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
Melioidosis,a disease of public health importance in Southeast Asia and Northern Australia,of late has shown an increasing trend in India,particularly Southern India.We describe a ease of a 39-year-old diabetic patien...Melioidosis,a disease of public health importance in Southeast Asia and Northern Australia,of late has shown an increasing trend in India,particularly Southern India.We describe a ease of a 39-year-old diabetic patient with left elbow septic arthritis,multiple liver,splenic abscesses, pneumonia,pleural effusion,followed by sepsis syndrome.Blood cultures and culture of the joint aspirate yielded pure growth of Burkholderia psettdomallei(B.pesudomallei),sensitive to carbapenem,co-trimoxazole and resistant to ceftazidime.The patient was successfully treated with imipenem- cilastin.He was discharged on co-trimoxazole to complete the 24 weeks course and follow-up has continued to date.The patient continues to remain asymptomatic.The case re-emphasizes the need to monitor the trend of B.pseudomallei in India,particularly the development of ceftazidime resistance,which incidentally is the drug of choice.展开更多
Pyogenic liver abscess is a common entity in Indian subcontinent and is mostly caused by gram negative bacteria. Melioidosis is not commonly seen in India and only a few cases are reported. It can give rise to multipl...Pyogenic liver abscess is a common entity in Indian subcontinent and is mostly caused by gram negative bacteria. Melioidosis is not commonly seen in India and only a few cases are reported. It can give rise to multiple abscesses at different sites including liver. We report a case of isolated liver abscess caused by Burkholderia pseudomallei(B. pseudomallei) in a 29-yearold recently diagnosed diabetic, immunocompetent male. Diagnosis was made by imaging and culture of pus aspirated from the abscess and he was treated with percutaneous pigtail catheter drainage followed by antibiotics(meropenem and trimethoprim-sulphmethoxazole). Melioidosis is an emerging infection in India and has high mortality rate, so early diagnosis and promptmanagement is warranted which requires clinical vigilance and an intensive microbiological workup. Clinicians should be aware of isolated liver abscess caused by B. pseudomallei in appropriate clinical settings.展开更多
Objective:To investigate the banding patterns of whole cell protein(WCP) and outer membrane protein (OMP) of Burkholderia pseudomallei(B.pseudomallei) in clinical isolates from patients with melioidosis. Methods:WCP a...Objective:To investigate the banding patterns of whole cell protein(WCP) and outer membrane protein (OMP) of Burkholderia pseudomallei(B.pseudomallei) in clinical isolates from patients with melioidosis. Methods:WCP and OMP of of B.pseudomallei in 50 clinical isolates,from 47 patients with melioidosis were prepared and separated by polyacrylamide gel electrophoresis(SDS-PAGE) using 10%gels and stained with Coomassie brilliant blue.The banding patterns were compared by using a laser densitometer and dendrogram. Results:There were 6 different banding patterns of WCP and 2 types of OMP.Type 1 -5 WCP had 8 common protein bands at 19.0 - 45.0 kDa with identical OMP pattern.The banding patterns of WCP in type 6 were distinct from the others and also its OMP profile.The majority of clinical isolates(37/50,74%) were in type 1 WCP.Of the remaining isolates,8 were in type 2,2 in type 3,and one each was in type 4 to 6.There was no significant association between the WCP typing and the demographic or clinical features of the investigated patients.Conclusion:Despite the wide variation of clinical features of melioidosis,the results of this study show that B.pseudomallei had a few differences in the WCP and OMP profiles.Therefore typing of WCP and OMP,using SDS-PAGE analysis,could be an alternative method for phenotypic differentiation in clinical isolates of B.pseudomallei.展开更多
A 19-year-old Asian Indian female presented with productive cough since the past one month and low grade fever since the pasl two weeks.She was diagnosed with pulmonary tuberculosis and treated with anlilubercular dru...A 19-year-old Asian Indian female presented with productive cough since the past one month and low grade fever since the pasl two weeks.She was diagnosed with pulmonary tuberculosis and treated with anlilubercular drugs.Subsequently,delayed cultures of bronclioalveolar lavage fluid grew Burkholderia pseudomallei(B.pseudomallei).On follow up the patient reported significant subjective improvement and ESR progressively returned to normal.In summary',this case report raises two distinct and equally intriguing roles for B.pseudomallei,i.e.respiratory colonization and spontaneously resolving pulmonary infection.The pathogenic potential of B.pseudomallei,the eliologic agent of melioidosis,is well known.Confirmation of eilher colonization or spontaneous resolution,would potentially spare many patients unnecessary and oxpensivo therapy with broad-spectruin antibiotics,and contribute to more rational usage of antibiotics,especially in co-infecliou with Mycobacterium tuberculosis and B.pseudomallei-two bacterial diseases with closely similar clinical,radiologic and histopathologic features.展开更多
