Use of bacteriophage-resistant mutants to study Actinomyces viscosus cell surface receptors.

Spontaneously occurring bacteriophage-resistant mutants of Actinomyces viscosus were isolated. The mutants exhibited altered coaggregation patterns with streptococci. From analysis of the data, it appears that a cell surface structure on A. viscosus may function both as a phage receptor and as a binding site for co-aggregation with certain oral streptococci. These mutants will be valuable in the study of surface structures that mediate one type of the cell-to-cell interactions that occur between these two important groups of oral bacteria.