Mycobacterium tuberculosis is the causative agent of human tuberculosis. Through the genotyping of Mycobacterium tuberculosis, we can find the epidemic situation and characteristics of tuberculosis in time, analyze the transmission chain between patients in different jurisdictions, and formulate effective intervention measures in time, to provide a strong basis for clinical diagnosis and treatment. At present, several genotyping techniques for Mycobacterium tuberculosis have their advantages and disadvantages in application. This article reviews the genotyping technology, population genetics and genotyping naming rules of Mycobacterium tuberculosis.
Objective To investigate the clinical application value of GeneXpert Mycobacterium tuberculosis (MTB)/ rifampin (RIF) in urine samples for tuberculosis diagnosis. Methods The patients with clinically highly suspected tuberculosis admitted to West China Hospital of Sichuan University between January 1, 2018 and June 1, 2023 were selected retrospectively. The diagnostic efficacy of urine GeneXpert MTB/RIF detection, such as sensitivity, specificity, positive predictive value, and negative predictive value, were retrospectively analyzed to evaluate its clinical value in the diagnosis of tuberculosis. Correlation analysis was further conducted to explore the correlation between positive levels of GeneXpert MTB/RIF in urine samples and laboratory test indicators. Results A total of 400 patients were included. Among them, 163 cases were in the clinical tuberculosis group and 237 cases were in the clinical non tuberculosis group. In the clinical tuberculosis group, 112 cases were urogenital tuberculosis patients and 51 cases were non-urogenital tuberculosis patients. The sensitivity, specificity, positive predictive value, and negative predictive value of urine GeneXpert MTB/RIF in the diagnosis of tuberculosis were 55.2%, 97.5%, 93.8% and 76.0%, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value of urine GeneXpert MTB/RIF in the diagnosis of urogenital tuberculosis were 65.2%, 92.0%, 76.0% and 87.2%, respectively, and the diagnostic sensitivity was further improved. Correlation analysis showed that the positive degree of urine GeneXpert MTB/RIF was correlated with the levels of hemoglobin, serum total protein, blood serum albumin, and other indicators. Conclusions Urine GeneXpert MTB/RIF detection offers high sensitivity and specificity in the diagnosis of tuberculosis, especially in urogenital tuberculosis, which is helpful for the early and rapid diagnosis of tuberculosis patients. The positive degree reported by the GeneXpert MTB/RIF in urine may indicate disease severity.
Objective To analyze the drug resistance of Mycobacterium tuberculosis complex (MTBC) in West China Hospital of Sichuan University in recent years to provide reference for drug resistance monitoring and prevention strategies of tuberculosis in general hospitals. Methods The clinical strains of MTBC that performed drug susceptibility tests in West China Hospital of Sichuan University between January 2019 and December 2022 were collected. The drug susceptibility information of 13 anti-tuberculosis drugs, namely rifampicin, isoniazid, ethambutol, streptomycin, rifabutin, amikacin, kanamycin, ofloxacin, levofloxacin, moxifloxacin, para-aminosalicylic acid, ethionamide, and capreomycin, was collected and retrospectively analyzed. Results A total of 502 clinical strains of MTBC were included, and 366 of them were isolated from newly-treated patients while 136 form re-treated patients. The resistance rates of MTBC strains to the first-line anti-tuberculosis drugs in descending order were 28.69% (isoniazid), 19.72% (ethambutol), and 14.94% (rifampicin). Among the second-line drugs, the resistance rates to ofloxacin, levofloxacin, and moxifloxacin were 13.55%, 12.15%, and 11.95%, respectively. The resistance rates to amikacin, kanamycin, para-aminosalicylic acid, and ethionamide were all less than 10%. The resistance rates to streptomycin, capreomycin, and rifabutin were 17.53%, 13.55%, and 12.15%, respectively. The resistance rates to the remaining 12 anti-tuberculosis drugs except capreomycin of MTBC strains isolated from re-treated patients were higher than those of MTBC strains isolated from newly-treated patients, and the differences were statistically significant (P<0.05). The isolation rates of monodrug-resistant, polydrug-resistant, multidrug-resistant (MDR) and pre-extensively drug-resistant (pre-XDR) strains were 9.36%, 7.37%, 7.17%, and 7.77%, respectively. The isolation rates of strains with the four drug-resistant phenotypes generally showed a downward trend during the four years, and the changing trends were statistically significant (P<0.05). The isolation rates of MDR and pre-XDR strains from re-treated patients were higher than those from newly-treated patients, and the differences were statistically significant (P<0.001). Conclusion Tuberculosis drug resistance in West China Hospital of Sichuan University, which is a comprehensive tuberculosis-designated hospital, remained severe during the four years from 2019 to 2022, and the prevention of tuberculosis and the monitoring of drug resistance should be further strengthened.
