不同基因型金黄色葡萄球菌临床分离株体外侵袭力差异性研究

doi:10.3969/j.issn.1673-8640.2015.07.017

摘要/Abstract

摘要： 目的

分析不同基因型金黄色葡萄球菌临床分离株体外侵袭能力的差异,为进一步阐明金黄色葡萄球菌致病机制及防控医院感染提供新的实验依据。

方法

采用脉冲场凝胶电泳(PFGE)和多位点序列分型法(MLST)对43株金黄色葡萄球菌临床分离株进行分子分型,采用抗菌药物保护试验和流式细胞内化试验检测不同基因型金黄色葡萄球菌体外侵袭能力。

结果

按照80%相似度为计算依据,43株金黄色葡萄球菌共分12个PFGE基因型,2个优势型(Ⅰ和Ⅱ型)分别占25.6%(11/43)和34.9%(15/43),其它型别为少见型,占39.5%(17/43)。体外药物敏感性试验结果显示,Ⅰ型和少见型主要为甲氧西林敏感金黄色葡萄球菌(MSSA)(85.7%,24/28),而Ⅱ型均为耐甲氧西林金黄色葡萄球菌(MRSA)(100.0%,15/15)。MLST结果显示,Ⅱ型菌株为ST-239型,Ⅰ型及其它型菌株ST型不定。抗菌药物保护试验结果显示,侵袭能力最强的3株菌的侵入率分别为3.27%、3.15%和3.09%,侵袭力最弱的3株菌的侵入率分别为0.22%、0.24%和1.16%。Ⅰ型菌株和Ⅱ型菌株比较差异不明显(P>0.05);Ⅰ型和Ⅱ型菌株体外侵袭力均显著高于少见型(P均<0.01)。

结论

不同基因型金黄色葡萄球菌体外侵袭力差异显著,优势克隆株特别是ST-239型MRSA菌株显示出较强的体外侵袭能力。金黄色葡萄球菌分离率较高的科室应对该克隆株给予更多关注,加强感染防控措施,降低其医院内传播及感染率。

关键词: 金黄色葡萄球菌, 耐药性, 体外侵袭, 分子分型

Abstract: Objective

To determine the diversity of in vitro invasion abilities of Staphylococcus aureus clinical isolates with different genotypes, and further to investigate the pathogenesis mechanism of Staphylococcus aureus and provide experimental reference for controlling its nosocomial infection and transmission.

Methods

Pulse field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) were used to do molecular typing for 43 isolates of Staphylococcus aureus, and antibiotics protection assay and flow cytometry internalization assay were used to determine the diversity of in vitro invasion abilities of Staphylococcus aureus clinical isolates with different genotypes.

Results

A total of 43 isolates of Staphylococcus aureus were classified into 12 PFGE genotypes according to 80% similarity, among which type Ⅰ and type Ⅱ were the predominant types and accounted for 25.6% (11/43)and 34.9%(15/43), respectively. Other non-predominant types accounted for 39.5%(17/43). In vitro antibiotics susceptibility test results showed that type Ⅰ and other non-predominant types were mainly composed of methicillin-sensitive Staphylococcus aureus (MSSA)(85.7%, 24/28), while type Ⅱ were mainly composed of methicillin-resistant Staphylococcus aureus (MRSA)(100.0%, 15/15). MLST revealed that type Ⅱ isolates were all ST-239 type, but type Ⅰ and other types belonged to diverse ST types. Antibiotics protection assay showed that the invasion rates of the 3 isolates with the strongest invasion abilities were 3.27%, 3.15% and 3.09%, respectively. The in vitro invasion abilities of type Ⅰ and type Ⅱ isolates were significantly higher than those of other non-predominant types (P<0.01).

Conclusions

Staphylococcus aureus clinical isolates with different genotypes shows the diversity of in vitro invasion abilities,and the predominant clones revealed stronger in vitro invasion abilities,especially for ST-239 type.The units with higher Staphylococcus aureus isolation rates should pay more attention to this clone and strengthen infection control measures.

Key words: Staphylococcus aureus, Drug resistance, In vitro invasion, Molecular typing

中图分类号:

R378.1

王俊瑞, 魏常梅, 塔拉, 崔晶花, 杜小莉, 韩艳秋. 不同基因型金黄色葡萄球菌临床分离株体外侵袭力差异性研究[J]. 检验医学, 2015, 30(7): 740-746.

WANG Junrui, WEI Changmei, TA La, CUI Jinghua, DU Xiaoli, HAN Yanqiu. Study on the diversity of in vitro invasion abilities of Staphylococcus aureus clinical isolates with different genotypes[J]. Laboratory Medicine, 2015, 30(7): 740-746.

图/表 3

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