Hypercholesterolemia is a great threat to humans.Bile salt hydrolase(BSH)-producing lactic acid bacteria(LAB)may alleviate it,but current screening methods are inadequate.This study aimed to establish a more comprehen...Hypercholesterolemia is a great threat to humans.Bile salt hydrolase(BSH)-producing lactic acid bacteria(LAB)may alleviate it,but current screening methods are inadequate.This study aimed to establish a more comprehensive in vitro method to screen BSH-producing LAB with greater potential for anti-hypercholesterolemia.Fortyone LAB were initially isolated from infant feces and 37 strains could produce BSH.Strains with BSH over 2 U/mg for sodium glycodeoxycholate and sodium taurodeoxycholate were used to analyse cholesterol degradation rate,hydrophobicity,self-aggregation,gastric fluid tolerance,and intestinal fluid tolerance.Based on the results of these indicators,Lactococcus lactis Y17,L.rhamnosus Q2,and L.fermentum Q11 with the top scores were considered anti-hypercholesterolemia candidates using a principal component analysis evaluation.Antioxidant and Caco-2 adhesion assays showed that these three strains exhibited excellent antioxidant ability and Caco-2 adhesion ability.Their total antioxidant capacity was above 0.99μmol/L,while the Caco-2 adhesion rate was higher than 8.22%.Safety assessments,via antibiotic susceptibility and hemolysis tests,confirmed their safety.In the HepG2 cells assay,the total cholesterol content of the Y17,Q2,and Q11 groups was reduced by 0.525 mmol/L,0.426 mmol/L,and 0.581 mmol/L,which verified the potential of the three LAB in anti-hypercholesterolemia.In addition,they could enhance cholesterol uptake and bile acid synthesis in HepG2 cells by upregulating the mRNA expression of bile acid synthase(CYP7A1 and CYP8B1)and cholesterol uptake receptors(NPC1L1 and LDLR).The results showed that the three LAB could be developed into anti-hypercholesterolemia foods with beneficial properties.展开更多
Exopolysaccharides(EPS)are important metabolites produced by lactic acid bacteria(LAB),exhibiting diverse biological activities.However,their application is limited by low production levels.This study aimed to isolate...Exopolysaccharides(EPS)are important metabolites produced by lactic acid bacteria(LAB),exhibiting diverse biological activities.However,their application is limited by low production levels.This study aimed to isolate,characterize,and evaluate the bioactivities of an EPS(EPS-PAD)from high-yield LAB in kefir grains.A novel EPSPAD was isolated,purified and analyzed using molecular weight determination,monosaccharide composition analysis,nuclear magnetic resonance(NMR),and methylation analysis.Moreover,the antioxidant activity and anti-inflammatory activity of EPS-PAD were investigated as well.The results showed that EPS-PAD had a relatively low molecular weight(42.7 kDa)and consisted of arabinose,glucose,and galactose(molar ratio 1:1:3).Furthermore,structural analysis indicated it possessed anα-pyranose configuration with branched chain residues.Remarkably,EPS-PAD exhibited potent radical scavenging activities,with rates of 62%(1,1-diphenyl-2-picrylhydrazyl radicals),64%(2,2′-azinobis(3-ethlybenzothiazoline)-6-sulfonic acid radicals),and 76%(hydroxyl radical).In addition,at 400μg/mL,EPS-PAD significantly suppressed the production and mRNA expression of pro-inflammatory cytokines(IL-1β,IL-6,TNF-α)and upregulated the production of antiinflammatory cytokine IL-10 in RAW264.7 cells.These findings provide a scientific basis for EPS-PAD from kefir grain LAB as a promising natural antioxidant and anti-inflammatory agent with significant application potential.展开更多
Background Ventilator-associated pneumonia(VAP)is a significant and common health concern.The epidemiological landscape of VAP is poorly understood in neurosurgery patients.This study aimed to explore the epidemiology...Background Ventilator-associated pneumonia(VAP)is a significant and common health concern.The epidemiological landscape of VAP is poorly understood in neurosurgery patients.This study aimed to explore the epidemiology of VAP in this population and devise targeted surveillance,treatment,and control efforts.Methods A 10-year retrospective study spanning 2011 to 2020 was performed in a large Chinese tertiary hospital.Surveillance data was collected from neurosurgical patients and analyzed to map the demographic and clinical characteristics of VAP and describe the distribution and antimicrobial resistance profile of leading pathogens.Risk factors associated with the presence of VAP were explored using boosted regression tree(BRT)models.Results Three hundred ten VAP patients were identified.The 10-year incidence of VAP was 16.21 per 1000 ventilation days.All-cause mortality was 6.1%.The prevalence of gram-negative bacteria,fungi,and gram-positive bacteria among the 357 organisms isolated from VAP patients was 86.0%,7.6%,and 6.4%,respectively;most were multidrug-resistant organisms.Acinetobacter baumannii,Klebsiella pneumoniae,and Pseudomonas aeruginosa were the most common pathogens.The prevalence of carbapenem-resistant A.baumannii,P.aeruginosa,and K.pneumoniae was high and increased over time in the study period.The BRT models revealed that VAP was associated with number of days of ventilator use(relative contribution,47.84±7.25),Glasgow Coma Scale score(relative contribution,24.72±5.67),and tracheotomy(relative contribution,21.50±2.69).Conclusions Our findings provide a better understanding of the epidemiology of VAP and its risk factors in neurosurgery patients.展开更多
基金Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX23_1892)A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)are gratefully acknowledged.
