[Frequency and antibiotic susceptibility of oxacillin resistant Staphylococcus aureus in a teaching hospital]

From October 1993 till October 1994, 115 oxacillin resistant Staphylococus aureus strains were isolated in the laboratory of a teaching hospital. This was 2.4% of all of the Staphylococcus aureus strains. The bacteria were isolated from 30 patients, 7 medical personnel and in the environment of the infected patients. Most of the isolates were cultured from blood cultures, wound swabs and drains. If the referring hospitals has been informed about the MRSA status of the patients, several transmissions could have been prevented. In 10 infected patients, the MRSA strains were isolated from the nose, throat and hands. The isolates were also found on the hands of several personnel and in the patients environment, suggesting that the strains had been widely spread. The MRSA strains predominated in the medical and surgical intensive care units and in 2 general surgical wards. They were only found sporadically in other departments (Ophthalmology, Gynaecology, Paediatrics and Urology). MRSA-strains were more resistant to imipenem, ofloxacin, gentamicin, trimethoprim-sulfamethoxazole, tetracycline, erythromycin and clindamycin as oxacillin-sensitive Straphylococcus aureus strains. Genotyping (Restriction-Fragment-Length-Polymorphism) revealed six different strain patterns. The same RFLP types were mainly found on different wards. We conclude that various clones of MRSA may have emerged independently within one hospital and that their spread between wards was remarkably limited. Subsequent intensive hygiene measures have been successful in reducing the number of new isolates.