The pathogens of blood stream infection in the patients who applied to emergency medicine service: a three year retrospective analysis of a university hospital

Blood stream infection (BSI) is a critical clinic situation that requires immediate diagnosis and treatment. In this study, we aimed to determine the BSI pathogens among the patients who admitted to emergency medicine clinic (EC). A retrospective surveillance study was conducted to evaluate the results of blood culture of the emergency patients in a university hospital between January 2015 and December 2017. Total 4569 blood culture were performed between the study period, and 802 (17.5%) of them yielded positive result, of which 14 (1.7%) were fungi, and remaining 788 (98.3%) were bacteria. Except the coagulase-negative staphylococci (CNSs) which was the major contaminant of blood cultures; Escherichia coli (n: 170; 21.2%) was the most frequently isolated organisms in this survey, and this was followed by Klebsiella spp. (n: 55; 6.8%) and Staphylococcus aureus (n: 54; 6.7%). The frequency of extended spectrum beta-lactamases (ESBLs) among the members of Enterobacteriaceae was measured as 38.2%, and the methicillin resistance of S. aureus was 7.4%. The common community acquired bacteremia agents were detected as relatively less, in such an order as Streptococcus pneumoniae (n: 14; 1.7%), beta-hemolytic streptococci (n: 11; 1.3%), and Brucella spp. (n: 7; 0.8%). This study indicates that gram negative enteric bacteria are the most frequent pathogens of BSI, and the high antimicrobial resistance mediated by ESBL resistance poses a substantial therapeutic problem in our region. The results also suggest that S. pneumoniae seems to be circulating in the community despite the vaccination campaigns. Emergency departments are critical units to diagnose community-acquired bacteremia and to commence appropriate antimicrobial chemotherapy for the patients with BSI.