TABLE II. Results of the antimicrobial susceptibility testing of Haemophilus influenzae-resistant isolates recovered from patients in Rio de Janeiro state, Brazil, 1993-2014.
| Time period Serotype (number of isolates) | β-lactamase-positive | Ampicillin MIC ≥ 4 µg/mL | Chloramphenicol MIC ≥ 8 µg/mL | Ampicillin* and chloramphenicol | Cotrimoxazole MIC ≥ 1 µg/mL |
|---|---|---|---|---|---|
| 1993 - 1999 (72) | |||||
| Serotype b (69) | 12% (8/69) | 12% (8/69) | 14% (10/69) | 12% (8/69) | 10% (7/69) |
| b- variant (2) | 0% | 0% | 0% | 0% | 0% |
| Unencapsulated (1) | 0% | 0% | 0% | 0% | 0% |
| 2000 - 2014 (65) | |||||
| Serotype a (12) | 0% | 0% | 0% | 0% | 8% (1/12) |
| Serotype b (32) | 16% (5/32) | 16% (5/32) | 9% (3/32) | 9% (3/32) | 3% (1/32) |
| b- variant (1) | 0% | 0% | Single isolate | 0% | 0% |
| Unencapsulated (20) | 25% (5/20) | 25% (5/20) | 5% (1/20) | 5% (1/20) | 30% (6/20) |
MIC: minimal inhibitory concentration; *: ampicilin MIC ≥ 4 µg/mL and chloranphenicol MIC ≥ 8 µg/mL.