Activity of beta-lactam beta-lactamase inhibitor combinations against extended spectrum Beta-lactamase producing Enterobacteriaceae in urinary isolates.
OBJECTIVE
To determine the susceptibility pattern of beta-lactam beta-lactamase inhibitor combinations against extended-spectrum beta-lactamase (ESBL) producing Enterobacteriaceae in urinary isolates.


METHODS
Observational study.


METHODS
Ziauddin University Hospital, Karachi, from February to October 2008.


METHODS
A total of 190 consecutive non-duplicate isolates of ESBL producing Enterobacteriaceae from urine samples of in-patients were included in the study. Urinary samples from out-patients, repeat samples and non-ESBL producing isolates were excluded. Detection of ESBL was carried out by double disk diffusion technique. Antimicrobial susceptibility testing was performed using modified Kirby Bauer's disk diffusion method according to CLSI guidelines. Statistical analysis was performed by SPSS version 10.


RESULTS
Of the 190 ESBL isolates tested, 88 cases (46.31%) were sensitive and 6 cases (3.15%) were resistant to all three combinations, the rest 96 cases (50.52%) were resistant to at least one of the combinations. Susceptibility pattern of cefoperazone/sulbactam, piperacillin/tazobactam, and amoxicillin/clavulanic acid was 95.26, 92.10, and 44.31 percent respectively.


CONCLUSIONS
Cefoperazone/sulbactam exhibited the best activity against ESBL producing Enterobacteriaceae followed by piperacillin/tazobactam. Hospital antibiotic policies should be reviewed periodically to reduce the usage of extended spectrum cephalosporins and replace them with beta-lactam beta-lactamase inhibitor combinations agent for treating urinary tract infections.
Department of Clinical Microbiology, Dr. Ziauddin University Hospital, Karachi. afridi03@hotmail.com
Faisal Iqbal
FI
Afridi
Badar Jahan
BJ
Farooqi
D000658:Amoxicillin / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002438:Cefoperazone / Q000494:pharmacology; D002969:Clavulanic Acids / Q000494:pharmacology; D004755:Enterobacteriaceae / Q000187:drug effects* / Q000302:isolation & purification*; D004756:Enterobacteriaceae Infections / Q000188:drug therapy* / Q000382:microbiology*; D006801:Humans; D008826:Microbial Sensitivity Tests; D010397:Penicillanic Acid / Q000031:analogs & derivatives; D010878:Piperacillin; D000077725:Piperacillin, Tazobactam Drug Combination; D012680:Sensitivity and Specificity; D013407:Sulbactam / Q000494:pharmacology; D014552:Urinary Tract Infections / Q000188:drug therapy* / Q000382:microbiology*; D018440:beta-Lactam Resistance / Q000187:drug effects*; D065093:beta-Lactamase Inhibitors
D000900:Anti-Bacterial Agents; D002969:Clavulanic Acids; D065093:beta-Lactamase Inhibitors; D000077725:Piperacillin, Tazobactam Drug Combination; D002438:Cefoperazone; D000658:Amoxicillin; D010397:Penicillanic Acid; D013407:Sulbactam; D010878:Piperacillin