Molecular cloning of the K1 capsular polysaccharide genes of E. coli

Abstract

E. coli K1 capsular polysaccharide exert an anti-phagocytic effect in humans, laboratory animals and domestic animals, similar to that observed with other pathogenic encapsulated bacteria. One approach to studying whether the K1 antigen is sufficient to confer virulence or if other E. coli structures are necessary is to isolate the K1 genes for genetic and biochemical analysis. Recombinant DNA methodology provides a powerful tool for such an approach. The E. coli K1 antigen genes were cloned. The cloned K1 genes synthesize a capsule in E. coli K12 which is chemically and immunologically indistinguishable from that of wild-type K1 strains.