ENDOPHTHALMITIS induced by mycobacterium tuberculosis （TB） was rarely reported. Here we present and characterize this typical case to establish the diagnosis.
Objective: To develop a new high sensitivity, rapid and simple mycobacterium tuberculosis DNA detection method using fluorescence polarization technology. Methods: In our asymmetric PCR protocol, 100 times mole of TB-...Objective: To develop a new high sensitivity, rapid and simple mycobacterium tuberculosis DNA detection method using fluorescence polarization technology. Methods: In our asymmetric PCR protocol, 100 times mole of TB-R primer was added than in the usual symmetric PCR to get enough single strands PCR product. The probe TB-5′-TAMRA and PCR products were mixed in a tube and incubate for 5-15 min at 46 ℃.The polarization (mp) was measured using victor2 Multilabel Plate Reader. Results: Asymmetric and symmetric PCR products were analyzed by the FP method. Asymmetric PCR products are detected more sensitively than symmetric ones. The polarization values of probe associated with asymmetric products were much higher than with symmetric products. Conclusion: This fluorescence polarization assay in conjunction with asymmetric PCR is a powerful and widely applicable method for the rapid and sensitive detection of micro-organisms in clinical laboratories.展开更多
To study the characteristics of drug-resistant genetic mutation of rpoB on coal workers＇ pneumoconiosis complicated with L-form of Mycobacterium tuberculosis. Methods： A total of 42 clinical isolated strains of Myco...To study the characteristics of drug-resistant genetic mutation of rpoB on coal workers＇ pneumoconiosis complicated with L-form of Mycobacterium tuberculosis. Methods： A total of 42 clinical isolated strains of Mycobacterium tuberculosis L-forms were collected, including 31 drug-resistant strains. Their genomes DNA were extracted, the target genes were amplified by PCR, and the hot regions in the rpoB gene were analyzed by automated DNA sequenator. Results： No mutation of rpoB gene was identified in 11 rifampicin-sensitive strains while conformation changes were found in 31 rifampicin-resistant strains. The mutation rate was 93.55% （29/31） in resistant strains, mainly concentrated in codon 531 （51.6%, 16/31） and 526 （32.26%, 10/31）. Base substitutions happened, including 27 unit point mutation and 2 two point mutation. The mutation of codon 516 that new found wasn＇t reported by internal and overseas scholars. Conclusion： The substitution of highly conserved amino acids encoded by rpoB gene results in the molecular mechanism responsible for rifampicin resistance in Mycobacterium tuberculosis L-forms. It also proves that rpoB gene is diversiform.展开更多
Mycobacterium tuberculosis(Mtb),the pathogen of tuberculosis,has latently infected about one-third of the world's population and may lead to severe clinical symptoms and death.The WhiB4 protein,a transcription fac...Mycobacterium tuberculosis(Mtb),the pathogen of tuberculosis,has latently infected about one-third of the world's population and may lead to severe clinical symptoms and death.The WhiB4 protein,a transcription factor,plays a crucial role in the survival and pathology of Mtb.WhiB4 leads to the condensation of mycobacterial nucleoids and regulates the expression of genes involved in central metabolism,respiration,and maintaining redox homeostasis.Here,we report the solution structure of reduced apo-WhiB4 monomer,which consists of an unstructured N-terminal domain with four cysteine residues and a helix-turnhelix C-terminal domain that plays a major role in DNA binding.The C-terminal domain of WhiB4 binds DNA at the minor groove,with five positively charged lysine/arginine residues contacting DNA sugar-phosphate backbones through electrostatic interactions.AT-rich DNA sequences with narrower minor grooves are more preferred by WhiB4.The binding affinity of a single C-terminal domain of WhiB4 is weak.When oxidized,WhiB4 can form dimers and oligomers in different forms through disulfide bonds,which should significantly enhance its DNA binding ability through multivalent effect and change the local structure of target genes and influence their transcription.These structural features form the basis for WhiB4 to function as a redox-sensitive transcription factor in Mtb.展开更多
Background:Tuberculosis is a leading cause of death worldwide.BCG is an effective vaccine,but not widely used in many parts of the world due to a variety of issues.Mycobacterium vaccae(M.vaccae)is another vaccine used...Background:Tuberculosis is a leading cause of death worldwide.BCG is an effective vaccine,but not widely used in many parts of the world due to a variety of issues.Mycobacterium vaccae(M.vaccae)is another vaccine used in human subjects to prevent tuberculosis.In the current study,we investigated the potential mechanisms of M.vaccae vaccination by determining differentially expressed genes in mice infected with M.tuberculosis before and after M.vaccae vaccination.Methods:Three days after exposure to M.tuberculosis H37 Rv strain(5×10~5 CFU),adult BALB/c mice randomly received either M.vaccae vaccine(22.5μg)or vehicle via intramuscular injection(n=8).Booster immunization was conducted 14 and 28 days after the primary immunization.Differentially expressed genes were identified by microarray followed by standard bioinformatics analysis.Results:M.vaccae vaccination provided protection against M.tuberculosis infection(most prominent in the lungs).We identified 2,326 upregulated and 2,221 downregulated genes in vaccinated mice.These changes could be mapped to a total of 123 signaling pathways(68 upregulated and 55 downregulated).Further analysis pinpointed to the MyD88-dependent TLR signaling pathway and PI3 K-Akt signaling pathway as most likely to be functional.Conclusions:M.vaccae vaccine provided good protection in mice against M.tuberculosis infection,via a highly complex set of molecular changes.Our findings may provide clue to guide development of more effective vaccine against tuberculosis.展开更多
文摘ENDOPHTHALMITIS induced by mycobacterium tuberculosis （TB） was rarely reported. Here we present and characterize this typical case to establish the diagnosis.
