非结核分枝杆菌肺病临床特征及其菌种鉴定

Clinical features of non-tuberculous Mycobacteria pulmonar disease and identification of its species

目的分析非结核分枝杆菌肺病(NTMPD)临床特征,通过宏基因组测序进行非结核分枝杆菌(NTM)菌种鉴定及聚类分析。方法收集2015年1月-2020年12月福建省立医院确诊NTMPD患者共计79例,收集相关临床资料,利用宏基因组二代测序(mNGS)技术对29株NTM临床分离株进行全基因组测序,分析平均核苷酸一致性(ANI)进行菌种鉴定,绘制NTM临床分离株的ANI值聚类热图。结果NTMPD确诊病例数呈逐年上升趋势,79例NTMPD患者中,男性40例、女性39例,平均年龄为(60.78±12.04)岁,约55.70%(44/79)存在支气管扩张。NTMPD患者主要表现为咳嗽(86.08%)、咳痰(75.95%),CT影像特征以支气管扩张(55.70%,44/79)、树芽征(43.04%,34/79)及结节(35.44%,28/79)表现多见,NTM培养阳性标本中肺泡灌洗液占比最高,达60.76%(48/79)。29株NTM临床分离株共鉴定出10种NTM菌种,其中鸟分枝杆菌复合群(MAC)占58.62%,其次为脓肿分枝杆菌占24.14%。MAC中的胞内分枝杆菌、副胞内分枝杆菌、奇美拉分枝杆菌具有较近的亲缘关系,快生长的脓肿分枝杆菌与慢生长NTM菌株亲缘关系均较远。结论NTMPD患者缺乏典型的临床症状,CT影像上表现为支气管扩张伴结节和树芽征者,应警惕NTM感染可能。NTM菌株的基因型与表型之间可能存在一定相关性。

OBJECTIVE To investigate the clinical characteristics of non-tuberculous Mycobacteria pulmonary disease(NTMPD),identify the species of non-tuberculous Mycobacteria(NTM)with metagenomic sequencing and perform the cluster analysis.METHODS A total of 79 patients who were diagnosed with NTMPD in Fujian Provincial Hospital from Jan 2015 to Dec 2020 were enrolled in the study,the related clinical data were collected,the whole genome sequencing was carried out for 29 clinical NTM isolates by means of metagenomic next generation sequencing(mNGS),the average nucleotide identity(ANI)analysis was performed for identification of the strains,and the cluster heat map of the ANI value was drawn for the clinical NTM isolates.RESULTS The number of confirmed cases of NTMPD was increased year by year.Among the 79 patients with NTMPD,there were 40 male cases and 39 female cases,the average age was(60.78±12.04)years old,and about 55.70%(44/79)had bronchiectasia.Cough(86.08%)and expectoration(75.95%)were the major clinical manifestations of the NTMPD patients;bronchiectasis(55.70%,44/79),tree-in-bud signs(43.04%,34/79)and nodules(35.44%,28/79)were the common CT imaging features.Alveolar lavage fluid specimens were dominant among the specimens cultured positive for NTM,accounting for 60.76%(48/79).Totally 10 species of NTM were identified among the 29 strains of NTM,58.62%of which were Mycobacterium avium complex,and 24.14%were Mycobacterium abscess.Among the M.avium complex strains,M.intracellulare,M.paraintracellulare and M.chimera had close ties of consanguinity,and the fast-growing M.abscess was distantly related to slow-growing NTM strains.CONCLUSION The patients with NTMPD lack typical clinical symptoms.It is necessary to remain vigilant for the possibility of NTM infection among the patients with CT imaging manifested as bronchiectasis complicated with nodules and tree-in-bud signs.There is certain association between the genotypes and the phenotypes of the NTM strains.