TABLE 3.
Antimicrobial resistance profiles of 145 nonduplicate ESBL-producing E. coli isolates
| Antimicrobial agentb | No. of resistant isolates of each CTX-M typea |
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| CTX-M-1 group |
CTX-M-2 group, CTX-M-2 (n = 19) | CTX-M-8 group, CTX-M-8 (n = 7) | CTX-M-9 group |
Non- CTX-Mc (n = 7) | Total (n = 145) | |||||
| CTX-M-1 (n = 2) | CTX-M-15 (n = 26) | CTX-M-3 (n = 1) | CTX-M-55 (n = 1) | CTX-M-14 (n = 63) | CTX-M-27 (n = 19) | |||||
| Ceftazidime | 0 | 17 | 0 | 1 | 0 | 0 | 1 | 1 | 5 | 25 |
| Aztreonam | 2 | 25 | 0 | 1 | 10 | 0 | 11 | 3 | 7 | 59 |
| Gentamicin | 0 | 6 | 1 | 0 | 4 | 0 | 23 | 0 | 0 | 34 |
| Amikacin | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 1 |
| Minocycline | 2 | 17 | 1 | 1 | 15 | 3 | 37 | 15 | 5 | 96 |
| Chloramphenicol | 0 | 7 | 0 | 0 | 1 | 0 | 14 | 0 | 1 | 23 |
| Fosfomycin | 0 | 1 | 1 | 0 | 1 | 0 | 5 | 1 | 0 | 9 |
| Ciprofloxacin | 0 | 16 | 1 | 1 | 1 | 0 | 28 | 18d | 2 | 67 |
| Levofloxacin | 0 | 16 | 1 | 1 | 0 | 0 | 28 | 18d | 2 | 66 |
a
Interpretation of MIC results was done in accordance with the CLSI criteria in document M7-A9 (19).
b
All ESBL-producing E. coli isolates were resistant to piperacillin and cefotaxime but were susceptible to cefmetazole, flomoxef, and imipenem.
c
Isolates harboring a blaSHV-5-group gene, such as blaSHV-12.
d
Sixteen of 18 E. coli isolates harboring the blaCTX-M-27 gene were serogroup O25.