Mycobacterium Leprae Isolates Research Articles

Identification of antimicrobial resistance determinants in Mycobacterium leprae using SNaPshot technique

Objective. The development of a method for identifying frequent genetic determinants of Mycobacterium leprae clinical isolates resistance to three groups of antimicrobial drugs: dapsone, rifampicin and fluoroquinolones using SNaPshot technique. Materials and Methods. The study included M. leprae clinical isolates obtained from skin biopsies of patients undergoing leprosy treatment at the Sergiev Posad branch of the State Research Center of Dermatovenereology and Cosmetology of the Ministry of Health of Russia. One of the patients has the diagnosis ‘Leprosy, lepromatous type’, the second one has the diagnosis ‘Leprosy. Multibacterial leprosy, borderline’. The selection of oligonucleotide sequences and hybridization probes for M. leprae drug resistance-determining genomic regions PCR was carried out according to information from the BLAST, the synthesis was performed by ‘Synthol’ LLC (Russia). The first PCR was carried out using the QIAGEN Multiplex PCR kit (Germany), and subsequent SNP analysis using the “SNaPshot” kit at the ABI 3130 Genetic Analyzer. The data obtained were depicted using Peak Scanner Software. Results. A method of six most frequent genetic determinants of antimicrobial resistance of M. leprae identification in patient skin biopsies was developed. Drug resistance of the disease is caused by the M. leprae genome mutations located in drug resistance-determining regions in the genomic loci: folP1 for dapsone, rpoB for rifampicin and gyrA for fluoroquinolones resistance. The SNP polymorphisms stipulated drug resistance as a result of changes in the amino acid sequence of the transcribed protein, are determined in following M. leprae genome regions: rpoB: D441, H451, S456; gyrA: A91; folp1: T53, T55. The technique is SNaPshot determination of nine SNP performed on DNA isolated from the patient’s biological material. The control reaction confirming the presence of M. leprae DNA in the sample is PCR using primers to the non-coding repeat element of the leprosy genome RLEP. The pilot application of the technique developed to the samples of clinical material from patients showed the absence of M. leprae resistance determinants to antimicrobial drugs most often used to treat leprosy. Conclusions. The use of a system for rapid identification of leprosy clinical isolates resistance to antimicrobial therapy will personalize the provision of medical care and provide the opportunity to select the optimal chemotherapy regimen, which will lead to increased efficiency of treatment of the disease.

Risk factors for dapsone resistance in leprosy patients: a systematic meta-analysis

Dapsone is one of the important drugs in the treatment of leprosy. The present study aims to evaluate the resistance of Mycobacterium leprae isolates to dapsone, in turn assisting in implementing better control strategies for leprosy elimination. A systematic literature search was conducted in PubMed, Embase, Medline, and Web of Science. Two independent reviewers selected the literature according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), extracted data, and evaluated the risk of bias. Drug resistance data were pooled using the random-effects model. Subgroup analysis was performed based on across sampling time, region, study population (treatment status, relapses status), and sample size. A total of 30 studies were included. The results of meta-analysis showed that the dapsone resistance rate of leprosy patients after treatment was 8% (95% confidence interval [CI], 6%-10%). Compared to the rates of primary resistance of new cases without treatment therapy (pooled incidence, 4% [95% CI, 2%-5%]), treatment cases (13% [95% CI 9%-16%]) had secondary resistance, and relapse cases (26% [95% CI, 18%-33%]) had drug resistance. In addition, the drug resistance rate of monotherapy was significantly increased than that of relapsed patients treated with diamino-diphenylsulfonemonotherapy. Subgroup analysis showed that the patients in the Western Pacific have the highest dapsone resistance, and the resistance to dapsone was slightly lower after 2005. For sample size, the rate in the group under 100 samples was significantly higher than in the other. Dapsone resistance is closely related to leprosy relapse and long-term drug use. Dapsone monotherapy is one of important reasons for drug resistance in relapsed cases. Drug resistance varies among different populations and regions of the world.

SNP Typing of Mycobacterium leprae Clinical Strains in Côte d'Ivoire Reveals Genotype 4 Circulating

Despite years of chemotherapy and the consequent reduction in the prevalence of leprosy in Cote d'Ivoire, there are still high levels of new detection cases. Thus the slow onset of leprosy and the reliance on physical examination for detection of the disease have limited the epidemiological follow-up necessary to understand and control transmission. The differentiation of isolates of Mycobacterium leprae, the causative organism of leprosy, has not yet been established in Cote d'Ivoire. Three SNP loci have been found informative and have been used to understand the evolution and global spread of M. leprae. Based on these reports and the availability of the whole genome sequence, a SNP analysis for strain typing has been realized. This preliminary study present the results of the M. leprae genotype study circulating in Cote d'Ivoire. For each clinically confirmed case of multibacillary leprosy (new cases or relapses), a sample of dermal juice was examined after Ziehl-Neelsen staining and a specific PCR targeting the RLEP repeat sequence. 31 isolates were used to search for single nucleotide polymorphism (SNP) present in the M. leprae genome at positions 14676, 1642875 and 2935685, then determined after sequencing of the mutation zones. The SNPs were determined with a yield of 44,92% (31/69). Genotype 4 was the only genotype founded from the 31 strains identified. This genotype corresponds to those previously reported as widespread in West African countries including Cote d'Ivoire.

