Objective:To analyze the mutation characteristics of inhA and katG genes in isoniazid-resistant Mycobacterium tuberculosis in Xinjiang.Methods:The katG and inhA in 148 strains of isoniazid-resistant Mycobacterium tube...Objective:To analyze the mutation characteristics of inhA and katG genes in isoniazid-resistant Mycobacterium tuberculosis in Xinjiang.Methods:The katG and inhA in 148 strains of isoniazid-resistant Mycobacterium tuberculosis were amplified through fluorescence quantitative PCR,and the amplified products were sequenced and compared.Results:The inhA gene mutation rate of 148 strains of isoniazid-resistant mycobacterium tuberculosis was 13.51%(20/148),among which the inhA gene mutation rate among patients of Han,Uygur,and Kazakh ethnicity were 15.87%,13.21%,and 17.65%,respectively.There was no significant difference in the inhA mutation rate among nationalities(c^(2)=2.897,P>0.05).The mutation rate of the katG gene was 84.46%(125/148),among which the mutation rates of patients of Han,Uyghur,and Kazak ethnicities were 82.54%,84.91%,and 76.47%,respectively.The Hui and other ethnic groups were all affected by the katG gene mutation.There was no significant difference in the mutation rate of the katG gene among different ethnicities(c^(2)=3.772,P>0.05).The mutation rates of the inhA gene in southern Xinjiang,northern Xinjiang,and other provinces were 18.60%,9.28%,and 37.50%,respectively.The mutation rates of the inhA gene in different regions were statistically different(c^(2)=6.381,P<0.05).There was no significant difference in the inhA mutation rate between patients from southern and northern Xinjiang(c^(2)=2.214,P>0.05)and between southern Xinjiang and other provinces(c^(2)=1.424,P>0.05).However,the mutation rate of the inhA gene in patients from other provinces was higher than that in northern Xinjiang(c^(2)=5.539,P<0.05).The mutation rates of the katG gene in southern Xinjiang,northern Xinjiang,and other provinces were 81.40%,87.63%,and 62.50%,respectively.There was no significant difference in the mutation rates of the katG gene among different regions(c^(2)=3.989,P>0.05).Conclusion:katG gene mutation was predominant in isoniazid-resistant tuberculosis patients in Xinjiang Uygur Autonomous Region,and inhA and katG gene mutation were no different among different ethnic groups.展开更多
Mycobacterium tuberculosis(M.tuberculosis)can replicate in the macrophage by interfering with many host protein functions.While it is far from known these host proteins for controlling M.tuberculosis infection.Herein,...Mycobacterium tuberculosis(M.tuberculosis)can replicate in the macrophage by interfering with many host protein functions.While it is far from known these host proteins for controlling M.tuberculosis infection.Herein,we infected macrophages including THP-1 and Raw264.7 cells with M.tuberculosis and identified the differentially expressed genes(DEGs)in the interferon signaling pathway.Among them,2'-5'oligoadenylate synthetase-like(OASL)underwent the greatest upregulation in M.tuberculosis-infected macrophages.Knockdown of the expression of OASL attenuated M.tuberculosis survival in macrophages.Further,bioinformatics analysis revealed the potential interaction axis of OASL-TAB3-RvO127,which was further validated by the yeast-two-hybrid(Y2H)assay and Co-IP.This interaction axis might regulate the M.tuberculosis survival and proliferation in macrophages.The study reveals a possible role of OASL during M.tuberculosis infection as a target to control its propagation.展开更多
Objective:To obtain fbpB-esxA fusing gene of Mycobacterium tuberculosis(MTU),express the encoded fusing protein in Escherichia coli(E.coli),identify protein acquired,and predict the structure and function of the p...Objective:To obtain fbpB-esxA fusing gene of Mycobacterium tuberculosis(MTU),express the encoded fusing protein in Escherichia coli(E.coli),identify protein acquired,and predict the structure and function of the protein utilizing methods of bioinformatics.Methods:fbpB and esxA gene were amplified from genome of MTB H37Rv by PCR.The fbpB-esxA fusing gene Iigated by(Gly<sub>4</sub>Ser)<sub>3</sub> linker was gained by means of Gene Splicing by Overlapping Extension PCU(SOEPCR), and fusing gene was cloned into expression vector pET-30a.The recombinant plasmid was sequenced and expressed in E.coli BL21(DE3).The protein was identified by Western blot using anti-HIS antibody.Secondary structure and antigenic epitopes of the protein were predicting using tools of bioinformatics.Results:The UNA sequences fbpB-esxA were identical with that published by GenBank.The Ag85B-ESAT-6 fusion protein about 50 kDa comprised 485 amino acids was efficiently produced from expression system in E.coli B1.21(DE3) under the induction of IPTG.Bioinformatics analysis showed the protein contained one transmembrane region and fourteen potential antigenic epitopes.Conclusions:The Ag85B-ESAT-6 fusion protein is successfully expressed with N-terminal HIS-tag.Gel filtration demonstrated that it exists as insoluble inclusion bodies mainly.The existence of linker doesn’t affect immunogenicity of Ag85B and ESAT-6.It will allow lor characterization in vitro and establish a foundation of further function research such as vaccine or diagnostic reagent.展开更多
