| 摘要: | 鳥型分枝桿菌群由緩慢生長的分枝桿菌所組成。很多研究顯示非結核分枝桿菌所引發的臨床表徵以慢性肺部疾病較常見，以最常見的非結核分枝桿菌肺病病原體而言，其順序為M. avium complex、 M. kansasii和M. abscessus。我們發現在2007年7月至2008年12月之間由非結核分枝桿菌所引發的肺部疾病超越了結核分枝桿菌的感染，而其中鳥型分枝桿菌群躍升為非結核分枝桿菌感染中的第一名。期間收集二組痰培養陽性的病人(感染鳥型分枝桿菌群及感染結核分枝桿菌群)各30人，固定性別、診別及居住地，藉此利用「個案對照研究法」分析不同變項 (年齡、身高、體重、BMI、DM、抽菸、肺部病變之位置及是否造成開洞)是否為感染的危險因子。再藉由基因定序比對，找出鳥型分枝桿菌群之Rifampicin的抗藥性基因。 M.avium complex的感染常發生於下肺野(McNemar test﹐p < 0.05)，而開洞(cavity)較常出現在結核分枝桿菌的感染上(Logistic regression﹐p < 0.05)。序列與EMBOSS資料庫M.avium AF060366分析比對發現三株同時在核苷酸序列433位置具點突變(Aspartic acid取代Glycine)。其中體外試驗之表現型對Rifampicin呈抗藥性的有26株(87％)，呈敏感性的有4株(13％)，而基因型對Rifampicin呈抗藥性的約11％，顯現臨床所使用之藥敏試驗應建立一準則，提供能更方便、便宜及精確的體外藥敏試驗。
Mycobacterium avium complex (MAC) belongs to a group of slow growing mycobacteria. Many studies showed that chronic pulmonary disease is most commonly manifestated by a non-tuberculous mycobacteria (NTM) infection. MAC, M. kansasii, and M. abscessus, in order of frequency, are the most common pathogens of NTM lung disease. We found the patients with NTM lung disease were more than those with pulmonary tuberculosis between July, 2007 and December, 2008 and MAC was the most common pathogen of NTM lung disease. A case-control was conducted study and 30 patients with a positive sputum culture for MAC as the case group and 30 patients with a positive sputum culture for M. tuberculosis as the control group were enrolled. The two groups were matched with sex, residential areas, and patient services (outpatients or inpatients). Several variables as predictors of risk factors were used to evaluate acquiring NTM lung disease, including age, height, weight﹐BMI﹐DM, smoking, upper lung fields﹐lower lung fields, and pulmonary cavities. We also compared the gene sequence by sequencing to identify the Rifampicin resistance gene of MAC. Involvement of lower lung fields were more common in MAC lung disease (McNemar test, p <0.05), while the pulmonary cavities were more common in pulmonary tuberculosis (Logistic regression, p <0.05). Finally, EMBOSS were used for the database of M.avium AF060366 and sequence analysis. Three strains with a point mutation (Glycine→Aspartic acid) in the nucleotide sequence 433 was noted. Twenty-six strains (87%) presented the phenotype of Rifampicin resistance, while 4 strains were sensitive to Rifampicin (13%). However, genotypes of Rifampicin resistance were noted for only 11% of the strains. It implies that a new criteria for clinical susceptibility test should be established to provide a more convenient, cheap and accurate method for the in-vitro susceptibility test. |
