Status of extended spectrum beta lactamase producing Escherichia Coli and Klebsiella species in urinary tract infection

Abstract

Background: Production of Extended Spectrum Beta Lactamases (ESBLs) is an important mechanism of beta-lactam resistance in Enterobacteriaceae. And the occurrence of ESBL producing isolates has increased worldwide.

Methods: The study was carried out in bacteriology laboratory of TUTH from March 2005 to May 2005 that included 371 midstream urine samples (msu). During these three months period, the MSU samples were investigated by conventional semi-quantitative culture technique, antibiotic susceptibility test and ESBL detection test.

Results: Out of 98 significant positive cases, 60 cases were due to E. coli, 5 were due to Klebsiella oxytoca and 4 were due to Klebsiella pneumoniae. Multidrug resistance (MDR, resistant to two or more than two classes of antibiotics) was observed in 61.7% (37/60) of Escherichia coli, 40% (2/5) of Klebsiella oxytoca and 75% (3/4) of Klebsiella pneumoniae. Out of total 69 cases of E. coli and Klebsiella species that were subjected to preliminary Ceftazidime ESBL screening test, 22 isolates were suspected of ESBL production. Finally 27.5% (19/69) were confirmed for production of ESBL by Double Disc Synergy Test (DDST). Out of 19 ESBL producing strains, 16 were found out to be E. coli, one was K. oxytoca and 2 were K. pneumoniae. All ESBL producing strains were found to be multidrug resistant.

Conclusion: There is a great need to conduct this type of study throughout the year to determine their seasonal variation and also for the study of increasing trends of MDR and ESBL . This type of study should also be conducted in other hospital as well.