呼吸道快速生长分枝杆菌的检出率及与肺部疾病的相关性

Frequency and clinical relevance of rapidly growing mycobacterium isolated from respiratory samples

目的 研究呼吸道快速生长分枝杆菌（RGM）的检出率及与肺部疾病的相关性.方法 分析首都医科大学附属北京胸科医院呼吸道分泌物中分离的228株非结核分枝杆菌菌种的鉴定结果,初步判断为非结核分枝杆菌的所有菌株使用基因测序方法鉴定至种水平.结合临床资料,参照RGM肺病诊断标准,判断RGM与疾病的临床相关性.计数资料采用x2检验或Fisher精确检验,计量资料采用￡检验,P＜0.05为差异有统计学意义.结果 非结核分枝杆菌临床分离株中脓肿分枝杆菌和偶发分枝杆菌分别占28.9％（66株）和8.8％（20株）,未发现龟分枝杆菌.从具有完整临床资料的32例患者中分离出66株脓肿分枝杆菌,其中包括确诊脓肿分枝杆菌肺病28例,可能脓肿分枝杆菌肺病4例.一次分离出偶发分枝杆菌8例,判断为不符合RGM肺病.确诊脓肿分枝杆菌肺病的患者,分枝杆菌生长指示管法阳性率高于改良罗氏培养法（23/24和18/28）.结论 快速生长分枝杆菌是常见的非结核分枝杆菌,呼吸道标本分离出脓肿分枝杆菌往往与RGM肺病相关,分离出的偶发分枝杆菌多不符合RGM肺病.

Objective To assess the frequency and clinical relevance of rapidly growing mycobacterium （RGM） isolates in a tuberculosis referral center in Beijing,China.Methods All isolates were identified by using targeted gene sequencing.Results of species identification for 228 nontuberculous Mycobacterium （NTM） isolates from respiratory samples were analyzed,and available medical files of patients from whom NTM were isolated were reviewed retrospectively.Diagnostic criteria for RGM pulmonary disease issued by the American Thoracic Society （ATS） were used to determine clinical relevance.Results Isolates of Mycobacterium abscessus （M.abscessus） and Mycobacterium fortuitum （M.fortuitum） accounted for 28.9% （66 isolates） and 8.8% （20 isolates） of NTM isolates,respectively.Sixty-six M.abscessus isolates from 32 patients had evaluable medical files,including 28 cases diagnosed as definite M.abscessus lung disease,and 4 as probable M.abscessus lung disease.Eight M.fortuitum isolates from 8 cases had evaluable medical files,and all of them were diagnosed as unlikely lung disease.Mycobacteria Growth Indicator Tube （MGIT） was more effective to diagnose M.abscessus lung disease,as compared with Lowestein-Jensen medium （23/24 vs 18/28）.Conclusions RGM is a common NTM in our institute.M.abscessus is mostly associated with RGM lung disease,but M.fortuitum is not.