Özkarataş Müge Hacer, Arslan Nazlı, Esen Nuran, Özkütük Ayşe Aydan
Bursa Provincial Health Directorate, Public Health Laboratory, Bursa, Türkiye.
Dokuz Eylül University Institute of Health Sciences, Department of Medical Microbiology, İzmir, Türkiye.
Mikrobiyol Bul. 2023 Apr;57(2):220-237. doi: 10.5578/mb.20239917.
Infections related to the rapidly growing mycobacteria (RGM), which are common in the environment, have clinical significance as they can affect both immunocompromised and immunocompetent patients. Treatment of RGM related infections is difficult, because they are resistant to many of the first-line tuberculosis agents, require a long-term multiple drug regimen, which is costly, and is associated with drugrelated toxicities. The aim of this study was to investigate the in vitro antimicrobial susceptibility profiles of RGM isolated in Dokuz Eylül University Hospital and also to reveal epidemiological data. A total of 58 isolates [(Mycobacterium fortuitum (n= 35), Mycobacterium abscessus (n= 19) and Mycobacterium chelonae (n= 4)], which were isolated in Dokuz Eylül University Hospital between 2013 and 2018, were subjected to in vitro testing for nine antimicrobial agents (amikacin, cefoxitin, ciprofloxacin, clarithromycin, doxycycline, imipenem, linezolid, moxifloxacin and tobramycin) with the broth microdilution method recommended by the Clinical and Laboratory Standards Institute (CLSI). For M.abscessus; 73.68% of the isolates were found susceptible to amikacin; 73.68% of isolates were susceptible to clarithromycin at early reading and only 21.05% of them remained susceptible at late reading time. No resistance to imipenem were observed. M.abscessus isolates were highly resistant to tobramycin, doxycycline and fluoroquinolones. Antibiotic susceptibility testing of M.chelonae isolates demonstrated 100% susceptibility for amikacin, clarithromycin and tobramycin. No resistance to linezolid, imipenem and moxifloxacin were observed. None of the isolates were susceptible to cefoxitin. Ciprofloxacin and doxycycline also showed poor in vitro activity against M.chelonae isolates. For M.fortuitum clarithromycin susceptibility decreased from 32.35% to 2.94% after an additional incubation until 14 days. All tested isolates of the M.fortuitum were susceptible to amikacin, ciprofloxacin and moxifloxacin. None of the M.fortuitum isolates exhibited resistance to cefoxitin and imipenem. Most of the M.fortuitum isolates were resistant to tobramycin and doxycycline. When the results were evaluated together, RGM isolates in this study were highly susceptible to amikacin; and were highly resistant to doxycycline. In conclusion, this study supported that the status of antimicrobial susceptibilities were different between species and also showed the importance for hospitals to know susceptibility patterns of isolates in their region. It should be noted that accurate species determination is critical for treatment as well as susceptibility status of rapidly growing mycobacteria to the antimicrobials in use.
与快速生长分枝杆菌（RGM）相关的感染在环境中很常见，由于其可影响免疫功能低下和免疫功能正常的患者，因此具有临床意义。RGM相关感染的治疗很困难，因为它们对许多一线抗结核药物耐药，需要长期使用多种药物联合治疗方案，成本高昂，且与药物相关毒性有关。本研究的目的是调查在多库兹艾吕尔大学医院分离出的RGM的体外抗菌药敏谱，并揭示流行病学数据。对2013年至2018年期间在多库兹艾吕尔大学医院分离出的58株菌株（偶然分枝杆菌（n = 35）、脓肿分枝杆菌（n = 19）和龟分枝杆菌（n = 4）），采用临床和实验室标准协会（CLSI）推荐的肉汤微量稀释法，对九种抗菌药物（阿米卡星、头孢西丁、环丙沙星、克拉霉素、多西环素、亚胺培南、利奈唑胺、莫西沙星和妥布霉素）进行体外测试。对于脓肿分枝杆菌；73.68%的菌株对阿米卡星敏感；在早期读数时，73.68%的菌株对克拉霉素敏感，而在后期读数时，只有21.05%的菌株仍敏感。未观察到对亚胺培南耐药的情况。脓肿分枝杆菌菌株对妥布霉素、多西环素和氟喹诺酮类药物高度耐药。龟分枝杆菌菌株的抗生素药敏测试显示，对阿米卡星、克拉霉素和妥布霉素的敏感性为100%。未观察到对利奈唑胺、亚胺培南和莫西沙星耐药的情况。所有菌株对头孢西丁均不敏感。环丙沙星和多西环素对龟分枝杆菌菌株的体外活性也较差。对于偶然分枝杆菌，在额外培养至14天后，克拉霉素敏感性从32.35%降至2.94%。所有测试的偶然分枝杆菌菌株对阿米卡星、环丙沙星和莫西沙星敏感。偶然分枝杆菌菌株均未表现出对头孢西丁和亚胺培南耐药。大多数偶然分枝杆菌菌株对妥布霉素和多西环素耐药。综合评估结果时，本研究中的RGM菌株对阿米卡星高度敏感；对多西环素高度耐药。总之，本研究支持不同菌种之间抗菌药敏情况不同，也表明医院了解其所在地区分离菌株的药敏模式很重要。应当指出，准确的菌种鉴定对于治疗以及快速生长分枝杆菌对所用抗菌药物的药敏情况至关重要。
