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Physiology and Biochemistry

Serological Relationships Among Strains of Erwinia chrysanthemi. M. Yakrus, Graduate assistant, University of Georgia, Department of Plant Pathology, Athens, 30602, and Experiment, GA 30212, Current address of senior author: Department of Plant Pathology, University of Nebraska, Lincoln, 68503; N. W. Schaad, associate professor, University of Georgia, Department of Plant Pathology, Athens, 30602, and Experiment, GA 30212. Phytopathology 69:517-522. Accepted for publication 30 November 1978. Copyright 1979 The American Phytopathological Society. DOI: 10.1094/Phyto-69-517.

Serological relationships among 27 strains of Erwinia chrysanthemi isolated from 18 different hosts were determined by agglutination and Ouchterlony double-diffusion tests of a membrane protein complex (MPC) extracted from whole cells. Antisera were prepared to MPC of five strains of E. chrysanthemi and one strain each of E. carotovora and Salmonella typhimurium. Agglutination tests were useful only for differentiation strains of E. chrysanthemi from other Erwinia spp. Strains of E. chrysanthemi were grouped into four serovars. There was no correlation between host of origin and serovar. Immunoelectrophoretic studies revealed that the MPC of E. chrysanthemi contained two immunogens, one neutral and one acidic. Polyacrylamide gel electrophoresis profiles of MPC of E. chrysanthemi showed one to four major protein bands with molecular weights ranging from 26,000 to 43,000. Agglutination and agar double diffusion tests with MPC proved to be a rapid, accurate method of identifying E. chrysanthemi.