One hundred and seventy four isolates of group A beta-hemolytic
Streptococcus, which were obtained in 1978-80 from 174 children with various streptococcal infections at Asahikawa district, Japan, were typed serologically, and their antibiotic susceptibilities were determined, and compared with those isolated in 1974-75.
One hundred and six (61%) of 174 patients has streptococcal pharyngitis, 60 (35%) carlet fever, three glomerulonephritis, two anaphylactoid purpura, and one each had septicemia, pneumonia and impetigo, respectively. The peak number of patients occurred at the age of 5 years.
One hundred and seventy one strains (98.3%) were typable by means of T-typing, with an occurrence of type 12 in 64 (36.8%), type 4 in 30 (17.2%), type 1 in 29 (16.7%), type 6 in 22 (12.6%); and small numbers of strains were distributed in other serotypes. Type 1 strains were prevalent in patients with nephritis and purpura.
Out of the 174 strains tested, 94 (54.0%) were resistant to tetracycline (TC), 44 (25.3%) to chloramphenicol (CP), and 28 (16.1%) to erythromycin (EM) and lincomycin (LCM), atan antibiotic concentration of 32μg/ml. None of the 174 strains was resistant against each three of penicillin and cephalosporin antibiotics tested.
Rates of antibiotic-resistant strains among isolates in 1978-80 were appreciably lower than those in 1974-75 were appreciably lower than those in 1974-75, in which rate of resistant strains was 72.8% to TC, 69.1% to CP, 61.8% to EM and 64.7% to LCM. 61.8% of strains in 1974-75 were multiply resistant to TC, CP, EM and LCM, in contrast to 13.2% in those in 1978-80.
The serotype of multiply resistant strains was almost exclusively type 12 in either studies. The decline in antibiotic resistance among group A streptococci, accompanied by decrease in occurrence of type 12 strains, was presumably related with decreased use of TC, CP and macrolide antibiotics in Japan since 1975.
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