Clonal Diversity of Streptococcus Mutans Clarke (1924) in Caries-Free Adults

Very few information about the clonal profile of Streptococcus mutans in caries-free adults is available. Microbial samples of saliva, tongue dorsum, and dental biofilm were taken from eight caries-free volunteers (DMFT = 0). Presumptive colonies of mutans streptococci were identified until species level. After confirmation, S. mutans strains were grown in liquid culture media and harvested for whole-cell protein extraction. Multilocus Enzyme Electrophoresis (MLEE) separated protein extracts and the bands’ patterns were assessed for six enzymes. Results showed that two or more distinct clonal types (avg = 4.75) were found cocolonizing all the enrolled subjects, confirming the premise that caries-free subjects are prone to be colonized by more than one strain of S. mutans.