Prevalence and Antimicrobial Susceptibility of Mycobacterium abscessus in a General Hospital, China

To gain greater insight into the prevalence drug resistant profiles of M. abscessus from a general hospital in Beijing, China.

Partial gene sequencing of 16S, hsp65, and rpoB were used to distinguish the species of NTM isolates. All strains identified as M. abscessus were further enrolled in the drug susceptibility testing by using broth microdilution method.

We found that M. avium complex was the most frequent NTM organism, accounting for 54.1% (33/61) of all isolates. Behind MAC, the second most common organisms were M. abscessus (22 out of 61, 36.1%). Average rates of resistance were 4.5% for AMK, 9.1% for LZD, and 13.6% for CLA, respectively. In contrast, resistance to LEV (17/22, 77.3%), IMI (9/22, 40.9%), and SMX (10/22, 45.5%) was noted in more than 40% of M. abscessus isolates. DNA sequencing revealed that all the CLA-resistant isolates harbored nucleotide substitutions in position 2058 (1/3, 33.3%) or 2059 (2/3, 66.7%) of 23S rRNA.

In conclusion, our data demonstrated that M. intracellulare and M. abscessus were the most common NTM species in the general hospital of Beijing. CLA, AMK, LZD showed promising activity, where as LEV, IMI, and SMX exhibited poor activity against M. abscessus in vitro.