Background:The maturation of the immune system is critical during early life,as it involves the differentiation,maturation,and establishment of immune tolerance of immune cells.This process is influenced not only by g...Background:The maturation of the immune system is critical during early life,as it involves the differentiation,maturation,and establishment of immune tolerance of immune cells.This process is influenced not only by genetic factors but also by en-vironmental factors,particularly the symbiotic microbiota.Bifidobacterium animalis subsp.lactis(BB-12),originally found in dairy products,is widely used in infant for-mula and dietary supplements.However,its role and mechanisms in immune develop-ment during early life remain unclear.Methods:Using GF mice as the experimental model,B.animalis subsp.lactis BB-12 was administered via gavage during early life.In the juvenile stage,changes in T-cell subsets in the spleen,thymus,and gut intraepithelial lymphocytes(IEL)were assessed using spectral flow cytometry.Additionally,targeted metabolomics analysis of trypto-phan metabolism and short-chain fatty acid pathways in colonic tissue was conducted to explore how B.animalis subsp.lactis BB-12 influences the immune system through gut microbiota metabolism.Results:BB-12 effectively modulates the gut immune microenvironment,leading to beneficial changes in T-cell subsets in key immune tissues such as the spleen,thymus,and gut IELs.Metabolomics analysis further supports these findings by showing that BB-12 intervention greatly increased the production of tryptophan derivatives and acetic acid in the colon of GF mice.Conclusion:The findings provide theoretical evidence for the role of B.animalis subsp.lactis in immune system development and support its application in dietary supple-ments,suggesting potential as a component for infant immune health and in prevent-ing immune-related diseases.展开更多
1)Bifidobacterium longum subsp.iuvenis(Modesto et al.IJSEM.2023,73:6013;Type strain:NCC 5000 T=CCOS 2034 T=LMG 32752^(T))Etymology:iu’ve.nis.L.gen.masc./fem.n.iuvenis,of child,because the type strain was isolated fro...1)Bifidobacterium longum subsp.iuvenis(Modesto et al.IJSEM.2023,73:6013;Type strain:NCC 5000 T=CCOS 2034 T=LMG 32752^(T))Etymology:iu’ve.nis.L.gen.masc./fem.n.iuvenis,of child,because the type strain was isolated from a 2 year old Bangladeshi child.长双歧杆菌幼儿亚种.展开更多
Aeromonas spp.are commonly found in spoilage of chilled meat.Aeromonas salmonicida NCM 29 and A.salmonicida NCM 57 have been discovered the spoilage heterogeneity in degrading myofibrillar protein.In this study,the tw...Aeromonas spp.are commonly found in spoilage of chilled meat.Aeromonas salmonicida NCM 29 and A.salmonicida NCM 57 have been discovered the spoilage heterogeneity in degrading myofibrillar protein.In this study,the two strains were tested to uncover the discrepancy of meat spoilage in collagen-rich chilled meat and extracted collagen.The results revealed that chicken claws,riched in collagen,inoculated with NCM 29 showed higher values of total viable counts(TVC),total volatile basic nitrogen(TVB-N),pH,adhered cells,trichloroacetic acid(TCA)-soluble peptides,and protease activity compared to those inoculated with NCM 57.Furthermore,NCM 29 generated higher quantity of volatile organic compounds related to meat spoilage.The collagenase((hemagglutinin protease(Hap))secreted by NCM 29 has been identified as the key factor responsible for the observed discrepancies in spoilage,which gradually degraded collagen into peptides and hydroxyproline.The capacity of Hap to degrade type Ⅰ collagen in vitro indicated that it has apparent proteolytic activity,which could reduce the average particle size and alter secondary structure of collagen.Sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE)further confirmed the degradation of theβ-chain in collagen.These findings not only provide a theoretical basis for in-depth investigation of the meat spoilage mechanisms of Aeromonas spp.,but also encourage us to take measures to avoid the spoilage of related bacteria such as Aeromonas spp.during the preservation process.展开更多
