Background The antibacterial and immunomodulatory activities of bacteriocins make them attractive targets for development as anti-infective drugs.Although the importance of the enteric nervous system(ENS)in the strugg...Background The antibacterial and immunomodulatory activities of bacteriocins make them attractive targets for development as anti-infective drugs.Although the importance of the enteric nervous system(ENS)in the struggle against infections of the intestine has been demonstrated,whether it is involved in bacteriocins anti-infective mecha-nisms is poorly defined.Results Here,we demonstrated that the bacteriocin Microcin J25(J25)significantly alleviated diarrhea and intesti-nal inflammation in piglets caused by enterotoxigenic Escherichia coli(ETEC)infection.Mechanistically,macrophage levels were significantly downregulated after J25 treatment,and this was replicated in a mouse model.Omics analysis and validation screening revealed that J25 treatment induced significant changes in the dopaminergic neuron pathway,but little change in microbial structure.The alleviation of inflammation may occur by down-regulating dopamine receptor(DR)D1 and the downstream DAG-PKC pathway,thus inhibiting arachidonic acid decomposition,and the inhibition of macrophages may occur through the up-regulation of DRD5 and the downstream cAMP-PKA pathway,thus inhibiting NF-κB.Conclusions Our studies’findings provide insight into the changes and possible roles of the ENS in J25 treatment of ETEC infection,providing a more sophisticated foundational understanding for developing the application poten-tial of J25.展开更多
Background:Since the overuse of antibiotics in animal production has led to a selection of antibiotic-resistant pathogens that affect humans and animals as well.Scientists are therefore searching for novel natural alt...Background:Since the overuse of antibiotics in animal production has led to a selection of antibiotic-resistant pathogens that affect humans and animals as well.Scientists are therefore searching for novel natural alternatives to antibiotics.In this study Lactobacillus reuteri and a combination of reuterin and microcin J25(RJ)were evaluated as promoters of growth and modulators of the cecal microbiota and metabolite profiles in broiler chickens.Oneday-old Cobb 500 male broilers were distributed to 8 treatments:negative control(without antibiotic),positive control(bacitracin),three concentrations of RJ and three doses of L.reuteri plus glycerol.The birds(2176,34 per pen,8 pens per treatment)were reared for 35 d.Results:The body weight of the bacitracin and 5 mmol/L reuterin combined with 0.08μmol/L microcin J25(10RJ)treatment group was significantly higher than that of the negative control group(P<0.05).L.reuteri had no significant effect on broiler growth.MiSeq high-throughput sequencing of 16S rRNA showed clustering of cecal microbial operational taxonomic unit diversity according to treatment.The influence of bacitracin and 10RJ on bacterial community overall structure was similar.They promoted Ruminococcaceae,Lachnospiraceae and Lactobacillaceae,increased the relative abundance of Faecalibacterium and decreased the abundance of Bacteroides and Alistipes,while the negative control condition favored Bacteroidaceae and Rikenellaceae.Furthermore,10RJ increased the concentration of short-chain fatty acid in the cecum and changed the metabolome overall.Conclusions:These overall suggest that 10RJ can promote a host-friendly gut environment by changing the cecal microbiome and metabolome.This combination of natural antimicrobial agents in the drinking water had a positive effect on broiler growth and may be suitable as an alternative to antibiotic growth promoters.展开更多