Heat shock protein 65 (HSP65) is one of the most important protective immunogens against the tuberculosis infection. The signal sequence of antigen 85B and the whole HSP65 DNA sequence of human Mycobacterium tuberculo...Heat shock protein 65 (HSP65) is one of the most important protective immunogens against the tuberculosis infection. The signal sequence of antigen 85B and the whole HSP65 DNA sequence of human Mycobacterium tuberculosis (M. tuberculosis) were amplified from BCG genome and plasmid pCMV-MTHSP65 respectively by polymerase chain reactions (PCR). These two sequences were cloned into the plasmid pBCG-2100 under the control of the promoter of heat shock protein 70 (HSP70) from human M. tuberculosis, yielding the prokaryotic shuttle expression plasmid pBCG-SP-HSP65. Results of restriction endonuclease analysis, PCR detection and DNA sequencing analysis showed that the two cloned DNA sequences were consistent with those previously reported, and the direction of their inserting into the recombinant was correct and the reading frame had been maintained. The recombinants were electroporated into BCG to construct the recombinant BCG vaccine and induced by heating. The induced expression detected by SDS-PAGE showed that the content of 65 kD protein expressed in recombinant BCG was 35.69 % in total bacterial protein and 74.09 % in the cell lysate supernatants, suggesting that the recombinant HSP65 gene could express in BCG with high efficiency and the expressed proteins were mainly soluble. Western-blot showed that the secretive recombinant proteins could specifically combine with antibody against M. tuberculosis HSP65, indicating that the recombinant proteins possess the biological activity of HSP65.展开更多
When devoured by macrophages,Mycobacterium tuberculosis remains persistent in macrophages and gains energy through the glyoxylate bypass to maintain its long-term existence in host cells.Therefore it is possible to st...When devoured by macrophages,Mycobacterium tuberculosis remains persistent in macrophages and gains energy through the glyoxylate bypass to maintain its long-term existence in host cells.Therefore it is possible to stop persistent infections by interdicting the glyoxylate bypass in which the isocitrate lyase(ICL) is the key rate-limiting enzyme and a persistence factor.ICL is the target of anti-TB(TB:tubercular) drugs,which could screen ICL out and effectively inhibit the activity of ICL in Mycobacterium tuberculosis,and because of this,anti-TB drugs can be used to kill persistent Mycobacterium tuberculosis.In this study,the ICL gene of the Mycobacterium tuberculosis H37Rv was cloned successfully and recombinant protein with bioactivity was obtained through the enzyme characteristic appraisal.The specific activity of the recombined ICL is 24μmol·mg-1·min-1.The recombined ICL protein was used as the target,and phages which can specifically combine to ICL were screened in the phage 7 peptide library.According to the results of the ELISA and DNA sequence detection,eventually three 7-peptide chains were synthesized.Then the peptide chains were reacted with ICL,respectively,to detect their inhibitory effects on ICL.The results show that all the three 7-peptide chains possessed varying inhibitory effects on the activity of ICL.This study provided lead compounds for the research and development of new peptide anti-TB drugs.展开更多
Objective: The increase in the development of resistance to multiple drugs in mycobacterium tuberculosis(MTB) poses a substantial obstacle to the prevention and management of tuberculosis(TB). A thorough investigation...Objective: The increase in the development of resistance to multiple drugs in mycobacterium tuberculosis(MTB) poses a substantial obstacle to the prevention and management of tuberculosis(TB). A thorough investigation of the genotypes linked to multidrug resistance is crucial for comprehending the mechanisms underlying drug resistance. The objective of this research was to assess the attributes of gene mutations associated with multidrug resistance in clinical isolates of mycobacterium tuberculosis through the utilization of whole-genome sequencing. Methods: A total of 124 strains of drug-resistant