Frequency, phage types and antibiotic resistance of Staphylococcus aureus isolated from blood cultures in Denmark 1975-1981.

In the period 1975-1981, 4060 cases of Staphylococcus aureus bacteremia were recorded in Denmark, and the corresponding strains were examined. The percentage of strains, resistant to penicillin only, rose to 82, and the percentage of multiply-resistant strains fell to five. Newer phage types (94, 96 and 95) increased from 10% to 27% of the material. These strains were usually resistant only to penicillin, but produced large amounts of penicillinase. The ample penicillinase production has also been characteristic for previous epidemic strains, and it is furthermore correlated to mortality. The overall mortality of 34.6% was lower than that of the preceding period. Mortality rates were highest in elderly patients, nosocomial cases, patients with serious primary diseases and endocarditis cases.