Table 2.
Summary of antimicrobial co-resistance rates determined for a) E . coli, b) K . pneumoniae, c) K . oxytoca, d) E . cloacae, and e) P . aeruginosa
| a) E. coli | ||||||
|---|---|---|---|---|---|---|
| No. of isolates (n) | Resistance to | Co-resistance rate with antibiotic (%) | ||||
| 2002-06 | Ceftriaxone | Ciprofloxacin | Pip-tazo | TMP-SMX | Tic-clav | |
| 44 | Ceftriaxone | 73 | 14 | 59 | 59 | |
| 194 | Ciprofloxacin | 16 | 8 | 62 | 31 | |
| 3 | Pip-tazo | 33 | 67 | 67 | nd | |
| 193 | TMP-SMX | 13 | 63 | 8 | 31 | |
| 91 | Tic-clav | 29 | 67 | nd | 66 | |
| 2007-11 | ||||||
| 146 | Ceftriaxone | 73 | 18 | 72 | 48 | |
| 357 | Ciprofloxacin | 30 | 10 | 58 | 26 | |
| 28 | Pip-tazo | 57 | 71 | 79 | nd | |
| 373 | TMP-SMX | 28 | 56 | 10 | 27 | |
| 64 | Tic-clav | 42 | 61 | nd | 61 | |
| 2002-11 | ||||||
| 190 | Ceftriaxone | 73 | 18 | 69 | 53 | |
| 551 | Ciprofloxacin | 25 | 10 | 60 | 29 | |
| 31 | Pip-tazo | 55 | 71 | 77 | nd | |
| 566 | TMP-SMX | 23 | 58 | 9 | 30 | |
| 155 | Tic-clav | 34 | 65 | nd | 64 | |
| b) K. pneumoniae | ||||||
| No. of isolates (n) | Resistance to | Co-resistance rate with antibiotic (%) | ||||
| 2002-2011 | Ceftriaxone | Ciprofloxacin | Pip-tazo | TMP-SMX | Tic-clav | |
| 20 | Ceftriaxone | 60 | 35 | 83 | 53 | |
| 54 | Ciprofloxacin | 22 | 22 | 46 | 29 | |
| 10 | Pip-tazo | 60 | 50 | 40 | nd | |
| 44 | TMP-SMX | 30 | 57 | 16 | 37 | |
| 19 | Tic-clav | 26 | 58 | nd | 53 | |
| c) K. oxytoca | ||||||
| No. of isolates (n) | Resistance to | Co-resistance rate with antibiotic (%) | ||||
| 2002-2011 | Ceftriaxone | Ciprofloxacin | Pip-tazo | TMP-SMX | Tic-clav | |
| 8 | Ceftriaxone | 38 | 20 | 25 | 50 | |
| 5 | Ciprofloxacin | 60 | 0 | 20 | 25 | |
| 2 | Pip-tazo | 50 | 0 | 0 | nd | |
| 5 | TMP-SMX | 40 | 20 | 0 | 100 | |
| 3 | Tic-clav | 67 | 33 | nd | 33 | |
| d) E. cloacae | ||||||
| No. of isolates (n) | Resistance to | Co-resistance rate with antibiotic (%) | ||||
| 2002-2011 | Ceftriaxone | Ciprofloxacin | Pip-tazo | TMP-SMX | Tic-clav | |
| 43 | Ceftriaxone | 26 | 47 | 37 | 81 | |
| 17 | Ciprofloxacin | 65 | 17 | 59 | 91 | |
| 9 | Pip-tazo | 100 | 11 | 11 | nd | |
| 24 | TMP-SMX | 67 | 42 | 6 | 80 | |
| 33 | Tic-clav | 67 | 30 | nd | 24 | |
| e) P. aeruginosa | ||||||
| No. of isolates (n) | Resistance to | Co-resistance rate with antibiotic (%) | ||||
| 2002-2011 | Ceftazidime | Ciprofloxacin | Pip-tazo | Imipenem | Gentamicin | |
| 11 | Ceftazidime | 45 | 50 | 27 | 9 | |
| 22 | Ciprofloxacin | 23 | 24 | 23 | 23 | |
| 6 | Pip-tazo | 83 | 67 | 33 | 33 | |
| 13 | Imipenem | 23 | 38 | 18 | 23 | |
| 9 | Gentamicin | 11 | 56 | 29 | 33 | |
Co-resistance rates were analyzed as a summary of isolates from 2002–2011 except for E. coli, where it was possible to analyze two time periods from 2002–06 and 2007–11 due to higher isolate numbers. Co-resistance rates are rounded to the nearest percent, and those that are ≥50% are highlighted in bold font. Note: Pip-tazo is piperacillin-tazobactam, TMP-SMX is trimethoprim-sulfamethoxazole, Tic-clav is ticarcillin-clavulanate; nd is not determined as isolates did not consistently have both Pip-tazo and Tic-clav susceptibilities reported.