C-174. Comparison of BACTEC PLUS Blood Culture Media to VersaTREK Blood Culture Media to Detect Bacterial Pathogens in Samples Containing Antibiotics

H. Carrero, L. Ortega, R. Van Brakle, G. Van Horn, M. Scheckelhoff, A. Ewell;
Walter Reed Army Med. Ctr., Washington, DC.

Blood cultures are critical for the diagnosis and treatment of bacteremia. Early diagnosis and treatment results in better patient outcome. This study compared the ability of two blood culturing systems, BD BACTEC and VersaTREK to remove vancomycin, piperacillin and cefoxitin and allow bacterial pathogens to grow. Each bottle was inoculated with human blood, antibiotic and strains of methicillin susceptible Staphylococcus aureus, methicillin resistant Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa susceptible to the appropriate antibiotic. Two rounds of testing in triplicate were completed using 100 CFU/ml of organisms with three concentrations of each antibiotic. Bottles were mixed and loaded onto instruments as per manufacturer's instructions. Antibiotic removal was evaluated on the basis of time to detection of organism growth for up to five days of incubation. Overall, the BACTEC Plus recovered 100% of strains from test bottles and growth control bottles, the TREK system recovered 55.45% of strains from test bottles and 100% of strains from growth control bottles. This study demonstrates the ability of BACTEC Plus to detect and recover bacterial pathogens more efficiently than the TREK system in the presence of antibiotics.