Antibiotic profile of enterobacter isolates from various clinical samples – A study from a tertiary care hospital

Introduction: Enterobacter species, especially Enterobacter cloacae are important nosocomial pathogens. They cause infections of the lower respiratory tract, skin, soft tissue, urinary tract and occasionally sepsis. Enterobacter species are often seen in natural habitats like water and soil. Enterobacter species are often resistant to various antibiotics in a hospital setting. Resistance to antimicrobials can also develop during therapy. The emergence of antimicrobial resistance, especially to third generation cephalosporins is a concern in the management of Enterobacter infections. Objectives: To evaluate the antimicrobial resistance pattern of Enterobacter species isolated from patients attending a tertiary care hospital. Materials and Methods: The present study was conducted in the Microbiology department of a tertiary care hospital. The study was conducted from January 2012 to December 2012. Enterobacter species were isolated from the clinical samples of patients using standard microbiological methods of bacterial culture and identification. Antibiotic susceptibility testing was done by Kirby-Bauer disc diffusion method, according to Clinical laboratory standard institute (CLSI) guidelines. Minimum inhibitory concentration (MIC) of cefotaxime was determined by the micro-broth dilution method. Results: During the study period, 100 isolates of Enterobacter species were isolated from clinical samples. The predominant species of Enterobacterisolated was Enterobacter cloacae(69%), followed by Enterobacter aerogenes (25%). Antibiotic susceptibility testing showed that most of the isolates were resistant to ampicillin (86%). The resistance to cefotaxime was 33%. Conclusion: Enterobacter species in a tertiary care setting could be resistant to common antibiotics like ampicillin and cephalosporins. Clinicians should be aware of these resistance pattern while choosing an empiric antibiotic regimen.