Vegetables are important dietary sources of folate for human nutrition.The influence of different nitrogen doses and forms on changes in primary nitrogen metabolism,such as amino acid and protein synthesis,in plants i...Vegetables are important dietary sources of folate for human nutrition.The influence of different nitrogen doses and forms on changes in primary nitrogen metabolism,such as amino acid and protein synthesis,in plants is well established.However,the impacts of the nitrate-N(NO_(3)^(-))-to-ammonium-N(NH_(4)^(+))ratio on folate synthesis and accumulation in vegetables are unclear.This study used a hydroponic experiment with six different NO_(3)^(-)/NH_(4)^(+)ratio treatments to investigate the effects of the integrated application of NO_(3)^(-)and NH_(4)^(+)on the folate constituents and contents of pakchoi(Brassica rapa subsp.chinensis).The results indicated that an appropriate NO_(3)^(-)/NH_(4)^(+)ratio in nutrient solution could promote pakchoi growth and increase folate contents by increasing polyglutamylated 5-formyl-tetrahydrofolate(5-CHO-THF)and polyglutamylated 5-methyl-THF(5-CH3-THF).The activities of enzymes related to folate biosynthesis(except folylpolyglutamate synthase(FPGS))were lower with an NH_(4)^(+)-N supply at the same nitrogen concentration.The statistical results revealed a significant negative correlation between folate contents and 14 detected metabolites(including fructose,sucrose,glutamine(Gln),shikimate,citrate,succinate,malate,α-oxoglutarate,p-aminobenzoate(pABA),and 6-hydroxymethyldihydropterin pyrophosphate(HMDH-P_(2))in the folate biosynthesis pathway),implying that the enhancement of folates biosynthesis with NH_(4)^(+)-N supply increased the consumption of the folate precursors and intermediate metabolites.Additionally,NH_(4)^(+)-N supply could improve folate stability by increasing polyglutamylated folates and reducingγ-glutamyl hydrolase(GGH)activity;the latter could weaken folate deglutamylation.As the best growth and highest total folate content were obtained at the appropriate NO_(3)^(-)/NH_(4)^(+)ratio,strategic selection of the NO_(3)^(-)/NH_(4)^(+)ratio should be considered for the hydroponic cultivation of foliar vegetable crops.展开更多
Bacterial soft rot(BSR)caused by Pectobacterium carotovorum subsp.brasiliense(Pcb)is a serious bacterial disease which negatively impact yield and quality in cucumber.However,the genetic mechanism of BSR resistance in...Bacterial soft rot(BSR)caused by Pectobacterium carotovorum subsp.brasiliense(Pcb)is a serious bacterial disease which negatively impact yield and quality in cucumber.However,the genetic mechanism of BSR resistance in cucumber has not been reported.Here,we investigated the BSR resistance of 119 cucumber core germplasm worldwide at the seedling stage and identified 26 accessions highly resistant to BSR.A total of 1642740 single-nucleotide polymorphisms(SNPs)were used to conduct GWAS,and five loci associated with BSR resistance were detected on four chromosomes:gBSR2.1,gBSR2.2,gBSR3.1,gBSR4.1 and gBSR5.1.Based on haplotype analysis,sequence polymorphisms,functional annotation and qRT-PCR analysis,six candidate genes were identified within the five loci.CsaV3_2G014450,CsaV3_2G014490,CsaV3_2G016000,CsaV3_3G000850,CsaV3_4G033150,and CsaV3_5G000390 each had nonsynonymous SNPs,and were significantly up-regulated in the resistant genotypes after inoculation.And CsaV3_5G000390 in the susceptible genotype was significantly up-regulated after inoculation.The identification of these candidate genes lays a foundation for understanding the genetic mechanism of BSR resistance in cucumber.Generally,our study mined genes associated with BSR resistance in cucumber seedlings and will assist the breeding of BSR-resistant cucumber cultivars.展开更多
Bifidobacterium longum subsp.infantis and Bifidobacterium adolescentis play important roles in the guts of infants and adolescents,respectively.In this study,using a neonatal rat model,we compared the protective effec...Bifidobacterium longum subsp.infantis and Bifidobacterium adolescentis play important roles in the guts of infants and adolescents,respectively.In this study,using a neonatal rat model,we compared the protective effects of these 2 bifidobacterial species against Salmonella infection.The results demonstrated that B.longum subsp.infantis was more effective than B.adolescentis in alleviating the severity of infection in newborn rats exposed to Salmonella enterica serovar Typhimurium strain SL1344.B.longum subsp.infantis attenuated intestinal inflammation and mucosal damage induced by Salmonella infection,as well