Characterization of Rough and Smooth Morphotypes of Mycobacterium abscessus Isolates from Clinical Specimens
Characterization of Rough and Smooth Morphotypes of Mycobacterium abscessus Isolates from Clinical Specimens
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DOI：
10.1128/jcm.01249-13
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发表时间：
2014-01-01
影响因子：
9.4
通讯作者：
Bange, Franz-Christoph
中科院分区：
文献类型：
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作者：
Rueger, Kai;Hampel, Annegret;Bange, Franz-Christoph
脓肿分枝杆菌由脓肿分枝杆菌脓肿亚种和脓肿分枝杆菌Bolletii亚种组成，能产生粗糙或光滑的菌落形态。在这里，我们分析了从34名患者的呼吸道标本中培养出的50株脓肿支原体，其中28例(82%)患有囊性纤维化(CF)，分析了它们的菌落形态和抗生素敏感性。这两种形态出现的总体比例是相似的，50%的患者标本显示粗糙，38%的患者显示光滑形态。共有12%的患者标本同时显示这两种形态。在亚种水平上，粗糙和光滑形态的比例有很大差异，88%的粗糙形态属于脓肿分支杆菌亚种，85%的光滑形态类型属于脓肿分支杆菌亚种。由Erm(41)甲基酶诱导的克拉霉素耐药，以及由RRL基因突变引起的克拉霉素高水平耐药，与形态类型无关。阿米卡星和头孢西丁对两种形态的MIC值(50)S相同，而替格环素对粗糙型和光滑型的MIC值(50)S分别为0.25mU/ml和2.0mU/ml。我们的结果表明，在CF患者的呼吸道标本中，光滑的形态类型比之前认为的更占优势。在耐药性方面，菌落形态不影响脓肿分枝杆菌对一线抗生素克拉霉素、阿米卡星和头孢西丁的敏感性。
Mycobacterium abscessus, which consists of the two subspecies M. abscessus subspecies abscessus and M. abscessus subspecies bolletii, can produce rough or smooth colony morphologies. Here we analyzed 50 M. abscessus isolates cultured from the respiratory specimens of 34 patients, 28 (82%) of whom had cystic fibrosis (CF), with respect to their colony morphologies and antibiotic susceptibilities. The overall proportions of occurrences of the two morphotypes were similar, with specimens from 50% of the patients showing a rough and 38% showing a smooth morphotype. A total of 12% of the specimens from the patients showed both morphotypes simultaneously. At the subspecies level, the proportions of rough and smooth morphotypes differed substantially; 88% of rough morphotypes belonged to M. abscessus subspecies abscessus, and 85% of smooth morphotypes belonged M. abscessus subspecies bolletii. Inducible clarithromycin resistance due to the Erm(41) methylase, as well as high-level resistance to clarithromycin due to mutations within the rrl gene, occurred independently of the morphotype. The MIC(50)s of amikacin and cefoxitin were identical for the two morphotypes, whereas the MIC(50)s of tigecycline were 0.25 mu g/ml for the rough morphotype and 2.0 mu g/ml for the smooth morphotype. Our results show that the smooth morphotype was more dominant in respiratory specimens from CF patients than previously thought. With respect to resistance, colony morphology did not affect the susceptibility of Mycobacterium abscessus to the first-line antibiotics clarithromycin, amikacin, and cefoxitin.