title: Glucosyltransferase A (GtfA) and inulosucrase (Inu) of Lactobacillus reuteri TMW1.106 contribute to cell aggregation, in vitro biofilm formation, and colonization of the mouse gastrointestinal tract.
abstract: Members of the genus Lactobacillus are common inhabitants of the proximal gastrointestinal tract of animals such as mice, rats, chickens and pigs, where they form epithelial biofilms. Little is known about the traits that facilitate biofilm formation and gut colonization. This study investigated the ecological role of a glucosyltransferase (GtfA) and inulosucrase (Inu) of Lactobacillus reuteri TMW1.106 and a fructosyltransferase (FtfA) of L. reuteri LTH5448. In vitro experiments using isogenic mutants revealed that GtfA was essential for sucrose-dependent autoaggregation of L. reuteri TMW1.106 cells under acidic conditions, while inactivation of Inu slowed the formation of cell aggregates. Experiments using an in vitro biofilm assay showed that GtfA and Inu contributed to biofilm formation of L. reuteri TMW1.106. Experiments using ex-Lactobacillus-free mice revealed that the ecological performance of the inu mutant, but not of the gtfA or ftfA mutant, was reduced in the gastrointestinal tract when in competition with the parental strain. In the absence of competition, the gtfA mutant showed delayed colonization of the murine gut relative to the wild-type. In addition, the gtfA mutant showed reduced ecological performance in competition experiments with Lactobacillus johnsonii #21. From the evidence provided in this study we conclude that GtfA and Inu confer important ecological attributes of L. reuteri TMW1.106 and contribute to colonization of the mouse gastrointestinal tract.
authors.affiliation: Department of Food Science and Technology, University of Nebraska, Lincoln, NE 68583-0919, USA.|Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand.
authors.forename: Jens
authors.initials: J
authors.lastname: Walter
authors.affiliation: Department of Agricultural Food and Nutritional Science, University of Alberta, Edmonton, Canada.
authors.forename: Clarissa
authors.initials: C
authors.lastname: Schwab
authors.affiliation: Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand.
authors.forename: Diane M
authors.initials: DM
authors.lastname: Loach
authors.affiliation: Department of Agricultural Food and Nutritional Science, University of Alberta, Edmonton, Canada.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Gänzle
authors.affiliation: Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand.
authors.forename: Gerald W
authors.initials: GW
authors.lastname: Tannock
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D018441:Biofilms / Q000254:growth & development*; D015169:Colony Count, Microbial; D005260:Female; D041981:Gastrointestinal Tract / Q000382:microbiology*; D017353:Gene Deletion; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism*; D006602:Hexosyltransferases / Q000235:genetics / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000382:microbiology; D052200:Limosilactobacillus reuteri / Q000201:enzymology* / Q000235:genetics / Q000502:physiology*; D008297:Male; D051379:Mice; D001426:Bacterial Proteins
chemical_list: D005964:Glucosyltransferases; D006602:Hexosyltransferases; C021451:inulosucrase; D001426:Bacterial Proteins