Objective:In the realm of Class I pathogens,Burkholderia pseudomallei(BP)stands out for its propensity to induce severe pathogenicity.Investigating the intricate interactions between BP and host cells is imperative fo...Objective:In the realm of Class I pathogens,Burkholderia pseudomallei(BP)stands out for its propensity to induce severe pathogenicity.Investigating the intricate interactions between BP and host cells is imperative for comprehending the dynamics of BP infection and discerning biomarkers indicative of the host cell response process.Methods:mRNA extraction from BP-infected mouse macrophages constituted the initial step of our study.Employing gene expression arrays,the extracted RNA underwent conversion into digital signals.The percentile shift method facilitated data processing,with the identification of genes manifesting significant differences accomplished through the application of the t-test.Subsequently,a comprehensive analysis involving Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway was conducted on the differentially expressed genes(DEGs).Leveraging the ESTIMATE algorithm,gene signatures were utilized to compute risk scores for gene expression data.Support vector machine analysis and gene enrichment scores were instrumental in establishing correlations between biomarkers and macrophages,followed by an evaluation of the predictive power of the identified biomarkers.Results:The functional and pathway associations of the DEGs predominantly centered around G protein-coupled receptors.A noteworthy positive correlation emerged between the blue module,consisting of 416 genes,and the StromaScore.FZD4,identified through support vector machine analysis among intersecting genes,indicated a robust interaction with macrophages,suggesting its potential as a robust biomarker.FZD4 exhibited commendable predictive efficacy,with BP infection inducing its expression in both macrophages and mouse lung tissue.Western blotting in macrophages confirmed a significant upregulation of FZD4 expression from 0.5 to 24 h post-infection.In mouse lung tissue,FZD4 manifested higher expression in the cytoplasm of pulmonary epithelial cells in BP-infected lungs than in the control group.Conclusion:Thesefindings underscore the upregulation of FZD4 expression by BP in both macrophages and lung tissue,pointing to its prospective role as a biomarker in the pathogenesis of BP infection.展开更多
Objective:To characterize biofilm production by clinical(n=21)and environmental(n=11)isolates of Burkholderia pseudomallei and evaluate the production of proteases,hemolysins and siderophores.Methods:Initially,the 32 ...Objective:To characterize biofilm production by clinical(n=21)and environmental(n=11)isolates of Burkholderia pseudomallei and evaluate the production of proteases,hemolysins and siderophores.Methods:Initially,the 32 strains were evaluated for biofilm production in Müller-Hinton broth-1%glucose(MH-1%glucose)and BHI broth-1%glucose,using the crystal violet staining technique.Subsequently,growing(48 h)and mature(72 h)biofilms were evaluated by confocal microscopy.Finally,the production of proteases,hemolysins and siderophores by planktonic aggregates,growing biofilms and mature biofilms was evaluated.Results:All isolates produced biofilms,but clinical isolates had significantly higher biomass in both MH-1%glucose(P<0.001)and BHI-glucose 1%(P=0.005).The structural analyses by confocal microscopy showed thick biofilms,composed of multiple layers of cells,homogeneously arranged,with mature biofilms of clinical isolates presenting higher biomass(P=0.019)and thickness of the entire area(P=0.029),and lower roughness coefficient(P=0.007)than those of environmental isolates.Protease production by growing biofilms was significantly greater than that of planktonic(P<0.001)and mature biofilms(P<0.001).Hemolysin release by planktonic aggregates was higher than that of biofilms(P<0.001).Regarding siderophores,mature biofilms presented higher production than growing biofilms(P<0.001)and planktonic aggregates(P<0.001).Conclusions:Clinical isolates have higher production of biofilms than their environmental counterparts;protease and siderophores seem important for growth and maintenance of Burkholderia pseudomallei biofilms.展开更多
Burkholderia pseudomallei is a causative agent of melioidosis that can infect humans and animals in endemic countries,specifically in Southeast Asia and tropical Australia.A fundamental component for the pathogenesis ...Burkholderia pseudomallei is a causative agent of melioidosis that can infect humans and animals in endemic countries,specifically in Southeast Asia and tropical Australia.A fundamental component for the pathogenesis of Burkholderia pseudomallei is the capability of the bacterium to enter,survive,replicate,and cause disease in a host cell by inducing the host cell fusion.Cell fusion results in multinucleated-giant cell formation,thus enabling the dissemination of Burkholderia pseudomallei intracellularly.cGAS reacts to Burkholderia pseudomallei infection by activating the cGAS-STING pathway and subsequently limiting host's aberrant cell division and cellular replication by inducing autophagic cell death.In this review,we discuss the host-pathogen interactions between the typeⅥsecretion system 5(T6SS-5)of Burkholderia pseudomallei and human cGAS pathway in melioidosis infections.Since T6SS-5 is a main virulent factor in Burkholderia pseudomallei and the c GAS pathway is vital for host immune response,elucidating their functions is important for better understanding the pathogenesis of Burkholderia pseudomallei.展开更多
