We investigated the spread of Methicillin-resistant staphylococci (MRS) in Osaka Dental University Hospital. We examined the nasal carriage of the medical staff and patients, and tested the antimicrobial susceptibility of isolates. MRS were isolated from three inpatients and a location in a hospital room, but not from any of the medical staff or outpatients. MRS were classified into 9 types according to sensitivity to antibiotics. All strains were susceptible to both chloramphenicol and vancomycin. Classification of the MRS samples indicated that the same substrains were found among the inpatients, suggesting that cross infection was occurring in the hospital.
