MICROBIOLOGICAL ANALYSIS OF BLOOD CULTURES: A Gram stain will be performed on each positive blood culture. The positive blood cultures in the aerobic media will be subcultured on blood agar and chocolate agar in an atmosphere of 5 to 10% carbon monoxide and on MacConkey agar under aerobic conditions. The same protocol will be used for the positive blood cultures in the anaerobic media, with subculture on Schaedler agar and incubation in an anaerobic atmosphere. The bacteria isolated will be identified by using the battery of biochemical tests provided with the Vitek system for Gram-positive bacteria, Neisseria spp., Haemophilus spp., and obligate anaerobic bacteria. The viridans group streptococci will be classified into five groups, the Streptococcus mitis, S. anginosus, S. salivarius, S. mutans, and S. bovis groups, by applying the Ruoff criteria. Facklam's criteria will be used to identify unusual Streptococcus spp. and other gram-positive cocci in chains.