【摘要】： 目的： 用脈沖場凝膠電泳(Pulsed Field Gel Electrophoresis, PFGE)及多重PCR技術(shù)對天津市南開醫(yī)院臨床分離的耐甲氧西林金黃色葡萄球菌(Methicillin-resistant Staphylococcus aureus, MRSA)株進(jìn)行染色體指紋圖譜分析和葡萄球菌染色體mec基因盒(Staphylococcal Cassette Chromosome mec, SCCmec)基因分型,以了解該院院內(nèi)感染MRSA菌株的流行特征。 方法： (1)臨床送檢標(biāo)本按常規(guī)方法初步鑒定為葡萄球菌屬,然后根據(jù)血漿凝固酶及生化反應(yīng)的結(jié)果鑒定金黃色葡萄球菌,再進(jìn)行頭孢西丁藥敏試驗(yàn),確定MRSA,質(zhì)控菌株為金黃色葡萄球菌ATCC25923。 (2)耐甲氧西林金黃色葡萄球菌藥物敏感試驗(yàn)采用K—B紙片擴(kuò)散法,測試其對14種抗菌藥物的敏感性,藥敏結(jié)果按NCCLS(2004年版)的標(biāo)準(zhǔn)判讀。 (3)對40株MRSA進(jìn)行PFGE分析、mecA基因檢測及SCCmec基因分型。 結(jié)果： (1)菌株來源：40株MRSA中28株來源于痰液,占70%；來自腹水或腹腔引流液的7株(17.5%)；傷口引流液和血液各2株(5.0%)；咽拭子1株(2.5%)。 (2) SCCmec分型：Oliveira法和Zhang法將40株MRSA分為四個(gè)型別,Ⅲ型為主,共33株,占82.5%；V型5株(12.5%)；Ⅰ型和Ⅳ型均為1株(2.5%)。 (3) PFGE分型：40株MRSA可被分為A—E五個(gè)型別,其中A型21株,52.5%；B型8株(20.0%)；C型4株(10.0%)；D型6株(15.0%)；E型]株(2.5%)。 (4) PFGE各型別與耐藥譜：除對共同的5種抗生素(克林霉素、紅霉素、頭孢西丁、苯唑西林、青霉素)耐藥外,各型還另對其他種類的藥物耐藥,如A型對6種,B型對2種,C型對4種,D型對5種,E型對4種藥物耐藥。 (5)通過分析不同PFGE型別的院內(nèi)感染MRSA菌株的時(shí)間和空間分布,可清晰地追溯各型菌株在該院的分布和傳播情況。 結(jié)論： (1)本研究所用菌株來源于住院患者的不同感染部位,但痰液的MRSA檢出率最高,這顯然與呼吸道為葡萄球菌的主要定植部位有關(guān)。 (2)在07至08兩年的時(shí)間里,僅收集到40株院內(nèi)感染MRSA,這40株菌又分屬于A-E五個(gè)PFGE型別,說明天津市南開醫(yī)院住院患者所感染的MRSA不是來自同一克隆株,故呈散發(fā)流行。 (3)所有40株MRSA菌株均為多重耐藥,但表現(xiàn)出各PFGE型菌株共有耐藥性和型相關(guān)性耐藥表型；這種耐藥譜的差別對指導(dǎo)用藥有參考意義。 (4)本研究所涉及的MRSA菌株,SCCmec分型以Ⅲ型為主,符合院內(nèi)感染MRSA菌株的特征。PFGE分型和SCCmec分型分別從不同方面研究這組MRSA菌株,通過綜合兩方面的研究結(jié)果,可在分子水平對醫(yī)院內(nèi)分離到的MRSA菌株進(jìn)行分析,從而確定相關(guān)院內(nèi)感染病原菌的遺傳學(xué)特征、感染來源、傳播途徑及分布規(guī)律,為院內(nèi)感染的監(jiān)控提供可靠的依據(jù)。
[Abstract]:Objective: to study the clinical isolation of methicillin resistant Staphylococcus aureus (Methicillin-resistant Staphylococcus aureus,) by pulsed field gel electrophoresis (Pulsed Field Gel Electrophoresis, PFGE) and multiple PCR techniques in Nankai Hospital of Tianjin City. The MRSA strain was analyzed by chromosome fingerprinting and (Staphylococcal Cassette Chromosome mec, SCCmec) genotyping of staphylococcus chromosome mec gene box in order to understand the epidemic characteristics of MRSA strains infected in hospital. Methods: (1) Staphylococcus aureus was preliminarily identified as Staphylococcus by routine method, and then staphylococcus aureus was identified according to the results of plasma coagulase and biochemical reaction. The drug sensitivity test of cefoxitin was carried out to determine the MRSA, of Staphylococcus aureus. The quality control strain is Staphylococcus aureus ATCC25923. (2) the susceptibility of methicillin-resistant Staphylococcus aureus to 14 antimicrobial agents was tested by K-B disk diffusion method. The results were interpreted according to the standard of NCCLS (2004 edition). (3) 40 MRSA strains were analyzed by PFGE, mecA gene and SCCmec genotyping. Results: (1) strain sources: 28 out of 40 strains of MRSA were from sputum (70%), 7 strains (17. 5%) from ascites or peritoneal drainage, 2 strains from wound drainage and 2 strains from blood (5.0%). Throat swabs 1 strain (2.5%). (2) SCCmec typing: 40 strains of MRSA were classified into four types by Oliveira and Zhang, 33 strains were classified as type 鈪，

本文編號：2372000