Serogroups of potato pathogenicErwinia carotovorastrains: identification by lipopolysaccharide electrophoretic patterns

摘要

Lipopolysaccharides were purified from 51 strains ofErwinia carotovorasubsp.carotovora, atrosepticaandbetavasculorumrepresenting 12 different serogroups. Analysis of the lipopolysaccharides by SDS‐PAGE showed that, irrespective of the strain or serogroup from which they were extracted, the lipopolysaccharides were composed of up to 30 components. The mobility of the components decreased in a regular fashion giving a ladder‐like appearance on the gel. The relative mobilities of components of lipopolysaccharide from each serogroup was constant so that each serogroup gave an easily identifiable ladder profile. The potato pathogenic serogroups I, XVIII, XX and XXII were examined in detail. Of 20 strains received as serogroup I, 18 gave a pattern identical to an authentic serogroup I strain. The two strains which did not give the same pattern were shown by immunological tests not to be serogroup I. Fiveatrosepticastrains of serogroup XXII gave a distinct pattern characteristic of the serogroup whileatrosepticastrains of serogroups XVIII (four strains) and XX (five strains) gave patterns that could not be distinguished from each other. Analysis of lipopolysaccharides by SDS‐PAGE has been shown to be an alternative to immunological tests to identify serogroups ofErwinia carotovoraassociated with blackleg. It is also capable of differentiating these serogroups from erwinia serogroups not normally regarded as causing blackleg. The analysis has the advantage that, irrespective of serogroup, a positive result is always obt