title: Additive function of Vibrio vulnificus MARTX(Vv) and VvhA cytolysins promotes rapid growth and epithelial tissue necrosis during intestinal infection.
abstract: Vibrio vulnificus is a pathogen that causes both severe necrotizing wound infections and life-threatening food-borne infections. Food-borne infection is particularly lethal as the infection can progress rapidly to primary septicemia resulting in death from septic shock and multiorgan failure. In this study, we use both bioluminescence whole animal imaging and V. vulnificus bacterial colonization of orally infected mice to demonstrate that the secreted multifunctional-autoprocessing RTX toxin (MARTX(Vv)) and the cytolysin/hemolysin VvhA of clinical isolate CMCP6 have an important function in the gut to promote early in vivo growth and dissemination of this pathogen from the small intestine to other organs. Using histopathology, we find that both cytotoxins can cause villi disruption, epithelial necrosis, and inflammation in the mouse small intestine. A double mutant deleted of genes for both cytotoxins was essentially avirulent, did not cause intestinal epithelial tissue damage, and was cleared from infected mice by 36 hours by an effective immune response. Therefore, MARTX(Vv) and VvhA seem to play an additive role for pathogenesis of CMCP6 causing intestinal tissue damage and inflammation that then promotes dissemination of the infecting bacteria to the bloodstream and other organs. In the absence of these two secreted factors, we propose that this bacterium is unable to cause intestinal infection in humans.
authors.affiliation: Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America.
authors.forename: Hee-Gon
authors.initials: HG
authors.lastname: Jeong
authors.forename: Karla J F
authors.initials: KJ
authors.lastname: Satchell
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism; D001427:Bacterial Toxins / Q000378:metabolism*; D003603:Cytotoxins / Q000378:metabolism*; D004195:Disease Models, Animal; D005260:Female; D006460:Hemolysin Proteins / Q000378:metabolism*; D007410:Intestinal Diseases / Q000382:microbiology* / Q000473:pathology; D007413:Intestinal Mucosa / Q000378:metabolism / Q000382:microbiology / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D009336:Necrosis; D041261:Vibrio vulnificus / Q000378:metabolism* / Q000472:pathogenicity
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D003603:Cytotoxins; D006460:Hemolysin Proteins; C470630:VvhA protein, Vibrio vulnificus