Latent tuberculosis infection status among freshmen in boarding middle schools in Longgang District of Shenzhen City / 中国学校卫生

Objective@#To analyze the current status of latent tuberculosis infection (LTBI) among freshmen in boarding middle schools in Longgang District, Shenzhen, so as to provide reference for formulating tuberculosis prevention and control strategies in the next stage.@*Methods@#Data for tuberculosis health examination conducted among primary and secondary school students in Longgang District of Shenzhen in September 2022 to May 2023 were utilized to analyze the latent tuberculosis infection rate, and to explore the differences in latent tuberculosis infection rate among different grades, school nature, school categories and school levels.@*Results@#The latent tuberculosis infection rate among freshmen in boarding secondary schools in Longgang District, Shenzhen in 2022 was 2.45%. The infection rate among full middle school (6.45%) and high school (3.37%) were higher than that in boarding junior high school (0.28%), nine year education school (0) and twelve year education school (1.00%) ( P <0.01). Moreover, the infection rate of high school freshmen (2.68%) was higher than that of bording junior high school (0.33%), and the rate of public schools (2.87%) and municipal schools (3.24%) were higher than those of private schools (1.78%) and distric-level schools (2.13%) respectively, with statistical significance observed for all differences( χ 2=43.58, 25.15, 22.69, P <0.01).@*Conclusions@#The latent tuberculosis infection rate among new boarding secondary students is relatively low in Longgang District of Shenzhen. However, the infection rate is higher in high school, public and municipal school. School should fully guarantee sports participation of students, enhance students awareness of tuberculosis through health knowledge lectures, and reduce the incidence of tuberculosis among students.

Purification,antiserum preparation and antigenic characters of ClpC2 in Myco-bacterium tuberculosis / 中国免疫学杂志

Objective:To investigate the antigenicity of ClpC 2 and the feasibility of polyclonal antibodies of ClpC 2 as detected antibody.Methods:rClpC2 was induced with IPTG.The rClpC2 was identified by SDS-PAGE and Western blot ,and purified by affinity chromatography ,with which rabbit were immunized and the specificity of rabbit antiserum was detected by Western blot , the titer of rabbit antiserum against ClpC2 was detected by double immunodiffusion and indirect enzyme-linked immunosorbent assay (ELISA).The antigenicity of the rClpC2 was detected by ELISA.The polyclonal antibodies of ClpC 2 were prepared to detect the ClpC 2 in clinical serum of TB patients by ELISA.Results:SDS-PAGE showed specific protein band with a relative molecular mass of 46 kD.The rClpC2 could bind with the antibody in the blood serum of the mouse immuned by MTB.By Bandscan analysis rClpC 2 accounted for about 58.7%of the total bacteria protein ,the purity of rClpC2 was 88.5% after purification.The ClpC2 of BCG could bind with the rabbit antiserum.The titer of antiserum were 1∶32 and 1∶320 000 by double immunodiffusion and ELISA detected respectively.ELISA results showed that clinical serum positive rate of rClpC 2 antigen was 46%in TB patients,the sensitivity of this protein was 46%,and the spe-cificity of this protein was 90%.ELISA results showed that the sensitivity of rabbit antiserum against ClpC 2 was 40%, and the specificity was 90%.Conclusion: Successfully expressed and purified rClpC 2 and high titer polyclonal antibody were successfully prepared,and these results will provide basements for further study on the biological functions of ClpC 2 and its candidate potentiality as serological diagnosis and drug-target and biological functions of antiserum against ClpC 2.

Comparison of TB-IGRA and Protein Chip in the Diagnosis of Mycobacterium Tuberculosis / 现代检验医学杂志

Objective To evaluate the advantages of TB-IGRA and protein chip to detect the Mycobacterium tuberculosis. Methods From October 2013 to March 2014,collected 78 cases of clinical diagnosis of tuberculosis and normal control’s pe-ripheral blood specimens,used TB-IGRA kits and Mycobacteriumtuberculosis IgG kit(protein chip)to detected respectively. The results were analyzed and compared.Results The sensitivity of protein chip and TB-IGRA in the detection of Mycobac-teriumtuberculosis were 34.5% and 89.7% respectively,which was statistically significant (χ2=26.95,P 0.05).The positive rate of TB-IGRA and Protein chip in tuberculosis were 90.5% and 42.9%.The positive rate of TB-IGRA and Protein chipin extrapulmonary tuberculosis were 89.20% and 29.7% respectively.Conclusion Compared TB-IGRA and protein chip,either diagnose tuberculosis or extrapulmonary tuberculosis has highly positive rate and sensitivity, TB-IGRA can be widely used in the early screening of tuberculosis.

