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Objective To investigate the genetic diversity of variable number tandem repeats (VNTR) of Mycobacterium tuberculosis (M,ib) isolates and their impact factors on transmission.Methods A total of 1 310 patients with smear-positive pulmonary tuberculosis registered during 2013 from 30 counties of drug-resistance monitoring sites in Guangxi were enrolled.The VNTR genotyping technique was used to identify and analyze M.tb genotypes.Count data was analyzed by Chi-square test using descriptive statistical method,unconditioned Logistic regression was used to analyze the characteristics of gene clusters.Results A total of 1 310 strains of M.tb were classified into 964 genotypes,of which 779 strains were classified into a single gene cluster,531 strains were classified into 185 clusters.Each cluster contained 2 to 40 strains (mean 6.6).Patients aged between 41 and 60 years old had a highest gene cluster proportion (45.5％).Seven hundred and forty-six strains were Beijing genotype,while 564 were nonBeijing genotype,among which 7.4％ was original Beijing genotype.The estimated recent infection (cluster rate) was 26.41％.The cluster rate was higher in sensitive strains (24.40％) than in drugresistant strains (9.55 ％,x2 =23.621,P =0.000) and multi-drug resistant (MDR) strains (8.97 ％,x2=-9.675,P=0.002),and that was higher in Beijing genotype (28.69％) than Non-Beijing genotype (23.40％,x2 =4.610,P=0.032).The clusters proportion in sensitive strain (37.43％) was higher than drug-resistant strains (14.09％) and MDR strains (15.38％),and that was higher in Beijing genotype (40.88％) than Non-Beijing genotype (37.77％).Conclusions M.tb genetic polymorphisms display highly diversity in Guangxi region.Sensitive strains and Beijing genotype strains are the main epidemic strains.
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Objective To study the genotypes of Mycobacterium tuberculosis(M.tuberculosis)strains isolated from Jiangsu province and to explore the relationship between the 'Beijing family' and the drug resistance of M.tuberculosis.Methods Two hundred and sixty M.tuberculosis strains were isolated from 30 drug surveillance sites in Jiangsu province.Susceptibility of the isolates to the first-line antituberculosis drugs(isoniazid,streptomycin,rifampicin and ethambutol)was tested by using the proportion method.Molecular typing of M.tuberculosis strains was determined by Spoligotyping and analyzed with BioNumerics software.Results Based on Spoligotyping fingerprint,260 strains showed 34 different genotypes,including 27 exclusive genotypes and 7 shared genotypes.These strains could be clustered into two groups:the Beijing family(80.4％,209/260)and the Non-Beijing family(19.6％,51/260).Data from logistic regression analysis revealed that infection by the Beijing family was related to an increased risk of multi-drug resistant M.tuberculosis,with the OR(95％ CI)of 11.07(1.45-84.50).Non-Beijing families including T1,T2,H3,H4,CAS,LAM,U and MANU2 families were also found.Among them,the CAS,LAM and MANU2 families were first reported in Jiangsu province.Conclusion It was revealed that the marked gene polymorphisms did exist in M.tuberculosis strains.The Beijing family had been the predominant strain circulating in Jiangsu province,which might be related to multi-drug resistant M.tuberculosis strains.
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Molecular strain typing of Mycobacterium tuberculosis is important for the detection of outbreaks of tuberculosis and laboratory cross contamination, as well as the differentiation between re-infection and reactivation of tuberculosis. In the present review, the authors investigated the currently available typing methods for M. tuberculosis and the current status of strain distribution in Korea. IS6110-restriction fragment length polymorphism (RFLP), which is considered a standard method, is based on numbers and positions of the insertion sequence, IS6110. The method has an excellent discriminatory power with a considerable amount of worldwide data, although it is time-consuming and labor-intensive. Spoligotyping is based on the presence or absence of spacer sequences between direct repeat (DR) regions. PCR amplification allows for the possibility of application in the early suspicious stage. The data can be easily digitized; however, it shows identical profiles in Beijing family strains. Mycobacterial interspersed repetitive unit-variable number of tandem repeat (MIRU-VNTR) is another PCR-based genotyping method with a good discrimination power whose data can also be easily digitized. In Korea, the prevalence of Beijing family strains have been as high as 80 to 87%.
Subject(s)
Humans , Discrimination, Psychological , Disease Outbreaks , Korea , Mycobacterium , Mycobacterium tuberculosis , Polymerase Chain Reaction , Prevalence , Repetitive Sequences, Nucleic Acid , Sprains and Strains , Tandem Repeat Sequences , TuberculosisABSTRACT
The Beijing family of Mycobacterium tuberculosis has been emerging in the world. However, there are few nationwide data of genotypic distribution in Korea. This study aimed to identify the genotypic diversity of clinical isolates of M. tuberculosis and to demonstrate the population of Beijing family in Korea. We collected 96 clinical M. tuberculosis isolates from 11 university hospitals nationwide in Korea from 2008 to 2009. We observed 24 clusters in IS6110-RFLP analysis and 19 patterns in spoligotyping. Seventy-five isolates were confirmed to be Beijing family. Two isolates of the K strain and 12 isolates of the K family strain were also found. We found that drug resistance phenotypes were more strongly associated with Beijing family than non-Beijing family (P=0.003). This study gives an overview of the distribution of genotypes of M. tuberculosis in Korea. These findings indicate that we have to pay more attention to control of M. tuberculosis strains associated with the Beijing family.