Objective:To investigate the inhibitory effect on Burkholderia pseudomallei(B.pseudomallei)strain HNBP001 of a bacillomycin D-like cyclic lipopeptide compound named bacillomycin DC isolated from Bacillus amyloliquefac...Objective:To investigate the inhibitory effect on Burkholderia pseudomallei(B.pseudomallei)strain HNBP001 of a bacillomycin D-like cyclic lipopeptide compound named bacillomycin DC isolated from Bacillus amyloliquefaciens HAB-2.Methods:The antibacterial effect of bacillomycin DC on B.pseudomallei was determined using the disk diffusion method.The minimum inhibitory concentrations were evaluated by microdilution assay.In addition,transmission electron microscopy was performed and quantitative real-time polymerase chain reaction assay was carried out to determine the expression of Mex B,Opr D2,and qnr S genes.Results:Bacillomycin DC produced an inhibition zone against B.pseudomallei with minimum inhibitory concentration values of 12.5μg/mL 24 h after treatment and 50μg/mL at 48 and 72 h.Transmission electron microscopy showed that bacillomycin DC resulted in roughening cell surface and cell membrane damage.Quantitative real-time polymerase chain reaction analysis showed low expression of Mex B,Opr D2 and qnr S genes.Conclusions:Bacillomycin DC inhibits the growth of B.pseudomallei and can be a new candidate for antimicrobial agents of B.pseudomallei.展开更多
Objective: To evaluate the genetic diversity of clinical and environmental isolates of Burkholderia pseudomallei(B.pseudomallei) recovered in Ceara, Brazil, and screen these isolates for the presence of type three sec...Objective: To evaluate the genetic diversity of clinical and environmental isolates of Burkholderia pseudomallei(B.pseudomallei) recovered in Ceara, Brazil, and screen these isolates for the presence of type three secretion system virulence gene.Methods: Nineteen B.pseudomallei isolates(9 from clinical cases and 10 from soils)were analyzed.Random amplified polymorphic DNA was performed with primers OPQ-2, OPQ-4 and OPQ-16 to evaluate the genetic diversity, and type three secretion system gene was detected through polymerase chain reaction.Results: Random amplified polymorphic DNA showed a genetic relatedness of approximately 50% among the tested B.pseudomallei isolates, which were grouped into two clades, of which the biggest ones comprised 18/19 isolates for primer OPQ-2, and 17/19 isolates for primer OPQ-16.Primer OPQ-4 grouped the isolates into three clades comprising 1/19, 3/19 and 15/19 isolates.Additionally, type three secretion system gene was detected in all tested isolates.Conclusions: This is an effort to type B.pseudomallei strains from Ceara, which is important for better understanding this pathogen, contributing for the epidemiological surveillance of melioidosis in this endemic region.展开更多
Objective: The relA gene,a gene associated with the synthesis of rigorous response signaling molecule (p)ppGpp in Burkholderia pseudomallei, was knocked out and its effects on the biological functions of bacterial gro...Objective: The relA gene,a gene associated with the synthesis of rigorous response signaling molecule (p)ppGpp in Burkholderia pseudomallei, was knocked out and its effects on the biological functions of bacterial growth, motility and biofilm formation were investigated. Methods: The plasmids with trimethoprim resistance (TPR) were modified by enzyme digestion and enzyme ligation method. The TPR fragment was linked to the suicide plasmid pK18mobSacB containing SacB sucrose killing gene by Bgl Ⅱ enzyme digestion site, and trimethoprim resistance was obtained Plasmid(TPR-pK18mobSacB);The relA gene of Burkholderia pseudomallei HNBP001 was knocked out by homologous recombinant gene knockout method, and the relA mutant was obtained. The growth, motility and biofilm phenotypes of Burkholderia pseudomallei HNBP001 were compared before and after the deletion of relA gene. Results: The relA mutant was successfully constructed. The growth rate, motility and biofilm formation of ΔrelA decreased. Conclusion: The modified plasmid TPR- pK18mobSacB can improve the knockout efficiency of HNBP001 strain, which can be widely used in the gene knockout of Burkholderia pseudomallei, and provide convenience for the laboratory to study the gene function of Burkholderia pseudomallei at the molecular level;The mutant of the relA gene inhibits the growth, motility and biofilm formation of HNBP001.展开更多
BACKGROUND Melioidosis,an infectious disease caused by Burkholderia pseudomallei(B.pseudomallei),occurs endemically in Southeast Asia and Northern Australia and is a serious opportunistic infection associated with a h...BACKGROUND Melioidosis,an infectious disease caused by Burkholderia pseudomallei(B.pseudomallei),occurs endemically in Southeast Asia and Northern Australia and is a serious opportunistic infection associated with a high mortality rate.CASE SUMMARY A 58-year-old woman presented with scattered erythema on the skin of her limbs,followed by fever and seizures.B.pseudomallei was isolated successively from the patient’s urine,blood,and pus.Magnetic resonance imaging showed abscess formation involving the right forehead and the right frontal region.Subsequently,abscess resection and drainage were performed.The patient showed no signs of relapse after 4 months of follow-up visits post-treatment.CONCLUSION We present here a unique case of multi-systemic melioidosis that occurs in nonendemic regions in a patient who had no recent travel history.Hence,it is critical to enhance awareness of melioidosis in non-endemic regions.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.
