Characterization of uropathogenic E. coli strains with reduced susceptibility or resistance to extended spectrum cephalosporines.
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| Year of publication | 2009 |
| Type | Conference abstract |
| MU Faculty or unit | |
| Citation | |
| Description | AmpC beta-lactamases and ESBL are enzymes produced by a range of Gram-negative bacteria and able to hydrolyse penicillins, monobactams, cephalosporins and cephamycins and are now big epidemiological, diagnostic and therapeutical problem. During the period June 08- June 09 we have collected 106 E.coli isolates showing reduced susceptibility to extended-spectrum cephalosporines from the urine specimens of hospitalised patients with diagnosis of urinary tract infection. ESBL production was confirmed by DDST (double-disk synergy test). We also ascertained AmpC production. The production of inducible AmpC was assayed by modified DDST and that of constitutive AmpC was tested on agar containing oxacillin as an AmpC inhibitor. All producers were tested for antimicrobial susceptibility to amikacin, imipenem, meropenem, colisitin, piperacillin/tazobactam, cefepime, cefoperazone/sulbactam and tigecycline by the disk diffusion method. We also used modified Christensen method to find out the ability of isolates to produce biofilm. There were detected 88 (83.01 %) ESBL producers, 15 (14.15 %) constitutive AmpC producers, 2 (1.89 %) isolates producing both ESBL and constitutive AmpC and 1 (0.94 %) strain producing both ESBL and inducible AmpC. Eighty eight, i.e. 83.02 % of tested strains were susceptible to amikacin, 105 (99.06 %) to imipenem as well as to meropenem, 103 (97.17 %) to colistin, 43 ( 40.57 %) to piperacilllin/tazobactam, 82 (77.36 %) to cefepime and 49 (46.22 %) to cefoperazone/sulbactam. All the tested strains were susceptible to tigecycline. Biofilm was produced by 6 (5.66 %) strains. |
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