TABLE 2.
Comparison of MICs according to antimicrobial and anatomic site of infection
| Antimicrobial and measured parametera | Pharyngeal (n = 205) | Rectal (n = 261) | Urethral (n = 976) |
|---|---|---|---|
| Azithromycin | |||
| MIC50 (μg/ml) | 0.25 | 0.25 | 0.25 |
| MIC90 (μg/ml) | 1 | 0.5 | 1 |
| MIC range (μg/ml) | ≤0.03-32 | ≤0.03-16 | ≤0.03-32 |
| No. (%) with elevated MIC (≥2 μg/ml) | 4 (2.0) | 4 (1.5) | 12 (1.2) |
| Crude OR (95% CI) | 1.6 (0.4–6.3) | 1.3 (0.3–4.9) | Reference |
| City-adjusted OR (95% CI) | 2.2 (0.6–8.5) | 1.6 (0.4–6.0) | Reference |
| Cefixime | |||
| MIC50 (μg/ml) | 0.03 | 0.03 | 0.03 |
| MIC90 (μg/ml) | 0.06 | 0.06 | 0.06 |
| MIC range (μg/ml) | ≤0.015-0.25 | ≤0.015-0.5 | ≤0.015-0.5 |
| No. (%) with elevated MIC (≥0.25 μg/ml) | 3 (1.5) | 11 (4.2) | 29 (3.0) |
| Crude OR (95% CI) | 0.5 (0.1–2.0) | 1.4 (0.6–3.3) | Reference |
| City-adjusted OR (95% CI) | 0.8 (0.2–3.2) | 1.6 (0.7–3.9) | Reference |
| Ceftriaxone | |||
| MIC50 (μg/ml) | 0.015 | 0.015 | 0.015 |
| MIC90 (μg/ml) | 0.06 | 0.03 | 0.06 |
| MIC range (μg/ml) | ≤0.008-0.125 | ≤0.008-0.25 | ≤0.008-0.5 |
| No. (%) with elevated MIC (≥0.125 μg/ml) | 1 (0.5) | 4 (1.5) | 17 (1.7) |
| Crude OR (95% CI) | 0.3 (0.0–3.1) | 0.9 (0.2–3.3) | Reference |
| City-adjusted OR (95% CI) | 0.4 (0.0–3.9) | 0.9 (0.2–4.2) | Reference |
| Ciprofloxacin | |||
| MIC50 (μg/ml) | 0.015 | 0.015 | 0.015 |
| MIC90 (μg/ml) | 16 | 16 | 16 |
| MIC range (μg/ml) | ≤0.015 to ≥16 | ≤0.015 to ≥16 | ≤0.015 to ≥16 |
| No. (%) resistant (MIC of ≥1 μg/ml) | 69 (32.2) | 98 (37.6) | 314 (32.2) |
| Crude OR (95% CI) | 1.0 (0.7–1.5) | 1.3 (0.9–1.8) | Reference |
| City-adjusted OR (95% CI) | 0.9 (0.6–1.3) | 1.2 (0.9–1.7) | Reference |
| Penicillin | |||
| MIC50 (μg/ml) | 0.5 | 0.5 | 0.5 |
| MIC90 (μg/ml) | 2 | 2 | 4 |
| MIC range (μg/ml) | ≤0.25 to ≥16 | ≤0.25 to ≥16 | ≤0.25 to ≥16 |
| No. (%) resistant (β-lactamase positive or MIC of ≥2 μg/ml) | 37 (18.1) | 57 (21.8) | 255 (26.1) |
| Crude OR (95% CI) | 0.6 (0.4–1.0)b | 0.8 (0.5–1.2) | Reference |
| City-adjusted OR (95% CI) | 0.8 (0.5–1.3) | 1.0 (0.6–1.4) | Reference |
| Tetracycline | |||
| MIC50 (μg/ml) | 1 | 1 | 1 |
| MIC90 (μg/ml) | 4 | 16 | 16 |
| MIC range (μg/ml) | ≤0.25 to ≥16 | ≤0.25 to ≥16 | ≤0.25 to ≥16 |
| No. (%) resistant (MIC of ≥2 μg/ml) | 77 (37.6) | 117 (44.8) | 418 (42.8) |
| Crude OR (95% CI) | 0.8 (0.6–1.2) | 1.1 (0.8–1.5) | Reference |
| City-adjusted OR (95% CI) | 0.8 (0.6–1.2) | 1.1 (0.8–1.6) | Reference |
a
Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by employing generalized linear models.
b
P < 0.05.