CC92 members as the major fraction but with different antibiotic susceptibilities.