title: Naturally occurring InlB variants that support intragastric Listeria monocytogenes infection in mice.
abstract: Listeria monocytogenes is a causative agent of foodborne infection in humans and animals. The virulence factor InlB interacts with mammalian receptor c-Met via its internalin domain to provide L. monocytogenes invasion in non-professional phagocytes. Naturally occurring InlB internalin domain variants form four subclusters on the maximal likelihood tree. Four variants belonging to distinct subclusters were cloned into the vector carrying 3΄ and 5΄-flanking sequences to restore full length inlB and expressed in the L. monocytogenes strain EGDeΔinlB. The substitutions Val132Ile, Thr117Ala and Ile138Leu, Thr251Met/Ser were specific for variants 13, 14 and 1, respectively, the variant 9 carried Ser73Asn, Ile91Val, Leu164Pro, Met251Ser/Thr substitutions. All InlB variants improved invasion of the parental strain in murine colon carcinoma C26 cells with 4.6-fold difference between the most and least effective variants (variants 14 and 13, respectively, P < 0.05). Bacterial loads in livers of intragastrically infected mice were 258, 149 and 92 times higher for variant 14, 13 and 1 carrying strains, respectively, than for EGDeΔinlB (P < 0.01). In contrast, the variant 9 did not noticeably improve infection comparatively to the parental strain. Overall, obtained results demonstrated that naturally occurred InlB internalin domain variants differed in their ability to support intragastric infection in mice.
authors.affiliation: Gamaleya Research Center of Epidemiology and Microbiology, Department of Infections with Natural Foci, Gamaleya St. 18, Moscow 123098, Russia.
authors.forename: Konstantin
authors.initials: K
authors.lastname: Sobyanin
authors.affiliation: Gamaleya Research Center of Epidemiology and Microbiology, Department of Infections with Natural Foci, Gamaleya St. 18, Moscow 123098, Russia.
authors.forename: Elena
authors.initials: E
authors.lastname: Sysolyatina
authors.affiliation: Gamaleya Research Center of Epidemiology and Microbiology, Department of Bacterial Genetics and Molecular Biology, Gamaleya St. 18, Moscow 123098, Russia.
authors.forename: Mikhail
authors.initials: M
authors.lastname: Krivozubov
authors.affiliation: Gamaleya Research Center of Epidemiology and Microbiology, Department of Infections with Natural Foci, Gamaleya St. 18, Moscow 123098, Russia.
authors.forename: Yaroslava
authors.initials: Y
authors.lastname: Chalenko
authors.affiliation: Gamaleya Research Center of Epidemiology and Microbiology, Department of Bacterial Genetics and Molecular Biology, Gamaleya St. 18, Moscow 123098, Russia.|Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskye gory, House 1, Building 40, Moscow 119992, Russia.|Institute of Agricultural Biotechnology, Timiryazevskaya St. 42, Moscow 127550, Russia.
authors.forename: Anna
authors.initials: A
authors.lastname: Karyagina
authors.affiliation: Gamaleya Research Center of Epidemiology and Microbiology, Department of Infections with Natural Foci, Gamaleya St. 18, Moscow 123098, Russia.
authors.forename: Svetlana
authors.initials: S
authors.lastname: Ermolaeva
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D045744:Cell Line, Tumor; D003001:Cloning, Molecular; D005260:Female; D014644:Genetic Variation; D005822:Genetic Vectors; D008089:Listeria monocytogenes / Q000235:genetics* / Q000472:pathogenicity*; D008088:Listeriosis / Q000382:microbiology*; D008099:Liver / Q000382:microbiology; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D000072417:Protein Domains; D037521:Virulence Factors / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D008565:Membrane Proteins; D037521:Virulence Factors; C095768:inlB protein, Listeria monocytogenes
keywords: Listeria monocytogenes; intracellular parasitism; polyhostality