Similarity of bacteriocins of Streptococcus mutans from mother and infant

Bacteriocin typing has been used as an epidemiological tool for tracing bacterial infections in man. The production of bacteriocins by 120 Streptococcus mutans isolates from 4 mother-infant pairs was studied to test the likelihood of maternal transmission of this species. The patterns of inhibition were sufficiently different to allow differentiation of the 120 isolates into 42 bacteriocin types. The bacteriocin codes of isolates within one pair did not correspond to the codes of strains isolated from any other pair examined. The number of infant strains (per 10 infant isolates) matching maternal strains within each mother-infant pair were $\text{5}\text{10}$, $\text{10}\text{10}$, $\text{7}\text{10}$, and $\text{9}\text{10}$ for each of the pairs respectively. The results demonstrated significant intra-pair homogeneity of Strep. mutans strains based on bacteriocin production.