Streptocci of the mutans group: confirmation of intrafamilial transmission by mutacin typing / Estreptococus de grupo mutans: confirmação da transmissão intra familiar pela sepajem por mutacina

ABSTRACT

We selected 22 families of different socioeconomic levels residing within the urban perimeter of Ribeirão Preto, State of São Paulo, and consisting of parents and at least two children, one of whom had to be edentulous on the occasion of the first collection of material. A total of 397 mutans strains isolated from 112 individuals were submitted to mutacin typing; 391 of them were from dental plaque and 6 from gingival mucosa, and only 95 (23.93 percent) were found to be mutacin producers. Seventy-one different bacteriogenic patterns were detected, as well as a greater proportion of individuals with multiple bacteriocin types. In all families there were similarities between strains isolated from one or more family members. The mother was not considered to be the most likely source of infection and intrafamilial transmission of streptococci from buccal cavity was confirmed