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Objective To identify the cross-reactive antigens shared by Mycobacteria smegmatis(MS) and Mycobacteria tuberculosis(MTB) and to analyze their antigenicity.Methods Bacterial antigens were extracted from strains of MS and MTB by ultrasonication.Western blot assay was performed to analyze common antigens that reacted with both of the antiserum samples against MS and MTB.The extracted bacterial antigens were mixed with incomplete Freund′s adjuvant and then were injected into muscles of mice.Cytokines secreted by murine spleen lymphocytes following stimulation with various antigens of MS and MTB were determined by ELISPOT and flow cytometry on the 7th day.IgG levels in serum samples were detected by ELISA 7 days after injection.Results There were cross-reactive antigens shared by MS and MTB.Potent humoral immune responses and cellular immunity against both MS and MTB could be induced by those cross-reactive antigens after sensitization the mice by either MS or MTB antigens.Cytokines of IL-2 and IFN-γ in CD4+ and CD8+T cells of mice stimulated with MS or MTB antigens were significantly increased as compared with those of non-sensitization group and those of Brucella antigens stimulation group.ConclusionCross-reactive antigens shared by MS and MTS can effectively promote specific immune reactions to the infection of MTB, which provides a scientific basis for the development of tuberculosis vaccines.
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Objective To investigate the effect of interleukin 23 receptor (IL-23R) on T helper cell 17 (Th17) call-mediated immune response in mycobacterium tuberculosis (TB) infection,and to explore the role of IL-23R in the pathogenesis of pulmonary tuberculosis.Methods 21 active lung tuberculosis (ATB) patients were enrolled in Beijing chest hospital from July to October in 2015,21 cases of latent tuberculosis infection (LTBI) and 21 healthy Healthy Donors (HD) were selected from Beijing Changping center for tuberculosis control and prevention from May to July in 2015.The peripheral blood mononuclear cells (PBMCs) were isolated and cultured.The expression of IL-23R mRNA in PBMCs was detected,IL-23 and IL-17A levels in the supernatant of PBMCs were measured.The expression of IL-23R mRNA in different groups and the effect of IL-23R expression on IL-17A level were analyzed.Results The expression of IL-23R mRNA in ATB group was lower than that in LTBI group (Z =-2.528,P =0.011),and in ATB group was higher than that in HD group (Z =-3.849,P ＜ 0.001).The expression of IL-17A in ATB group was lower than that in LTB group (t =2.238,P =0.031),and ATB group was higher than that in HD group (t =4.733,P ＜ 0.001).There was no significant difference in IL-23 level between the three groups (F =0.432,P =0.651).IL-23R mRNA expression was positively correlated with IL-17A level (rs =0.438,P =0.047).Conclusions The expression level of IL-23R in mycobacterium tuberculosis infection can regulate the immune response mediated by Th17 cells,which may affect the susceptibility and infection outcome of pulmonary tuberculosis.
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Background: Tuberculosis is still a major global health problem. Human tuberculosis is caused by species of bacteria belonging to the Mycobacterium genus. In this study we determined mycobacterial species affecting patients from Botucatu, Brazil, and tested M. tuberculosis sensitivity to different drugs. Methods: Data were obtained from Clinical Laboratory Analysis records at Botucatu Medical School University Hospital, UNESP. All samples were processed according to standard isolation procedures from the 2008 Brazil Ministry of Health Mycobacteria Manual, which consist of staining smears by the Ziehl-Neelsen technique and seeding cultures in the Löwenstein-Jensen medium. Results: Samples were isolated from sputum (80.5%), bronchoalveolar lavage (13.8%), pleural fluid (4.6%), and cerebrospinal liquor (1.1%). Smears were evaluated in 87 cases and a total of 59 patients showed positive smears; 55 from 70 sputum samples and 4 from 12 bronchoalveolar lavage samples. No pleural fluid (4) or cerebrospinal liquor (1) samples showed positive smears. The most commonly identified strain was M. tuberculosis (61 cases); followed by M. avium and M. gordonae 2 cases each, and M. peregrinum and M. abscessus 1 case each. Mycobacteria were not identified in 20 patients. Only two strains of M. tuberculosis were multidrug resistant; one was resistant to isoniazid, rifampicin, and pyrazinamide. These two patients evolved to cure. Conclusion: This study highlights a small but troubling percentage of multidrug resistant samples and reveals the occurrence of nontuberculous mycobacteria, emphasizing the importance of correctly identifying species and testing sensitivity to antibacilar drugs to assure an adequate therapy.
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This article reviewed the gene markers and the sequences for the detection of the species and strains of Mycobacteria tuberculosis. The gene markers and the sequences conclude insertion sequences, tandem repeat sequences, the polymorphic GC-rich repetitive sequences contained in the plasmid pTBN12, 36 bp direct repetitive sequences, spacer oligonucleotides.
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Objective To investigate the feasibility of multiplex PCR for rapid identification of Mycobacterium tuberculosis and non-tuberculosis Mycobacteria. Methods According to MTP40 gene sequence of Mycobacterium tuberculosis, 32kD gene sequence of Mycobacterium and IS6110 insertion sequence gene sequence of Mycobacterium tuberculosis complex, three specific pairs of primers (PT1-PT2, MT1-MT2 and IS5-IS6) for Mycobacterium were designed, and the target DNA for MTP40, 32kD and IS6110 was 396bp, 506bp and 984bp, respectively. The genome of 92 Mycobacterium tuberculosis clinically isolated strains and 5 non-tuberculosis Mycobacteria clinical strains were amplified in the same system, and the results were compared with reference strains. Results Among 92 clinical strains of Mycobacterium tuberculosis, the DNA fragments of 396bp, 506bp and 984bp were found in 90 Mycobacterium tuberculosis clinical strains, as well as in the reference strain H37Rv; the sensitivity of multiplex PCR for Mycobacterium tuberculosis was 97.8%, and the specificity was 100.0%. The DNA fragments of 506bp were all found in 5 non-tuberculosis Mycobacteria clinical strains, the sensitivity and specificity for non-tuberculosis Mycobacterium were both 100.0%. Conclusion The multiplex PCR is a rapid, sensitive and specific method for identification of Mycobacterium tuberculosis and non-tuberculosis Mycobacteria, and it may provide an effective way for clinical diagnosis of Mycobacterium tuberculosis and non-tuberculosis Mycobacteria, therefore useful in clinical application.