mycobacterium tuberculosis were collected, and the genomic DNA of both multidrug-resistant and rifampin-resistant strains were extracted and sequenced. Bioinformatics was used to analyze and compare multidrug resistance-related gene sequences in order to detect the variation of multidrug resistance genes. Results: The results revealed that the resistance spectrum of XDR-TB group was much wider than that of the other three groups, with the RR-TB group having the most limited resistance spectrum.Within the MDR-TB strains, fabG1 exhibited the highest frequency of mutations, while RRS, gyrA, and rpoB were identified as the predominant mutation bases in XDR-TB strains. Additionally, rpoB emerged as the primary mutation base in MDR-TB and RR-TB strains. Notably, the fabG1 mutation was found to be closely associated with PDR-TB. Furthermore, the correlation between the mutation rate of rpoB and multidrug resistance was deemed to be of secondary importance. Conclusion: Various strains of MTB exhibited distinct mechanisms of drug resistance, with the gene mutations of fabG1,RRS, gyrA, and rpoB potentially playing a pivotal role in the development of drug resistance. However, the primary genes responsible for drug resistance mutations varied among different strains of TB.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
Objective To examine the global effects of Mycobacterium tuberculosis ( M tuberculosis ) infection on macrophages Methods The gene expression profiling of macrophage U937, in response to infection with M ...Objective To examine the global effects of Mycobacterium tuberculosis ( M tuberculosis ) infection on macrophages Methods The gene expression profiling of macrophage U937, in response to infection with M tuberculosis H 37 R a, was monitored using a high density cDNA microarray Results M tuberculosis infection caused 463 differentially expressed genes, of which 366 genes are known genes registered in the Gene Bank These genes function in various cellular processes including intracellular signalling, cytoskeletal rearrangement, apoptosis, transcriptional regulation, cell surface receptors, cell mediated immunity as well as a variety of cellular metabolic pathways, and may play key roles in M tuberculosis infection and intracellular survival Conclusions M tuberculosis infection alters the expression of host cell genes, and these genes will provide a foundation for understanding the infection process of M tuberculosis The cDNA microarray is a powerful tool for studying pathogen host cell interaction展开更多
Mycobacterium tuberculosis is the causative agent of tuberculosis(TB), which is still the leading cause of mortality from a single infectious disease worldwide. The development of novel anti-TB drugs and vaccines is s...Mycobacterium tuberculosis is the causative agent of tuberculosis(TB), which is still the leading cause of mortality from a single infectious disease worldwide. The development of novel anti-TB drugs and vaccines is severely hampered by the complicated and time-consuming genetic manipulation techniques for M. tuberculosis. Here, we harnessed an endogenous type Ⅲ-A CRISPR/Cas10 system of M. tuberculosis for efficient gene editing and RNA interference(RNAi).This simple and easy method only needs to transform a single mini-CRISPR array plasmid, thus avoiding the introduction of exogenous protein and minimizing proteotoxicity. We demonstrated that M. tuberculosis genes can be efficiently and specifically knocked in/out by this system as confirmed by DNA high-throughput sequencing. This system was further applied to single-and multiple-gene RNAi. Moreover, we successfully performed genome-wide RNAi screening to identify M. tuberculosis genes regulating in vitro and intracellular growth. This system can be extensively used for exploring the functional genomics of M. tuberculosis and facilitate the development of novel anti-TB drugs and vaccines.展开更多
Tuberculosis remains a serious threat to public health. Its causative agent Mycobacte- rium tuberculosis is an intracellular pathogen which survives and replicates within cells of the host immune system, primarily mac...Tuberculosis remains a serious threat to public health. Its causative agent Mycobacte- rium tuberculosis is an intracellular pathogen which survives and replicates within cells of the host immune system, primarily macrophages. Knowledge of the bacteria-macrophage interaction can help to develop novel measures to combat the disease. The global gene expression of macro- phage following invasion by and growth of M. tuberculosis was studied by cDNA microarray. Of the 12800 human genes analyzed, totally 473 (3.7%) macrophage genes were differentially expressed after being infected by M. tuberculosis, among which, only 25 (5.2%, corresponding to less than 0.2% of the 12800 genes) genes were up-regulated, while others (94.8%) were down-regulated against the control. Of the 473 genes, 376 genes are registered in the GenBank, and 97 are novel genes. Expression of 5 up-regulated genes has been induced by more than 3-fold. 25 genes were down-regulated by more than 3-fold. Syndecan binding protein has been down-regu- lated up to 12.5-fold. The data gave an insight into the early gene expression in macrophage ensuing M. tuberculosis infection and a basis for further study.展开更多