Species and drug resistance of Mycobacterium isolated from sputum smear positive patients / 中国感染控制杂志

Objective To study the species and drug resistance of Mycobacterium isolated from patients with spu-tum smear positive for acid-fast bacillus in Wuj iang city,and provide reference for the prevention and control of tu-berculosis. Methods Sputum specimens with positive smear were cultured,isolated bacteria were identified and performed drug susceptibility testing,drug resistance among different species of strains and between patients with initial and repeated treatment were compared.Results A total of 1 03 Mycobacterium isolates were included in the study,13 of which were nontuberculous Mycobacterium,drug resistance rate was 100.00% ,multidrug resistance (MDR)rate was 84.62% ;90 isolates were Mycobacteriumtuberculosis,81(90.00% )of which were Mycobacteri-umhominis. Drug resistance rate of Mycobacteriumtuberculosiswas 35.56% ,MDR rate was 14.44% . Of 70 ini-tially treated tuberculosis patients with positive sputum smear,14(20.00% )were resistant to drugs,MDR rate was 4.28% (3/70);Of 20 repeatedly treated tuberculosis patients with positive sputum smear,18(90.00% )were resist-ant to drugs,MDR rate was 50.00% (10/20).Conclusion Mycobacteriumtuberculosisis the major isolated strain from patients with positive sputum smear. Drug resistance and MDR rates of nontuberculous Mycobacterium are very high. Drug resistance and MDR rates of Mycobacteriumtuberculosisin repeatedly treated patients are higher than initially treated patients.

The exploratory development of the related genes with rifampin and isoniazid in Mycobacterium tuberculosis / 中华检验医学杂志

Objective To detect the related genes with rifampin and isoniazid in Mycobacterium tuberculosis in sputums using the DNA chip technique and evaluate the fensibility of the clinical application of the DNA chip technique.Methods 586 sputum smear specimen was detected using the L-J cultivation to determine their drug resistance.Simultaneously.DNA chip was employed to detect the mutation of the frequent mutable points rpoB,katG/inhA in mycobaeterium tuberculosis isolates.These two assays were compared and samples showing discrepancy were chosen for additional sequencing to evaluate the accuracy of the detection.Results(1)There were 584 culture positive sputum smear specimens including 3(+)163 specimens,2(+)204 specimens,and 1(+)217 specimens.The drug fast results displayed that 361 strains were sensitive to INH,223 strains tolerated INH in which 93 strains tolerated it in low concentration while sensitive to it in high concentration.and 130 strains tolerated it in both low and high concentration.While 327 strains were sensitive to RFP.247 strains tolerated RFP in which 59 strains tolemted it in low concentration while sensitive to it in high concentration,and 188 strains tolerated it in both low and high concentration.(2)There were 367 positive strains(62.8%)and 217 negative strains(37.2%)identified by PCR amplification of the specific resistance gene fragments.The detection rate of the katG/inhA was 28.4%,and the mutation sites were mainly focused on the katG315(89.8%).The detection rate of the rpoB was 55.9%(137/247),and the mutation sites were mainly focused on rpoB531(68.6%)and rpoB 526(16.1%).(3)The sequencing of sample,which showed discrepancy with L-J cultivation and the DNA chip confirm a certain omission ratio.Conclusions It is feasible to detect the related resistant genes in Mycobacterium tuberculosis isolates using the DNA chip technique.The key factor is to raise the efficiency of the DNA extraction,the effciency of the PCR and the quality control of the experiment to facilitate its clinical application.

Preparation and antigenicity analysis of 38 ku protein of mycobacterium tuberculosis / 中国实用内科杂志

Objective To Clone,express,purify 38 ku protein of mycobacterium tuberculosis,to study its immunological characteristics,and to evaluate its potenial value for serodiagnosis of tuberculosis.Methods Extract DNA from standard strain of H37Rv as the template,amplify gene of 38 ku protein by PCR,insert to PET-30a(+)and construct the recombinant plasmid,express 38 ku protein in E.coli BL21(DE3),purify by Nickel affinity chromatography,at last get target proteins of higher purity,analyze its immol/Lunological characteristics by Western blotting and ELISA technology from Feb.2003 to Mar.2004. Results The clone was analyzed at the nucleotide lever and showed the same DNA sequence coding for natural 38 ku protein. The recombinant protein expressed in inclusion body in E.coli BL21(DE3). The purity of terget protein was 92.7% by Nickel affinity chromatography,Western blotting assays showed that the recombinant protein had satisfactory antigenicity . 38 ku protein detected TB postive and negative refference serum based on the mechanism of indirect ELISA,results showed that the sensitivity was 80.5%(33/41)and the specificity reached to 96%(25/26).Conclusion The recombinant protein expressed in inclusion body in E.coli BL21(DE3)and had satisfactory antigenicity,and might be selected as one of serodiagnostic antigen of tuberculosis.