BACKGROUND Burkholderia pseudomallei(B.pseudomallei)is a short,straight,medium-sized Gramnegative bacterium that mostly exists alone,without a capsule or spores,has more than three flagella at one end,and actively mov...BACKGROUND Burkholderia pseudomallei(B.pseudomallei)is a short,straight,medium-sized Gramnegative bacterium that mostly exists alone,without a capsule or spores,has more than three flagella at one end,and actively moves.B.pseudomallei confers high morbidity and mortality,with frequent granulocytopenia in B.pseudomallei sepsisrelated deaths.However,mortality may be related to hemophagocytic lymphohistiocytosis(HLH)secondary to B.pseudomallei infection.CASE SUMMARY A 12-year-old female was referred from a local hospital to the pediatric intensive care unit with suspected septic shock and fever,cough,dyspnea,and malaise.After admission,supportive symptomatic treatments including fluid resuscitation,anti-infective therapy,mechanical ventilation,and a vasoactive drug maintenance cycle were carefully initiated.The patient became unconscious,her blood pressure could not be maintained even under the exposure of vasoactive drugs,and she experienced cardiorespiratory arrest.The patient died due to ineffective high-quality in-hospital cardiopulmonary resuscitation.A subsequent bone marrow smear examination revealed extensive phagocytosis,and the blood culture was positive for B.pseudomallei.Family history revealed a sibling death from B.pseudomallei sepsis 5 years earlier.CONCLUSION The higher mortality rate in patients with B.pseudomallei sepsis may be related to secondary HLH after infection,wherein multiorgan dysfunction syndrome may be directly related to infection or immune damage caused by secondary HLH.Patients with B.pseudomallei can be asymptomatic and can become an infective source.展开更多
Burkholderia pseudomallei is the pathogen that causes melioidosis.Melioidosis has a long duration of chronic infection,atypical clinical manifestations at acute onset,and is prone to life-threatening complications and...Burkholderia pseudomallei is the pathogen that causes melioidosis.Melioidosis has a long duration of chronic infection,atypical clinical manifestations at acute onset,and is prone to life-threatening complications and poor prognosis.Understanding the pathogenesis and drug resistance mechanism of Burkholderia pseudomallei will effectively help the diagnosis and treatment of the disease and improve the prognosis.This review focuses on the extracellular movement of Burkholderia pseudomallei in host cells,the way of infecting host cells,virulence factors,and drug resistance mechanisms(efflux pumps,changes in target sites,etc.).This study provides a possible direction for the early diagnosis,treatment and control of melioidosis caused by this bacterium.展开更多
Objective:Construction of Burkholderia pseudomallei(B.pseudomallei)sRNA knockout strains and observation of their biological function.Methods:Design 9sF/9sR,9xF/9xR and R1/F1 primers,which were used to amplify the hom...Objective:Construction of Burkholderia pseudomallei(B.pseudomallei)sRNA knockout strains and observation of their biological function.Methods:Design 9sF/9sR,9xF/9xR and R1/F1 primers,which were used to amplify the homologous arm fragment upstream and downstream of the sRNA gene,through enzyme cutting,ligation,and transformation,the sRNA gene was knocked out from the B.pseudomallei by homologous recombination method.Results:The sRNA mutant was successfully constructed.In comparison with wild strain HNBP001,the growth rate,motility and biofilm formation ofΔsRNA decreased,but the antibiotic sensitivity has no differences.Conclusion:The sRNA knockout strain of B.pseudomallei was successfully constructed,laying a foundation for further research on its mechanism of regulating B.pseudomallei.展开更多
对BurkholderiacepeciaJS 02"一菌双酶法"制备对羟基 D 苯甘氨酸过程的调控进行了研究,探讨了反应液pH值对于酶反应各个进程的影响,实施了调节反应液pH恒定为7 2的调控策略,使得D 海因酶与D N 氨甲酰基氨基酸水解酶同时具有...对BurkholderiacepeciaJS 02"一菌双酶法"制备对羟基 D 苯甘氨酸过程的调控进行了研究,探讨了反应液pH值对于酶反应各个进程的影响,实施了调节反应液pH恒定为7 2的调控策略,使得D 海因酶与D N 氨甲酰基氨基酸水解酶同时具有较高的活力,并且较未调控前更有利于L 对羟基苯海因的消旋及DL 对羟基苯海因的溶解,底物转化率与产品收率分别由未调控时的92%与85%提高至99 5%与94%,反应时间由40h缩短至30h,生产速率由0 462g/(L·h)提高至0 681g/(L·h)展开更多
基金The study was supported by Yuying Program Incubation Project of General Hospital of Center Theater(ZZYFH202104)Wuhan Young and Middle-Aged Medical Backbone Talent Project 2020(2020-55)Logistics Research Program Project 2019(CLB19J029).
