O-antigen-negative Salmonella enterica serovar Typhimurium is attenuated in intestinal colonization but elicits colitis in streptomycin-treated mice.
Lipopolysaccharide (LPS) is a major constituent of the outer membrane and an important virulence factor of Salmonella enterica subspecies 1 serovar Typhimurium (serovar Typhimurium). To evaluate the role of LPS in eliciting intestinal inflammation in streptomycin-treated mice, we constructed an O-antigen-deficient serovar Typhimurium strain through deletion of the wbaP gene. The resulting strain was highly susceptible to human complement activity and the antimicrobial peptide mimic polymyxin B. Furthermore, it showed a severe defect in motility and an attenuated phenotype in a competitive mouse infection experiment, where the DeltawbaP strain (SKI12) was directly compared to wild-type Salmonella. Nevertheless, the DeltawbaP strain (SKI12) efficiently invaded HeLa cells in vitro and elicited acute intestinal inflammation in streptomycin-pretreated mice. Our experiments prove that the presence of complete LPS is not essential for in vitro invasion or for triggering acute colitis.
Institut für Mikrobiologie, Eidgenössische Technische Hochschule, ETH Zürich, Zürich, Switzerland.
Karin
K
Ilg
Kathrin
K
Endt
Benjamin
B
Misselwitz
Bärbel
B
Stecher
Markus
M
Aebi
Wolf-Dietrich
WD
Hardt
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002432:Cecum / Q000382:microbiology; D003092:Colitis / Q000382:microbiology*; D015169:Colony Count, Microbial; D003165:Complement System Proteins / Q000276:immunology; D017353:Gene Deletion; D006367:HeLa Cells; D006801:Humans; D008124:Locomotion; D051379:Mice; D008810:Mice, Inbred C57BL; D019081:O Antigens / Q000235:genetics*; D011112:Polymyxin B / Q000494:pharmacology; D012480:Salmonella Infections / Q000382:microbiology*; D012481:Salmonella Infections, Animal / Q000382:microbiology*; D012486:Salmonella typhimurium / Q000187:drug effects / Q000276:immunology / Q000472:pathogenicity*; D013154:Spleen / Q000382:microbiology
D000900:Anti-Bacterial Agents; D019081:O Antigens; D003165:Complement System Proteins; D011112:Polymyxin B