Bacteremia in a university hospital: study of etiological agents and theirsusceptibility patterns

Objective, To determine the bacterial etiology of bacteremic episodes recor ded at our hospital during 1995 and their antimicrobial susceptibility patt erns. Methods. The microbiological records of all bacteremic episodes detected at our hospital from January to December 1995 were analysed, The susceptibili ty patterns of the 334 gram-positive aerobic isolates to 11 antimicrobials and of 236 gram-negative aerobic isolates to 16 antimicrobial agents were d etermined. The reference agar dilution method was used for these determinat ions. Results. The incidence of bacteremia was 19.3/1,000 admissions. Gram-positi ve aerobic bacteria accounted for 56.6% of monomicrobial bacteremias; the m icroorganisms recovered most frequently were coagulase-negative staphylococ ci (22.4%), Escherichia coil (16.5%) and Staphylococcus aureus (14.2%); 75 polymicrobial episodes were recorded. Over half of bacteremic episodes occu rred at medical services. Hematologic diseases and solid tumours were the m ost common underlying diseases. No resistance to glycopeptides was observed among the staphylococci studied. The incidence of resistance to vancomycin in enterococci was small (1.5%). The aminoglycosides tested and some betal actams showed good activity against the gram-negative bacilli studied. Conclusions. To carry out an epidemiologic surveillance of bacteremic episo des occurring at every hospital it is necessary to provide information on t rends observed in the etiology of such infections, possible outbreaks, anti microbial resistance, and uncommon pathogens.