SUSCEPTIBILITY PATTERN AND FREQUENCY OF EXTENDED SPECTRUM β-LACTAMASE PRODUCERS IN A TERTIARY CARE HOSPITAL

Abstract

Objectives: Infections with extended spectrum β-lactamase (ESBL) producing organisms continue to be associated with higher rates of mortality, morbidity and health care costs. This study was carried out to find out frequency and sensitivity pattern of ESBL producers among Gram negative rods (GNRs) from clinical isolates of a tertiary care Hospital.

Design: Descriptive Study

Setting: The study was carried out in the Microbiology Department of Army Medical College - NUST over a period of 1 year (1^st Jan 08 - 31st Dec 08).

Materials & Method:  A total of 1430 GNRs were recovered from 2347 clinical samples received from admitted patients in Military Hospital Rawalpindi. All samples were dealt by standard microbiological methods.  Extended spectrum β-lactamase detection in these isolates was done by double disc approximation test of Jarlier et al, 1988.

Results: Frequency of GNRs among clinical isolates was 61% and about 33% of these were ESBL producers.  Escherichia coli were the most frequent ESBL producers followed by Klebsiella pneumoniae. Most of the ESBL producers were isolated from urine followed by catheter tips and pus. Among all the antibiotics tested, ESBL producers showed highest susceptibility to carbapenems followed by amikacin. Organisms showing resistance pattern similar to ESBLs were also significant.

 

Conclusion: Continued surveillance by clinical microbiology laboratories, judicious use of antimicrobial agents and implementation of infection control measures are recommended to reduce the frequency of ESBL isolates.

 

Key Words: Extended spectrum β lactamase producers, Gram negative rods, Frequency, Sensitivity, Imipenem

, Meropenem.