杭州地区流行非结核分枝杆菌鉴定、易感因素和耐药性分析

目的了解近年杭州地区非结核分枝杆菌(NTM)感染、优势菌种及其耐药性。方法采用PNB/TCH生长试验对1 972例患者分枝杆菌阳性培养物标本中NTM进行初步鉴定。采用分枝杆菌分子线性探针法和16SrRNA基因PCR产物测序鉴定NTM菌种。分析性别和年龄对NTM易感性的影响。采用浓度比例法检测NTM分离菌株对异烟肼(INH)、利福平(RFP)、链霉素(SM)、乙胺丁醇(EMB)、氧氟沙星(OFX)、卡那霉素(KM)的敏感性。结果 9.8%(193/1 972)分枝杆菌阳性培养物标本PNB/TCH生长试验结果阳性。分子线性探针法和16SrRNA基因PCR产物测序结果显示,193例PNB/TCH生长试验阳性标本中,66.3%为单一NTM、18.1%为2种分枝杆菌、8.3%为结核分枝杆菌、7.3%为非分枝杆菌属细菌感染。173株NTM(单一感染128株+混合感染45株)中,胞内分枝杆菌占57.8%,其次为脓肿分枝杆菌、堪萨斯分枝杆菌、龟分枝杆菌和鸟分枝杆菌(12.1%、9.8%、9.8%和5.8%)。35例分枝杆菌混合感染标本中,28.5%和20.0%分别为胞内分枝杆菌或龟分枝杆菌与结核分枝杆菌混合感染。NTM感染者男性多于女性(1.67∶1),50岁以上人群感染率(80.4%)高于50岁以下人群(P0.01),肺部感染比例(95.1%)远高于其他部位(P0.01)。NTM分离株对INH耐药率为100%,对其他5种抗结核药物的耐药率也高达70.3%~90.6%。结论胞内分枝杆菌是杭州地区近年优势流行的NTM菌种,NTM主要引起肺部感染且中老年人易感,NTM临床菌株对常用抗结核药物有很高的耐药性。

Identification of predominant prevailing nontuberculosis mycobacteria in Hangzhou and analysis of their predisposing factors and drug resistance

This study is aim to determine the predominant prevailing nontuberculosis mycobacteria (NTM) in Hangzhou and to understand the predisposing factors and drug resistance of NTM.PNB/TCH growth tests were used to preliminarily identify the NTM in the mycobacterium-positive culture samples from 1 972 patients.The species of NTM isolates were con firmed using mycobacterium molecular linear probe method and sequencing of PCR product of 16S rRNA gene.The influence of sex and age on predisposing factors of NTM was subsequently analyzed.Concentration proportional method was applied to de tect the susceptibility of NTM isolates to armazide,rifampicin,streptomycin,ethambutol,ofloxacin and kanamycin.Results of PNB/TCH growth tests showed that 9.8％ (193/1 972) of the 1 972 mycobacterium-positive culture samples were positive.The mycobacterium molecular linear probe hybridization and PCR product sequencing confirmed that in the 193 samples with positive results of PNB/TCH growth tests,66.3％,18.1％,8.3％ and 7.3％ were infected with NTM alone,two mycobacteria,Mycobacterium tuberculosis and bacteria that not belonging to the genus of Mycobacteria,respectively.In the 173 NTM isolates (128 with single infection and 45 with mixed infection),57.8％ were identified as Mycobacterium intracellulare,followed by Mycobacterium abscessus (12.1％),Mycobacterium kansasi i (9.8％),Mycobacterium chelonei (9.8％) and Mycobacterium avium (5.8％).In the 35 mixed infection samples,28.5％ and 20.0％ were the co-infection of M.intracellulare and M.chelonei with M.tuberculosis,respectively.Male patients infected with NTM were more than female patients (1.67 ∶ 1) and the infection rate (80.4％) of populations with age over 50 years old was significantly high than that with lower than 50 years old (P＜0.01).Pulmonary infection proportion (95.1 ％) of NTM was significantly higher than other positions of body (P＜0.01).100％ of NTM isolates were resistant to armazide while the resistance rates of the isolates against the other 5 antituberculosis drugs were as high as 70.3 ％ 90.6 ％.As the conclusion of this study,M.intracellulare is the predominant prevailing NTM species in the recent years in Hangzhou,NTM mainly causes pulmonary infection and middle-aged and old people are easily infected by NTM.Moreover,NTM isolates have high resistance against commonly used antituberculosis drugs.