Epidemiologic Characteristics of T Serotyping in Relation to the Outbreak of Erythromycin Resistant Streptocccus pyogenes

ABSTRACT

PURPOSE: The identification of antigenic specificity of Streptococcus pyogenes using T serotyping is important to understand biologic characteristics of microorganisrns. We would like to disover the association of the occurrence of predominant T type, with possible outbreak of erythromycin resistant Streptococcus pyogenes in this country, which has been documented since the late 1990s. METHODS: Throat swab cultures were taken from a total of 1,294 normal school children(Subject A) in two different geographical areas. A total of 92 strains(Subject B) were obtained from the patients with group A streptococcal infections from Jan. 1998 to Dec. 1998. All strains were serotyped with T protein antisera. RESULTS: The distribution of T12 in Uljin increased from 4.2%(1996) to 45.7%(1998). T4 increased from 6.3% to 20.0%. Thirty-eight out of 92 strains were resistant to erythromycin. Twenty-seven out of 41 strains(T12) were multidrug resistant to erythromycin, clindarnycin, and tetracycline. CONCLUSION: We can see the sudden increase in T12 strains, one of the strains that are resistant to erythromycin in 1998, compared with previous years. T protein serotyping could be epidemiologically useful as a screening methods for detecting erythromycin resistant group A streptococci in hospitals where the routine antibiotic sensitivity test dose not examin for streptococci.