'O'-antigens are essential virulence factors of Shigella sonnei and Shigella dysenteriae 1.
A novel transposon mutagenesis system has been developed for Shigella. We have used it to isolate specific mutants of Shigella sonnei and Shigella dysenteriae 1 that fail to produce lipopolysaccharide 'O' side chains. The virulence of the mutants was evaluated in the Sereny test and in a HeLa cell invasion assay. All HO'-minus mutants failed to provoke a positive Sereny reaction but retained the ability to invade HeLa cells. This demonstrates that 'O' side chains are virulence factors of S. sonnei and S. dysenteriae 1. 'O'-minus mutants of S. sonnei which still contained the Form I plasmid were capable of invading HeLa cells whilst plasmid-minus mutants were not, demonstrating that this plasmid encodes properties other than 'O'-antigen production that are involved in virulence.
M M
MM
Binns
S
S
Vaughan
K N
KN
Timmis
D000942:Antigens, Bacterial / Q000235:genetics; D004251:DNA Transposable Elements; D006367:HeLa Cells; D006801:Humans; D008242:Lysogeny; D009154:Mutation; D019081:O Antigens; D010957:Plasmids; D012762:Shigella dysenteriae / Q000235:genetics / Q000276:immunology / Q000472:pathogenicity*; D012764:Shigella sonnei / Q000235:genetics / Q000276:immunology / Q000472:pathogenicity*; D014774:Virulence
D000942:Antigens, Bacterial; D004251:DNA Transposable Elements; D019081:O Antigens