Objective To detect the specific mutations in rpoB gene of Mycobacterium tuberculosis by oligonucleotide microarray. Methods Four wild-type and 8 mutant probes were used to detect rifampin resistant strains. Target DN...Objective To detect the specific mutations in rpoB gene of Mycobacterium tuberculosis by oligonucleotide microarray. Methods Four wild-type and 8 mutant probes were used to detect rifampin resistant strains. Target DNA of M. tuberculosis was amplified by PCR, hybridized and scanned. Direct sequencing was performed to verify the results of oligonucleotide microarray Results Of the 102 rifampin-resistant strains 98 (96.1%) had mutations in the rpoB genes. Conclusion Oligonucleotide microarray with mutation-specific probes is a reliable and useful tool for the rapid and accurate diagnosis of rifampin resistance in M. tuberculosis isolates.展开更多
With high morbidity and mortality worldwide, tuberculosis (TB) is still an important public health threat. The majority of human TB cases are caused by Mycobacterium tuberculosis. Although pulmonary TB is the most c...With high morbidity and mortality worldwide, tuberculosis (TB) is still an important public health threat. The majority of human TB cases are caused by Mycobacterium tuberculosis. Although pulmonary TB is the most common presentation, M. tuberculosis can disseminate into other organs and causes extrapulmonary TB (EPTB). The dissemination of bacteria from the initial site of infection to other organs can lead to fatal diseases, such as miliary and meningeal TB. Thoroughly understanding the mechanisms and pathways of dissemination would develop therapies to prevent the lethal prognosis of EPTB (miliary and meningeal TB) and vaccines to promote the development of adaptive immunity. This review focuses on risk factors of EPTB, bacterial and host genes involved in EPTB, and potential mechanisms of M. tuberculosis extrapulmonary dissemination.展开更多
基金Xinjiang Uygur Autonomous Region Health Youth Medical Science and Technology Talents Special Project(Project number:WJW-202116)。
文摘Objective:To analyze the mutation characteristics of inhA and katG genes in isoniazid-resistant Mycobacterium tuberculosis in Xinjiang.Methods:The katG and inhA in 148 strains of isoniazid-resistant Mycobacterium tuberculosis were amplified through fluorescence quantitative PCR,and the amplified products were sequenced and compared.Results:The inhA gene mutation rate of 148 strains of isoniazid-resistant mycobacterium tuberculosis was 13.51%(20/148),among which the inhA gene mutation rate among patients of Han,Uygur,and Kazakh ethnicity were 15.87%,13.21%,and 17.65%,respectively.There was no significant difference in the inhA mutation rate among nationalities(c^(2)=2.897,P>0.05).The mutation rate of the katG gene was 84.46%(125/148),among which the mutation rates of patients of Han,Uyghur,and Kazak ethnicities were 82.54%,84.91%,and 76.47%,respectively.The Hui and other ethnic groups were all affected by the katG gene mutation.There was no significant difference in the mutation rate of the katG gene among different ethnicities(c^(2)=3.772,P>0.05).The mutation rates of the inhA gene in southern Xinjiang,northern Xinjiang,and other provinces were 18.60%,9.28%,and 37.50%,respectively.The mutation rates of the inhA gene in different regions were statistically different(c^(2)=6.381,P<0.05).There was no significant difference in the inhA mutation rate between patients from southern and northern Xinjiang(c^(2)=2.214,P>0.05)and between southern Xinjiang and other provinces(c^(2)=1.424,P>0.05).However,the mutation rate of the inhA gene in patients from other provinces was higher than that in northern Xinjiang(c^(2)=5.539,P<0.05).The mutation rates of the katG gene in southern Xinjiang,northern Xinjiang,and other provinces were 81.40%,87.63%,and 62.50%,respectively.There was no significant difference in the mutation rates of the katG gene among different regions(c^(2)=3.989,P>0.05).Conclusion:katG gene mutation was predominant in isoniazid-resistant tuberculosis patients in Xinjiang Uygur Autonomous Region,and inhA and katG gene mutation were no different among different ethnic groups.