文摘Objective:In the realm of Class I pathogens,Burkholderia pseudomallei(BP)stands out for its propensity to induce severe pathogenicity.Investigating the intricate interactions between BP and host cells is imperative for comprehending the dynamics of BP infection and discerning biomarkers indicative of the host cell response process.Methods:mRNA extraction from BP-infected mouse macrophages constituted the initial step of our study.Employing gene expression arrays,the extracted RNA underwent conversion into digital signals.The percentile shift method facilitated data processing,with the identification of genes manifesting significant differences accomplished through the application of the t-test.Subsequently,a comprehensive analysis involving Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway was conducted on the differentially expressed genes(DEGs).Leveraging the ESTIMATE algorithm,gene signatures were utilized to compute risk scores for gene expression data.Support vector machine analysis and gene enrichment scores were instrumental in establishing correlations between biomarkers and macrophages,followed by an evaluation of the predictive power of the identified biomarkers.Results:The functional and pathway associations of the DEGs predominantly centered around G protein-coupled receptors.A noteworthy positive correlation emerged between the blue module,consisting of 416 genes,and the StromaScore.FZD4,identified through support vector machine analysis among intersecting genes,indicated a robust interaction with macrophages,suggesting its potential as a robust biomarker.FZD4 exhibited commendable predictive efficacy,with BP infection inducing its expression in both macrophages and mouse lung tissue.Western blotting in macrophages confirmed a significant upregulation of FZD4 expression from 0.5 to 24 h post-infection.In mouse lung tissue,FZD4 manifested higher expression in the cytoplasm of pulmonary epithelial cells in BP-infected lungs than in the control group.Conclusion:Thesefindings underscore the upregulation of FZD4 expression by BP in both macrophages and lung tissue,pointing to its prospective role as a biomarker in the pathogenesis of BP infection.
文摘Objective:To characterize biofilm production by clinical(n=21)and environmental(n=11)isolates of Burkholderia pseudomallei and evaluate the production of proteases,hemolysins and siderophores.Methods:Initially,the 32 strains were evaluated for biofilm production in Müller-Hinton broth-1%glucose(MH-1%glucose)and BHI broth-1%glucose,using the crystal violet staining technique.Subsequently,growing(48 h)and mature(72 h)biofilms were evaluated by confocal microscopy.Finally,the production of proteases,hemolysins and siderophores by planktonic aggregates,growing biofilms and mature biofilms was evaluated.Results:All isolates produced biofilms,but clinical isolates had significantly higher biomass in both MH-1%glucose(P<0.001)and BHI-glucose 1%(P=0.005).The structural analyses by confocal microscopy showed thick biofilms,composed of multiple layers of cells,homogeneously arranged,with mature biofilms of clinical isolates presenting higher biomass(P=0.019)and thickness of the entire area(P=0.029),and lower roughness coefficient(P=0.007)than those of environmental isolates.Protease production by growing biofilms was significantly greater than that of planktonic(P<0.001)and mature biofilms(P<0.001).Hemolysin release by planktonic aggregates was higher than that of biofilms(P<0.001).Regarding siderophores,mature biofilms presented higher production than growing biofilms(P<0.001)and planktonic aggregates(P<0.001).Conclusions:Clinical isolates have higher production of biofilms than their environmental counterparts;protease and siderophores seem important for growth and maintenance of Burkholderia pseudomallei biofilms.
