Infective endocarditis--changes in the microbiological profile.

The clinical material from 120 patients, with clinical diagnosis of infectious endocarditis (IE) (65 patients with IE on native valves and 55 patients with IE on artificial valves, i.e. mechanical or biological prosthesis) treated during the period of 1986-1994 was investigated. Sixty positive cultures were obtained from the valves and 40 positive cultures from the blood, which accounted for 76% and 60% of the confirmed IE cases, respectively. Bacteriological confirmation of IE was obtained in 91 (75.8%) patients, 80.2% of the isolated microorganisms being gram-positive bacteria, 17.6% gram-negative, and 2.2%-fungi. The most frequently isolated bacteriawere coagulase-negative staphylococci. They accounted for 40.5% of infections in the IE patients on native valves, and for 63.3% in those with artificial valves. Streptococci were isolated from 11.8% of the patients with IE on native valves and from only 2% of cases of IE on artificial valves. The multiresistant strains were most frequently isolated from the patients with IE on artificial valves.