Table 1. Antimicrobial activity of 6 antimicrobial agents against 417 Mycoplasma pneumoniae strains, Japan, 2002–2016*.
| Antimicrobial agent and M. pneumoniae macrolide-resistance level |
MIC, μg/mL† | ||
|---|---|---|---|
| 50% |
90% |
Range |
|
| Clarithromycin | |||
| Susceptible | 0.0039 | 0.0078 | 0.00195 to 0.031 |
| Resistant |
64 |
>64 |
0.5 to >64 |
| Azithromycin | |||
| Susceptible | 0.00049 | 0.00098 | 0.00012 to 0.00195 |
| Resistant |
64 |
64 |
0.031 to >64 |
| Minocycline | |||
| Susceptible | 0.5 | 1 | 0.031 to 1 |
| Resistant |
0.25 |
1 |
0.063 to 1 |
| Doxycycline | |||
| Susceptible | 0.5 | 0.5 | 0.063 to 0.5 |
| Resistant |
0.25 |
0.5 |
0.125 to 0.5 |
| Levofloxacin | |||
| Susceptible | 0.5 | 1 | 0.125 to 1 |
| Resistant |
0.5 |
1 |
0.5 to 1 |
| Tosufloxacin | |||
| Susceptible | 0.5 | 0.5 | 0.25 to 1 |
| Resistant | 0.5 | 0.5 | 0.25 to 2 |
*Macrolide-susceptible M. pneumoniae = 232; macrolide-resistant M. pneumoniae = 185. †MIC ranges for macrolides were 16 to >64 μg/mL for A2063G (n = 163) and A2064G (n = 10) and >64 μg/mL for A2063C (n = 1). MIC for azithromycin was affected by the mutations A2063T (1–4 μg/mL) (n = 10) and C2617A (0.031 μg/mL) (n = 1). MIC for clarithromycin was affected by C2617A (0.5 μg/mL). MICs for quinolone and tetracycline in both macrolide-susceptible and macrolide-resistant M. pneumoniae were almost the same.