Publikationsdatenbank

Through the labyrinth: how Salmonella penetrates the gastrointestinal mucus (2023)

Art

Vortrag

Autoren

Ghazisaeedi, F. (WE 7)

Diestelhorst, K.

Klimek, A.

Braetz, Sebastian (WE 7)

Tedin, Karsten (WE 7)

Weinhart, M.

Netz, R.

Block, S.

Fulde, Marcus (WE 7)

Kongress

75th annual conference Deutsche Gesellschaft für Hygiene und Mikrobiologie [DGHM]

Lübeck, 18. – 20.09.2023

Quelle

75th ANNUAL CONFERENCE for Hygiene and Microbiology e. V. (DGHM): Abstracts — Deutsche Gesellschaft für Hygiene und Mikrobiologie e. V. (Hrsg.)

Jena: Conventus Congressmanagement & Marketing GmbH, 2023 — S. 18

ISBN: 978-3-948023-34-8

Verweise

URL (Volltext): https://nbn-resolving.org/urn:nbn:de:101:1-2023092513362384082518

Kontakt

Institut für Mikrobiologie und Tierseuchen

Robert-von-Ostertag-Str. 7-13
14163 Berlin
+49 30 838 51843 / 66949
mikrobiologie@vetmed.fu-berlin.de

Abstract / Zusammenfassung

Motile enteropathogenic bacteria such as Salmonella enterica and Escherichia coli swim through aqueous environments or near solid boundaries using flagellum. The motility and virulence of pathogenic bacteria have been shown to connected by complex regulatory networks. Apart from motility, sophisticated flagellum nanomachine can also contribute to bacterial chemotaxis and evasion of host immune responses1.
For the successful host infection, pathogens need to initially penetrate the mucus layer to be able to disrupt the mucosal barrier and invade the epithelial cells in the gut. The mucus layer, secreted by goblet cells, is a biological hydrogel and play a key role in maintaining the integrity of the intestinal mucosal barrier and contribute to protection of underlying epithelial cells against gut content, microbiota and primary pathogens2. Previous studies showed the importance of the flagella driven motility in breaching of the mucosal barrier and gut colonization3. However, the exact bacterial navigation strategies and mechanisms of interaction between bacteria and mucus layer/underlying cells are unknown.
The aim of our study is to elucidate the molecular mechanism of interaction between enteric pathogen Salmonella Typhimurium and the gastrointestinal mucus prior to intestinal epithelium invasion with a focus on the role of bacterial flagellar apparatus. Thus, we generated a group of Salmonella Typhimurim ATCC 14028 mutants lacking different structural, antigenic and functional parts of flagellum such as ΔfliB, ΔfliC, ΔflijB/fliC, ΔfliL, ΔmotA and ΔcheY. GFP-expressing pFPV25.1 plasmid introduced into these mutants enable us to track bacteria during microscopy. To this end, we use optical microscopy to follow the motion of Salmonella Typhimurium at interfaces and within biological hydrogels such as mucus. We will give examples, how the motility of this bacterium is affected by the properties of its environment or the Salmonella mutant probed.
Furthermore, by continuously recording z-stacks of samples, in which Salmonella interact with mucus-producing cells (HT29-MTX), we succeeded to follow the dynamics of bacterial penetration through a biologically relevant hydrogel. We will show that bacterial penetration predominantly proceeds via hydrogel voids, which are either already present or actively generated by the bacteria.