Table 3.

MICs by Etest of seven antimicrobial agents for M. chelonae reported by four separate laboratories

DrugMIC (μg/ml) for isolate:
181418311866
Mode (range)% AgreementaMode (range)% AgreementaMode (range)% Agreementa
Amikacin256 (32–256)61.164 (16–256)72.264 (16–256)55.5
Cefoxitin512 (512)100512 (512)100512 (512)100
Ciprofloxacin32 (8–32)97.232 (0.25–32)77.832 (32)100
Clarithromycin0.125 (0.06–0.5)94.40.25 (0.06–64)80.5128 (8–128)b 91.7
Doxycycline0.25 (0.25–8)36.164 (64)10064 (64)100
Imipenem64 (32–64)10064 (64)10064 (64)100
Trimethoprim-sulfamethoxazole64 (64)10064 (64)10064 (64)100
  • a Percent MICs in each 3-dilution range (mode ± log2).

  • b Strain contains 23S rRNA gene mutation at position 2058 or 2059 that confers high-level resistance to clarithromycin (11, 15).