摘要:Adhesion to fibrin clots of 21 strains of streptococci isolated from the blood of endocarditis patients was tested before and after the bacteria were exposed to protease, lipase, penicillin, erythromycin and chloramphenicol. The adhesion of all strains, three each of Streptococcus sanguis, S. mutans, S. milleri, S. salivarius and S. faecalis and six of S. mitior (three dextran positive and three dextran negative) was drastically reduced after pretreatment with protease, i.e. adhesion was reduced by at least 62 per cent. S. mutans was the only species to be significantly affected by lipase pretreatment, adhesion being reduced to less than 65 per cent of control. Exposure to penicillin at 1 μg/ml reduced the adhesion of all species except S. fuecalis by at least 25 per cent; chloramphenicol (100 μg/ml) and erythromycin (2.5 μg/ml) reduced the adhesion of only one strain, a different strain of S. mutans in each case.Keywords: Streptococci; Adhesion; Antibiotics; SABE; Fibrin.