Clinical study of the application of phage amplified biologically assay in the detection of mycobacterium tuberculosis in sputum / 中国实用内科杂志

Objective To assess the application of the phage amplified biologically assay (PhaB) in the detection of the mycobacterium tuberculosis (TB) in sputum.Methods To determine the TB patients in the 53 suspected patients we detected 53 sputum samples by PhaB method,BACTEC MGIT960 rapid culture method,and conventional methods (direct auramine smear microscopy and concentrated auramine smear microscopy) individually.Results TB positive samples detected by PhaB,BACTEC MGIT960 rapid culture,direct auramine smear microscopy and concentrated auramine smear microscopy were 24,22,11 and 17 respectively.Thus the sensitivity,specificity,positive predictive value and negative predictive value were 86.4%,83.9%,79.2% and 89.7%,when the PhaB is combined with concentrated auramine smear microscopy,the sensitivity,specificity,positive predictive value and negative predictive value were increased up to 90.9%,83.9%,80.8% and 92.9%.Conclusion PhaB method is a simple and rapid method to detect the Mycobacterium Tuberculosis in sputum with a relatively higher sensitivity and specificity than the conventional methods.When combined with concentrated auramine smear microscopy,PhaB method is even more sensitive.Thus the PhaB method is accessible and applicable in the clinical use of the TB detection.

The analyses of detection for sputum specimens of mycobacterium tuberculosis of pulmonary tuberculosis patients / 中国基层医药

Objective To explore the clinical effect of mycobacterium tuberculosis determination by culture and microscopy assay from sputum specimens of pulmonary tuberculosis patients.Methods The sputum specimens were dyed with the Ziehl-Neelsen anti-acid dyeing direct microscopy and examined by BACTEC-TB 960 culture system.Results The positive rate of culture and microscopy were 36.6% and 24.6%,the difference in the positive rate between the two methods was significant(P

Molecular biological on rifampim-depending M.Tuberculosis straims isolated from patients / 中华检验医学杂志

Objective To study the molecular biology of rifampin-depending M. Tuberculosis. Methods The seguence (a 319-bp DNA fragment) of rpoB gene were analyzed by automated DNA sequencing machine. (2) The fingerprints of genomic DNA were obtained by random amplified polymorphic DNA (RAPD) fingerprinting. (3)The protein electrophoresis of bacterium by SDS-polyacrylamide gel (SDS-PAG).(4) The cases of pulmonary tuberculosis by rifampin-depending strains were retrospectively analyzed. Results (1) rpoB gene sequenced: The point mutationrate of rifampin-depending strainswas 96.7%(29/30) and that of rifampin-residtant strains 81.1%(30/37), P

Study of rpoB Mutation in Rifampin Resistants Mycobacterium Tuberculosis / 中国医师杂志

Objective To understand the rpoB gene mutation in M.tuberculosis isolates,and to evaluate their clinical value.Method 335 clinical isolates of mycobacterium tuberculosis(109 isolates drug susceptible,246 isolates rifampin-resistance or multidrug resistance including rifampin) were detected using polymerase chain reaction-single strand conformation polymorphism(PCR-SSCP).Results SSCP pattern of reference mycobacterium tuberculosis H37Rv as control,no mutation was found in rifampin-suscepitible 109 strains.SSCP patterns of 225/246 rifampin resistant clinical isolates were different from the normal control.The sensitivity was 91 5%.31 resistant isolates,included 25 abnormal isolates and 6 normal isolates of SCCP were identified.Sequencing showed 29 isolates had rpoB gene mutations and 3 isolates were not found rpoB gene mutations.The 3 most frequent rpoB gene mutation situs were Leu-531(19 isolates.TCGTTG) and His-526(7 isolates,CACTAC) and Asp-516(3 isolates,GACGTC).Conclusions The results confirm that rpoB gene mutation is the most important mechanism in rifampin resistant tuberculosis mutation situs are 531 tryptophan and 526 histidine;respectively.It is feasible that using PCR-SSCP to detect drug resistance in mycobacterium tuberculosis.