Endogenous H_(2)O_(2) production by intestinal cells and commensal lactic acid bacteria plays an important role in reducing pathogenic infection.Few reports have addressed the influence of catalase-mimetic gold nanopa...Endogenous H_(2)O_(2) production by intestinal cells and commensal lactic acid bacteria plays an important role in reducing pathogenic infection.Few reports have addressed the influence of catalase-mimetic gold nanoparticles(AuNPs)on intestinal barrier function against invading pathogens.In this study,citrate-and tannic acid-stabilized 5 nm-sized AuNPs were orally administered to C57BL/6 mice daily for 21 day before and during 6 day of Salmonella enterica serovar Typhimurium(S.Typhimurium)exposure.High-throughput sequencing of fecal 16S rRNA revealed that AuNPs did not significantly alter gut microbiota diversity and community before S.Typhimurium challenge.Fecal bacterial enumeration with selective media during the 6-day S.Typhimurium challenge period unveiled that AuNPs markedly induced the increased Salmonella colonization and the decreased Lactobacillus abundance.AuNPs exacerbated S.Typhimuriuminduced food intake reduction,body weight loss,cecum/colon histopathological lesions,and mortality.In vitro growth kinetic and virulence assays demonstrated that AuNPs notably counteracted the H_(2)O_(2)-induced suppression of S.Typhimurium growth in liquid medium,migration on agar plate,and adhesion and invasion of Caco-2 cell monolayers.In comparison with AuNPs coated by tannic acid,citrate-coated AuNPs exerted significantly greater effects on S.Typhimurium-induced weight loss and mortality in vivo,as well as S.Typhimurium growth,migration,and invasion in the presence of H_(2)O_(2) in vitro,which correlated well with the superior catalase-mimetic activity of citrate-coated AuNPs than tannic acid-coated ones in serumsupplemented cell culture media according to the results of electron spin resonance oximetry.Overall,AuNPs may increase the risk of pathogenic Salmonella infection through catalytic decomposition of endogenous H_(2)O_(2).展开更多
基金financially supported by National Natural Science Foundation of China(No.82003444)Hainan Province’s Key Research and Development Project(No.ZDYF2024XDNY191)+3 种基金Major Science and Technology Project of Haikou City(No.2023-001)Science and Technology Innovation Program of Sanya City(No.2022KJCX59)Yantai Development Zone Science and Technology Leading Talent Project(No.2021RC014)Major Scientific and Technological Innovation Project in Shandong Province(No.2022CXGC020414).
文摘Endogenous H_(2)O_(2) production by intestinal cells and commensal lactic acid bacteria plays an important role in reducing pathogenic infection.Few reports have addressed the influence of catalase-mimetic gold nanoparticles(AuNPs)on intestinal barrier function against invading pathogens.In this study,citrate-and tannic acid-stabilized 5 nm-sized AuNPs were orally administered to C57BL/6 mice daily for 21 day before and during 6 day of Salmonella enterica serovar Typhimurium(S.Typhimurium)exposure.High-throughput sequencing of fecal 16S rRNA revealed that AuNPs did not significantly alter gut microbiota diversity and community before S.Typhimurium challenge.Fecal bacterial enumeration with selective media during the 6-day S.Typhimurium challenge period unveiled that AuNPs markedly induced the increased Salmonella colonization and the decreased Lactobacillus abundance.AuNPs exacerbated S.Typhimuriuminduced food intake reduction,body weight loss,cecum/colon histopathological lesions,and mortality.In vitro growth kinetic and virulence assays demonstrated that AuNPs notably counteracted the H_(2)O_(2)-induced suppression of S.Typhimurium growth in liquid medium,migration on agar plate,and adhesion and invasion of Caco-2 cell monolayers.In comparison with AuNPs coated by tannic acid,citrate-coated AuNPs exerted significantly greater effects on S.Typhimurium-induced weight loss and mortality in vivo,as well as S.Typhimurium growth,migration,and invasion in the presence of H_(2)O_(2) in vitro,which correlated well with the superior catalase-mimetic activity of citrate-coated AuNPs than tannic acid-coated ones in serumsupplemented cell culture media according to the results of electron spin resonance oximetry.Overall,AuNPs may increase the risk of pathogenic Salmonella infection through catalytic decomposition of endogenous H_(2)O_(2).
