Table 1

In vitro antimicrobial activities of macrolides and moxifloxacin against 62 clinical isolates of M. abscessus and M. massiliense and each reference strain

Species (no. of isolates)AgentNo. of strains distributed at each MIC (μg/ml)Resistance rate, no. of strains (%)
≤0.250.512481632≥64
M. abscessus (32)AZM45152336a (18.8)
CLR31552111136a (18.8)
MXF67109
M. massiliense (32)AZM12623
CLR2012
MXF1210333b14b (12.5)
  • a Six isolates of M. abscessus that were resistant to both macrolides due to a point mutation in the 23S rRNA were excluded from the subsequent experiments.

  • b Four isolates of M. massiliense that were resistant to moxifloxacin were excluded from the subsequent experiments.