Antibiotic susceptibilities and serotypes of hemolytic streptococci isolated in Japan from 1980 to 1982

Abstract

During the period of 1980-1982, a total of 2, 457 strains of group A hemolytic streptococci were isolated in Japan. We examined the susceptibility to antibiotics and 1927 strains of them were typed serologically by T-agglutination procedure. 86 strains of group B hemolytics isolated in 1982 were also subjected to the antibiotics susceptibility test.The results were as follow:1) None of the resistant strains against β-lactam group of antibiotics was found as former survey.2) Incidence of the TC-resistant strains in whole isolates has not been changed since 1976. Those of CP-and MLs-resistant isolates increased since 1978 till 1981, then decreased in 1982.3) The main sources of a resistant isolates were scarlet fever patients and next to them were the patients of infectious disease other than scarlet fever.4) Serotype 12 was the main type in isolates from infectious disease patients including scarlet fever, but from the healthy pupil, serotype 12, 1, 6, 13, 28 were isolated nearly same rate.5) The number of multiple resistant strains of serotype 12 decreased remarkably in 1982. We found that the isolates of serotype 1 tend to be sensitive to all antibiotics, those of type 4 TC monoresistant, and type 6 TC-CP biresistant. All of the type 18 strains were sensitive to all antibiotics studied.6) One of the 86 strains of group B hemolytic storeptococci had ≥ 400, μ g/ml MIC against OL, but remained relatively sensitive to EM.