Abstract:

Objective To analyze the distribution and drug resistance of clinical rapidly growing Mycobacterium（RGM）. Methods The clinical isolates of the patients infected with nontuberculous Mycobacterium（NTM） from January 2019 to December 2022 were collected. All the isolates were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry，and the antimicrobial susceptibility was determined using a broth microdilution method. The related clinical data of patients were analyzed retrospectively. Results A total of 103 RGM isolates were isolated，including Mycobacterium abscessus（89 isolates，86.4%），Mycobacterium fortuitum（13 isolates，12.6%） and Mycobacterium chelonae（1 isolate，1.0%）. The average age of patients was（54.0±16.2） years old，with 66.0%（68/103） females. Cough and expectoration（69.9%，72/103） were the most common clinical symptoms，followed by fever and hemoptysis. RGM isolates were all sensitive to amikacin（100.0%） and highly resistant to doxycycline（82.5%）. Mycobacterium abscessus was highly resistant to a variety of antibiotics. The resistance rate of induced clarithromycin was 49.4%. Mycobacterium fortuitum showed high sensitive rates to trimethoprim/sulfamethoxazole，linezolid，moxifloxacin and ciprofloxacin（90.0%-100.0%），but resistant to doxycycline（53.8%），clarithromycin（53.8%） and imipenem（30.8%）. Conclusions The susceptibility of RGM to antibiotics varies. Species identification and drug susceptibility testing are necessary to ensure appropriate treatment regimens for patients.

Key words: Nontuberculous Mycobacterium, Rapidly growing Mycobacterium, Mycobacterium abscessus, Species, Drug resistance