Subject(s)
Humans , Drug Resistance, Bacterial , Genotype , Microbial Sensitivity Tests , Mycobacterium tuberculosis/classification , Phenotype , Polymorphism, Restriction Fragment Length , Republic of Korea , Tuberculosis/epidemiologyABSTRACT
Objective To study and preliminarily evaluate the standard spacer oligonucleotide typing (Spoligotyping) method and the application on Mycobacterium tuberculosis (M.tuberculosis).Methods Spoligotyping on 224 M.tuberculosis strains was studied by the molecular biological techniques, including DNA isolation, PCR, reverse line blot hybridization, together with data analysis software BioNumerics (Version 5.0). Results Standardization on both Spoligotyping method and parameters in result analysis and the usage of the analysis software were studied. Through this method, 224 M.tuberculosis clinical strains were classified into 2 clusters including 129 Beijing family strains and 95 non-Beijing family strains. The predominant strains belonged to Beijing family. Conclusion Standard Spoligotyping method was preliminary determined in China, showing that it was a simple, rapid, and robust method for simultaneous detection and typing of M.tubereulosis. This method can be used for tracing the source of infection and understanding the epidemic trend of M.tuberculosis. Spoligotyping can also be served as a method for simultaneous detection and typing ofM.tuberculosis, and to identify Beijing family strains.
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Objective To examine the foasibility of a new method for Mycobacterium tuberculosis (M. tuberculosis)"Beijing family"strain identifjcation——RD105 deletion test. Methods Two methods,Spoligotyping and RD105 deletion test,were used for M. tuberculosis"Beijing family"strain identification,respectively. The difference of the two identification methods was compared. Results Three hundred and forty-two clinical isolates from four areas(Beijing,Fujian,Xinjiang and Jilin)were assayed in this study.Among the total samples,261 isolates belonged to"Beijing family"accounting for 76.32%,while the other 81 isolates belonged to"non-Beijing family"accounting for 23.68%. The coincidence rate for these two methods was 100%. Conclusion The simple and rapid new method——RD105 deletion test can be used to identify"Beijing family"instead of the traditional method——Spoligotyping.
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BACKGROUND: Development of rapid drug susceptibility testing provides the opportunity for rapid identification of individuals with drug resistant tubercle bacilli, allowing selection of appropriate therapeutic regimens. METHODS: A total of 502 drug resistant isolates were subjected to reverse blot hybridization assay to detect mutations within genes (rpoB, katG, inhA, and ahpC) associated with rifampicin (RMP) and isoniazid (INH) resistance. RESULTS: Among the 264 RMP resistant strains (RMPR) tested, the most prevalent mutation was the Ser531Leu seen in 121 strains (46%). The second common mutation occurred in 84 strains (32%) at codon 526. And 27 strains (10%) showed the mutation at codon 516. Among all 469 INH resistant strains (INHR), the katG mutation was responsible for INH. The inhA mutation was present in 88 strains (19%). In 11 isolates (2%), coexisting of the katG and inhA mutations were identified. Reverse hybridization assay successfully detected over 80% of INHR and over 92% of RMPR among Korean isolates. CONCLUSION: Reverse hybridization was useful for rapid detection of INHR and RMPR.
Subject(s)
Codon , Genotype , Isoniazid , Korea , Mycobacterium tuberculosis , RifampinABSTRACT
BACKGROUND: The DNA DNA fingerprinting of Mycobacterium tuberculosis with RFLP is very a useful tool for deciphering the molecular epidemiology of tuberculosis. Since standardization of RFLP methodology using Pvu-II restricted IS-6110 has been proposed international comparison of the RFLP pattern became possible, and some predominance of RFLP pattern in the East Asia was noticed. An international comparison of the RFLP pattern became possible with the proposal to standardize RFLP methodology using Pvu-II restricted IS-6110, and the comparison has noted some predominance of RFLP pattern in East Asia. We studied (The) RFLP patterns of tuberculosis strains collected in at SNUH was studied and was compared them with with the strains from another East Asia strains other strains from East Asia. METHOD: Fifty strains of M.tuberculosis were isolated from patients who visited or were admitted to the SNUH in 1998. We also received some isolates that belong to Beijing family. Some isolates belonging to the Beijing family were also received. After the extraction of DNA from M. tuberculosis isolates, the chromosomal DNAs were digested with Pvu-II, and we analyzed them by and analyzed by the Southern blot method with DNA probe to IS6110. RESULT: There were 6 strains that belong to Six strains belonged to the Beijing family. And The RFLP patterns of another other 9 strains were similar to each other. There were no No statistically significant differences among the groups in terms of age, sex, drug resistance, endobronchial tuberculosis, having presence of underlying disease, and the province they live of residence were found. CONCLUSION: There were a few Few groups of M. tuberculosis strains in from SNUH that (delete) showed similar RFLP patterns. But, their clinical meaning is not clear yet., but their clinical implications are not yet clear.