ELECTROPHORETIC AND IMMUNOLOGICAL ANALYSIS OF LIPOPOLYSACCHARIDES OF XANTHOMONAS-ALBILINEANS FROM 3 GEOGRAPHICAL REGIONS

Lipopolysaccharides (LPS) were extracted from the type species of the sugarcane leaf scald pathogen Xanthomonas albilineans from Fiji and ad ditional isolates from Australia, Mauritius and South Africa. After re solution by sodium dodecyl sulphate-polyacrylamide gel electrophoresis , the LPS were visualized using a modified silver staining method and analysed by densitometric scanning. Three distinct electrophoretic pat terns were identified: the LPS pattern of the Fijian isolate differed from those of the other isolates. Immunological cross-reactivity of th e LPS and gamma globulins was assessed by immunoblotting. Immunoblotti ng showed that although IgG raised against other isolates cross-reacte d with the LPS of one another, they did not react with the purified LP S of the Fijian isolate. Differences in LPS patterns and serological c ross-reactivity may be due to differences in the length and conformati on of the O-polysaccharide chains of the LPS.