as protecting intestinal nerves and intestinal barrier function through TLR4/My D88 signalling.B.longum subsp.infantis also displayed the potential to modulate gut metabolites by promoting the biosynthesis of unsaturated fatty acids(arachidonic acid,eicosapentaenoic acid andα-linolenic acid)and purine metabolism(guanine,adenine,inosine and adenosine),thereby regulating metabolic disturbances.Additionally,the benefits of B.longum subsp.infantis were also observed in the liver,spleen and brain,improving nerve reflexes and suppressing hepatosplenomegaly.Overall,these findings provide novel insights into the prevention and treatment of gutrelated diseases in newborns,highlighting the potentially significant role of B.longum subsp.infantis in clinical applications.展开更多
Background:The genus Rickettsia in the order Rickettsiales(Alphaproteobacteria)consists of gram-negative obligate intracellular bacteria that infect a wide range of hosts.Epidemiological studies on the occurrence of R...Background:The genus Rickettsia in the order Rickettsiales(Alphaproteobacteria)consists of gram-negative obligate intracellular bacteria that infect a wide range of hosts.Epidemiological studies on the occurrence of Rickettsia spp.and their associated tick vectors are essential to understand their distribution,host range,and transmission mechanisms in nature.This is particularly relevant within the One Health framework,which emphasizes the interconnectedness of animal,human,and environmental health.Methods:To investigate the presence of Rickettsia spp.in dogs and their ticks in Malawi,a molecular survey was conducted.A total of 209 dog blood and 259 tick samples of the species Haemaphysalis elliptica(n=16)and Rhipicephalus linnaei(n=243)were screened using real-time quantitative PCR(qPCR)targeting the citrate synthase(gltA)gene.Positive samples were further characterized via the conventional PCR and Sanger sequencing of gltA and the outer membrane protein A(ompA)genes.Results:Rickettsia DNA was not detected in any dog samples.However,the detection rates in R.linnaei and H.elliptica were 2.5%(n=6)and 6.3%(n=1),respectively.The obtained sequences showed 100% identity with Rickettsia conorii subsp.conorii(n=4),99%-100% with Rickettsia massiliae(n=2),and 100% with Rickettsia rhipicephali(n=1).Phylogenetic analysis clustered these sequences with the corresponding sequences of R.conorii subsp.conorii,R.massiliae,and R.rhipicephali reported from other countries in both gltA and ompA gene-based phylogenetic trees.The detection of R.massiliae and R.rhipicephali in southern Africa suggests expansion of the geographical distribution of these potentially zoonotic Rickettsia species.Conclusion:This is the first report of Rickettsia species detection in ticks collected from dogs in Malawi.The findings highlight the need for further surveillance,including humans and other animals,to better assess the public and veterinary health risks.Public engagement is needed to raise awareness on the role of dogs and their ticks in the transmission of Rickettsia within the One Health approach.展开更多
Microbial food is an important direction of sustainable food development in the future.Microorganisms such as lactic acid bacteria(LAB)are important sources of natural radioprotectors.Moderate environmental stress can...Microbial food is an important direction of sustainable food development in the future.Microorganisms such as lactic acid bacteria(LAB)are important sources of natural radioprotectors.Moderate environmental stress can induce stress response and improve biological activity of LAB.In the previous study,Lactococcus lactis subsp.lactis IL1403(L.lactis IL1403)cell-free extract induced by ionizing radiation(IR)of 500 Gy(IR-CFE)presented the stronger radioprotective effect than untreated cell-free extract in mice.To explore the radioprotective active substances of IR-CFE,the key protein was screened by proteomics and its radioprotective effect in vivo was further evaluated.The Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment showed that two-component systems(TCS)were enhanced to adapt the IR induction.Meanwhile,the protein LlrG belonged to TCS was screened by the protein-protein interaction.Furthermore,the recombinant protein LlrG(rLlrG)could markedly alleviate the ^(60)Coγ-induced damage to the hematopoietic system,oxidative stress and inflammation in mice,thereby exerting its radioprotective function.These results suggested LlrG protein not only played an important role in the adaptation of L.lactis IL1403 to IR environment,but also exerted a good radioprotective effect,which could be applied in the development of protein-based radioprotectors.展开更多
