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.
Ilg
Karin
K
Institut für Mikrobiologie, Eidgenössische Technische Hochschule, ETH Zürich, Zürich, Switzerland.
Endt
Kathrin
K
Misselwitz
Benjamin
B
Stecher
Bärbel
B
Aebi
Markus
M
Hardt
Wolf-Dietrich
WD
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