ABSTRACT
Objective To make a comparative study of the immunogenicity of multi-epitope DNA vaccine and BCG of Mycobacterium tuberculosis and therapeutic effects of the vaccines combined with chemotherapy in a mouse model infected with multi-drug resistant (MDR)Mycobacterium tuberculosis.Methods The BALB/c mice were randomly divided into Group A,Group B and Group C,which received subcutaneous immunization with PBS,BCG and multi-epitope DNA vaccine,respectively,once at weeks 1 ,3 and 5 .Specific IgG antibody,IL2 and IFN-γin mice serum were determined with ELISA after the final vaccination.At the same time,the splenic lymphocytes of mice were separated and the lymphocytes proliferation was determined by MTT method.To study the therapeutic effects of multi-epitope DNA vaccine,the mice were infected by intravenous injection in the tail vein with Mycobacterium tuberculosis clinical isolates that were resistant to isoniazid (INH)and rifampin (RFP).Four weeks later,the model mice were divided into Groups D,E and F.The mice in Group D and control group received saline injection. The mice in Group E were treated with RFP and INH.The mice in Group F were treated with multi-epitope DNA vaccine combined with INH and RFP for 10 weeks.The lungs,livers and spleens of mice were removed and weighed;the colony number of Mycobacterium tuberculosis in the lungs and spleens was counted.Results The antibody IgG,IL2 and IFN-γwere obviously higher in multi-epitope DNA vaccine group than in BCG group (P<0.05).Multi-epitope DNA vaccine combined with chemotherapy could obviously reduce the colony number of Mycobacterium tuberculosis in the lungs and spleens as well as indexes of the lungs,livers and spleens (P<0.05). Conclusion Mycobacterium tuberculosis Hsp70,Ag85A,and ESAT-6 multi-epitope DNA vaccine could induce strong specific immune response in mice that produced a high level of specific IgG antibody,IL2 and IFN-γ,specific lymphocyte proliferation,and significantly improve the efficacy of anti-tuberculosis drug resistant tuberculosis in mice.
ABSTRACT
Bacground: DST by conventional methods takes several weeks, while early diagnosis of the disease and the rapid identification of resistant strains are essential for efficient treatment and control of the MDR strains. Rapid molecular testing of detecting MDR-TB is needed.Objective: The aim of this study was to assess performance of molecular line probe assay, Genotype16 MTBDRp/us, for rapid detection of RIF and INH resistance for M.Tuberculosis in Mongolia. The sensitivity and specificity of Genotype® MTBDRp/us to detect RIF and INH resistance-associated mutations in culture specimens and directly in smear-positive clinical specimens was examined and compared with conventional culture and drug susceptibility testing on solid medium.Material and Methods: The subjects of this study were 218 MDR-TB suspects aged 14-75 years from 8 districts in Ulaanbaatar city. The study was conducted from July 2009 to May 2010. The Genotype M. Tuberculosis drug resistance first line (MTBDR plus) assay (Hain Life-science, Nehren, Germany) was tested on directly on 41 sputum specimens and 109 clinical isolates.Results: The high correlation of the results from Genotype® MTBDRp/us and conventional drug susceptibility testing was obtained from this study. The results clearly show high performance of Genotype® MTBDRp/us with almost 100% accuracy for all the important indicators, such as sensitivity, specificity, positive and negative predictive values of detection of RIF and INH resistance. Some minor discrepancies were obtained in comparison with DNA sequencing results.Our study found that among high proportion for detection of RIF resistance, S531L mutation (MUT3 band) occurred the most commonly, with 80.0% of all RIF-resistant strains (83.6% of MDR) having the mutation. Other mutation in the 530-533 regions was common, as detected by the lack of binding to the WT8 probe in the absence of S531L mutation.In this study we observed that mutations in the promoter region of inhA gene played a major role (67.6 % (63.9% of MDR strains and 90% of INH-mono-resistant strains) had a mutation in the inhA.Conclusion: The Genotype® MTBDRp/us assay was demonstrated as a rapid, reliable and highly accurate tool for early detection of MDR-TB through examining smear positive cases enabling early start of appropriate therapeutic and public health measures to control of the spread of drug resistant M.tuberculosis in the population.
ABSTRACT
Enflurane is metabolized in the liver by the hepatic microsomal enzyme system, cytochrome P-450 and induces enzyme during the enflurane exposure. Enhanced biotransformation might occur after enflurane itself and several other drugs, isoniazid (INH), ethanol and cholorpromazine. Increased inorganic fluroide, one of the enflurane metaboites, could impair renal function. The possibility of increased enflurane defluorination follwing treatment with isoniazid, isoniazid group (n=10) and control group (n= 11) was investigated by the measuring the serum and urine F in the preoperative period and 2 hrs after anesthesia, immediate postoperative and 24th postoperative hour. According to the serum inorganic fluoride concentration, the isoniazid group was divided again into INH high F- and INH low F- groups. In the preoperative, immediate postoperative period and 24th postoperative hour, the changes of renal function were measured by the BUN and creatinine and liver function was measured by the SGOT and SGPT. The results were as follows: 1) Serum inorganic fluoride increased in enflurane anesthesia significantly in all three groups and decreased in the 24th postoperative hour. Among the three groups, enhanced defluorination was the highest in the INH high F group. 2) Urine inorganic fluoride was increased in the control and INH high F group. 3) There were no changes in renal and hepatic function after enflurane anesthesia. Our study indicated that enflurane does not harm the INH treated patient.