Accumulating evidence suggests that probiotics affect the microbial-gut-brain axis in a way that can prevent and treat Alzheimer's disease(AD).However,the mechanism underlying the therapeutic effects still needs t...Accumulating evidence suggests that probiotics affect the microbial-gut-brain axis in a way that can prevent and treat Alzheimer's disease(AD).However,the mechanism underlying the therapeutic effects still needs to be further investigated.This study aimed to examine the alleviating effect of Lacticaseibacillus paracasei L9 and Bifidobacterium animalis subsp.lactis A6 and possible mechanism in mice with AD.In this study,the administration of probiotics L9 and A6 effectively improved memory and learning functions in AD mice.The hippocampal cells of mice were partly recovered in morphology and rearranged more neatly after probiotics intervention.Meanwhile,L9 and A6 exhibited inhibitory effects on the phosphorylation of Tau and the deposition of Aβ,which were mediated via GSK-3βand PP2A kinases.Meanwhile,by metagenomic sequencing,we found interventions with L9 and A6 altered the intestinal microbiome's taxonomic composition,reduced the abundance of pathogenic Desulfovibrio genera,and increased beneficial Clostridium and Paramuribaculum genera abundance.The fatty acids metabolism and biosynthesis of gut microbiome were also enhanced.Serum untargeted metabolomics also showed noticeable alternation in lipidrelated metabolites,which may alleviate the pathogenesis of AD.These results revealed a mitigating role for probiotic L9 and A6 in AD prevention and offer new insights into AD prevention via gut-brain connection.展开更多
Bifidobacterium longum subsp.infantis is a commensal bacterium that predominates in the infant gut,playing a critical role in both preventing foreign infections and facilitating immune development.This study aimed to ...Bifidobacterium longum subsp.infantis is a commensal bacterium that predominates in the infant gut,playing a critical role in both preventing foreign infections and facilitating immune development.This study aimed to explore the effects of B.longum subsp.infantis supplementation on interferon-beta(IFN-β)secretion and intestinal barrier improvement in growing mice.Female and male mice were orally administered either saline or B.longum subsp.infantis CCFM1269 or I5TI(1×10^(9) CFU/mice per day,n=8)from 1-week-age until 3-,4-,and 5-week-age.RNA sequencing analysis revealed that CCFM1269 exhibited potential antiviral capacity through increasing 2'-5'oligoadenylate synthetase(OAS).Additionally,CCFM1269 supplementation significantly increased colonic IFN-β levels which combined with OAS in 3-week-old female and male mice by activating the TLR4-TRIF-dependent signaling pathway.However,this effect was not observed in 4-and 5-week-old mice.Furthermore,both CCFM1269 were found to modulate the gut microbiota composition and enhance the intestinal barrier function in 3-,4-,and 5-week-old mice.In summary,the results of this study suggested that B.longum subsp.infantis CCFM1269 promoting intestinal barrier and releasing IFN-β in growing mice was in a strain-specific and time-dependent manner.展开更多
【目的】分离鉴定江苏省扬州市养殖场异育银鲫患病病原。【方法】采用常规的理化特性和分子生物学的方法,对从濒死异育银鲫肝脏处分离到的菌株YZ-1进行表型生物学、分子生物学及药敏试验的系统研究。【结果】该菌株16S r RNA基因(序列长...【目的】分离鉴定江苏省扬州市养殖场异育银鲫患病病原。【方法】采用常规的理化特性和分子生物学的方法,对从濒死异育银鲫肝脏处分离到的菌株YZ-1进行表型生物学、分子生物学及药敏试验的系统研究。【结果】该菌株16S r RNA基因(序列长度1 446 bp,Gen Bank登录号为JX164202)与其它杀鲑气单胞菌16S r RNA基因一致性在99%-100%之间,构建发育树确定该菌株为杀鲑气单胞菌杀鲑亚种(Aeromonas salmonicida subsp.salmonicida)。人工回感可导致异育银鲫死亡。药敏试验结果显示:对头孢呋辛、复方新诺明、恩诺沙星等23种抗生素敏感;对阿米卡星、四环素、大观霉素、头孢拉定等11种抗生素中度敏感;对青霉素G、链霉素、庆大霉素、氟苯尼考、万古霉素等10种抗生素耐药。【结论】研究结果证实引起异育银鲫死亡的病原为杀鲑气单胞菌杀鲑亚种。展开更多
基金supported by the National Key R&D Programs of China(2022YFF0710701,2022YFF0710702)Guangzhou Key Research and Development Program(202206010157)+2 种基金Guangzhou Joint Fund for Key Laboratory(202201020381)Medical Joint Fund of Jinan University(YXJC202204)Open Research Project of the Key Laboratory of Viral Pathogenesis and Infection Prevention and Control of the Ministry of Education(2023VPPC-R02).
