Salmonella Research Today is a free monthly online journal that collates and summarizes the latest research about Salmonella, including details on salmonella typhimurium, food poisoning, infection, treatment.

Altering the length of the lipopolysaccharide O antigen has an impact on the interaction of Salmonella enterica serovar Typhimurium with macrophages and complement.

Murray GL, Attridge SR, Morona R

Australian Bacterial Pathogenesis Program, Discipline of Microbiology and Immunology, School of Molecular and Biomedical Sciences, The University of Adelaide, Adelaide, Australia 5005.

A panel of isogenic Salmonella enterica serovar Typhimurium strains that vary only in the length of the O antigen was constructed through complementation of a wzz double mutant (displaying unregulated O-antigen length) with one of two homologous (wzzST and wzzfepE) or three heterologous (wzzO139 of Vibrio cholerae and wzzSF and wzzpHS-2Departamento de Química, Bioquímica y Biología Molecular, Universidad Cardenal Herrera-CEU, 46113 Moncada, Valencia) of Shigella flexneri) wzz genes. Each gene was functional in the S. enterica serovar Typhimurium host and specified production of O-antigen polymers with lengths typical of those synthesized by the donor bacteria (ranging from 2 to >100 O-antigen repeat units). By use of this panel of strains, it was found that O-antigen length influences invasion/uptake by macrophage cells; this is the first time this has been shown with Salmonella. O-antigen length was confirmed to be related to complement resistance, with a minimum protective length of >4 and <15 repeat units. O antigen of 16 to 35 repeat units was found to activate complement more efficiently than other lengths, but this was unrelated to complement resistance. No evidence was found to suggest that modifying the length of the O-antigen polymer affected expression of the O1, O4, or O5 antigenic factors.

Published 20 March 2006 in J Bacteriol, 188(7): 2735-9.
Full-text of this article is available online (may require subscription).

© 2004-2008 Salmonella Research Today. All Rights Reserved.