文摘Melioidosis,a disease of public health importance in Southeast Asia and Northern Australia,of late has shown an increasing trend in India,particularly Southern India.We describe a ease of a 39-year-old diabetic patient with left elbow septic arthritis,multiple liver,splenic abscesses, pneumonia,pleural effusion,followed by sepsis syndrome.Blood cultures and culture of the joint aspirate yielded pure growth of Burkholderia psettdomallei(B.pesudomallei),sensitive to carbapenem,co-trimoxazole and resistant to ceftazidime.The patient was successfully treated with imipenem- cilastin.He was discharged on co-trimoxazole to complete the 24 weeks course and follow-up has continued to date.The patient continues to remain asymptomatic.The case re-emphasizes the need to monitor the trend of B.pseudomallei in India,particularly the development of ceftazidime resistance,which incidentally is the drug of choice.
文摘Pyogenic liver abscess is a common entity in Indian subcontinent and is mostly caused by gram negative bacteria. Melioidosis is not commonly seen in India and only a few cases are reported. It can give rise to multiple abscesses at different sites including liver. We report a case of isolated liver abscess caused by Burkholderia pseudomallei(B. pseudomallei) in a 29-yearold recently diagnosed diabetic, immunocompetent male. Diagnosis was made by imaging and culture of pus aspirated from the abscess and he was treated with percutaneous pigtail catheter drainage followed by antibiotics(meropenem and trimethoprim-sulphmethoxazole). Melioidosis is an emerging infection in India and has high mortality rate, so early diagnosis and promptmanagement is warranted which requires clinical vigilance and an intensive microbiological workup. Clinicians should be aware of isolated liver abscess caused by B. pseudomallei in appropriate clinical settings.
基金supported by the Mahidol-Oxford Tropical Medicine Research Unit,UK.
文摘Objective:To investigate the banding patterns of whole cell protein(WCP) and outer membrane protein (OMP) of Burkholderia pseudomallei(B.pseudomallei) in clinical isolates from patients with melioidosis. Methods:WCP and OMP of of B.pseudomallei in 50 clinical isolates,from 47 patients with melioidosis were prepared and separated by polyacrylamide gel electrophoresis(SDS-PAGE) using 10%gels and stained with Coomassie brilliant blue.The banding patterns were compared by using a laser densitometer and dendrogram. Results:There were 6 different banding patterns of WCP and 2 types of OMP.Type 1 -5 WCP had 8 common protein bands at 19.0 - 45.0 kDa with identical OMP pattern.The banding patterns of WCP in type 6 were distinct from the others and also its OMP profile.The majority of clinical isolates(37/50,74%) were in type 1 WCP.Of the remaining isolates,8 were in type 2,2 in type 3,and one each was in type 4 to 6.There was no significant association between the WCP typing and the demographic or clinical features of the investigated patients.Conclusion:Despite the wide variation of clinical features of melioidosis,the results of this study show that B.pseudomallei had a few differences in the WCP and OMP profiles.Therefore typing of WCP and OMP,using SDS-PAGE analysis,could be an alternative method for phenotypic differentiation in clinical isolates of B.pseudomallei.
文摘A 19-year-old Asian Indian female presented with productive cough since the past one month and low grade fever since the pasl two weeks.She was diagnosed with pulmonary tuberculosis and treated with anlilubercular drugs.Subsequently,delayed cultures of bronclioalveolar lavage fluid grew Burkholderia pseudomallei(B.pseudomallei).On follow up the patient reported significant subjective improvement and ESR progressively returned to normal.In summary',this case report raises two distinct and equally intriguing roles for B.pseudomallei,i.e.respiratory colonization and spontaneously resolving pulmonary infection.The pathogenic potential of B.pseudomallei,the eliologic agent of melioidosis,is well known.Confirmation of eilher colonization or spontaneous resolution,would potentially spare many patients unnecessary and oxpensivo therapy with broad-spectruin antibiotics,and contribute to more rational usage of antibiotics,especially in co-infecliou with Mycobacterium tuberculosis and B.pseudomallei-two bacterial diseases with closely similar clinical,radiologic and histopathologic features.
基金supported in part by the Key Research and Developement Program of Hainan Province(ZDYF2018240)National Natural Science Foundation of China(31660033,81560002 and 81960002)+1 种基金National Key R&D Program of China(No.2018YFD0201105)National Science and Technology Major Project(No.2018ZX10101003-001-009).