文摘Background:The maturation of the immune system is critical during early life,as it involves the differentiation,maturation,and establishment of immune tolerance of immune cells.This process is influenced not only by genetic factors but also by en-vironmental factors,particularly the symbiotic microbiota.Bifidobacterium animalis subsp.lactis(BB-12),originally found in dairy products,is widely used in infant for-mula and dietary supplements.However,its role and mechanisms in immune develop-ment during early life remain unclear.Methods:Using GF mice as the experimental model,B.animalis subsp.lactis BB-12 was administered via gavage during early life.In the juvenile stage,changes in T-cell subsets in the spleen,thymus,and gut intraepithelial lymphocytes(IEL)were assessed using spectral flow cytometry.Additionally,targeted metabolomics analysis of trypto-phan metabolism and short-chain fatty acid pathways in colonic tissue was conducted to explore how B.animalis subsp.lactis BB-12 influences the immune system through gut microbiota metabolism.Results:BB-12 effectively modulates the gut immune microenvironment,leading to beneficial changes in T-cell subsets in key immune tissues such as the spleen,thymus,and gut IELs.Metabolomics analysis further supports these findings by showing that BB-12 intervention greatly increased the production of tryptophan derivatives and acetic acid in the colon of GF mice.Conclusion:The findings provide theoretical evidence for the role of B.animalis subsp.lactis in immune system development and support its application in dietary supple-ments,suggesting potential as a component for infant immune health and in prevent-ing immune-related diseases.
文摘1)Bifidobacterium longum subsp.iuvenis(Modesto et al.IJSEM.2023,73:6013;Type strain:NCC 5000 T=CCOS 2034 T=LMG 32752^(T))Etymology:iu’ve.nis.L.gen.masc./fem.n.iuvenis,of child,because the type strain was isolated from a 2 year old Bangladeshi child.长双歧杆菌幼儿亚种.
基金supported by projects funded by grants from the Natural Science Foundation of Jiangsu Province in China(BK20221515)the National Natural Science Foundation of China(32172266).
文摘Aeromonas spp.are commonly found in spoilage of chilled meat.Aeromonas salmonicida NCM 29 and A.salmonicida NCM 57 have been discovered the spoilage heterogeneity in degrading myofibrillar protein.In this study,the two strains were tested to uncover the discrepancy of meat spoilage in collagen-rich chilled meat and extracted collagen.The results revealed that chicken claws,riched in collagen,inoculated with NCM 29 showed higher values of total viable counts(TVC),total volatile basic nitrogen(TVB-N),pH,adhered cells,trichloroacetic acid(TCA)-soluble peptides,and protease activity compared to those inoculated with NCM 57.Furthermore,NCM 29 generated higher quantity of volatile organic compounds related to meat spoilage.The collagenase((hemagglutinin protease(Hap))secreted by NCM 29 has been identified as the key factor responsible for the observed discrepancies in spoilage,which gradually degraded collagen into peptides and hydroxyproline.The capacity of Hap to degrade type Ⅰ collagen in vitro indicated that it has apparent proteolytic activity,which could reduce the average particle size and alter secondary structure of collagen.Sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE)further confirmed the degradation of theβ-chain in collagen.These findings not only provide a theoretical basis for in-depth investigation of the meat spoilage mechanisms of Aeromonas spp.,but also encourage us to take measures to avoid the spoilage of related bacteria such as Aeromonas spp.during the preservation process.
基金supported by the Ministry of Agriculture and Rural Affairs of China Major Project for Support System Construction of Agriculture Green Development in Anji County(No.NG/LS2020-71-05).