Microcin J25(MccJ25)has received substantial attention as a potential solution to the global threat of infection caused by antibiotic-resistant bacteria.However,the industrial fermentation of MccJ25 faces production b...Microcin J25(MccJ25)has received substantial attention as a potential solution to the global threat of infection caused by antibiotic-resistant bacteria.However,the industrial fermentation of MccJ25 faces production bottlenecks.It is imperative to further explore the production optimization strategies for MccJ25 to formulate comprehensive approaches for its industrial-scale production and other downstream applications.Here,Fe^(2+)in tap water was identified as a critical inhibitor of MccJ25 biosynthesis,selectively repressing mcjA transcription,which was reversible via 2,2'-bipyridine-mediated chelation.To decouple production from growth phase dependency and Fe^(2+)interference,we engineered Escherichia coli BL21 cells by performing two genetic modifications.First,we replaced the native mcjA promoter with a constitutive promoter(PQ)to allow its mid-log phase expression.Second,we replaced the native mcjBCD promoter with a medium-strength variant(P2223)that delayed production kinetics without affecting final yields.However,the genomic integration of mcjD alleviated plasmid-borne toxicity,increasing the expression timing and doubling the yield to 240 mg/L.Finally,we computationally optimized the mcjA ribosome-binding site(RBS)to enhance translation efficiency.RBS optimization revealed that a moderate translation initiation efficiency(550,584 arbitrary units[au])maximized production,whereas excessive efficiency(2,019,712 au)impaired growth and output.These interventions synergistically increased the MccJ25 titer 10-fold,reaching 430 mg/L in batch culture.Our findings establish a robust platform for MccJ25 overproduction,highlighting promoter engineering and translational tuning as pivotal strategies for antimicrobial peptide biosynthesis.This study provides insights for overcoming metabolic constraints in microbial fermentation,advancing the development of peptide-based therapeutics against multidrug-resistant pathogens.展开更多
The overuse and misuse of traditional antimicrobial drugs have led to their weakened effectiveness and the emergence of pathogenic bacterial resistance.Consequently,there has been growing interest in alternative op-ti...The overuse and misuse of traditional antimicrobial drugs have led to their weakened effectiveness and the emergence of pathogenic bacterial resistance.Consequently,there has been growing interest in alternative op-tions such as antimicrobial peptides(AMPs)in the pharmaceutical industry.Microcin J25(MccJ25)has gained significant attention for its potent inhibitory effect on a diverse range of pathogens.Its unique rotaxane structure provides exceptional stability against extreme thermal,pH,and protease degradation,including chymotrypsin,trypsin,and pepsin.Given its remarkable stability and diverse bioactivity,we aim to provide an overview of the physicochemical properties,the mechanism underlying its antimicrobial activity,and the critical functional residues of MccJ25.Additionally,we have summarized the latest strategies for the heterologous expression of MccJ25,and its potential medical use and other applications.展开更多
基金supported by the National Key Research and Development Program of China(Grant number 32030105)National Pig Technology Innovation Center Leading Technology Projects(NCTIP XD/B05)Beijing Innovation Consortium of Livestock Research System(BAIC05-2024).
文摘Background The antibacterial and immunomodulatory activities of bacteriocins make them attractive targets for development as anti-infective drugs.Although the importance of the enteric nervous system(ENS)in the struggle against infections of the intestine has been demonstrated,whether it is involved in bacteriocins anti-infective mecha-nisms is poorly defined.Results Here,we demonstrated that the bacteriocin Microcin J25(J25)significantly alleviated diarrhea and intesti-nal inflammation in piglets caused by enterotoxigenic Escherichia coli(ETEC)infection.Mechanistically,macrophage levels were significantly downregulated after J25 treatment,and this was replicated in a mouse model.Omics analysis and validation screening revealed that J25 treatment induced significant changes in the dopaminergic neuron pathway,but little change in microbial structure.The alleviation of inflammation may occur by down-regulating dopamine receptor(DR)D1 and the downstream DAG-PKC pathway,thus inhibiting arachidonic acid decomposition,and the inhibition of macrophages may occur through the up-regulation of DRD5 and the downstream cAMP-PKA pathway,thus inhibiting NF-κB.Conclusions Our studies’findings provide insight into the changes and possible roles of the ENS in J25 treatment of ETEC infection,providing a more sophisticated foundational understanding for developing the application poten-tial of J25.