目的 探讨肾移植患者非结核分枝杆菌（NTM）病临床特点及分子诊断。 方法 回顾性分析2011年4月1例皮肤软组织NTM感染的肾移植患者的临床特点，并以其病变组织DNA为模板，聚合酶链反应（PCR）扩增hsp65基因和rpoB基因序列，测序比对鉴定其NTM菌种。结合文献复习NTM病及分析分子生物学技术在移植患者NTM感染诊断中的作用。 结果 该肾移植患者系皮肤软组织胞内分枝杆菌感染，临床特点与结核病极其相似，难以进行鉴别诊断。PCR扩增、测序的结果显示hsp65产物和rpoB产物序列与胞内分枝杆菌GeneBank中FJ643456.1及CP003324.1序列100%一致。 结论 NTM病的临床表现与结核病相似，分子生物学方法鉴定菌种对移植患者胞内分枝杆菌病的诊断有帮助。
Objectives To evaluate the effect and safety of mycobacterium vaccae in the treatment of recurrent treated pulmonary tuberculosis. Methods We searched PubMed (1997 to 2006), VIP (1997 to 2006), Wanfang database (1997 to 2006), The Cochrane Central Register of Controlled Trials (Issue 4, 2006) and the National Research Register (1996 to 2006). Randomized controlled trials comparing the mycobacterium vaccae immunotherapy group and the control group were included. Two reviewers independently performed data extraction and quality assessment. Data were analyzed using RevMan 4.2.2 software by The Cochrane Collaboration. Results Eleven high quality trials were included. Meta-analyses showed that mycobacterium vaccae immunotherapy plus chemotherapy resulted in higher sputum negative conversion rate (RR=1.36, 95%CI 1.21 to 1.54), higher lesion absorption rate (RR=1.39, 95%CI 1.13 to 1.72), and lower lesion non-absorption rate (RR=0.46, 95%CI 0.36 to 0.60), compared with the control group. These differences were all statistically significant. No serious adverse events were reported. Conclusion As an adjunct to chemotherapy, mycobacterium vaccae is helpful for patients with recurrent treated pulmonary tuberculosis in terms of improving cell-medicated immunity, sputum negative conversion and X-ray manifestation. More high quality studies are needed for further analysis.
ObjectiveTo understand the drug resistance of Mycobacterium tuberculosis complex in West China Hospital, Sichuan University, analyze its drug resistance characteristics, and provide reference for the monitoring of drug-resistant tuberculosis.MethodsFrom January 2016 to March 2018, Mycobacterium tuberculosis drug susceptibility testing kit was used to detect the drug susceptibility of Mycobacterium tuberculosis culture-positive strains in Department of Laboratory Medicine, West China Hospital, Sichuan University. The tested drugs included four of the first-line anti-tuberculosis drugs: rifampicin, isoniazid, ethambutol, and streptomycin, and ten of the second-line anti-tuberculosis drugs: capreomycin, ofloxacin, ethionamide, p-aminosalicylic acid, levofloxacin, moxifloxacin, rifabutin, amikacin, kanamycin, and chlorine phenazine.ResultsA total of 130 patients (130 strains) were enrolled, including 82 newly diagnosed patients (82 strains) and 48 re-treated patients (42 strains). The drug resistance rate of the 130 patients was 37.69%. The drug resistance rate of the newly diagnosed patients (28.05%) was significantly lower than that of the re-treated patients (54.17%), and there was a statistical difference (χ2=8.794, P=0.003). The multi-drug resistance rate of the newly diagnosed patients (6.10%) was significantly lower than that of the re-treated patients (25.00%), and the difference was statistically significant (χ2=9.517, P=0.002). The resistance rate of isoniazid, rifampicin, and streptomycin in newly diagnosed patients (23.17%, 8.54%, and 7.32%, respectively) were significantly lower than those in the re-treated patients (45.83%, 41.67%, and 29.17%, respectively), and the differences were statistically significant (P<0.05). The resistance rate of ofloxacin, moxifloxacin, rifabutin and ethionamide in the newly diagnosed patients (9.76%, 8.54%, 7.31%, and 4.88%, respectively) were significantly lower than those in the re-treated patients (39.58%, 27.08%, 25.00%, and 22.92%, respectively), and the differences were statistically significant (P<0.05).ConclusionIt is necessary to strengthen the standardized treatment of patients with newly diagnosed tuberculosis, increase the treatment and management of re-treated tuberculosis patients, and prevent the generation and spread of drug-resistant patients, especially multidrug-resistant patients.