基金supported by the Ministry of Higher Education Malaysia for Fundamental Research Grant Scheme with Project Code:FRGS/1/2019/SKK11/USM/02/5。
文摘Burkholderia pseudomallei is a causative agent of melioidosis that can infect humans and animals in endemic countries,specifically in Southeast Asia and tropical Australia.A fundamental component for the pathogenesis of Burkholderia pseudomallei is the capability of the bacterium to enter,survive,replicate,and cause disease in a host cell by inducing the host cell fusion.Cell fusion results in multinucleated-giant cell formation,thus enabling the dissemination of Burkholderia pseudomallei intracellularly.cGAS reacts to Burkholderia pseudomallei infection by activating the cGAS-STING pathway and subsequently limiting host's aberrant cell division and cellular replication by inducing autophagic cell death.In this review,we discuss the host-pathogen interactions between the typeⅥsecretion system 5(T6SS-5)of Burkholderia pseudomallei and human cGAS pathway in melioidosis infections.Since T6SS-5 is a main virulent factor in Burkholderia pseudomallei and the c GAS pathway is vital for host immune response,elucidating their functions is important for better understanding the pathogenesis of Burkholderia pseudomallei.
文摘BACKGROUND Burkholderia pseudomallei(B.pseudomallei)is a short,straight,medium-sized Gramnegative bacterium that mostly exists alone,without a capsule or spores,has more than three flagella at one end,and actively moves.B.pseudomallei confers high morbidity and mortality,with frequent granulocytopenia in B.pseudomallei sepsisrelated deaths.However,mortality may be related to hemophagocytic lymphohistiocytosis(HLH)secondary to B.pseudomallei infection.CASE SUMMARY A 12-year-old female was referred from a local hospital to the pediatric intensive care unit with suspected septic shock and fever,cough,dyspnea,and malaise.After admission,supportive symptomatic treatments including fluid resuscitation,anti-infective therapy,mechanical ventilation,and a vasoactive drug maintenance cycle were carefully initiated.The patient became unconscious,her blood pressure could not be maintained even under the exposure of vasoactive drugs,and she experienced cardiorespiratory arrest.The patient died due to ineffective high-quality in-hospital cardiopulmonary resuscitation.A subsequent bone marrow smear examination revealed extensive phagocytosis,and the blood culture was positive for B.pseudomallei.Family history revealed a sibling death from B.pseudomallei sepsis 5 years earlier.CONCLUSION The higher mortality rate in patients with B.pseudomallei sepsis may be related to secondary HLH after infection,wherein multiorgan dysfunction syndrome may be directly related to infection or immune damage caused by secondary HLH.Patients with B.pseudomallei can be asymptomatic and can become an infective source.
基金Supported by the National Natural Science Foundation of China(No.82260001)Key Special Project Supported by the National Key R&D Plan of the Ministry of Science and Technology(No.2022YFC2305004)。
文摘Burkholderia pseudomallei is the pathogen that causes melioidosis.Melioidosis has a long duration of chronic infection,atypical clinical manifestations at acute onset,and is prone to life-threatening complications and poor prognosis.Understanding the pathogenesis and drug resistance mechanism of Burkholderia pseudomallei will effectively help the diagnosis and treatment of the disease and improve the prognosis.This review focuses on the extracellular movement of Burkholderia pseudomallei in host cells,the way of infecting host cells,virulence factors,and drug resistance mechanisms(efflux pumps,changes in target sites,etc.).This study provides a possible direction for the early diagnosis,treatment and control of melioidosis caused by this bacterium.
基金National Natural Science Foundation of China(No.81960002)。
文摘Objective:Construction of Burkholderia pseudomallei(B.pseudomallei)sRNA knockout strains and observation of their biological function.Methods:Design 9sF/9sR,9xF/9xR and R1/F1 primers,which were used to amplify the homologous arm fragment upstream and downstream of the sRNA gene,through enzyme cutting,ligation,and transformation,the sRNA gene was knocked out from the B.pseudomallei by homologous recombination method.Results:The sRNA mutant was successfully constructed.In comparison with wild strain HNBP001,the growth rate,motility and biofilm formation ofΔsRNA decreased,but the antibiotic sensitivity has no differences.Conclusion:The sRNA knockout strain of B.pseudomallei was successfully constructed,laying a foundation for further research on its mechanism of regulating B.pseudomallei.
