[An epidemiological study of group A, B, C and G hemolytic streptococci isolated from elementary school children in the recent 12 years. Part II. Susceptibility to antibiotics. Streptococcal Diseases Study Group].

During a 12-years period between 1980 and 1992, 5,023 strains of hemolytic streptococci were detected from throats of school children, and described in part I. Among them, the following strains their susceptibility were tested to 14 kinds of antibiotics; 1,511 strains of group A, 1,038 of group B, 125 of group C, 553 of group G. 1. No resistant strains against both penicillins (PCG, AMPC, ABPC, ACPC) and cephems (CER, CET, CCL, CEX) could be found. Strains of group B were less susceptible than the others to penicillins and cephems. 2. Some resistant strains were found against macrolides (EM, OL & JM), 5.9-8.6%. These resistant strains belonged many to group A and a few to group B & G. Since 1983, the gradual decrease of the resistant strains was noted though few were found after 1986. 3. To TC a number of resistant strains were detected in group A, B, C & G through this study, (12.5-48.4%). 4. To CP some resistant strains were found from 1980 to 1985 among group A, B & G, 3.0-5.1%. Since 1986, the sharp decrease of the resistant strains was noted. 5. Multiresistant strains to TC, CP and macrolides were found since 1980 to 1982. They were found in many of group A and a few of group B and G, but after 1986 decreased sharply. 6. Most of the multiresistant strains of group A belonged to serotype T-12 and group B to serotype Ia. Ia/c, III and III/R. 7. Among the strains of group A type T-13, there were many resistant strains to TC. The rate of resistant occupied over 60% from 1980 to 1986, but decreased slightly thereafter.