Epidemiology of diphtheria: polypeptide and restriction enzyme analysis in comparison with conventional phage typing.

Several methods for epidemiological typing of Corynebacterium diphtheriae were compared with the well accepted phage typing analysis. For this purpose, isolates from outbreaks of diphtheria in specific areas of the FRG and Sweden were analyzed by phage typing, their bacterial polypeptide profiles were examined and their phage-DNA restriction enzyme patterns were compared. All techniques were able to identify whether certain outbreaks were epidemiologically linked or not. Phage typing and phage-DNA restriction enzyme fragment analysis were limited in their application to lysogenic strains, whereas bacterial polypeptide analysis was universally applicable. Analysis of bacterial polypeptides was superior to all methods, especially in terms of speed and simplicity.