Table I.
Temporal comparison of minimum inhibitory concentration 50 (MIC50) and minimum inhibitory concentration 90 (MIC90) for azithromycin in enteric fever isolates
| Year | Salmonella Typhi | Salmonella Paratyphi A | ||||||
|---|---|---|---|---|---|---|---|---|
| Total number of isolates | S % (95% CI) | MIC50 (μg/ml) | MIC90 (μg/ml) | Total number of isolates | S % (95% CI) | MIC50 (μg/ml) | MIC90 (μg/ml) | |
| 1993-2007 | 71 | 98.6 (92.4-99.8) | 8 | 12 | 11 | 100 (74.1-100) | 8 | 12 |
| 2008 | 81 | 92.6 (84.8-96.6) | 6 | 12 | 24 | 75 (55.1-88) | 12 | 16 |
| 2009 | 76 | 84.2 (74.4-90.7) | 8 | 12 | 21 | 76.2 (54.9-89.4) | 8 | 16 |
| 2010 | 98 | 92.9 (85.9-96.5) | 6 | 12 | 23 | 73.9 (53.5-87.4) | 12 | 16 |
| 2011 | 11 | 90.9 (62.3-98.4) | 8 | 12 | 4 | 100 (51.0-100) | 12 | 16 |
| 2012 | 13 | 92.3 (66.7-98.6) | 8 | 12 | 4 | 100 (51.0-100) | 12 | 16 |
| 2013 | 17 | 88.2 (65.7-96.7) | 6 | 12 | 6 | 83.3 (43.6-96.9) | 12 | 16 |
| 2014 | 14 | 92.9 (68.5-98.7) | 8 | 12 | 4 | 100 (51.0-100) | 16 | 16 |
| 2015 | 15 | 100 (79.6-100) | 12 | 16 | 11 | 45.4 (21.3-71.9) | 16 | 24 |
| 2016 | 73 | 98.6 (92.6-99.8) | 12 | 12 | 25 | 72 (52.4-85.7) | 16 | 24 |
| Total | 469 | 93.2 (90.5-95.1) | 12 | 12 | 133 | 76.7 (68.8-83.0) | 16 | 16 |
Antimicrobial susceptibility results are given for disk diffusion method (same results were obtained by all the methods used for susceptibility testing). Isolates from 1993 to 2007 are grouped together for analysis. MIC50, the concentration of drug inhibiting 50% of the isolates; MIC90, the concentration of drug inhibiting 90% of the isolates; CI, confidence interval; S, susceptible