Origin of the heterogeneity of cell wall O-polysaccharides from Salmonella zuerich (1,9,12,(46),27).

The heterogeneity of the cell wall O-polysaccharide of Salmonella zuerich (factor 1 present or absent) is probably not due to mutations in the stock since it was seen in essentially similar fashion (proportion one 1+ to four 1-forms) in four separate lots of polysaccharide extracted from separate culture batches. The results of indirect fluorescent antibody studies suggest that form variation of factor 1, occurring at an unusually high rate, is the most probable basis of the heterogeneity.