[Hospital infection with methicillin-resistant Staphylococcus aureus (MRSA) in Saga Medical School Hospital, a rapid increase in coagulase type-VIII strains].

Hospital infection with MRSA has increased in Saga Medical School Hospital. The causative MRSA consisted predominantly of coagulase type-II strain before 1989, but after 1990, coagulase type-VII MRSA increased rapidly. This type-VII strain has marked multiple drug-resistance, and the pattern of drug sensitivity of MRSA in this hospital was different from that of MRSA detected in other facilities, which are clinically serious problems, therefore, we conducted an etiological study of the background of the increase in MRSA infection in our hospital. The results of the study are summarized as follows: 1) The proportions of MRSA (on strain from one patient) to all types of S. aureus detected in the hospital were 26% for 1986, 23% for 1988, 37% for 1989, 30% for 1990 and 60% for 1991. The proportion increased greatly in 1991. 2) Coagulase type VII-MRSA was first detected only in 5 patients in 1989, then it tended to spread, and this type (probably derived from the same strain) accounted for 47% of MRSA infection in patients examined in 1991. 3) The study of the drug sensitivity pattern and etiological survey of the infection showed that coagulase type VII-MRSA prevalent in the hospital consisted of two types: CLDM, and EM-sensitive, IPM/CS, and MINO-resistant and TSST-1 non-producing and enterotoxin non-producing type, and CLDM, and EM-sensitive, IPM/CS, and MINO-resistant and TSST-1 non-producing type with enterotoxin serotype A. 4) Coagulase type VII-MRSA (Probably derived from the same strain) was detected in physicians and nurses working in affected wards and also in the patients's room.(ABSTRACT TRUNCATED AT 250 WORDS)