UMMS Affiliation

Department of Emergency Medicine

Publication Date


Document Type



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.

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© 2004 Karlowsky et al; licensee BioMed Central Ltd. This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original URL.

DOI of Published Version



Ann Clin Microbiol Antimicrob. 2004 May 10;3:7. Link to article on publisher's site

Journal/Book/Conference Title

Annals of clinical microbiology and antimicrobials

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Link to Article in PubMed

PubMed ID