Bloodstream Infections: Etiologic Agents and Their Antibiotic Resistance Rates

Abstract

Objective: In this study, we aimed to investigate the etiological agents of bloodstream infections (BSIs) and their antibiotic resistance rates.

Methods: The rates of antibiotic resistance of the microorganisms isolated from blood cultures in the microbiology laboratory between 2012 and 2013 were evaluated retrospectively. Blood cultures were performed by using BACTEC (TM) 9120 (Becton Dickinson, Sparks, MD, USA) automated system. Microorganisms that were isolated were identified by routine microbiological methods.

Results: In our study, BSIs were most frequently detected in the cardiovascular surgery clinic. Out of 95 bacteria isolated from blood culture, 61 (64.2) were Gram-negative bacteria (46% enteric, 18% nonfermentative), 20 (21%) were Candida spp. and 14 (15%) were Gram-positive bacteria. The most effective antibiotics for enteric bacteria were found as colistin, followed by imipenem, meropenem and amikacin and for nonfermentative Gram-negative bacteria as colistin, cefepime, piperacillin-tazobactam, imipenem and amikacin.

Conclusions: When the resistance rates were compared within two years, significant increases in resistance were observed for quinolones and ceftazidime in nonfermentative bacteria, and for carbapenems in enteric bacteria. Regular monitoring of etiological agents of BSIs and their antibiotic resistance rates will guide the selection of empiric therapy.