大理地区13株疑似非结核分枝杆菌临床分离株的鉴定

Identification of 13 suspicious clinical isolates of non-tuberculosis mycobacteria in Dali, China

目的对云南大理地区13株疑似非结核分枝杆菌(Non-Tuberculous mycobacteria,NTM)进行鉴定,了解其菌种构成。方法大理州疾控中心提供的疑似非结核分枝杆菌13株,经罗氏培养基(L-J)、噻吩-2-羧酸肼(TCH)和对硝基苯甲酸(PNB)鉴别培养基初步鉴别培养确定为NTM后分别通过16S rRNA、hsp65和rpoB基因片段测序进行菌种鉴定。结果 13株疑似NTM临床分离株经16S rRNA、rpoB和hsp65基因DNA测序分析鉴定为NTM 11株(84.62%),束村氏菌1株(7.69%),戈登氏菌1株(7.69%)。11株NTM中鸟分枝杆菌(M.avium)9株,脓肿分支杆菌(M.abcessus)2株。结论经抗酸染色筛查、L-J和PNB/TCH培养基初步鉴定为NTM的临床分离株通过3种不同基因测序分析鉴定为NTM、束村氏菌和戈登氏菌,以NTM中的鸟分枝杆菌占多数。

Objective To identify suspected non-tuberculous mycobacteria(NTM) in clinical isolates from the Dali area and to ascertain the proportion of different strains.Methods Thirteen clinical isolates of mycobacteria were obtained from the Dali State Center for Disease Control,and all of the strains were preliminary identified as NTM through culturing on Lowenstein-Jensen culture medium containing p-nitrobenzoic acid and thiophene-2-carboxylic acid hydrazine.Gene fragments of 16 S rRNA,rpoB,and hsp65 were sequenced and subsequently used to identify strains.Results The 13 clinical isolates suspected of being NTM were ultimately identified as 11 strains of NTM(84.62%),1 strain of Tsukamurella(7.69%),and 1 strain of Gordonia(7.69%) through sequencing using DNA from the gene fragments of 16 S rRNA,rpoB,and hsp65.Of the 11 strains of NTM,2 were strains of Mycobacterium abscessus and 9 were strains of M.avium.Conclusion Based on the results of acid-fast staining,13 clinical isolates were preliminarily identified as NTM according to culturing on Lowenstein-Jensen culture medium containing p-nitrobenzoic acid and thiophene-2-carboxylic acid hydrazine.Those isolates were ultimately identified as NTM,Tsukamurella,and Gordonia according to sequencing using 3 different genes.M.avium was the predominant species of NTM.