文摘Vegetables are important dietary sources of folate for human nutrition.The influence of different nitrogen doses and forms on changes in primary nitrogen metabolism,such as amino acid and protein synthesis,in plants is well established.However,the impacts of the nitrate-N(NO_(3)^(-))-to-ammonium-N(NH_(4)^(+))ratio on folate synthesis and accumulation in vegetables are unclear.This study used a hydroponic experiment with six different NO_(3)^(-)/NH_(4)^(+)ratio treatments to investigate the effects of the integrated application of NO_(3)^(-)and NH_(4)^(+)on the folate constituents and contents of pakchoi(Brassica rapa subsp.chinensis).The results indicated that an appropriate NO_(3)^(-)/NH_(4)^(+)ratio in nutrient solution could promote pakchoi growth and increase folate contents by increasing polyglutamylated 5-formyl-tetrahydrofolate(5-CHO-THF)and polyglutamylated 5-methyl-THF(5-CH3-THF).The activities of enzymes related to folate biosynthesis(except folylpolyglutamate synthase(FPGS))were lower with an NH_(4)^(+)-N supply at the same nitrogen concentration.The statistical results revealed a significant negative correlation between folate contents and 14 detected metabolites(including fructose,sucrose,glutamine(Gln),shikimate,citrate,succinate,malate,α-oxoglutarate,p-aminobenzoate(pABA),and 6-hydroxymethyldihydropterin pyrophosphate(HMDH-P_(2))in the folate biosynthesis pathway),implying that the enhancement of folates biosynthesis with NH_(4)^(+)-N supply increased the consumption of the folate precursors and intermediate metabolites.Additionally,NH_(4)^(+)-N supply could improve folate stability by increasing polyglutamylated folates and reducingγ-glutamyl hydrolase(GGH)activity;the latter could weaken folate deglutamylation.As the best growth and highest total folate content were obtained at the appropriate NO_(3)^(-)/NH_(4)^(+)ratio,strategic selection of the NO_(3)^(-)/NH_(4)^(+)ratio should be considered for the hydroponic cultivation of foliar vegetable crops.
基金supported by the National Key Research and Development Program of China(Grant No.2023YFD1200101)the Earmarked Fund for Modern Agro-industry Technology Research System(Grant No.CARS-23)Science and Technology Innovation Program of the Chinese Academy of Agricultural Science(Grant No.CAAS-ASTIP-IVFCAAS).
文摘Bacterial soft rot(BSR)caused by Pectobacterium carotovorum subsp.brasiliense(Pcb)is a serious bacterial disease which negatively impact yield and quality in cucumber.However,the genetic mechanism of BSR resistance in cucumber has not been reported.Here,we investigated the BSR resistance of 119 cucumber core germplasm worldwide at the seedling stage and identified 26 accessions highly resistant to BSR.A total of 1642740 single-nucleotide polymorphisms(SNPs)were used to conduct GWAS,and five loci associated with BSR resistance were detected on four chromosomes:gBSR2.1,gBSR2.2,gBSR3.1,gBSR4.1 and gBSR5.1.Based on haplotype analysis,sequence polymorphisms,functional annotation and qRT-PCR analysis,six candidate genes were identified within the five loci.CsaV3_2G014450,CsaV3_2G014490,CsaV3_2G016000,CsaV3_3G000850,CsaV3_4G033150,and CsaV3_5G000390 each had nonsynonymous SNPs,and were significantly up-regulated in the resistant genotypes after inoculation.And CsaV3_5G000390 in the susceptible genotype was significantly up-regulated after inoculation.The identification of these candidate genes lays a foundation for understanding the genetic mechanism of BSR resistance in cucumber.Generally,our study mined genes associated with BSR resistance in cucumber seedlings and will assist the breeding of BSR-resistant cucumber cultivars.
基金supported by the National Natural Science Foundation of China(32021005,32272332)the Fundamental Research Funds for the Central Universities(JUSRP622020,JUSRP51501)+1 种基金the Program of Collaborative Innovation Centre of Food Safety and Quality Control in Jiangsu ProvincePostgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX22_2391)。
文摘Bifidobacterium longum subsp.infantis and Bifidobacterium adolescentis play important roles in the guts of infants and adolescents,respectively.In this study,using a neonatal rat model,we compared the protective effects of these 2 bifidobacterial species against Salmonella infection.The results demonstrated that B.longum subsp.infantis was more effective than B.adolescentis in alleviating the severity of infection in newborn rats exposed to Salmonella enterica serovar Typhimurium strain SL1344.B.longum subsp.infantis attenuated intestinal inflammation and mucosal damage induced by Salmonella infection,as well as protecting intestinal nerves and intestinal barrier function through TLR4/My D88 signalling.B.longum subsp.infantis also displayed the potential to modulate gut metabolites by promoting the biosynthesis of unsaturated fatty acids(arachidonic acid,eicosapentaenoic acid andα-linolenic acid)and purine metabolism(guanine,adenine,inosine and adenosine),thereby regulating metabolic disturbances.Additionally,the benefits of B.longum subsp.infantis were also observed in the liver,spleen and brain,improving nerve reflexes and suppressing hepatosplenomegaly.Overall,these findings provide novel insights into the prevention and treatment of gutrelated diseases in newborns,highlighting the potentially significant role of B.longum subsp.infantis in clinical applications.
