Table 2.
Resistance of organisms to azithromycin
| Streptococcus pneumoniae | Streptococcus aureus | Escherichia coli | |
|---|---|---|---|
| Number isolated (%) | 454/1046 (43.4%) | 138/1046 (13.2%) | 646/1047 (61.7%) |
| Samples with further testing | 454 | 138 | 644 |
| Sensitive | (ZD ≥ 18) | (ZD ≥ 18) | (ZD ≥ 10) |
| n/N (%) | 353/454 (77.7) | 81/138 (58.7) | 537/644 (83.4) |
| Intermediate | (ZD 14–17) | (ZD 14–17) | – |
| n/N (%) | 36/454 (7.9) | 17/138 (12.3) | |
| Resistant | (ZD ≤ 13) | (ZD ≤ 13) | (ZD ≤ 9) |
| n/N (%) | 65/454 (14.3) | 40/138 (29.0) | 107/644 (16.6) |
| Etest done | 65/65 | 40/40 | 103/107 |
| Range of MICs (μg/mL) | (0.02–256) | (0.05–256) | (0.96–968) |
| % of specimens greater than cutoff for resistance | 37/65 (57% ≥ 16 µg/mL) | 32/40 (80% ≥ 8µg/mL) | 86/103 (83.4% ≥ 32 µg/mL) |
MIC = minimum inhibitory concentration; ZD = Zone diameter.