TABLE II. Antimicrobial resistance rates among Pseudomona aeruginosa isolates of the present study and those previously described (Pellegrino et al. 2002).
| Antimicrobial agent | Number and (%) of resistant isolates | ||
|---|---|---|---|
|
| |||
| Clinical isolates | Environmental isolates from present study (2007-2008) n = 17 | ||
|
| |||
| Present study (2007-2008) n = 88a | Pellegrino et al. (2002) (1999-2000) n = 115b | ||
| Amikacin | 16 (18.2) | 41 (35.6)* | 5 (29.4) |
| Cefepime | 33 (37.5) | 47 (41.0) | 3 (17.6) |
| Ceftazidime | 33 (37.5) | 42 (36.5) | 5 (29.4) |
| Ciprofloxacin | 30 (34.1) | 49 (43.0) | 9 (52.9) |
| Gentamicin | 30 (34.1) | 55 (48.0) | 7 (41.2) |
| Imipenem | 31 (35.2) - 27 (30.7)c | 44 (38.3) | 4 (23.5) |
| Meropenem | 24 (27.3) -20 (22.7)c | 35 (30.4) | 1 (5.9) |
| Piperacillin-tazobactam | 32 (36.4) - 25 (28.4)c | 42 (36.5) | 0 |
| Tobramycin | 29 (33.0) | Not tested | 8 (47.0) |
One isolate with resistance to the greatest number of antimicrobial agents was selected per patient from a total of 225a or 200b; all isolates were susceptible to colistin (minimum inhibitory concentration < 2 μg/mL). Data for interpretation with Clinical and Laboratory Standards Institute (NCCLS) 1999 are presented in c; *: comparison between clinical isolates exhibited p = 0.01; other comparisons were p-values > 0.06.