Department of Emergency Medicine
Bacterial Infections; Bacteremia; Anti-Infective Agents
Bacterial Infections and Mycoses | Emergency Medicine | Life Sciences | Medical Microbiology | Medicine and Health Sciences
BACKGROUND: Bloodstream infections are associated with significant patient morbidity and mortality. Antimicrobial susceptibility patterns should guide the choice of empiric antimicrobial regimens for patients with bacteremia.
METHODS: From January to December of 2002, 82,569 bacterial blood culture isolates were reported to The Surveillance Network (TSN) Database-USA by 268 laboratories. Susceptibility to relevant antibiotic compounds was analyzed using National Committee for Clinical Laboratory Standards guidelines.
RESULTS: Coagulase-negative staphylococci (42.0%), Staphylococcus aureus (16.5%), Enterococcus faecalis (8.3%), Escherichia coli (7.2%), Klebsiella pneumoniae (3.6%), and Enterococcus faecium (3.5%) were the most frequently isolated bacteria from blood cultures, collectively accounting for >80% of isolates. In vitro susceptibility to expanded-spectrum beta-lactams such as ceftriaxone were high for oxacillin-susceptible coagulase-negative staphylococci (98.7%), oxacillin-susceptible S. aureus (99.8%), E. coli (97.3%), K. pneumoniae (93.3%), and Streptococcus pneumoniae (97.2%). Susceptibilities to fluoroquinolones were variable for K. pneumoniae (90.3-91.4%), E. coli (86.0-86.7%), oxacillin-susceptible S. aureus (84.0-89.4%), oxacillin-susceptible coagulase-negative staphylococci (72.7-82.7%), E. faecalis (52.1%), and E. faecium (11.3%). Combinations of antimicrobials are often prescribed as empiric therapy for bacteremia. Susceptibilities of all blood culture isolates to one or both agents in combinations of ceftriaxone, ceftazdime, cefepime, piperacillin-tazobactam or ciprofloxacin plus gentamicin were consistent (range, 74.8-76.3%) but lower than similar beta-lactam or ciprofloxacin combinations with vancomycin (range, 93.5-96.6%).
CONCLUSION: Ongoing surveillance for antimicrobial susceptibility remains essential, and will enhance efforts to identify resistance and attempt to limit its spread.
Annals of clinical microbiology and antimicrobials
Karlowsky, James A.; Jones, Mark E.; Draghi, Deborah C.; Thornsberry, Clyde; Sahm, Daniel F.; and Volturo, Gregory A., "Prevalence and antimicrobial susceptibilities of bacteria isolated from blood cultures of hospitalized patients in the United States in 2002" (2004). Open Access Articles. 2262.