The Prevalence of ESBL Producing Gram Negative Isolates in a Private Laboratory Set Up - A Threat to the Community

Emergence of resistance to beta-lactam antibiotics began even before the first beta-lactam, penicillin, was developed. Many genera of gram-negative bacteria possess a naturally occurring chromosomally mediated beta-lactamase enzymes. Multidrug resistant property of these strains, presents a challenge to the clinician, as they are associated with high morbidity and mortality. The objective of the present study was to find out the prevalence of extended spectrum beta lactamase (ESBL) producing gram negative isolates from various clinical samples.

A retrospective record based study was conducted on the clinical samples collected from various hospitals and testing was done at Malnad Hi-Tech Diagnostic Centre in Shimoga City, Karnataka, between October 2011 and December 2011. ESBL activity was detected by double disk diffusion method with their inhibitors according to Kirby-Bauer technique.

Out of 378 samples collected, urine samples showed the highest prevalence (86.4%). Of the 118 strains of various Gram negative bacilli isolated, 60 showed positive for ESBL production. Out of 60 ESBL positive isolates, predominant organisms were Escherichia coli (49), followed by Klebsiella species (7).

Emergence and spread of multidrug resistant bacteria can minimised, if there is efficient infection control team and antibiotic policy in the hospital.