We studied the distribution and proportion of oral streptococci isolated from dental plaque and saliva of healthy adults and from subgingival plaque and fluid of gingival pocket of periodontitis patients to clarify the relation betweeen oral streptococci and periodontitis. α-hemolytic sreptococci were isolated from all materials of the healthy adults and the periodontitis patients. The isolation rate of β-hemolytic streptococci from dental plaque of the healthy adults was 20%, and the isolation rates of subgingival plaque and fluid of gingival pocket of the periodontitis patients were 25% and 65%, respectively. The isolation rate of non-hemolytic streptococci from dental plaque of the healthy adults was 35% and the isolation rates of subgingival plaque and subgingival fluid of periodontitis patients were 65% and 60%, respectively.The 670 strains of these isolated oral streptococci on the basis of hemolysis were identified as S. sanguis, S. gordonii, S. oralis, S. mitis, S. salivarius, S. mutans, S. sobrinus, S. anginosus, S. intermedius and S. constellatus through biochemical tests. The species which were identified by the biochemical tests, agree to the species identified by DNA-DNA hybridization. Eight of these strains were not identified by the biochemical tests, but were identified as S. sanguis, S. mitis and S. gordonii by DNA-DNA hybridization. The isolation rates of S. gordonii, S. anginosus, S. intermedius and S. constellatus from periodontitis patients were higher than those from healthy adults. These results suggest that those bacteria may be associated with periodontitis.

ヒト上気道に常在する菌として知られているHaemophilus 属菌の口腔内における実態を明らかにする目的で健康な成人38名の唾液と

38名の唾液,

各検体から分離されたH. influenzae, H. parainfluenzae, H. aphrophilus, H. paraphrophilus, H. parahaemolyticus を含む101株についてペニシリン系薬剤6剤, セフェム系薬剤8剤, アミノグリコシド系薬剤2剤, マクロライド系薬剤1剤, テトラサイクリン系薬剤2剤と Chloramphenicol の計20剤を用い, 最小発育阻止濃度を測定した。その結果ペニシリン系6剤のうち, PCGはやや抗菌力が劣り, 他の合成ペニシリン系5剤, なかでもPIPC, APPC, MZPCは優れた抗菌力を示した。セフェム系8剤のうちCZXは0.05μg/mlにピークがあり, 最も強い抗菌力を示した。

またPCG, ABPC, SBPC, CXM, CZX, CMX, CEX, CCL, CMZにMIC≧100μg/mlの高度耐性を示す株がみられ, そのうちペニシリン系耐性株に β-lactamase 産生を確認した。