Journal of Hygiene

Research Article

Differential typing of Salmonella agona: type divergence in a new serotype

Ruth Barkera1, D. C. Olda1 and Zofia Tyca2

a1 Bacteriology Department, University of Dundee Medical School, Ninewells Hospital, Dundee DD1 9SY

a2 Bacteriology Department, National Institute of Hygiene, Warsaw 36, Poland


An international collection of 419 isolates of Salmonella agona was phage typed, biotyped and colicine typed. Of 16 recognized phage types, 15 were represented. Three phage types (I, V and XVI) accounted for 84% of all isolates, were widely distributed and may be interconvertible. Biotyping afforded little type differentiation; thus 92·6% of the isolates belonged to biotype 1 a. A rhamnose non-fermenting variant line (of biotype 5a) became established in Zaire from 1979 to 1980. A maltose late-fermenting line of biotype 1 a, isolated in Scotland in 1974, did not thereafter become established. Two Col+ lines (producing colicine I b) accounted for 45 of 68 colicinogenic isolates. The implication of type diversification and the phylogenetic significance of these findings are discussed.

(Received November 20 1981)

(Accepted December 01 1981)