Bacteriocin patterns of strains belonging to various serotypes of Streptococcus mutans

A number of well-documented strains representative of the various serotypes of Streptococcus mutans were characterized by their ability to produce bacteriocin(s) against 14 selected indicator strains and by their sensitivity to 11 bacteriocinogenic strains of Strep. mutans. This method of characterizing the strains indicated, in agreement with previous suggestions, that strains belonging to serotypes a and b form readily recognizable sub-groups of Strep. mutans. Strains of the recently described serotype g also appeared to comprise a well-defined group but this was not so in the case of the serotypes c, d, e and f. It was concluded that the division of Strep. mutans into sub-species is unwarranted at the present time and that for epidemiological studies, methods such as bacteriocin typing may be of greater value.