English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Lactobacillus rhamnosus GG is one of the best-characterized lactic acid bacteria and can be considered a probiotic paradigm. Comparative and functional genome analysis showed thatL. rhamnosus GG harbors a genomic island including thespaCBA-srtC1 gene cluster, encoding the cell surface-decorating host-interacting pili. Here, induced mutagenesis was used to study pilus biogenesis inL. rhamnosus GG. A combination of two powerful approaches, mutation selection and next-generation sequencing, was applied toL. rhamnosus GG for the selection of pilus-deficient mutants from an enriched population. The isolated mutants were first screened by immuno-dot blot analysis using antiserum against pilin proteins. Relevant mutants were selected, and the lack of pili was confirmed by immunoelectron microscopy. The pilosotype of 10 mutant strains was further characterized by analyzing pilin expression using Western blot, dot blot, and immunofluorescence methods. A mucus binding assay showed that the mutants did not adhere to porcine intestinal mucus. Comparative genome sequence analysis using the Illumina MiSeq platform allowed us to determine the nature of the mutations in the obtained pilus-deficient derivatives. Three major classes of mutants with unique genotypes were observed: class I, with mutations in thesrtC1 gene; class II, with a deletion containing thespaCBA-srtC1 gene cluster; and class III, with mutations in thespaA gene. Only a limited number of collateral mutations were observed, and one of the pilus-deficient derivatives with a deficientsrtC1 gene contained 24 other mutations. This strain, PB12, can be considered a candidate for human trials addressing the impact of the absence of pili.

Genomic Characterization of Non-Mucus-Adherent Derivatives of Lactobacillus rhamnosus GG Reveals Genes Affecting Pilus Biogenesis