基金funded by the National Natural Science Foundation of China(Grant No.31602061,U21A20259,31872470)the National Key Research and Development Program of China(Grant No.2021YFD1800401).
文摘Mycobacterium tuberculosis(M.tuberculosis)can replicate in the macrophage by interfering with many host protein functions.While it is far from known these host proteins for controlling M.tuberculosis infection.Herein,we infected macrophages including THP-1 and Raw264.7 cells with M.tuberculosis and identified the differentially expressed genes(DEGs)in the interferon signaling pathway.Among them,2'-5'oligoadenylate synthetase-like(OASL)underwent the greatest upregulation in M.tuberculosis-infected macrophages.Knockdown of the expression of OASL attenuated M.tuberculosis survival in macrophages.Further,bioinformatics analysis revealed the potential interaction axis of OASL-TAB3-RvO127,which was further validated by the yeast-two-hybrid(Y2H)assay and Co-IP.This interaction axis might regulate the M.tuberculosis survival and proliferation in macrophages.The study reveals a possible role of OASL during M.tuberculosis infection as a target to control its propagation.
基金Supported by Research Program of The Health Department of Hainan Province(No.2007-44)Research Cultivation Program of Hainan Medical University(HY2010-006)+1 种基金Research Program in higher educational institutes of The Education Department of Hainan Province(No.Hj2010-21)Natural Science Fund of Hainan Province(No.2008~30837)
文摘Objective:To obtain fbpB-esxA fusing gene of Mycobacterium tuberculosis(MTU),express the encoded fusing protein in Escherichia coli(E.coli),identify protein acquired,and predict the structure and function of the protein utilizing methods of bioinformatics.Methods:fbpB and esxA gene were amplified from genome of MTB H37Rv by PCR.The fbpB-esxA fusing gene Iigated by(Gly<sub>4</sub>Ser)<sub>3</sub> linker was gained by means of Gene Splicing by Overlapping Extension PCU(SOEPCR), and fusing gene was cloned into expression vector pET-30a.The recombinant plasmid was sequenced and expressed in E.coli BL21(DE3).The protein was identified by Western blot using anti-HIS antibody.Secondary structure and antigenic epitopes of the protein were predicting using tools of bioinformatics.Results:The UNA sequences fbpB-esxA were identical with that published by GenBank.The Ag85B-ESAT-6 fusion protein about 50 kDa comprised 485 amino acids was efficiently produced from expression system in E.coli B1.21(DE3) under the induction of IPTG.Bioinformatics analysis showed the protein contained one transmembrane region and fourteen potential antigenic epitopes.Conclusions:The Ag85B-ESAT-6 fusion protein is successfully expressed with N-terminal HIS-tag.Gel filtration demonstrated that it exists as insoluble inclusion bodies mainly.The existence of linker doesn’t affect immunogenicity of Ag85B and ESAT-6.It will allow lor characterization in vitro and establish a foundation of further function research such as vaccine or diagnostic reagent.
文摘Heat shock protein 65 (HSP65) is one of the most important protective immunogens against the tuberculosis infection. The signal sequence of antigen 85B and the whole HSP65 DNA sequence of human Mycobacterium tuberculosis (M. tuberculosis) were amplified from BCG genome and plasmid pCMV-MTHSP65 respectively by polymerase chain reactions (PCR). These two sequences were cloned into the plasmid pBCG-2100 under the control of the promoter of heat shock protein 70 (HSP70) from human M. tuberculosis, yielding the prokaryotic shuttle expression plasmid pBCG-SP-HSP65. Results of restriction endonuclease analysis, PCR detection and DNA sequencing analysis showed that the two cloned DNA sequences were consistent with those previously reported, and the direction of their inserting into the recombinant was correct and the reading frame had been maintained. The recombinants were electroporated into BCG to construct the recombinant BCG vaccine and induced by heating. The induced expression detected by SDS-PAGE showed that the content of 65 kD protein expressed in recombinant BCG was 35.69 % in total bacterial protein and 74.09 % in the cell lysate supernatants, suggesting that the recombinant HSP65 gene could express in BCG with high efficiency and the expressed proteins were mainly soluble. Western-blot showed that the secretive recombinant proteins could specifically combine with antibody against M. tuberculosis HSP65, indicating that the recombinant proteins possess the biological activity of HSP65.
