An epidemiological study of methicillin-resistant Staphylococcus aureus (MRSA) isolated from medical staff, inpatients, and hospital environment in one ward at our hospital.

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most important causative microorganisms for nosocomial infections. Recently, the incidence of isolation of MRSA has been increasing every year in Japan and is, notably, much more frequently found in inpatients than in outpatients. Therefore, we have done epidemiological studies of MRSA isolated from medical staff, inpatients, and the hospital environment in one ward of our hospital. Thereafter, we examined the antibiotic susceptibility (ABPC, DMPPC, CET, CMZ, IPM, GM, MINO, OFLX, EM, CLDM, VCM), phage typing, and coagulase typing of these MRSA. MRSA were isolated more frequently from anterior nares of inpatients than from doctors and nurses. MRSA were isolated more frequently from the environment near carriers of MRSA. Coagulase type II and phage type N.T. (not typable) were the dominant types of MRSA in our hospital (69% and 61%). MRSA strains were resistant to most antibiotics with a few exceptions (VCM, IPM, CMZ, CET). The high isolation frequency of MRSA in our hospital seems to suggest that inpatients who are carrying MRSA spread MRSA throughout the hospital environment and that the anterior nares of inpatients are the major MRSA harbor.

[An epidemiological study of methicillin-resistant Staphylococcus aureus (MRSA) isolated from medical staffs, inpatients and hospital environments at our hospital].

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most important microorganisms which is causative of the nosocomial infections. Recently the incidence of isolation of MRSA is increasing from year to year in Japan. Especially MRSA isolated from inpatients are much higher than from outpatients. Therefore we have done epidemiological studies about MRSA isolated from medical staffs, inpatients and hospital environments in our hospital. Thereafter we examined phage typing and coagulase typing of those MRSA. MRSA were isolated more frequently from anterior nares of inpatients in compare with doctors and nurses. MRSA were isolated more frequently from the environments of MRSA carriers. Coagulase type II and phage type N.T. (not typable) were dominant type of MRSA in our hospital (69% and 61%). Our studies have revealed that the isolation frequency of MRSA is very high in our hospital. It seems to suggest that inpatients who are carrying MRSA are spreading MRSA out hospital environments and medical staffs.