1997 Volume 22 Issue 3 Pages 264-274
During the last 7-year period from 1991 to 1997, β-hemolytic streptococci, Haemophili and in Moraxella (Branhamella) catarrhalis in throat of healthy school children in Morioka were examined. The results were summerized as follows. 1. The rates of isolation of β-hemolytic streptococci in lower-grade children were higher than in upper-grade children. 2. In the isolated β-hemolytic streptococci, group A streptococci were the most prevalent. The isolation rates of the group were from 61.3% to 96.6%, followed by group B, group G and group C streptococci. 3. Type T3 and T12 were dominant in this period: the isolation rates of type T3 were at the top in 1993 and 1994, and those of type T12 were high in 1991, 1992, 1996 and 1997. Although type T1, T4 and T28 were low epidemic T types, these types were isolated almost every year. A similar tendency was seen in the results of clinical specimens. 4. Genome typing of type T3 group A streptococci, which were isolated dominantly, was performed by pulse-field gel electrophoresis (PFGE). These were divided into two PFGE types. The two types were provisionally designed as type I and Ⅱ. Most of the isolates tested belonged to type I, and isolates of type H were observed only in 1994.5. The average rate of isolation of Haemophili was 6.3% regardless of the grade or year. 6. The rates of isolation of M.(B.) catarrhalis were higher in the lower grades than in the upper grades: 49.9% in the first grade and 17.7% in the 6th grade. 7. In the isolated M.(B.) catarrhalis, the production rate of penicillinase positive isolates was 87.4% and that of cephalospolinase positive was 81.7%.