基金Supported by the Technology Development Funds of Education Department of Jilin Province,China(No.2008110)
文摘When devoured by macrophages,Mycobacterium tuberculosis remains persistent in macrophages and gains energy through the glyoxylate bypass to maintain its long-term existence in host cells.Therefore it is possible to stop persistent infections by interdicting the glyoxylate bypass in which the isocitrate lyase(ICL) is the key rate-limiting enzyme and a persistence factor.ICL is the target of anti-TB(TB:tubercular) drugs,which could screen ICL out and effectively inhibit the activity of ICL in Mycobacterium tuberculosis,and because of this,anti-TB drugs can be used to kill persistent Mycobacterium tuberculosis.In this study,the ICL gene of the Mycobacterium tuberculosis H37Rv was cloned successfully and recombinant protein with bioactivity was obtained through the enzyme characteristic appraisal.The specific activity of the recombined ICL is 24μmol·mg-1·min-1.The recombined ICL protein was used as the target,and phages which can specifically combine to ICL were screened in the phage 7 peptide library.According to the results of the ELISA and DNA sequence detection,eventually three 7-peptide chains were synthesized.Then the peptide chains were reacted with ICL,respectively,to detect their inhibitory effects on ICL.The results show that all the three 7-peptide chains possessed varying inhibitory effects on the activity of ICL.This study provided lead compounds for the research and development of new peptide anti-TB drugs.
文摘Objective: The increase in the development of resistance to multiple drugs in mycobacterium tuberculosis(MTB) poses a substantial obstacle to the prevention and management of tuberculosis(TB). A thorough investigation of the genotypes linked to multidrug resistance is crucial for comprehending the mechanisms underlying drug resistance. The objective of this research was to assess the attributes of gene mutations associated with multidrug resistance in clinical isolates of mycobacterium tuberculosis through the utilization of whole-genome sequencing. Methods: A total of 124 strains of drug-resistant mycobacterium tuberculosis were collected, and the genomic DNA of both multidrug-resistant and rifampin-resistant strains were extracted and sequenced. Bioinformatics was used to analyze and compare multidrug resistance-related gene sequences in order to detect the variation of multidrug resistance genes. Results: The results revealed that the resistance spectrum of XDR-TB group was much wider than that of the other three groups, with the RR-TB group having the most limited resistance spectrum.Within the MDR-TB strains, fabG1 exhibited the highest frequency of mutations, while RRS, gyrA, and rpoB were identified as the predominant mutation bases in XDR-TB strains. Additionally, rpoB emerged as the primary mutation base in MDR-TB and RR-TB strains. Notably, the fabG1 mutation was found to be closely associated with PDR-TB. Furthermore, the correlation between the mutation rate of rpoB and multidrug resistance was deemed to be of secondary importance. Conclusion: Various strains of MTB exhibited distinct mechanisms of drug resistance, with the gene mutations of fabG1,RRS, gyrA, and rpoB potentially playing a pivotal role in the development of drug resistance. However, the primary genes responsible for drug resistance mutations varied among different strains of TB.
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.
基金theNationalNaturalScienceFoundationofChina (No 3 0 10 0 0 0 7)theNational 973Project (No G1990 5 410 4)
文摘Objective To examine the global effects of Mycobacterium tuberculosis ( M tuberculosis ) infection on macrophages Methods The gene expression profiling of macrophage U937, in response to infection with M tuberculosis H 37 R a, was monitored using a high density cDNA microarray Results M tuberculosis infection caused 463 differentially expressed genes, of which 366 genes are known genes registered in the Gene Bank These genes function in various cellular processes including intracellular signalling, cytoskeletal rearrangement, apoptosis, transcriptional regulation, cell surface receptors, cell mediated immunity as well as a variety of cellular metabolic pathways, and may play key roles in M tuberculosis infection and intracellular survival Conclusions M tuberculosis infection alters the expression of host cell genes, and these genes will provide a foundation for understanding the infection process of M tuberculosis The cDNA microarray is a powerful tool for studying pathogen host cell interaction
基金supported by the National Key R&D Program of China(Grant No.2017YFD0500303)the National Natural Science Foundation of China(Grant Nos.C180501 and 31602061)+1 种基金the Huazhong Agricultural University Scientific&Technological Self-innovation Foundation,China(Grant Nos.2662017PY105 and 2662017PY105)the Doctoral Fund of Ministry of Education of China(Grant No.131012).
