Applications of BLIS typing to studies of the survival on surfaces of salivary streptococci and staphylococci.

A typing scheme based on detection of the production of bacteriocin-like inhibitory substances (BLIS) was a useful tool in a series of epidemiological studies of the spread and survival on surfaces of salivary streptococci and staphylococci. The organisms survived for longer periods on glass, plastic, stainless steel and latex surfaces than on unpainted wood or paper. The presence of saliva as a suspending medium prolonged the viability of Staphylococcus aureus C55 and Streptococcus pyogenes FF22 but not of Strep. salivarius Min 5. Young children were shown to carry Strep. salivarius of identical BLIS-types on their fingers and in their saliva. BLIS typing of Strep. salivarius strains obtained from telephone mouthpieces and from the tongue-sealed flap of envelopes was used as a method of tracing the human source of the salivary deposits.