基金supported in part by the Japan Society for the Promotion of Science(JSPS)KAKENHI(grant numbers JP23K23770,JP24KK0133,and JP25K02166)the Japan Agency for Medical Research and Developmen(AMED)(grant numbers JP18jm0510001 and JP23wm0225034)JST SPRING(grant number JPMJSP2119).
文摘Background:The genus Rickettsia in the order Rickettsiales(Alphaproteobacteria)consists of gram-negative obligate intracellular bacteria that infect a wide range of hosts.Epidemiological studies on the occurrence of Rickettsia spp.and their associated tick vectors are essential to understand their distribution,host range,and transmission mechanisms in nature.This is particularly relevant within the One Health framework,which emphasizes the interconnectedness of animal,human,and environmental health.Methods:To investigate the presence of Rickettsia spp.in dogs and their ticks in Malawi,a molecular survey was conducted.A total of 209 dog blood and 259 tick samples of the species Haemaphysalis elliptica(n=16)and Rhipicephalus linnaei(n=243)were screened using real-time quantitative PCR(qPCR)targeting the citrate synthase(gltA)gene.Positive samples were further characterized via the conventional PCR and Sanger sequencing of gltA and the outer membrane protein A(ompA)genes.Results:Rickettsia DNA was not detected in any dog samples.However,the detection rates in R.linnaei and H.elliptica were 2.5%(n=6)and 6.3%(n=1),respectively.The obtained sequences showed 100% identity with Rickettsia conorii subsp.conorii(n=4),99%-100% with Rickettsia massiliae(n=2),and 100% with Rickettsia rhipicephali(n=1).Phylogenetic analysis clustered these sequences with the corresponding sequences of R.conorii subsp.conorii,R.massiliae,and R.rhipicephali reported from other countries in both gltA and ompA gene-based phylogenetic trees.The detection of R.massiliae and R.rhipicephali in southern Africa suggests expansion of the geographical distribution of these potentially zoonotic Rickettsia species.Conclusion:This is the first report of Rickettsia species detection in ticks collected from dogs in Malawi.The findings highlight the need for further surveillance,including humans and other animals,to better assess the public and veterinary health risks.Public engagement is needed to raise awareness on the role of dogs and their ticks in the transmission of Rickettsia within the One Health approach.
基金supported by the National Natural Science Foundation of China(32172211,32572557)the Key Science Research Projects of Higher Education Institutions in Henan Province(21A530006)+3 种基金the Key Research and Development and Promotion Projects of Henan Province(232102310293)the Henan Provincial Natural Science Foundation General Program(252300421403)the Zhongyuan Sci-Tech Innovation Leading Talents(254200510040)the Innovative Research Team(in Science and Technology)in University of Henan Province(26IRTSTHN030).
文摘Microbial food is an important direction of sustainable food development in the future.Microorganisms such as lactic acid bacteria(LAB)are important sources of natural radioprotectors.Moderate environmental stress can induce stress response and improve biological activity of LAB.In the previous study,Lactococcus lactis subsp.lactis IL1403(L.lactis IL1403)cell-free extract induced by ionizing radiation(IR)of 500 Gy(IR-CFE)presented the stronger radioprotective effect than untreated cell-free extract in mice.To explore the radioprotective active substances of IR-CFE,the key protein was screened by proteomics and its radioprotective effect in vivo was further evaluated.The Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment showed that two-component systems(TCS)were enhanced to adapt the IR induction.Meanwhile,the protein LlrG belonged to TCS was screened by the protein-protein interaction.Furthermore,the recombinant protein LlrG(rLlrG)could markedly alleviate the ^(60)Coγ-induced damage to the hematopoietic system,oxidative stress and inflammation in mice,thereby exerting its radioprotective function.These results suggested LlrG protein not only played an important role in the adaptation of L.lactis IL1403 to IR environment,but also exerted a good radioprotective effect,which could be applied in the development of protein-based radioprotectors.