In this study, loop-mediated isothermal amplification (LAMP) assay in conjunction with calcein for visualized detection of Mycobacterium tuberculosis (MTB) was established. Firstly, four LAMP primers were designed according to the region of 16S rDNA sequences of MTB. Secondly, clinical sputum samples were collected, decontaminated and their DNA was extracted. Thirdly, standard MTB strains were used to evaluate the specificity and sensitivity of LAMP. At the same time, electrophoresis was used for products detection and calcein was used for visualized verification. At last, Chi-squared test function in SPSS 17.0 software was used for consistency evaluation of LAMP assay as compared with the gold standard (culture method). Results showed that there was no nonspecific amplification appeared in the specificity assay and the detection limit was 10 copies/tube in the sensitivity assay. In addition, visualized method by calcein had a comparable sensitivity with that of electrophoresis method. After evaluation of clinical practicability, the sensitivity of LAMP was calculated as 94.74% and the specificity was 90%, respectively. And Chi-squared test showed that LAMP and culture method had no statistic difference, and the two methods were in good consistency (P>0.05). In conclusion, LAMP assay introduced in our study has the characteristics of high efficiency and visualized detection so that this technique has great application prospects in the resource-limited environment, such as work field and primary care hospitals.
【摘要】 目的 分析成都市近年一线抗结核药的耐药状况，为耐药结核病预防控制提供依据。 方法 对成都市2007年1月-2009年12月就诊的结核患者，临床分离株培养鉴定为结核分枝杆菌的菌株采用绝对浓度法进行一线抗结核药:链霉素（SM）、异烟肼（INH）、利福平（RF）、乙胺丁醇（EMB）耐药性检测，分析结核分枝杆菌的耐药情况。 结果 1 235例结核患者中，总耐药率和总耐多药率分别为28.83%、14.01%，初始耐药率和获得性耐药率分别为12.82%、61.27%。近3年耐多药率有下降趋势，但获得性耐药率呈逐年上升趋势。 结论 成都市结核耐药状况仍然比较严重，进一步加强耐药结核的监测和控制非常重要。【Abstract】 Objective To analyze the drug resistant treating mycobacterium tuberculosis (MTB) in Chengdu in recent three years, and to provide the evidence for tuberculosis controlling. Methods The patients with MTB diagnosed from January 2007 to December 2009 in Chengdu were enrolled. Absolute concentration method was used to test the drug-resistance of streptomycin (SM), isoniazide (INH), rifampicin (RFP), and ethambutol (EMB). Results The total rate of drug resistance and multi-drug resistance were 28.83% and 14.01% respectively. The rates of initial drug resistance and the acquired drug resistance were 12.88% and 61.27% respectively. Multi-drug resistance rate showed a downward trend, but the rate of acquired drug resistance increased gradually. Conclusion The situation of drug resistance of tuberculosis in Chengdu is still serious, and it′s very important to further monitor and control the drug resistance treating tuberculosis.
Objective To evaluate the diagnostic value of all diagnostic tests detecting the ethambutol resistance in Mycobacterium tuberculosis. Methods PubMed, EMbase, Chinese Biomedical Database (CBM), Chinese Scientific Journals Full-Text Database (CSJD), and Chinese Journal Full-text Database (CJFD) were searched, and QUADAS items were used to evaluate the quality of included studies. Meta-disc software was used to handle data from included studies. Such index as sensitivity, specificity, and SROC were applied to assess the diagnostic value of individual diagnostic test. Results Nine studies were included. The results of meta-analyses showed that compared with proportion method, the summary sensitivity, summary specificity, positive likelihood ratio, negative likelihood ratio, and SROC area under curve of a nitrate reductase assay were 92%, 99%, 30.50, 0.13, and 0.975 2, respectively, while compared with BACTEC 460 TB, the above mentioned indexes of BACTEC MGIT 960 System were 92%, 99%, 6.27, 0.11, and 0.9, respectively. Bacteriophage biological amplification method revealed relative good analysis effectiveness on MB/BacT. Conclusion According to the results, it is recommended that nitrate reductase assay can replace proportion method as screening test of ethambutol resistance in Mycobacterium tuberculosis, and BACTEC MGIT 960 System can replace BACTEC 460 as final diagnostic test of ethambutol resistance in Mycobacterium tuberculosis.