title: Role for mannose-sensitive hemagglutinin in promoting interactions between Vibrio cholerae El Tor and mussel hemolymph.
abstract: The role of mannose-sensitive hemagglutinin (MSHA) in Vibrio cholerae O1 El Tor interactions with hemolymph of the mussel Mytilus galloprovincialis was studied. Bacterial adherence to and association with hemocytes were evaluated at 4 and 18 degrees C, respectively. In hemolymph serum, the wild-type strain N16961 adhered to and associated with hemocytes about twofold more efficiently than its mutant lacking MSHA. In artificial seawater (ASW), no significant differences between the two strains were observed. N16961 was also more sensitive to hemocyte bactericidal activity than its MSHA mutant; in fact, the percentages of killed bacteria after 120 min of incubation were 60 and 34%, respectively. The addition of D-mannose abolished the serum-mediated increase in adherence, association, and sensitivity to killing of the wild-type strain without affecting the interactions of the mutant. A similar increase in N16961 adherence to hemocytes was observed when serum was adsorbed with MSHA-deficient bacteria. In contrast, serum adsorbed with either wild-type V. cholerae El Tor or wild-type Escherichia coli carrying type 1 fimbriae was no longer able to increase adherence of N16961 to hemocytes. The results indicate that hemolymph-soluble factors are involved in interactions between hemocytes and mannose-sensitive adhesins.
authors.affiliation: Istituto di Microbiologia e Scienze Biomediche, Università Politecnica delle Marche, Ancona, Italy.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Zampini
authors.forename: Laura
authors.initials: L
authors.lastname: Canesi
authors.forename: Michele
authors.initials: M
authors.lastname: Betti
authors.forename: Caterina
authors.initials: C
authors.lastname: Ciacci
authors.forename: Renato
authors.initials: R
authors.lastname: Tarsi
authors.forename: Gabriella
authors.initials: G
authors.lastname: Gallo
authors.forename: Carla
authors.initials: C
authors.lastname: Pruzzo
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000302:isolation & purification / Q000502:physiology*; D049872:Bivalvia / Q000382:microbiology*; D036781:Fimbriae Proteins / Q000302:isolation & purification / Q000502:physiology*; D010861:Fimbriae, Bacterial / Q000502:physiology; D006388:Hemagglutinins / Q000302:isolation & purification / Q000502:physiology*; D006434:Hemocytes / Q000382:microbiology; D006458:Hemolymph / Q000382:microbiology*; D037601:Mannose-Binding Lectin; D014734:Vibrio cholerae / Q000302:isolation & purification / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D006388:Hemagglutinins; D037601:Mannose-Binding Lectin; C101032:MshA protein, Vibrio cholerae; D036781:Fimbriae Proteins