AUTHOR=Zuo Fanglei , Appaswamy Amulya , Gebremariam Hanna G. , Jonsson Ann-Beth 

TITLE=Role of Sortase A in Lactobacillus gasseri Kx110A1 Adhesion to Gastric Epithelial Cells and Competitive Exclusion of Helicobacter pylori

JOURNAL=Frontiers in Microbiology

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2019.02770

DOI=10.3389/fmicb.2019.02770

ISSN=1664-302X

ABSTRACT=<p>We have previously shown that <italic>Lactobacillus gasseri</italic> Kx110A1, a human stomach isolate, can colonize mouse stomach and reduce the initial colonization of <italic>Helicobacter pylori</italic>. Here, we investigated the role of sortase-dependent proteins (SDPs) involved in these functions by the construction of a mutant for <italic>srtA</italic>, the gene encoding the housekeeping sortase that covalently anchors SDPs to the cell surface. The <italic>srtA</italic> mutant showed a decrease in hydrophobicity and autoaggregation under acidic conditions, indicating the effect of SDPs on cell surface properties. Correspondingly, the <italic>srtA</italic> mutant lost the capacity to adhere to gastric epithelial cells, thus resulting in an inability to provide a physical barrier to prevent <italic>H. pylori</italic> adherence. These results indicate that sortase A is a key determinant of the cell surface properties of <italic>L. gasseri</italic> Kx110A1 and contributes to <italic>Lactobacillus</italic>-mediated exclusion of <italic>H. pylori</italic>. Understanding the molecular mechanisms by which lactobacilli antagonize <italic>H. pylori</italic> might contribute to the development of novel therapeutic strategies that take advantage of health-promoting bacteria and reduce the burden of antibiotic resistance.</p>