文摘Objective: To develop a new high sensitivity, rapid and simple mycobacterium tuberculosis DNA detection method using fluorescence polarization technology. Methods: In our asymmetric PCR protocol, 100 times mole of TB-R primer was added than in the usual symmetric PCR to get enough single strands PCR product. The probe TB-5′-TAMRA and PCR products were mixed in a tube and incubate for 5-15 min at 46 ℃.The polarization (mp) was measured using victor2 Multilabel Plate Reader. Results: Asymmetric and symmetric PCR products were analyzed by the FP method. Asymmetric PCR products are detected more sensitively than symmetric ones. The polarization values of probe associated with asymmetric products were much higher than with symmetric products. Conclusion: This fluorescence polarization assay in conjunction with asymmetric PCR is a powerful and widely applicable method for the rapid and sensitive detection of micro-organisms in clinical laboratories.
基金Supported by the Natural Science Foundation of Universities of Anhui Province (KJ2008A152)the Natural Science Foundation of the Committee of Education of Anhui Province (2005KJ238)
文摘To study the characteristics of drug-resistant genetic mutation of rpoB on coal workers＇ pneumoconiosis complicated with L-form of Mycobacterium tuberculosis. Methods： A total of 42 clinical isolated strains of Mycobacterium tuberculosis L-forms were collected, including 31 drug-resistant strains. Their genomes DNA were extracted, the target genes were amplified by PCR, and the hot regions in the rpoB gene were analyzed by automated DNA sequenator. Results： No mutation of rpoB gene was identified in 11 rifampicin-sensitive strains while conformation changes were found in 31 rifampicin-resistant strains. The mutation rate was 93.55% （29/31） in resistant strains, mainly concentrated in codon 531 （51.6%, 16/31） and 526 （32.26%, 10/31）. Base substitutions happened, including 27 unit point mutation and 2 two point mutation. The mutation of codon 516 that new found wasn＇t reported by internal and overseas scholars. Conclusion： The substitution of highly conserved amino acids encoded by rpoB gene results in the molecular mechanism responsible for rifampicin resistance in Mycobacterium tuberculosis L-forms. It also proves that rpoB gene is diversiform.
基金grant 2016YFA0501202 from the Ministry of Science and Technologygrant 31570734 from the National Natural Science Foundation of China,and grant 2018YFD0500900 from National Key R&D Program of China.
文摘Mycobacterium tuberculosis(Mtb),the pathogen of tuberculosis,has latently infected about one-third of the world's population and may lead to severe clinical symptoms and death.The WhiB4 protein,a transcription factor,plays a crucial role in the survival and pathology of Mtb.WhiB4 leads to the condensation of mycobacterial nucleoids and regulates the expression of genes involved in central metabolism,respiration,and maintaining redox homeostasis.Here,we report the solution structure of reduced apo-WhiB4 monomer,which consists of an unstructured N-terminal domain with four cysteine residues and a helix-turnhelix C-terminal domain that plays a major role in DNA binding.The C-terminal domain of WhiB4 binds DNA at the minor groove,with five positively charged lysine/arginine residues contacting DNA sugar-phosphate backbones through electrostatic interactions.AT-rich DNA sequences with narrower minor grooves are more preferred by WhiB4.The binding affinity of a single C-terminal domain of WhiB4 is weak.When oxidized,WhiB4 can form dimers and oligomers in different forms through disulfide bonds,which should significantly enhance its DNA binding ability through multivalent effect and change the local structure of target genes and influence their transcription.These structural features form the basis for WhiB4 to function as a redox-sensitive transcription factor in Mtb.
基金supported by Grants from the National Natural Science Foundation of China(81801643)the National Key Program for Infectious Disease of China(2018ZX10731301–005)+1 种基金Beijing Municipal Science&Technology Commission(Z181100001718005)the Medical Science and Technology Youth Cultivation Program of PLA(16QNP075)。
文摘Background:Tuberculosis is a leading cause of death worldwide.BCG is an effective vaccine,but not widely used in many parts of the world due to a variety of issues.Mycobacterium vaccae(M.vaccae)is another vaccine used in human subjects to prevent tuberculosis.In the current study,we investigated the potential mechanisms of M.vaccae vaccination by determining differentially expressed genes in mice infected with M.tuberculosis before and after M.vaccae vaccination.Methods:Three days after exposure to M.tuberculosis H37 Rv strain(5×10~5 CFU),adult BALB/c mice randomly received either M.vaccae vaccine(22.5μg)or vehicle via intramuscular injection(n=8).Booster immunization was conducted 14 and 28 days after the primary immunization.Differentially expressed genes were identified by microarray followed by standard bioinformatics analysis.Results:M.vaccae vaccination provided protection against M.tuberculosis infection(most prominent in the lungs).We identified 2,326 upregulated and 2,221 downregulated genes in vaccinated mice.These changes could be mapped to a total of 123 signaling pathways(68 upregulated and 55 downregulated).Further analysis pinpointed to the MyD88-dependent TLR signaling pathway and PI3 K-Akt signaling pathway as most likely to be functional.Conclusions:M.vaccae vaccine provided good protection in mice against M.tuberculosis infection,via a highly complex set of molecular changes.Our findings may provide clue to guide development of more effective vaccine against tuberculosis.
