Microorganisms Isolated from Blood Cultures and Their Antimicrobial Susceptibility in Hitit University Corum Training and Research Hospital

Abstract

Introduction: In the diagnosis of bacteremia and sepsis, blood culture is the gold standard. Determining the distribution and antibiotic sensitivity of the microorganisms isolated from blood cultures is very important in reducing mortality and morbidity. In this study, it was aimed to investigate the blood cultures sent to our laboratory from our hospital’s intensive care unit and other services and the distribution of isolated microorganisms, extended spectrum beta-lactamase (ESBL) positivity and the susceptibility to various antibiotics. Materials and Methods: Between 01.01.2014 and 31.03.2015, 3100 blood cultures taken from patients were incubated in automated blood culture system (BACT/ALERT 3D, bioMerieux, France) in the Microbiology Laboratory of Hitit University Corum Training and Research Hospital. From signal received bottles, inoculations were made on to blood agar, eosin methylene blue (EMB) and chocolate agar. Plates were incubated at 37°C for 18-24 hours and microorganisms such as Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Staphylococcus aureus, Enterococcus spp.) and antibiotic susceptibilities were determined in VITEK 2 (bioMerieux, France) fully automated bacterial identification device. Results: Among the 224 strains isolated from blood cultures, 80 (35.7%) of them were gram-positive and 144 (64.3%) of them were gram negative bacteria. ESBL-positive strains of E. coli and K. pneumoniae strains were found as 37.2%, 29.4%, respectively. 25% of S. aureus strains was found to be resistant to methicillin. S. aureus and Enterococcus spp. strains were highly sensitive to tigecycline, vancomycin and teicoplanin, while Enterobacteriaceae to carbapenem, colistin and aminoglycosides. Conclusion: Isolation, identification and determination of antibiotic sensitivity of the microorganisms cultivated in blood cultures give a lead in terms of empiric treatment. Since ESBL producing bacteria are multi drug resistant, broad spectrum antibiotics are needed to be used