Background Subclinical mastitis,caused by many pathogens including Staphylococcus aureus(S.aureus)and Staphylococcus chromogenes(S.chromogenes),presents a major challenge to the dairy industry due to its associated ec...Background Subclinical mastitis,caused by many pathogens including Staphylococcus aureus(S.aureus)and Staphylococcus chromogenes(S.chromogenes),presents a major challenge to the dairy industry due to its associated economic losses and poor milk quality.The molecular regulatory mechanisms,including the role of small nucleolar RNAs(snoRNAs),of the host response to mastitis pathogens remain unclear.Therefore,this study investigated snoRNA expression and potential roles during subclinical mastitis.Milk somatic cells from cows with naturally occurring S.aureus(n=14)and S.chromogenes(n=3)subclinical mastitis,and healthy cows(n=4)were subjected to transcriptome sequencing and bioinformatics analyses.Results We identified 255 expressed snoRNAs including 21 differentially expressed(DE)in S.aureus-positive cows and 20 DE in S.chromogenes-positive cows.Prediction of ribosomal RNA(rRNA)modification sites found several 18S rRNA and 28S rRNA modification(pseudouridylation and 2′-O-methylation)target sites essential for ribosome function for DE snoRNAs,such as SNORA79(18S-1319,28S-3001),SNORA1(18S-1496,28S-1747),suggesting their roles in translation and immune modulation during subclinical mastitis.Correlation analysis identified DE snoRNAs-mRNAs(from the same samples)pairs with majority of the correlated mRNAs(e.g.,CXCL8,IL6R,IL2,IL1R,IL18R1,STAT3,NFKB2,MYD88,VEGFA,and CD40)having immune related functions.Functional enrichment of correlated genes of snoRNAs for S.aureus-positive group(regulation of defense/immune response,leukocyte differentiation,response to cytokine,NF-κB signaling pathway,JAK-STAT signaling pathway etc.)and S.chromogenes-positive group(e.g.,regulation of defense response,response to cytokine,regulation of immune response,NF-κB signaling pathway,TNF signaling pathway,and JAK-STAT signaling pathway)revealed involvement in immune and inflammatory processes.Some functional terms were common to both pathogens(e.g.,NF-κB,JAK-STAT signaling,immune system processes)and suggest common regulatory mechanisms used by both pathogens to contain infection.Furthermore,snoRNA-mRNA network construction identified 7 key(hub)snoRNAs each for S.aureus-positive group(SNORA66,novelsnoRNA_26_14905(also denoted as novelSnoRNA_86),SNORD107,SNORA1,SNORA63,SNORA79,SNORA76)and S.chromogenes-positive group(SNORD18,SNORA79,SNORA46,U2-19,SNORA66,SNORD37,SNORD49)that correlated with the most protein coding genes(|r|>0.9;≥30 mRNAs).Functional enrichment of correlated genes of hub snoRNAs reveals their involvement in immune related functions(75%of enriched terms)and metabolic processes(20%of enriched terms).Conclusion These data suggest potential regulatory roles for the DE snoRNAs and in particular,the 14 hub snoRNAs during subclinical mastitis.This study presents the first evidence linking snoRNAs to bovine subclinical mastitis and offers new insights into the molecular mechanisms underlying subclinical mastitis caused by S.aureus and S.chromogenes.展开更多
This review article summarizes the efficacy, feasibility and potential mechanisms of the application of essential oils as antibiotic alternatives in swine production.Although there are numerous studies demonstrating t...This review article summarizes the efficacy, feasibility and potential mechanisms of the application of essential oils as antibiotic alternatives in swine production.Although there are numerous studies demonstrating that essential oils have several properties, such as antimicrobial, antioxidative and antiinflammatory effects, feed palatability enhancement and improvement in gut growth and health, there is still a need of further investigations to elucidate the mechanisms underlying their functions.In the past,the results has been inconsistent in both laboratory and field studies because of the varied product compositions, dosages, purities and growing stages and conditions of animals.The minimal inhibitory concentration(MIC) of essential oils needed for killing enteric pathogens may not ensure the optimal feed intake and the essential oils inclusion cost may be too high in swine production.With the lipophilic and volatile nature of essential oils, there is a challenge in effective delivery of essential oils within pig gut and this challenge can partially be resolved by microencapsulation and nanotechnology.The effects of essential oils on inflammation, oxidative stress, microbiome, gut chemosensing and bacterial quorum sensing(QS) have led to better production performance of animals fed essential oils in a number of studies.It has been demonstrated that essential oils have good potential as antibiotic alternatives in feeds for swine production.The combination of different essential oils and other compounds(synergistic effect) such as organic acids seems to be a promising approach to improve the efficacy and safety of essential oils in applications.High-throughput systems technologies have been developed recently,which will allow us to dissect the mechanisms underlying the functions of essential oils and facilitate the use of essential oils in swine production.展开更多
基金Agriculture and Agri-Food Canada funded this research(grant number J-002223).