文摘Hypercholesterolemia is a great threat to humans.Bile salt hydrolase(BSH)-producing lactic acid bacteria(LAB)may alleviate it,but current screening methods are inadequate.This study aimed to establish a more comprehensive in vitro method to screen BSH-producing LAB with greater potential for anti-hypercholesterolemia.Fortyone LAB were initially isolated from infant feces and 37 strains could produce BSH.Strains with BSH over 2 U/mg for sodium glycodeoxycholate and sodium taurodeoxycholate were used to analyse cholesterol degradation rate,hydrophobicity,self-aggregation,gastric fluid tolerance,and intestinal fluid tolerance.Based on the results of these indicators,Lactococcus lactis Y17,L.rhamnosus Q2,and L.fermentum Q11 with the top scores were considered anti-hypercholesterolemia candidates using a principal component analysis evaluation.Antioxidant and Caco-2 adhesion assays showed that these three strains exhibited excellent antioxidant ability and Caco-2 adhesion ability.Their total antioxidant capacity was above 0.99μmol/L,while the Caco-2 adhesion rate was higher than 8.22%.Safety assessments,via antibiotic susceptibility and hemolysis tests,confirmed their safety.In the HepG2 cells assay,the total cholesterol content of the Y17,Q2,and Q11 groups was reduced by 0.525 mmol/L,0.426 mmol/L,and 0.581 mmol/L,which verified the potential of the three LAB in anti-hypercholesterolemia.In addition,they could enhance cholesterol uptake and bile acid synthesis in HepG2 cells by upregulating the mRNA expression of bile acid synthase(CYP7A1 and CYP8B1)and cholesterol uptake receptors(NPC1L1 and LDLR).The results showed that the three LAB could be developed into anti-hypercholesterolemia foods with beneficial properties.
基金supported by A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education In-stitutions(PAPD).
文摘Exopolysaccharides(EPS)are important metabolites produced by lactic acid bacteria(LAB),exhibiting diverse biological activities.However,their application is limited by low production levels.This study aimed to isolate,characterize,and evaluate the bioactivities of an EPS(EPS-PAD)from high-yield LAB in kefir grains.A novel EPSPAD was isolated,purified and analyzed using molecular weight determination,monosaccharide composition analysis,nuclear magnetic resonance(NMR),and methylation analysis.Moreover,the antioxidant activity and anti-inflammatory activity of EPS-PAD were investigated as well.The results showed that EPS-PAD had a relatively low molecular weight(42.7 kDa)and consisted of arabinose,glucose,and galactose(molar ratio 1:1:3).Furthermore,structural analysis indicated it possessed anα-pyranose configuration with branched chain residues.Remarkably,EPS-PAD exhibited potent radical scavenging activities,with rates of 62%(1,1-diphenyl-2-picrylhydrazyl radicals),64%(2,2′-azinobis(3-ethlybenzothiazoline)-6-sulfonic acid radicals),and 76%(hydroxyl radical).In addition,at 400μg/mL,EPS-PAD significantly suppressed the production and mRNA expression of pro-inflammatory cytokines(IL-1β,IL-6,TNF-α)and upregulated the production of antiinflammatory cytokine IL-10 in RAW264.7 cells.These findings provide a scientific basis for EPS-PAD from kefir grain LAB as a promising natural antioxidant and anti-inflammatory agent with significant application potential.
基金Youth-Support Project of Chinese PLA General Hospital(QNF19044)Project on Bio-Safety Control and Prevention(2020-YJXTGCWQS-X9288).
文摘Background Ventilator-associated pneumonia(VAP)is a significant and common health concern.The epidemiological landscape of VAP is poorly understood in neurosurgery patients.This study aimed to explore the epidemiology of VAP in this population and devise targeted surveillance,treatment,and control efforts.Methods A 10-year retrospective study spanning 2011 to 2020 was performed in a large Chinese tertiary hospital.Surveillance data was collected from neurosurgical patients and analyzed to map the demographic and clinical characteristics of VAP and describe the distribution and antimicrobial resistance profile of leading pathogens.Risk factors associated with the presence of VAP were explored using boosted regression tree(BRT)models.Results Three hundred ten VAP patients were identified.The 10-year incidence of VAP was 16.21 per 1000 ventilation days.All-cause mortality was 6.1%.The prevalence of gram-negative bacteria,fungi,and gram-positive bacteria among the 357 organisms isolated from VAP patients was 86.0%,7.6%,and 6.4%,respectively;most were multidrug-resistant organisms.Acinetobacter baumannii,Klebsiella pneumoniae,and Pseudomonas aeruginosa were the most common pathogens.The prevalence of carbapenem-resistant A.baumannii,P.aeruginosa,and K.pneumoniae was high and increased over time in the study period.The BRT models revealed that VAP was associated with number of days of ventilator use(relative contribution,47.84±7.25),Glasgow Coma Scale score(relative contribution,24.72±5.67),and tracheotomy(relative contribution,21.50±2.69).Conclusions Our findings provide a better understanding of the epidemiology of VAP and its risk factors in neurosurgery patients.
