Table 2.
Minimum Inhibitory Concentration (MIC) for Ciprofloxacin, Azithromycin, and Ceftriaxone Tested Against Salmonella Typhi and Salmonella Paratyphi A
| Settings/region | Ciprofloxacin | Azithromycin | Ceftriaxone | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| %S/I/R | MIC Range (μg/mL) | MIC50 (μg/mL) | MIC90 (μg/mL) | %S/I/R | MIC Range (μg/mL) | Mean MIC (μg/mL) | MIC50 (μg/mL) | MIC90 (μg/mL) | %S/I/R | MIC Range (μg/mL) | Mean MIC (μg/mL) | MIC50 (μg/mL) | MIC90 (μg/mL) | ||
| S. Typhi | S. Typhi_Tier_1 (n = 290) | 3/83/14 | 0.015 to >4 | 0.25 | 4 | 99.6/-/0.4 | 1–64 | 4.70 | 4 | 8 | 100/-/- | 0.03–1 | 0.20 | 0.12 | 0.5 |
| S. Typhi_Tier_2 (n = 191) | 3/70/27 | 0.03 to >4 | 0.25 | >4 | 100/-/0 | 1–16 | 5.75 | 4 | 8 | 100/-/- | 0.06–1 | 0.10 | 0.12 | 0.5 | |
| S. Typhi_Tier_3 (n = 1551) | 3/55/42 | 0.007 to >4 | 0.5 | 4 | 100/-/0 | 0.5–16 | 5.65 | 4 | 8 | 100/-/- | 0.015–1 | 0.22 | 0.25 | 0.5 | |
| S. Typhi_cumulative (n = 2032) | 3/60/37 | 0.007 to >4 | 0.5 | >4 | 99.9/-/0.1 | 0.5–64 | 4.98 | 4 | 8 | 100/-/- | 0.015–1 | 0.22 | 0.12 | 0.5 | |
| Southern India (n = 834) | 3/68/29 | 0.007 to >4 | 0.25 | >4 | 100/-/0 | 0.5–16 | 5.31 | 4 | 8 | 100/-/- | 0.015–1 | 0.24 | 0.25 | 0.5 | |
| Northern India (n = 1089) | 3/56/41 | 0.007 to >4 | 0.5 | >4 | 100/-/0 | 0.5–16 | 5.56 | 4 | 8 | 100/-/- | 0.03–1 | 0.21 | 0.12 | 0.5 | |
| Western India (n = 71) | 3/49/48 | 0.015 to >4 | * | * | 100/-/0 | 2–16 | 6.47 | * | * | 100/-/- | 0.03–0.25 | 0.15 | * | * | |
| Eastern India (n = 38) | 5/42/53 | 0.03 to >4 | * | * | 97/-/3 | 2–64 | 7.42 | * | * | 100/-/- | 0.06–0.5 | 0.16 | * | * | |
| S. Paratyphi A | SPA_Tier_1 (n = 21) | 24/62/14 | 0.06 to >4 | * | * | 100/-/0 | 2–8 | 6.47 | * | * | 100/-/- | 0.12–0.5 | 0.21 | * | * |
| SPA_Tier_2 (n = 44) | 0/91/9 | 0.12 to >4 | * | * | 100/-/0 | 2–16 | 7.09 | * | * | 100/-/- | 0.06–0.5 | 0.20 | * | * | |
| SPA_Tier_3 (n = 276) | 1/78/21 | 0.007 to >4 | 0.5 | 4 | 100/-/0 | 0.25–16 | 7.50 | 8 | 16 | 100/-/- | 0.06–1 | 0.20 | 0.25 | 0.25 | |
| SPA_cumulative (n = 341) | 2/79/19 | 0.007 to >4 | 0.5 | 2 | 100/-/0 | 0.5–16 | 7.39 | 4 | 16 | 100/-/- | 0.06–1 | 0.20 | 0.25 | 0.25 | |
| Southern India (n = 115) | 3/76/21 | 0.007 to >4 | 0.5 | 4 | 100/-/0 | 0.25–16 | 7.22 | 8 | 16 | 100/-/- | 0.12–1 | 0.21 | 0.12 | 0.25 | |
| Northern India (n = 208) | 0/81/19 | 0.12 to >4 | 0.5 | 2 | 100/-/0 | 0.5–16 | 7.58 | 8 | 16 | 100/-/- | 0.06–0.5 | 0.20 | 0.25 | 0.25 | |
| Western India (n = 12) | 33/67/0 | 0.06 to 0.5 | * | * | 100/-/0 | 2–8 | 5.5 | * | * | 100/-/- | 0.12–0.5 | 0.17 | * | * | |
| Eastern India (n = 6) | 0/67/33 | 0.5 to 4 | * | * | 100/-/0 | 8 | 8 | * | * | 100/-/- | 0.12–0.25 | 0.20 | * | * |
Abbreviations: MIC, minimum inhibitory concentration.
*MIC50/MIC90 was not calculated due to fewer isolates <100.