STAPHYLOCOCCUS AUREUS STRAINS ISOLATED IN DANISH HOSPITALS FROM JANUARY 1st, 1966, TO DECEMBER 31st, 1974

Abstract

From 1966-1974, 167,297 [S. aureus] strains isolated from 167,297 patients or staff members in Danish hospitals were registered at Statens Seruminstitut. All strains were phage-typed and examined for production of a Tween-80-splitting enzyme and resistance to HgCl2. Strains (158,236) were examined for resistance to antibiotics. Since 1968, a steep decrease in the number of strains resistant to three or more antibiotics (multiple-resistant) and in strains to the 83A complex was noticed. In recent years an increase in strains belonging to phage-group I and in those referred to as miscellaneous and non-identified was registered. The increase in the non-typable strains might be explained by the shift of the concentration of the typing phages from 1000 .times. RTD [routine test dilution] to 100 .times. RTD. At least 2 factors may have contributed to the reduction of the multiple-resistant strains: an altered antibiotic policy, restricting the use of streptomycin and tetracyclines, and an improved hospital hygiene, diminishing the spread of identical strains within the various departments. It is emphasized that the consumption of methicillin is still increasing.