Susceptibility profile of Gram-negative bacteremic isolates to beta lactam-beta lactamase inhibitor agents in comparison to other antibiotics

Comprehensive understanding about the local antibiogram is an essential requirement for preparation of hospital or unit based antibiotic policy. Bacteremic isolates are the most useful ones for this purpose, representing invasive disease. To analyze susceptibility pattern of bacteremic Gram-negative isolates in our center, to various antibiotics, including beta lactam-beta lactamase inhibitor (BL-BLI) agents and carbapenem. This is a retrospective study done in Apollo Specialty Hospital, a tertiary care oncology center in South India. The susceptibility of Escherichia coli, Klebsiella, Acinetobacter and Pseudomonas blood culture isolates, identified between January 2013 and June 2014 to various antibiotics were analyzed. A total of 231-Gram-negative bacteremic isolates were analyzed. ESBL rate among E. coli isolates was 82.7% (67 out of 81) and 74.3% (58 out of 78) in Klebsiella. Carbapenem (imipenem) susceptibility rate in E. coli was 76.5%, Klebsiella 58.9%, Acinetobacter 32% and Pseudomonas 77.2%. Colistin susceptibility in E. coli was 96.2%, Klebsiella 93.5%, Acinetobacter 92.8% and Pseudomonas 97.7%. Difference in the susceptibility of Enterobacteriaceae to BL-BLI agents (especially cefepime-tazobactam) and carbapenem were minimal. In nonfermenters, BL-BLI susceptibility was better than that of carbapenem. Findings of the study make a strong argument for using BL-BLI agents and sparing carbapenem to curtail the spiraling scenario of carbapenem resistance.