Nosocomial septicemias due to methicillin-resistant staphylococcus aureus and Pseudomonas aeruginosa in a university hospital over a 12-year period--the same intractable infections.

Clinical features of nosocomial bacteremias due to methicillin-resistant Staphylococcus aureus (MRSA) (M group, n = 71) and Pseudomonas aeruginosa (P group, n = 25) in a university hospital during 1982-1993 were retrospectively analyzed. The majority of these patients had an underlying disease, and bacteremia occurred in hospital. There were no differences in the male to female ratio and the mean age of the patients between the two groups. The ratio of medical wards to surgical wards was higher in the P group (18/7 = 2.6) than for the M group (38/33 = 1.2). P. aeruginosa was more frequently isolated from patients with hematological malignancies and MRSA with solid tumors. The percentage of MRSA among gram-positive bacteremia and of P. aeruginosa among gram-negative bacteria has shown a tendency to increase in recent years, and antibiotic sensitivity of these two organisms showed, on a whole, a tendency to decrease. Attention should be called to the increase of these two pathogens.