TABLE 3.
Antimicrobial susceptibility comparison between the H. influenzae study group isolated in 2007 and the control group isolated in 1997
| Parameter | No. of isolates (%) for:
|
% Change | Fisher exact test
|
||
|---|---|---|---|---|---|
| 2007 (109) | 1997 (88) | OR (95% CI) | Pd | ||
| Amoxicillin resistance (MIC ≥ 4 μg/ml) | 33 (30.2) | 34 (38.6) | -8.4 | 0.69 (0.38-1.25) | 0.23 |
| β-Lactamase-positive isolates | 19 (17.4) | 29 (32.9) | -15.5 | 0.43 (0.22-0.83) | 0.01 |
| Amoxicillin resistance in β-lactamase-negative isolates | 14 (12.8) | 5 (5.7) | +7.1 | 1.99 (0.68-5.85) | 0.31 |
| Amoxicillin, MIC ≥ 2 μg/mla | 26 (28.9) | 8 (13.6) | +15.3 | 2.60 (1.08-6.20) | 0.04 |
| Amoxicillin, MIC ≥ 32 μg/mlb | 15 (78.9) | 29 (100) | -21.1 | 2.45 (1.02-5.90) | 0.04 |
| Amoxicillin-clavulanic acid, MIC = 2 to 4 μg/mlc | 25 (27.8) | 8 (13.6) | +14.2 | 0.05 (0.003-1.16) | 0.02 |
| gBLNAS | 60 (55) | 43 (48.9) | +6.1 | 1.30 (0.73-2.25) | 0.40 |
| gBLPAR | 16 (14.7) | 17 (19.3) | -4-.6 | 0.72 (0.34-1.52) | 0.44 |
| gBLNAR | 30 (27.5) | 16 (18.2) | +9.3 | 1.71 (0.86-3.40) | 0.13 |
| gBLPACR | 3 (2.8) | 12 (13.6) | -15.4 | 0.13 (0.036-0.45) | 0.0004 |
| Azithromycin, MIC = 2 to 8 μg/ml | 95 (87.2) | 58 (66) | +21.2 | 3.50 (1.72-7.20) | 0.0005 |
| Trimethoprim-sulfamethoxazole, MIC ≥ 4 μg/ml | 38 (34.9) | 44 (50) | -15.1 | 0.53 (0.30-0.95) | 0.04 |
| Trimethoprim-sulfamethoxazole and amoxicillin simultaneous resistance | 16 (14.7) | 23 (26.1) | -11.4 | 0.49 (0.24-1.00) | 0.04 |
a
This values includes intermediate and resistant isolates (9). Total β-lactamase-negative isolates: 90 in 2007 and 59 in 1997.
b
Total β-lactamase-positive isolates: 19 in 2007 and 29 in 1997.
c
Total β-lactamase-negative isolates: 90 in 2007 and 59 in 1997.
d
Significant values are indicated in boldface.