基金the Natural Sciences and Engineering Research Council (NSERC) of Canada industrial research chair METABIOLAC (grant number IRCPJ 499946–15)from Agriculture and Agri-Food Canada (project PSS#1781, J-002308)
文摘Background:Since the overuse of antibiotics in animal production has led to a selection of antibiotic-resistant pathogens that affect humans and animals as well.Scientists are therefore searching for novel natural alternatives to antibiotics.In this study Lactobacillus reuteri and a combination of reuterin and microcin J25(RJ)were evaluated as promoters of growth and modulators of the cecal microbiota and metabolite profiles in broiler chickens.Oneday-old Cobb 500 male broilers were distributed to 8 treatments:negative control(without antibiotic),positive control(bacitracin),three concentrations of RJ and three doses of L.reuteri plus glycerol.The birds(2176,34 per pen,8 pens per treatment)were reared for 35 d.Results:The body weight of the bacitracin and 5 mmol/L reuterin combined with 0.08μmol/L microcin J25(10RJ)treatment group was significantly higher than that of the negative control group(P<0.05).L.reuteri had no significant effect on broiler growth.MiSeq high-throughput sequencing of 16S rRNA showed clustering of cecal microbial operational taxonomic unit diversity according to treatment.The influence of bacitracin and 10RJ on bacterial community overall structure was similar.They promoted Ruminococcaceae,Lachnospiraceae and Lactobacillaceae,increased the relative abundance of Faecalibacterium and decreased the abundance of Bacteroides and Alistipes,while the negative control condition favored Bacteroidaceae and Rikenellaceae.Furthermore,10RJ increased the concentration of short-chain fatty acid in the cecum and changed the metabolome overall.Conclusions:These overall suggest that 10RJ can promote a host-friendly gut environment by changing the cecal microbiome and metabolome.This combination of natural antimicrobial agents in the drinking water had a positive effect on broiler growth and may be suitable as an alternative to antibiotic growth promoters.
基金supported by the Young Scientists Fund of the National Natural Science Foundation of China(32402807)the National Key Research and Development Program of China(Grant number 32030105)+2 种基金the Pioneer Technology Project of the National Center for Technology Innovation for Pigs(NCTIP-XD/B05)the PinduoduoChina Agricultural University Research Fund(PC2023A01001)the Chongqing Technology Innovation and Application Development Special Project(cstc2021jscx dxwtBX0005)。
文摘Microcin J25(MccJ25)has received substantial attention as a potential solution to the global threat of infection caused by antibiotic-resistant bacteria.However,the industrial fermentation of MccJ25 faces production bottlenecks.It is imperative to further explore the production optimization strategies for MccJ25 to formulate comprehensive approaches for its industrial-scale production and other downstream applications.Here,Fe^(2+)in tap water was identified as a critical inhibitor of MccJ25 biosynthesis,selectively repressing mcjA transcription,which was reversible via 2,2'-bipyridine-mediated chelation.To decouple production from growth phase dependency and Fe^(2+)interference,we engineered Escherichia coli BL21 cells by performing two genetic modifications.First,we replaced the native mcjA promoter with a constitutive promoter(PQ)to allow its mid-log phase expression.Second,we replaced the native mcjBCD promoter with a medium-strength variant(P2223)that delayed production kinetics without affecting final yields.However,the genomic integration of mcjD alleviated plasmid-borne toxicity,increasing the expression timing and doubling the yield to 240 mg/L.Finally,we computationally optimized the mcjA ribosome-binding site(RBS)to enhance translation efficiency.RBS optimization revealed that a moderate translation initiation efficiency(550,584 arbitrary units[au])maximized production,whereas excessive efficiency(2,019,712 au)impaired growth and output.These interventions synergistically increased the MccJ25 titer 10-fold,reaching 430 mg/L in batch culture.Our findings establish a robust platform for MccJ25 overproduction,highlighting promoter engineering and translational tuning as pivotal strategies for antimicrobial peptide biosynthesis.This study provides insights for overcoming metabolic constraints in microbial fermentation,advancing the development of peptide-based therapeutics against multidrug-resistant pathogens.
基金supported by grants from National Key R&D Pro-gram of China(2019YFA0905200)Natural Science Foundation Youth Project of Jiangsu Province(BK20220335)the Jiangsu Synergetic Innovation Center for Advanced Bio-Manufacture(NO.XTC2206).
文摘The overuse and misuse of traditional antimicrobial drugs have led to their weakened effectiveness and the emergence of pathogenic bacterial resistance.Consequently,there has been growing interest in alternative op-tions such as antimicrobial peptides(AMPs)in the pharmaceutical industry.Microcin J25(MccJ25)has gained significant attention for its potent inhibitory effect on a diverse range of pathogens.Its unique rotaxane structure provides exceptional stability against extreme thermal,pH,and protease degradation,including chymotrypsin,trypsin,and pepsin.Given its remarkable stability and diverse bioactivity,we aim to provide an overview of the physicochemical properties,the mechanism underlying its antimicrobial activity,and the critical functional residues of MccJ25.Additionally,we have summarized the latest strategies for the heterologous expression of MccJ25,and its potential medical use and other applications.
