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

Complex oligosaccharides from human milk (HMO) possess an antimicrobial activity and can promote the growth of bifidobacteria such as  Bifidobacterium bifidum  and  Bifidobacterium longum  subsp.  infantis . In addition, fermentation of carbohydrates by bifidobacteria can result in the production of metabolites presenting an antivirulence effect on several pathogenic bacteria. Whey is rich in complex bovine milk oligosaccharides (BMO) structurally similar to HMO and  B. crudilactis , a species of bovine origin, is able to metabolize some of those complex carbohydrates. This study focused on the ability of  B. bifidum  and  B. crudilactis  to grow in a culture medium supplemented in 3′-sialyllactose (3′SL) as the main source of carbon, a major BMO encountered in cow milk. Next, the effects of cell-free spent media (CFSM) were tested against virulence expression of  Escherichia coli  O157:H7 and  Salmonella enterica  serovar Typhimurium. Both strains were able to grow in presence of 3′SL, but  B. crudilactis  showed the best growth (7.92 ± 0.3 log cfu/ml) compared to  B. bifidum  (6.84 ± 0.9 log cfu/ml). Then, CFSM were tested for their effects on virulence gene expression by  ler  and  hilA  promoter activity of luminescent mutants of  E. coli  and  S . Typhimurium, respectively, and on wild type strains of  E. coli  O157:H7 and  S . Typhimurium using RT-qPCR. All CFSM resulted in significant under expression of the  ler  and  hilA  genes for the luminescent mutants and  ler  (ratios of −15.4 and −8.1 respectively) and  qseA  (ratios of −2.1 and −3.1) for the wild type strain of  E. coli  O157:H7. The 3′SL, a major BMO, combined with some bifidobacteria strains of bovine or human origin could therefore be an interesting synbiotic to maintain or restore the intestinal health of young children. These effects observed  in vitro  will be further investigated regarding the overall phenotype of pathogenic agents and the exact nature of the active molecules.

frontiers in microbiology

Cell-Free Spent Media Obtained from Bifidobacterium bifidum and Bifidobacterium crudilactis Grown in Media Supplemented with 3′-Sialyllactose Modulate Virulence Gene Expression in Escherichia coli O157:H7 and Salmonella Typhimurium