Nosocomial bacteremia:: epidemiology and current antimicrobial drugs resistances

Nosocomial bacteremia is a major cause of morbidity and mortality. A change is being observed in the distribution of its causative agents, as well as an increase in the resistances to some antimicrobial drugs. We have analyzed 600 significant bacteremia episodes during the year 2002, studying the resistances to antimicrobial drugs and some epidemiological aspects. Bacteremias caused by gram-positive were 57%, while the ones caused by gram-negative were 46.1%. The three microorganisms more frequently isolated were Staphylococcus epidermidis, Escherichia coli and Staphylococcus aureus. In S. aureus low resistance to oxacillin (10.3%) was observed. Streptococcus pneumoniae with lower sensitivity to penicillin was observed in 49.9%. Resistance of gram-positive microorganisms to vancomycin/teicoplanin was not observed. E. coli and Klebsiella pneumoniae showed low prevalence of expanded spectrum B-lactamase strains. There are differences in epidemiology of bacteremias at regional level, and continuous local programs for monitoring resistances to antimicrobial drugs are needed.