[Community- and hospital-acquired bacteremia: a retrospective study in a regional hospital. III. Microbiological aspects].

A retrospective study was made of all blood cultures performed over a 40-month period at the Ivrea-Castellamonte Hospital (Turin, Italy). A total of 4386 vials from 619 patients were examined. There were 619 positive vials (14.1%) from 131 patients (21.2%) corresponding to 145 bacteremia episodes, including 129 monomicrobial (89%) and 16 polymicrobial (11%). Ten patients (1.6%) had more than one episode. There were 73 polluted vials (1.7%). A total of 165 microorganism were isolated: Gram-positive (52.7%) and Gram-negative (46%) bacteria, and mycetes (1.2%), anaerobic flora (9.7%). The predominant families were: Enterobacteriaceae (29.5%), Micrococcaceae (27.3%), Pseudomonadaceae (4.8%), Bacteroidaceae (4.8%) and Streptococcus "Genus" (18.8%). The species frequencies were: Escherichia coli (20%), Staphylococcus aureus (15.8%), Enterococcus (8.5%), Staphylococcus epidermidis (7.3%), Pseudomonas aeruginosa (4.8%), Proteus mirabilis (4.2%), Brucella spp. (2.4%), Bacteroides fragilis, Streptococcus bovis e Propionibacterium acnes (1.8%). These findings are compared with those published in the Italian and international literature. Stress is laid on periodical review of the isolations from samples of this kind as a useful aid towards the diagnosis and treatment of hospital infections, and in their monitoring and epidemiological evaluation.