- A Nakamura: Division of Infectious Diseases, Chiba Children's Hospital.
Eleven hundreds and seventy-six strains of Streptococcus pneumoniae were isolated from pediatric clinics of Chiba Children's Hospital during 1990 through 1995. Annual penicillin-resistant rates of these strains were as follows; 24.0% (1990), 29.0% (1991), 36.2% (1992), 55.8% (1993), 58.6% (1994), and 59.3% (1995). Overall penicillin-resistance during these 6 years was 45.8%. Nine out of 11 cases of systemic pneumococcal infections were due to penicillin-resistant S. pneumoniae (PRSP) during the same period. Of PRSP strains, their PCG-MIC levels had become higher and their spectra of resistance had expanded not only to beta-lactam but also to non-beta-lactam antimicrobials. Although panipenem was the most efficacious antibiotics in this study and was recommended currently to use in the case of pneumococcal meningitis, it should be noted that a strain with high-level MIC (2 micrograms/ml) had emerged in 1995. Close surveillance of pneumococcal antimicrobial susceptibility including panipenem is necessary.