New patient of Hansen's disease in young Korean man / 나학회지

Hansen's disease (leprosy) is a chronic infectious disease caused by Mycobacterium leprae which affect mainly skin and nerve systems. Currently the incidence of leprosy reached the goals set by WHO in the year 2000. In recent 10 years, only 47 new patients were found in Koreans and their average age was over 70. A 21 year-old young man showed multiple erythematous papules, macules and plaque at face, extremities and trunk. In family history, his grandfather was diagnosed with leprosy at young age and leprosy was recurred when the patient was 7 years old. The patient lived with grandfather from birth to 7 years old. Clinico-pathologically he was diagnosed with a lepromatous leprosy. We performed VNTR both at the skin tissue of grandfather and patient to find out the infection pathway of the patient and found some consistent. Herein, we report a new case of young Korean male transmitted from grandfather.

Variable number tandem repeats diversity of Mycobacterium tuberculosis isolates / 中华传染病杂志

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.

Genotyping of Mycobacterium leprae present on Ziehl-Neelsen-stained microscopic slides and in skin biopsy samples from leprosy patients in different geographic regions of Brazil

We analysed 16 variable number tandem repeats (VNTR) and three single-nucleotide polymorphisms (SNP) in Mycobacterium leprae present on 115 Ziehl-Neelsen (Z-N)-stained slides and in 51 skin biopsy samples derived from leprosy patients from Ceará (n = 23), Pernambuco (n = 41), Rio de Janeiro (n = 22) and Rondônia (RO) (n = 78). All skin biopsies yielded SNP-based genotypes, while 48 of the samples (94.1%) yielded complete VNTR genotypes. We evaluated two procedures for extracting M. leprae DNA from Z-N-stained slides: the first including Chelex and the other combining proteinase and sodium dodecyl sulfate. Of the 76 samples processed using the first procedure, 30.2% were positive for 16 or 15 VNTRs, whereas of the 39 samples processed using the second procedure, 28.2% yielded genotypes defined by at least 10 VNTRs. Combined VNTR and SNP analysis revealed large variability in genotypes, but a high prevalence of SNP genotype 4 in the Northeast Region of Brazil. Our observation of two samples from RO with an identical genotype and seven groups with similar genotypes, including four derived from residents of the same state or region, suggest a tendency to form groups according to the origin of the isolates. This study demonstrates the existence of geographically related M. leprae genotypes and that Z-N-stained slides are an alternative source for M. leprae genotyping.

A combined approach of VNTR and MLST analysis: improving molecular typing of Argentinean isolates of Leptospira interrogans

Leptospirosis is an emerging infectious disease that has been identified as both a human and animal health problem worldwide. Regular outbreaks associated with specific risk factors have been reported in Argentina. However, there are no available data concerning the genetic population level for this pathogen. Therefore, the aim of this work was to describe the genetic diversity of Leptospira interrogans through the application of two molecular typing strategies: variable number of tandem repeats (VNTR) and multilocus sequence typing (MLST). For this purpose, seven reference strains and 18 non-epidemiologically related isolates from diverse hosts and Argentinean regions were analysed. Among them, nine genotypes and seven sequence types (STs), including three unreported STs, were described using VNTR and MLST, respectively. eBURST analysis demonstrated that ST37 was the most frequent and founder genotype of a clonal complex (CCs) containing STN1 and STN3, suggesting the importance of studying the serovars belonging to this CC in Argentina. The data from maximum parsimony analysis, which combined both techniques, achieved intra-serovar discrimination, surmounted microscopic agglutination test discrepancies and increased the discriminatory power of each technique applied separately. This study is the first to combine both strategies for L. interrogans typing to generate a more comprehensive molecular genotyping of isolates from Argentina in a global context.

Discrimination power evaluation for 45 loci of variable number tandem repeats in Mycobacterium tuberculosis strains isolated from China / 中华流行病学杂志

Objective To evaluate the discriminatory efficiency of multiple loci of variable numbers of tandem repeats (VNTR) in Mycobacterium tuberculosis genome.Genotyping and identification on Chinese M.tuberculosis clinical strains were used to locate a series of high discriminated loci,so as to provide the basis for creating a standardized multiple loci VNTR analysis (MLVA) to distribute fast typing and identification on Chinese M.tuberculosis.Methods VNTR loci which were chosen from the website http://minisatellites.u-psud.fr/ and referenced to the genome sequence of M.tuberculosis standard strain H37Rv were tested in Chinese M.tuberculosis clinical strains and H37Rv by means of PCR.The primers were designed by DNAStar software.The repeat member of VNTR unit was estimated by the result of PCR.The discrimination power of single locus or multiple loci was confirmed by the Hunter-Gaston index.Results 45 VNTR loci were tested in 135 Chinese M.tuberculosis clinical strains and H37Rv.The discrimination power of these loci appeared different from each other,with the biggest Hunter-Gaston index as 0.814 (0.797-0.830),the smallest one as 0.015 (0.001-0.028),and there were 13 loci with which the Hunter-Gaston index was bigger than 0.5.Results showed that the discrimination power was increasing by different loci that associated with each other.The more loci that were combined,the bigger the Hunter-Gaston index was,For example,the Hunter-Gaston index of Qub11-b associated with Qub 18 was 0.936,by which 136 strains could be divided into 44 groups.With the combination of 9 loci including Qub11-b,Qub18,Mtub21,Rv2372,MIRU26,Qub26,Qub4156c,Qub11-a and Qub15,the HunterGaston index could have reached 1 and by which the 136 strains could be divided into 136 groups,also showing that the biggest discrimination power to strain identification,viz.strain level genotype were reached.Conclusion The discrimination power of different locus was different.The discrimination power of multiple loci was much more satisfied than that of single locus.It was satisfied the combine discrimination power of 9 loci including Qubll-b,Qubl8,Mtub21,Rv2372,MIRU26,Qub26,Qub4156c,Qub11-a and Qubl5,by which the qualified typing method could gain to facilitate research on molecular epidemiology with the Hunter-Gaston index analysis.