【摘要】： 目的研究我國(guó)MRSA及血標(biāo)本亞組中hVISA的發(fā)生率,并對(duì)瓊脂篩選法和macroEtest(MET)法的敏感性和特異性做出評(píng)價(jià)。了解我國(guó)hVISA菌群體外藥敏和分子流行病學(xué)特征。通過(guò)病例對(duì)照研究獲得我國(guó)hVISA感染的相關(guān)臨床信息并對(duì)危險(xiǎn)因素和病死率相關(guān)性進(jìn)行分析。 方法從6個(gè)組別收集來(lái)自全國(guó)范圍的MRSA菌株共1012株,其中血標(biāo)本MRSA 200株,其他類(lèi)型標(biāo)本MRSA 812株。使用BHIT5(含替考拉寧5μg/ml的腦心浸液瓊脂平皿)、BHIV6(含萬(wàn)古霉素6μg/ml的腦心浸液瓊脂平皿)和MET法對(duì)200株血標(biāo)本MRSA進(jìn)行hVISA/VISA篩選并使用改良PAP-AUC(菌群分析策略)法進(jìn)行確認(rèn)。對(duì)812株其他類(lèi)型標(biāo)本MRSA中BHIT5陽(yáng)性者再進(jìn)行MET法篩選。對(duì)血標(biāo)本亞組的所有菌株進(jìn)行含多種新型抗菌藥物在內(nèi)的體外藥敏試驗(yàn),并通過(guò)多重PCR方法進(jìn)行SCCmec和agr分型。部分菌株進(jìn)行spa分型。通過(guò)病例調(diào)查表(CRF)的形式收集hVISA組和對(duì)照組的臨床相關(guān)信息,使用student t檢驗(yàn)、Mann-Whitney檢驗(yàn)、x~2檢驗(yàn)以及fisher精確檢驗(yàn)等統(tǒng)計(jì)方法對(duì)病例資料進(jìn)行回顧性分析。 結(jié)果我國(guó)血標(biāo)本中VISA的發(fā)生率為0.5%(1/200),hVISA的發(fā)生率為13.0%(27/200),hVISA/VISA的總發(fā)生率為13.5%。BHIT5的敏感性和特異性分別為88.8%和17.3%,BHIV6的敏感性和特異性分別為3.7%和98.8%;以MET MIC_(萬(wàn)古霉素)≥8μg/ml且METMIC_(替考拉寧)≥8μg/ml或MET MIC_(替考拉寧)≥12μg/ml為折點(diǎn),MET A法的敏感性和特異性分別為70.4%和48.0%,以MET MIC_(萬(wàn)古霉素)≥8μg/ml且MET MIC_(替考拉寧)≥8μg/ml為折點(diǎn),MET B法的敏感性和特異性分別為48.1%和85.0%。我國(guó)MRSA中hVISA的發(fā)生率估計(jì)為6.19%。200例血標(biāo)本中,除一例VISA的萬(wàn)古霉素MIC為3μg/ml以外,其他hVISA的萬(wàn)古霉素MIC值仍在敏感范圍內(nèi),且81.8%分布在萬(wàn)古霉素MIC=1μg/ml的水平,高于VSSA組且差異具有統(tǒng)計(jì)學(xué)意義(p=0.002)。hVISA對(duì)多種新一代抗菌藥物如達(dá)托霉素、頭孢吡普以及利奈唑胺均100%敏感。在分子流行病學(xué)方面,hVISA組中所占比例最高的是SCCmecⅢ型(70.4%)和agr1型(66.7%),其次為SCCmecⅡ型(22.2%)和agr2型(14.8%),VSSA組分子流行病學(xué)特征與hVISA組相似,兩組間差異無(wú)統(tǒng)計(jì)學(xué)意義。病例對(duì)照研究未能得出hVISA與臨床病死率具有相關(guān)性的結(jié)論。 結(jié)論我國(guó)hVISA的發(fā)生率較高。各種瓊脂篩選方法的敏感性和特異性差別很大,以MET MIC_(萬(wàn)古霉素)＞18μg/ml且MET MIC_(替考拉寧)≥18μg/ml為折點(diǎn)的MET法可能具有較高的臨床應(yīng)用價(jià)值。hVISA組萬(wàn)古霉素MIC水平顯著高于VSSA組,但多種新型抗菌藥物對(duì)其具有良好活性。對(duì)hVISA臨床意義的研究可能需要進(jìn)行大樣本的前瞻性隊(duì)列研究。
[Abstract]:Objective to study the incidence of hVISA in MRSA and blood subgroups in China and to evaluate the sensitivity and specificity of Agar screening and macroEtest (MET). Objective: to investigate the drug sensitivity and molecular epidemiology of hVISA bacteria in China. The clinical information of hVISA infection in China was obtained by case-control study and the correlation between risk factors and mortality was analyzed. Methods A total of 1012 strains of MRSA were collected from 6 groups, including 200 strains of blood MRSA and 812 strains of other types of MRSA. BHIT5 (Agar plate containing 5 渭 g/ml teicoplanin) was used. BHIV6 (brain heart extract Agar plate containing vancomycin 6 渭 g/ml) and MET method were used to screen 200 blood samples for hVISA/VISA screening and confirmed by modified PAP-AUC (microflora analysis strategy) method. The BHIT5 positive cases of 812 other types of MRSA were screened by MET method. In vitro susceptibility tests were carried out to all strains of blood subgroup containing new antimicrobial agents, and SCCmec and agr typing were carried out by multiple PCR method. Some strains were classified by spa. The clinical data of hVISA group and control group were collected by case questionnaire (CRF), and the data were analyzed retrospectively by student t test, Mann-Whitney test, x2 test and fisher accurate test. Results the incidence of VISA in Chinese blood samples was 0.5% (1 / 200), hVISA, 13.0%, 27 / 200). The sensitivity and specificity of hVISA/VISA to 13.5%.BHIT5 were 88.8% and 17.3%, respectively. The sensitivity and specificity of BHIV6 were 3.7% and 98.8%, respectively. The sensitivity and specificity of, MET A with MET MIC_ 鈮，

本文編號(hào)：2398241