One year trends in the gram-negative bacterial antibiotic susceptibility patterns in a medical intensive care unit in South India.

PURPOSE: To describe the changes in antibiotic susceptibility patterns of common intensive care unit pathogens with time from the medical intensive care unit of a tertiary care hospital.

METHODS: A prospective observational study was conducted in the medical intensive care unit (MICU) of a 2100 bed tertiary care hospital in South India. All data regarding patient characteristics, disease characteristics, infective agents, identified along with their antibiotic sensitivity patterns and patient outcomes were prospectively recorded in MICU data base. Various bacterial pathogen antibiotic sensitivity patterns from August 2004 to May 2005 were prospectively documented. During this period 491 patients were admitted to the MICU. Data were analyzed using excel spreadsheets.

RESULTS: Ceftazidime resistance reduced in Klebsiella spp. while cefotaxime resistance increased. In E. coli however, ceftazidime and cefotaxime resistance increased. Klebsiella resistance to cefotaxime and ceftazidime ranged from 25-50% and 14-91%, while E. coli resistance to these antibiotics ranged from 50-70% and 50 to 80% respectively. In Pseudomonas and the non-fermenting gram-negative bacteria (NFGNB) ceftazidime resistance decreased. Third generation cephalosporin resistance seemed to be reducing in the NFGNB, however, carbapenem resistance appeared to be increasing, possibly due to their increasing use.

CONCLUSIONS: This study demonstrates the trend in antibiotic susceptibility pattern (AST) of common gram negative infections seen in intensive care units. It demonstrates the changes seen especially after a change in the protocol antibiotic. Changes in the AST patterns of Klebsiella, E. coli, Pseudomonas and non-fermenting gram negative bacteria were seen. The data on the changing antibiotic susceptibility trends we believe is an important pillar in our efforts at infection control especially in intensive care settings.