[Streptococcus dysgalactiae subsp. equisimilis possessing Lancefield's group A antigen].
We isolated Streptococcus dysgalactiae subsp. equisimilis with Lancefield's group A antigen from a patient in Osaka City. This clinical isolate formed beta-hemolytic large colonies on sheep blood agar, and was catalase-negative gram-positive cocci carrying Lancefield's group A antigen. Therefore, Streptococcus pyogenes and this clinical isolate could not be classified by the conventional method on the basis of Lancefield's group antigen. In addition, the rapid detection system of group A streptococci based on group A antigen detection techniques could not divide into two species. Recently, S. dysgalactiae subsp. equisimilis with Lancefield's group G antigen has been isolated from severe invasive streptococcal infection in an increasing frequency in Japan. A possibility that group A S. dysgalactiae subsp. equisimilis cause a serious infection from now on cannot be denied. Thus the discrimination of S. pyogenes from group A S. dysgalactiae subsp. equisimilis is very important. To identify beta-hemolytic streptococci, it is necessary to consider a serogrouping test as one of characteristics of streptococci, and to identify by checking biochemical tests like the PYR test.
Katsukawa
Chihiro
C
Department of Microbiology, Osaka Prefectural Institute of Public Health.
Tamaru
Aki
A
Morikawa
Yoshiro
Y
D000368:Aged; D000942:Antigens, Bacterial / Q000032:analysis / Q000276:immunology*; D006801:Humans; D008297:Male; D012703:Serotyping; D013290:Streptococcal Infections / Q000382:microbiology; D013291:Streptococcus / Q000145:classification* / Q000276:immunology* / Q000302:isolation & purification; D013297:Streptococcus pyogenes / Q000276:immunology / Q000302:isolation & purification
D000942:Antigens, Bacterial