基金funded by the National Key R&D Program of China(2023YFF1104501)R&D Program of Beijing Municipal Education Commission(23JF0006)National Natural Science Foundation of China(31601443 and 32101938)。
文摘Accumulating evidence suggests that probiotics affect the microbial-gut-brain axis in a way that can prevent and treat Alzheimer's disease(AD).However,the mechanism underlying the therapeutic effects still needs to be further investigated.This study aimed to examine the alleviating effect of Lacticaseibacillus paracasei L9 and Bifidobacterium animalis subsp.lactis A6 and possible mechanism in mice with AD.In this study,the administration of probiotics L9 and A6 effectively improved memory and learning functions in AD mice.The hippocampal cells of mice were partly recovered in morphology and rearranged more neatly after probiotics intervention.Meanwhile,L9 and A6 exhibited inhibitory effects on the phosphorylation of Tau and the deposition of Aβ,which were mediated via GSK-3βand PP2A kinases.Meanwhile,by metagenomic sequencing,we found interventions with L9 and A6 altered the intestinal microbiome's taxonomic composition,reduced the abundance of pathogenic Desulfovibrio genera,and increased beneficial Clostridium and Paramuribaculum genera abundance.The fatty acids metabolism and biosynthesis of gut microbiome were also enhanced.Serum untargeted metabolomics also showed noticeable alternation in lipidrelated metabolites,which may alleviate the pathogenesis of AD.These results revealed a mitigating role for probiotic L9 and A6 in AD prevention and offer new insights into AD prevention via gut-brain connection.
基金funded by the National Key R&D Program of China(2021YFD2100700)National Natural Science Foundation of China(32021005)+1 种基金111 project(BP0719028)Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province。
文摘Bifidobacterium longum subsp.infantis is a commensal bacterium that predominates in the infant gut,playing a critical role in both preventing foreign infections and facilitating immune development.This study aimed to explore the effects of B.longum subsp.infantis supplementation on interferon-beta(IFN-β)secretion and intestinal barrier improvement in growing mice.Female and male mice were orally administered either saline or B.longum subsp.infantis CCFM1269 or I5TI(1×10^(9) CFU/mice per day,n=8)from 1-week-age until 3-,4-,and 5-week-age.RNA sequencing analysis revealed that CCFM1269 exhibited potential antiviral capacity through increasing 2'-5'oligoadenylate synthetase(OAS).Additionally,CCFM1269 supplementation significantly increased colonic IFN-β levels which combined with OAS in 3-week-old female and male mice by activating the TLR4-TRIF-dependent signaling pathway.However,this effect was not observed in 4-and 5-week-old mice.Furthermore,both CCFM1269 were found to modulate the gut microbiota composition and enhance the intestinal barrier function in 3-,4-,and 5-week-old mice.In summary,the results of this study suggested that B.longum subsp.infantis CCFM1269 promoting intestinal barrier and releasing IFN-β in growing mice was in a strain-specific and time-dependent manner.
文摘【目的】分离鉴定江苏省扬州市养殖场异育银鲫患病病原。【方法】采用常规的理化特性和分子生物学的方法,对从濒死异育银鲫肝脏处分离到的菌株YZ-1进行表型生物学、分子生物学及药敏试验的系统研究。【结果】该菌株16S r RNA基因(序列长度1 446 bp,Gen Bank登录号为JX164202)与其它杀鲑气单胞菌16S r RNA基因一致性在99%-100%之间,构建发育树确定该菌株为杀鲑气单胞菌杀鲑亚种(Aeromonas salmonicida subsp.salmonicida)。人工回感可导致异育银鲫死亡。药敏试验结果显示:对头孢呋辛、复方新诺明、恩诺沙星等23种抗生素敏感;对阿米卡星、四环素、大观霉素、头孢拉定等11种抗生素中度敏感;对青霉素G、链霉素、庆大霉素、氟苯尼考、万古霉素等10种抗生素耐药。【结论】研究结果证实引起异育银鲫死亡的病原为杀鲑气单胞菌杀鲑亚种。
