脓肿分枝杆菌菌种鉴定及药物敏感试验研究

The analysis of species identification and susceptibility testing of Mycobacterium abscessus

目的 对于将脓肿分枝杆菌分为2个亚种的菌种鉴定方法进行分析评价,并分别进行药物敏感试验,了解不同的抗生素对各亚种的抑菌活性.方法 通过16S rRNA鉴定的60株脓肿分枝杆菌临床分离株,再应用rpoB和hsp65基因序列将其分为Abscessus和Massiliense亚种.2个亚种的耐药率比较采用x2或Fisher精确概率法检验,对抗生素耐药与erm（41）基因28位点的碱基进行相关性分析.结果 脓肿分枝杆菌中Abscessus亚种占65％ （39/60）,Massiliense亚种占35％ （21/60）.阿米卡星敏感菌株中Abscessus亚种占97％ （38/39）,Massiliense亚种占95％ （20/21）;阿奇霉素敏感菌株中Abscessus亚种占92％ （36/39）,Massiliense亚种占95％ （20/21）;亚胺培南敏感菌株中Abscessus亚种占74％ （29/39）,Massiliense亚种占67％（14/21）.46％ （18/39）的Abscessus亚种和76％（16/21）的Massiliense亚种对头孢西丁中度敏感,82％ （32/39）的Abscessus亚种对克拉霉素耐药,95％ （20/21）的Massiliense亚种对克拉霉素敏感.28株erm（41）基因测序成功的Abscessus亚种中,克拉霉素耐药菌株23株,其中22株erm（41）基因的28位点为T,1株为C;克拉霉素敏感菌株5株erm（41）基因的28位点均为C.结论 采用rpoB和hsp65基因序列可将脓肿分枝杆菌分为Abscessus和Massiliense亚种.阿奇霉素、阿米卡星和亚胺培南在体外对脓肿分枝杆菌抑菌活性较强,头孢西丁的抑菌活性较好,克拉霉素对Abscessus亚种的抑菌活性较差,而对Massiliense亚种的抑菌活性较好.erm（41）基因与克拉霉素耐药有相关性.

Objectives To evaluate the method of differentiating Mycobacterium abscessus subsp.abscessus （subsp.M.abscessus） from Mycobacterium abscessus subsp.massiliense （subsp.M.massiliense）,and to investigate the activity of different antibiotics in vitro.Methods Sixty Mycobacterium abscessus （M.abscessus） isolates previously identified by using 16S rRNA sequence,were identified by comparativesequence analysis of rpoB and hsp65,and were divided into subsp.M.abscessus and subsp.M.massiliense.Two subspecies＇ resistant proportions were compared by chi-square test.Finally the relationship between clarithromycin resistance and erm（41） was analyzed.Results Of all the 60 M.abscessus isolates,65％ （39/60） belonged to subsp.M.abscessus,35％ （21/60） belonged to subsp.M.massiliense.97％ （38/ 39） subsp.M.abscessus and 95％ （20/21） subsp.M.massiliense were susceptible to amikacin.92％ （36/39） subsp.M.abscessus and 95％ （20/21） subsp.M.massiliense were susceptible to azithromycin.74％ （29/39） subsp.M.abscessus and 67 ％ （14/21） subsp.M.massiliense were susceptible to imipenem.46 ％ （18/39） subsp.M.abscessus and 76％ （16/21） subsp.M.massiliense were moderately susceptible to cefoxitin.82％ （32/39） subsp.M.abscessus were resistant to clarithromycin,and 95％ （20/21） subsp.M.massiliense were susceptible to clarithromycin.Of all the 28 subsp.M.abscessus isolates which were sequenced suscessfully,23 isolates were resistant to clarithromycin,and 22 isolates in them had T28 in erm （41）,and the rest one had C28 in erm（41）.However,all the 5 subsp.M.abscessus isolates which were susceptible to clarithromycin had C28 in erm（41）.Conclusions M.abscessus can be divided into subsp.M.abscessus and subsp.M.massiliense by using rpoB and hsp65.Amikacin,azithromycin and imipenem showed excellent inhibition activity against M.abscessus in vitro.Cefoxitin also showed a good inhibition activity.Clarithromycin had a poor inhibition activity against subsp.M.abscessus,but a good inhibition activity against subsp.M.massiliense.Erm（41） was related to clarithromycin resistance.