Abstract
The possible use of Dienes' phenomenon for typing proteus strains as an aid to bacteriological monitoring of barrier-maintained animal units was investigated. It was rare for more than 1 Dienes' type to be isolated from an individual animal. A persistent relationship between 1 or 2 Diene's types and each strain of animal was demonstrated, although these same types were shown to be capable of causing clinical disease in their normal host. The findings suggest that Dienes' phenomenon may be of value in detecting outside contamination of barrier-maintained animals and also might usefully be applied to experimental epidemiological studies.