文摘Mycobacterium tuberculosis is the causative agent of tuberculosis(TB), which is still the leading cause of mortality from a single infectious disease worldwide. The development of novel anti-TB drugs and vaccines is severely hampered by the complicated and time-consuming genetic manipulation techniques for M. tuberculosis. Here, we harnessed an endogenous type Ⅲ-A CRISPR/Cas10 system of M. tuberculosis for efficient gene editing and RNA interference(RNAi).This simple and easy method only needs to transform a single mini-CRISPR array plasmid, thus avoiding the introduction of exogenous protein and minimizing proteotoxicity. We demonstrated that M. tuberculosis genes can be efficiently and specifically knocked in/out by this system as confirmed by DNA high-throughput sequencing. This system was further applied to single-and multiple-gene RNAi. Moreover, we successfully performed genome-wide RNAi screening to identify M. tuberculosis genes regulating in vitro and intracellular growth. This system can be extensively used for exploring the functional genomics of M. tuberculosis and facilitate the development of novel anti-TB drugs and vaccines.
基金supported by the Key Basic Research Funding Scheme of China(G1990054)National Natural Science Foundation of China(Grant No.30100007)+1 种基金the Explore Fund of the Institute of Genetics,Fudan Universitythe National 973 Program(G199054104&2002CB512804).
文摘Tuberculosis remains a serious threat to public health. Its causative agent Mycobacte- rium tuberculosis is an intracellular pathogen which survives and replicates within cells of the host immune system, primarily macrophages. Knowledge of the bacteria-macrophage interaction can help to develop novel measures to combat the disease. The global gene expression of macro- phage following invasion by and growth of M. tuberculosis was studied by cDNA microarray. Of the 12800 human genes analyzed, totally 473 (3.7%) macrophage genes were differentially expressed after being infected by M. tuberculosis, among which, only 25 (5.2%, corresponding to less than 0.2% of the 12800 genes) genes were up-regulated, while others (94.8%) were down-regulated against the control. Of the 473 genes, 376 genes are registered in the GenBank, and 97 are novel genes. Expression of 5 up-regulated genes has been induced by more than 3-fold. 25 genes were down-regulated by more than 3-fold. Syndecan binding protein has been down-regu- lated up to 12.5-fold. The data gave an insight into the early gene expression in macrophage ensuing M. tuberculosis infection and a basis for further study.
基金supported by the grant from the National Natural Science Foundation of China (No. 30400018)
文摘Objective To detect the specific mutations in rpoB gene of Mycobacterium tuberculosis by oligonucleotide microarray. Methods Four wild-type and 8 mutant probes were used to detect rifampin resistant strains. Target DNA of M. tuberculosis was amplified by PCR, hybridized and scanned. Direct sequencing was performed to verify the results of oligonucleotide microarray Results Of the 102 rifampin-resistant strains 98 (96.1%) had mutations in the rpoB genes. Conclusion Oligonucleotide microarray with mutation-specific probes is a reliable and useful tool for the rapid and accurate diagnosis of rifampin resistance in M. tuberculosis isolates.
文摘With high morbidity and mortality worldwide, tuberculosis (TB) is still an important public health threat. The majority of human TB cases are caused by Mycobacterium tuberculosis. Although pulmonary TB is the most common presentation, M. tuberculosis can disseminate into other organs and causes extrapulmonary TB (EPTB). The dissemination of bacteria from the initial site of infection to other organs can lead to fatal diseases, such as miliary and meningeal TB. Thoroughly understanding the mechanisms and pathways of dissemination would develop therapies to prevent the lethal prognosis of EPTB (miliary and meningeal TB) and vaccines to promote the development of adaptive immunity. This review focuses on risk factors of EPTB, bacterial and host genes involved in EPTB, and potential mechanisms of M. tuberculosis extrapulmonary dissemination.