Staphylococcal Blood Stream Infections: Epidemiology, Resistance Pattern and Outcome at a Level 1 Indian Trauma Care Center

Abstract

Purpose:Blood stream infection (BSI)/bacteremia is a potentially life threatening infection and are associated with a high crude mortality. Coagulase negative Staphylococcus (CONS) and Staphylococcus aureus are the most commonly isolated gram positive bacteria from blood culture samples. While S. aureus is a known pathogen causing BSIs, CONS are considered to be common contaminants of blood culture. Of late many studies have challenged this traditional viewpoint. The aim of this study was to determine the epidemiology and significance of Staphylococcus aureus and CONS bacteremia, their resistance patterns and associated mortality in critically ill trauma patients admitted to a level 1 trauma center.Materials and Methods:The study was conducted from January 2009 to June 2011. All patients from whose blood samples yielded a S. aureus or CONS on culture were included in this study. A detailed history was obtained and follow-up of the patients was done. The isolates of Staphylococci were identified to species level. Antibiotic susceptibility was performed by the disc diffusion method and VITEK-2 system.Results:During this 30 month period, total of 10,509 blood samples were received from 2,938 patients. A total of 1,961 samples taken from 905 patients were positive for one or more pathogens. S. aureus/CONS were isolated from 469 samples from 374 patients. Crude mortality amongst the patients having Staphylococcal BSI was 25% (94/374).Conclusion:Staphylococcal blood stream infections are a leading cause of morbidity and mortality.