Prevalence of Multiple Beta Lactamases Producing Gram Negative Bacilli from Various Clinical Samples in a Tertiary Care Center at Kancheepuram.

Abstract

Introduction

The increasing numbers of multiple beta lactamases produced organisms leave very limited treatment options for clinicians. Single organism expressing multiple beta lactamase enzymes further complicated the treatment option. Hence this study investigated the co-existence of multiple beta lactamase enzymes in clinical isolates of gram negative bacteria.

Materials and methods

A total of 435 consecutive, non-repetitive, gram negative isolates were collected from various clinical samples included in this study. Antimicrobial susceptibility testing was performed as per CLSI. All the bacterial strains were subjected for detection of ESBL, AmpC, and MBL enzymes as recommended by CLSI.

Results

Out of 435 gram negative bacilli, 105 (24%) were ESBL producers, 40 (9%) were AmpC enzyme producer and 5 (1%) were MBL producers. E.coli was the predominant isolate accounting for (34.3%) of ESBL production, followed by Pseudomonas aeruginosa (31.5%), Klebsiella sps (19%) and Acinetobacter baumannii (31%). The highest incidence of AmpC was seen in E.coli 15.9%, followed by Pseudomonas aeruginosa 10.8%, Klebsiella sps 6.6% and Acinetobacter baumannii 6.8% respectively. While MBL production was only seen in 5 (1%) isolates. Co-existence of ESBL and AmpC was observed in 11 (2.5%), ESBL and MBL coproduction was detected in 4 (1%) and the coproduction of AmpC and MBL was observed in one isolate (0.2%).

Conclusion

Rapid identification of these enzymes along with routine sensitivity reports will help the clinicians in prescribing proper antibiotics and implementing infection control measures to prevent the dissemination of such resistance strains.