文摘Background Subclinical mastitis,caused by many pathogens including Staphylococcus aureus(S.aureus)and Staphylococcus chromogenes(S.chromogenes),presents a major challenge to the dairy industry due to its associated economic losses and poor milk quality.The molecular regulatory mechanisms,including the role of small nucleolar RNAs(snoRNAs),of the host response to mastitis pathogens remain unclear.Therefore,this study investigated snoRNA expression and potential roles during subclinical mastitis.Milk somatic cells from cows with naturally occurring S.aureus(n=14)and S.chromogenes(n=3)subclinical mastitis,and healthy cows(n=4)were subjected to transcriptome sequencing and bioinformatics analyses.Results We identified 255 expressed snoRNAs including 21 differentially expressed(DE)in S.aureus-positive cows and 20 DE in S.chromogenes-positive cows.Prediction of ribosomal RNA(rRNA)modification sites found several 18S rRNA and 28S rRNA modification(pseudouridylation and 2′-O-methylation)target sites essential for ribosome function for DE snoRNAs,such as SNORA79(18S-1319,28S-3001),SNORA1(18S-1496,28S-1747),suggesting their roles in translation and immune modulation during subclinical mastitis.Correlation analysis identified DE snoRNAs-mRNAs(from the same samples)pairs with majority of the correlated mRNAs(e.g.,CXCL8,IL6R,IL2,IL1R,IL18R1,STAT3,NFKB2,MYD88,VEGFA,and CD40)having immune related functions.Functional enrichment of correlated genes of snoRNAs for S.aureus-positive group(regulation of defense/immune response,leukocyte differentiation,response to cytokine,NF-κB signaling pathway,JAK-STAT signaling pathway etc.)and S.chromogenes-positive group(e.g.,regulation of defense response,response to cytokine,regulation of immune response,NF-κB signaling pathway,TNF signaling pathway,and JAK-STAT signaling pathway)revealed involvement in immune and inflammatory processes.Some functional terms were common to both pathogens(e.g.,NF-κB,JAK-STAT signaling,immune system processes)and suggest common regulatory mechanisms used by both pathogens to contain infection.Furthermore,snoRNA-mRNA network construction identified 7 key(hub)snoRNAs each for S.aureus-positive group(SNORA66,novelsnoRNA_26_14905(also denoted as novelSnoRNA_86),SNORD107,SNORA1,SNORA63,SNORA79,SNORA76)and S.chromogenes-positive group(SNORD18,SNORA79,SNORA46,U2-19,SNORA66,SNORD37,SNORD49)that correlated with the most protein coding genes(|r|>0.9;≥30 mRNAs).Functional enrichment of correlated genes of hub snoRNAs reveals their involvement in immune related functions(75%of enriched terms)and metabolic processes(20%of enriched terms).Conclusion These data suggest potential regulatory roles for the DE snoRNAs and in particular,the 14 hub snoRNAs during subclinical mastitis.This study presents the first evidence linking snoRNAs to bovine subclinical mastitis and offers new insights into the molecular mechanisms underlying subclinical mastitis caused by S.aureus and S.chromogenes.
基金supported by Natural Sciences and Engineering Council of Canada (NSERC) (CRDPJ 503580-16) Collaborative Research and Development Grants (C.Yang)the University of Manitoba Start-Up Grant (46561)+1 种基金Manitoba Pork Council (47370)Jefo Nutrition Inc (47369)
文摘This review article summarizes the efficacy, feasibility and potential mechanisms of the application of essential oils as antibiotic alternatives in swine production.Although there are numerous studies demonstrating that essential oils have several properties, such as antimicrobial, antioxidative and antiinflammatory effects, feed palatability enhancement and improvement in gut growth and health, there is still a need of further investigations to elucidate the mechanisms underlying their functions.In the past,the results has been inconsistent in both laboratory and field studies because of the varied product compositions, dosages, purities and growing stages and conditions of animals.The minimal inhibitory concentration(MIC) of essential oils needed for killing enteric pathogens may not ensure the optimal feed intake and the essential oils inclusion cost may be too high in swine production.With the lipophilic and volatile nature of essential oils, there is a challenge in effective delivery of essential oils within pig gut and this challenge can partially be resolved by microencapsulation and nanotechnology.The effects of essential oils on inflammation, oxidative stress, microbiome, gut chemosensing and bacterial quorum sensing(QS) have led to better production performance of animals fed essential oils in a number of studies.It has been demonstrated that essential oils have good potential as antibiotic alternatives in feeds for swine production.The combination of different essential oils and other compounds(synergistic effect) such as organic acids seems to be a promising approach to improve the efficacy and safety of essential oils in applications.High-throughput systems technologies have been developed recently,which will allow us to dissect the mechanisms underlying the functions of essential oils and facilitate the use of essential oils in swine production.
