应用IRS-PCR对金黄色葡萄球菌分型的研究

目的探讨低频限制性位点聚合酶链反应(infrequent-restriction-site PCR，IRS-PCR)在金黄色葡萄球菌(简称金葡菌)基因分型中的应用价值。方法建立本实验室IRS-PCR方法。同时用IRS-PCR和脉冲场凝胶电泳(PFGE)对金葡菌进行基因分型。根据49株社区感染分离菌的分型结果计算辨别力指数(ID)值估计分辨力。对其中30株社区感染菌重复实验一次估计重复性。比较两种基因分型方法的分型率、分辨力、重复性、结果的一致率及操作特点。结果建立IRS-PCR对金葡菌基因分型的方法。70株金葡菌均可被2种方法分型，分型率100％。IRS-PCR分为38个型，21株院内感染菌分为6个型，49株社区感染菌分为32个型，计算ID值为0．981。PFGE分为40个型，21株院内感染菌分为6个型，49株社区感染菌分为34个型，计算ID值为0．983。两种分型方法的重复性均为100％。对院内感染菌，两种方法分型的一致率为100％；对社区感染菌，两种方法分型的一致率为92％(45／49)。与PFGE相比，IRS-PCR更简单、省时、易于操作、不需特殊昂贵仪器。结论IRS-PCR能对金葡菌简易快速可靠分型，适合检验科对临床标本的快速有效分型，是一种有价值的分子流行病学研究工具。

The application of infrequent-restriction-site PCR as a typing method of Staphylococcus aureus

Objective To explore the value of infrequent-restriction-site PCR (IRS-PCR) as a typing method of Staphylococcus aureus(Sa). Methods Typing all strains by pulse-field gel electrophoresis(PFGE) and IRS-PCR. Discriminatory index (ID) was measured according to the typing situation of 49 community acquired(CA) strains. Repeating the typing process of 30 strains to examine reproducibility. Typing ability, discriminatory ability, reproducibility, accordance ratio and performance of two genotyping methods were compared. Results IRS-PCR as a genotyping method for Sa was established. 70 strains were all typed by two methods, and typing ability of two methods were both 100%. By IRS-PCR, 70 strains were sorted in to 38 types. 21 hospital acquired(HA) strains were sorted in to 6 types, 49 CA strains were sorted in to 32 types and ID was 0.981. By PFGE, 70 strains were sorted in to 40 types. 21 HA strains were sorted in to 6 types, 49 CA strains were sorted in to 34 types and ID was 0.983. The reproducibility of two typing methods was 100%. For HA strains, the accordance ratio of two typing methods was 100%. For CA strains, the accordance ratio of type was 92%(45/49). Comparing to PFGE , IRS-PCR was simpler, less time- consuming, easy to perform, and does not special need expensive equipments. Conclusion IRS-PCR is an easy, fast and reliable typing method for Sa and suitable for clinical laboratory to type clinical samples quickly and effectively.