GENETIC-RELATIONSHIP OF PENICILLIN-RESISTANT STREPTOCOCCUS-PNEUMONIAESEROTYPE 19B STRAINS IN JAPAN

Pulsed held gel electrophoresis (PFGE) of the genomic DNA of penicilli n resistant serotype 19B Streptococcus pneumoniae was carried out. Thi rteen strains form the Nagasaki area and 12 strains from other areas i n Japan were examined. Twenty-three strains were resistant to erythrom ycin, tetracycline and trimethoprim/sulfamethoxazole but susceptible t o chloramphenicol. Eight strains were resistant to ceftriaxone. All st rains were multiply resistant. Five strains isolated from Nagasaki wer e indistinguishable from each other by using restriction enzymes Apa I and Sma I. Two strains isolated from other areas were indistinguishab le from the above five strains. We could classify 13 Nagasaki strains into 3 groups and the total of 25 Japanese strains into 6 groups. Thes e results suggest that the increasing prevalence of multiply drug resi stant S. pneumoniae serotyped 19B in Japan is not due to a single clon e, but at least one clone has spread widely in Japan.