文摘Objective:To investigate the inhibitory effect on Burkholderia pseudomallei(B.pseudomallei)strain HNBP001 of a bacillomycin D-like cyclic lipopeptide compound named bacillomycin DC isolated from Bacillus amyloliquefaciens HAB-2.Methods:The antibacterial effect of bacillomycin DC on B.pseudomallei was determined using the disk diffusion method.The minimum inhibitory concentrations were evaluated by microdilution assay.In addition,transmission electron microscopy was performed and quantitative real-time polymerase chain reaction assay was carried out to determine the expression of Mex B,Opr D2,and qnr S genes.Results:Bacillomycin DC produced an inhibition zone against B.pseudomallei with minimum inhibitory concentration values of 12.5μg/mL 24 h after treatment and 50μg/mL at 48 and 72 h.Transmission electron microscopy showed that bacillomycin DC resulted in roughening cell surface and cell membrane damage.Quantitative real-time polymerase chain reaction analysis showed low expression of Mex B,Opr D2 and qnr S genes.Conclusions:Bacillomycin DC inhibits the growth of B.pseudomallei and can be a new candidate for antimicrobial agents of B.pseudomallei.
基金supported by FUNCAP/SESA/MS/CNPq(PPSUS 13192409-5)CNPq(process number 443943/2014-1)
文摘Objective: To evaluate the genetic diversity of clinical and environmental isolates of Burkholderia pseudomallei(B.pseudomallei) recovered in Ceara, Brazil, and screen these isolates for the presence of type three secretion system virulence gene.Methods: Nineteen B.pseudomallei isolates(9 from clinical cases and 10 from soils)were analyzed.Random amplified polymorphic DNA was performed with primers OPQ-2, OPQ-4 and OPQ-16 to evaluate the genetic diversity, and type three secretion system gene was detected through polymerase chain reaction.Results: Random amplified polymorphic DNA showed a genetic relatedness of approximately 50% among the tested B.pseudomallei isolates, which were grouped into two clades, of which the biggest ones comprised 18/19 isolates for primer OPQ-2, and 17/19 isolates for primer OPQ-16.Primer OPQ-4 grouped the isolates into three clades comprising 1/19, 3/19 and 15/19 isolates.Additionally, type three secretion system gene was detected in all tested isolates.Conclusions: This is an effort to type B.pseudomallei strains from Ceara, which is important for better understanding this pathogen, contributing for the epidemiological surveillance of melioidosis in this endemic region.
基金Fund Project:Major Science and Technology Program of Hainan Province(No.ZDKJ202003)。
文摘Objective: The relA gene,a gene associated with the synthesis of rigorous response signaling molecule (p)ppGpp in Burkholderia pseudomallei, was knocked out and its effects on the biological functions of bacterial growth, motility and biofilm formation were investigated. Methods: The plasmids with trimethoprim resistance (TPR) were modified by enzyme digestion and enzyme ligation method. The TPR fragment was linked to the suicide plasmid pK18mobSacB containing SacB sucrose killing gene by Bgl Ⅱ enzyme digestion site, and trimethoprim resistance was obtained Plasmid(TPR-pK18mobSacB);The relA gene of Burkholderia pseudomallei HNBP001 was knocked out by homologous recombinant gene knockout method, and the relA mutant was obtained. The growth, motility and biofilm phenotypes of Burkholderia pseudomallei HNBP001 were compared before and after the deletion of relA gene. Results: The relA mutant was successfully constructed. The growth rate, motility and biofilm formation of ΔrelA decreased. Conclusion: The modified plasmid TPR- pK18mobSacB can improve the knockout efficiency of HNBP001 strain, which can be widely used in the gene knockout of Burkholderia pseudomallei, and provide convenience for the laboratory to study the gene function of Burkholderia pseudomallei at the molecular level;The mutant of the relA gene inhibits the growth, motility and biofilm formation of HNBP001.
文摘BACKGROUND Melioidosis,an infectious disease caused by Burkholderia pseudomallei(B.pseudomallei),occurs endemically in Southeast Asia and Northern Australia and is a serious opportunistic infection associated with a high mortality rate.CASE SUMMARY A 58-year-old woman presented with scattered erythema on the skin of her limbs,followed by fever and seizures.B.pseudomallei was isolated successively from the patient’s urine,blood,and pus.Magnetic resonance imaging showed abscess formation involving the right forehead and the right frontal region.Subsequently,abscess resection and drainage were performed.The patient showed no signs of relapse after 4 months of follow-up visits post-treatment.CONCLUSION We present here a unique case of multi-systemic melioidosis that occurs in nonendemic regions in a patient who had no recent travel history.Hence,it is critical to enhance awareness of melioidosis in non-endemic regions.
