Analysis of an outbreak of staphylococcal scalded skin syndrome: strategies for typing 'non-typable' strains.

Thirteen newborn babies were studied during an outbreak of scalded skin syndrome. Staphylococci isolated from seven babies were non-typable using the international set of typing phages; the remainder were of phage group II. In only one instance was there transmission of phage group II strains other than within families. However, 'heat treatment' and plasmid profiles of the non-typable strains showed that five of the seven babies were infected by strains which were indistinguishable. These five strains were more closely related to phage III staphylococci than to phage group II. The identity of the epidermolytic toxin has not been established.