脓肿分枝杆菌(Mycobacteriumabscessus,MABS)是一种致病性最强、耐药性最强、生长最快的分枝杆菌。然而,MABS流行病学研究,尤其是那些关注亚种水平的人,是稀缺的。我们旨在确定MABS亚种分布及其与表型和基因型抗生素谱的相关性。对2016年至2021年马德里96株临床MABS分离株进行了回顾性多中心研究。通过GenoTypeNTM-DR测定进行亚种水平的鉴定以及对大环内酯类和氨基糖苷类的抗性。使用肉汤微量稀释法(RAPMYCOI敏感滴度滴定板)测定针对MABS分离物测试的11种抗微生物剂的MIC。临床分离株包括50个(52.1%)MABS亚种。脓肿;33(34.4%)MABS亚科。质量;和13个(13.5%)MABS亚种。bolletii.最低的耐药率对应于阿米卡星(2.1%),利奈唑胺(6.3%),头孢西丁(7.3%),和亚胺培南(14.6%),和最高的多西环素(100.0%),环丙沙星(89.6%),莫西沙星(82.3%),复方新诺明(82.3%),妥布霉素(81.3%),和克拉霉素(孵育第14天50.0%)。关于替加环素,虽然没有敏感性断点,除一个菌株外,所有菌株的MIC≤1μg/mL。四个分离株在rrl基因的2058/9位具有突变,一个菌株在rrl基因的1408位突变,18/50在erm(41)基因处具有T28C取代。GenoType结果与克拉霉素和阿米卡星药敏试验的一致性为99.0%(95/96)。MABS分离株的比率在研究期间呈上升趋势,是M.脓肿亚科。脓肿最常见的孤立亚种。阿米卡星,头孢西丁,利奈唑胺,亚胺培南显示出很强的体外活性。GenoTypeNTM-DR测定为用于耐药性检测的微量肉汤稀释提供了可靠且互补的工具。重要性由脓肿分枝杆菌(MABS)引起的感染在世界范围内越来越多地被报道。确定MABS亚种并评估其表型耐药性对于优化管理和更好的患者预后至关重要。脓肿分枝杆菌亚种在erm(41)基因功能上有所不同,这是大环内酯耐药性的关键决定因素。此外,MABS的抗性概况和亚种分布可能在地理上有所不同,强调了解当地流行病学和耐药模式的重要性。这项研究为马德里MABS及其亚种的流行病学和抗性模式提供了有价值的见解。观察到几种推荐的抗菌药物的耐药率升高,强调谨慎用药的必要性。此外,我们评估了GenoTypeNTM-DR测定,它检查了大环内酯类和氨基糖苷类耐药相关基因的主要突变。我们观察到GenoTypeNTM-DR测定和微量稀释方法之间的高度一致性,表明其作为早期启动适当治疗的初始工具的有用性。
Mycobacterium abscessus (MABS) is the most pathogenic and drug-resistant rapidly growing mycobacteria. However, studies on MABS epidemiology, especially those focusing on subspecies level, are scarce. We aimed to determine MABS subspecies distribution and its correlation with phenotypic and genotypic antibiotic profiles. A retrospective multicenter
study of 96 clinical MABS isolates in Madrid between 2016 to 2021 was conducted. Identification at the subspecies level and resistance to macrolides and aminoglycosides were performed by the GenoType NTM-DR assay. The MICs of 11 antimicrobials tested against MABS isolates were determined using the broth microdilution method (RAPMYCOI Sensititer titration plates). Clinical isolates included 50 (52.1%) MABS subsp. abscessus; 33 (34.4%) MABS subsp. massiliense; and 13 (13.5%) MABS subsp. bolletii. The lowest resistance rates corresponded to amikacin (2.1%), linezolid (6.3%), cefoxitin (7.3%), and imipenem (14.6%), and the highest to doxycycline (100.0%), ciprofloxacin (89.6%), moxifloxacin (82.3%), cotrimoxazole (82.3%), tobramycin (81.3%), and clarithromycin (50.0% at day 14 of incubation). Regarding tigecycline, although there are no susceptibility breakpoints, all strains but one showed MICs ≤ 1 μg/mL. Four isolates harbored mutations at positions 2058/9 of the rrl gene, one strain harbored a mutation at position 1408 of the rrl gene, and 18/50 harbored the T28C substitution at erm(41) gene. Agreement of the GenoType results with clarithromycin and amikacin susceptibility testing was 99.0% (95/96). The rate of MABS isolates showed an upward trend during the
study period, being M. abscessus subsp. abscessus the most frequently isolated subspecies. Amikacin, cefoxitin, linezolid, and imipenem showed great in vitro activity. The GenoType NTM-DR assay provides a reliable and complementary tool to broth microdilution for drug resistance detection. IMPORTANCE Infections caused by Mycobacterium abscessus (MABS) are increasingly being reported worldwide. Identifying MABS subspecies and assessing their phenotypic resistance profiles are crucial for optimal management and better patient outcomes. M. abscessus subspecies differ in erm(41) gene functionality, which is a critical determinant of macrolide resistance. Additionally, resistance profiles of MABS and the subspecies distribution can vary geographically, highlighting the importance of understanding local epidemiology and resistance patterns. This
study provides valuable insights into the epidemiology and resistance patterns of MABS and its subspecies in Madrid. Elevated resistance rates were observed for several recommended antimicrobials, emphasizing the need for cautious drug use. Furthermore, we assessed the GenoType NTM-DR assay, which examines principal mutations in macrolides and aminoglycosides resistance-related genes. We observed a high level of agreement between the GenoType NTM-DR assay and the microdilution method, indicating its usefulness as an initial tool for early initiation of appropriate therapy.