Genotyping comparison of Mycobacterium leprae isolates by VNTR analysis from nasal samples in a Brazilian endemic region

This study analyzed the genetic diversity by MIRU-VNTR of Mycobacterium leprae isolates from nasal cavities and related to epidemiological and clinical data. The sample consisted of 48 newly diagnosed leprosy cases that tested positive for M. leprae PCR in nasal secretion (NS) attending to the National Reference Center of Dermatology Dona Libania (CDERM), Fortaleza, Brazil. Total DNA was extracted from NS of each patient and used for amplification of four M. leprae VNTR loci. Four clusters of M. leprae isolates were formed with identical genotypes. In the spatial analysis, 12 leprosy cases presented similar genotypes organized into 4 clusters. The most common genotypes in the current study was AC8b: 8, AC9: 7, AC8a: 8, GTA9: 10, which may represent a genotype of circulating strains most often in Ceará. A minimum set of four MIRU-VNTR loci was demonstrated to study the genetic diversity of M. leprae isolates from NS.

Genomic diversity in Mycobacterium leprae isolates from leprosy cases in South India

ObjectiveThe Objective of this study was to identify the strain diversity of Mycobacterium leprae in terms of SNP types and subtypes stratified as per genomic single nucleotide polymorphisms, in clinical isolates of leprosy patients from a tertiary care leprosy center in South India. Further, the associations of SNP types with clinical outcomes in leprosy were also investigated. MethodsDNA was extracted from excisional skin biopsies of a total of 172 newly diagnosed untreated leprosy patients from a clinic in Tamil Nadu, in south India, that also serves patients from neighboring states. All the leprosy patients were those who voluntarily reported at the clinic during the study period of one year i.e., 2015. Clinical and histopathological details were collected at diagnosis and leprosy was confirmed through bacteriological smear examination and PCR for M. leprae specific RLEP region. SNP types and subtypes were determined by PCR amplification and Sanger sequencing of PCR products. ResultsM. leprae specific RLEP gene amplification was achieved in 160 out of 172 patients. Among 160 specimens 118(73.75%) were type 1 and 42 (26.25%) were type 2 and on subtyping it was noted that 88/160 (55.00%) were 1D, 25/160 (15.62%) 1C, 5/160 (3.12%) 1A, 33/160 (20.62%) 2G and 9/160 (5.62%) were 2H. ConclusionOur results indicated that subtype 1D is predominant in the south Indian population. We also noted 2G, 1C and 1A in the patient sample tested. Additionally we identified subtype 2H for the first time in India.

Drug resistance patterns in Mycobacterium leprae isolates from relapsed leprosy patients attending The Leprosy Mission (TLM) Hospitals in India

Implementation of multidrug therapy (MDT) in leprosy control programmes has significantly reduced the global prevalence of the disease in the last two decades. After many years of use of MDT, it is expected that drug resistance in Mycobacterium leprae may emerge. This is a major concern, especially during the stage of elimination. In the present study, slit-skin smears were collected from 140 leprosy relapse cases from different Leprosy Mission hospitals across India. DNA extracted from 111 (79%) of these samples was analysed for the genes associated with drug resistance in M. leprae. More than 90% of the patients relapsed as multibacillary (MB) cases. In our study, four (3.6%) of the DNA samples analysed showed mutations associated with rifampicin resistance. We also observed that mutations associated with resistance to dapsone and ofloxacin were observed in 9 (8.1%) of the DNA samples each; two samples had both dapsone and ofloxacin resistance. Further surveillance and appropriate interventions are needed to ensure the continued success of chemotherapy for leprosy.

Variation of TTC Repeat Pattern In The Dna of Mycobacterium Leprae Isolates Obtained from Archeological Bones and Leprosy Patients From East Nusa Tenggara

Variation of TTC Repeat Pattern In The Dna of Mycobacterium Leprae Isolates Obtained from Archeological Bones and Leprosy Patients From East Nusa Tenggara

Variation of TTC Repeat Pattern In The Dna of Mycobacterium Leprae Isolates Obtained from Archeological Bones and Leprosy Patients From East Nusa Tenggara

The existence of leprosy or kusta or Morbus Hansen or Hansens disease has been known for years, including in Indonesia. Starting from the discovery of Mycobacterium leprae isolates from ancient bone (about 1.000 years B.C), the archaeological excavations results in East Nusa Tenggara, interesting questions arise about how the development of leprosy in eastern Indonesia is. Biology molecular study would become a powerful tool to investigate the presence of leprosy bacillary whether there are similarities between the genomes of M. leprae isolates in the primeval and the present. PCR examinations were performed on mandibular bone fragments from ancient human who lived 1000 years B.C. discovered in archaeological surveys on the island of Lembata and three leprosy patients from East Nusa Tenggara. The DNA extraction was performed using a kit from Qiagen products and its TTC repeating pattern was seen with the method of direct sequencing. It turned out that the TTC profile obtained from samples of archaeological was as many as 13 copies, while the repetition of TTC in three samples of leprosy patients were 15, 17 and 26 copies. The different number of TTC repetition shows the different isolates of M. leprae between in the ancient times and the present. Further studies are needed to verify the differences in the genome that occur, for example from the study of SNPs (single nucleotide polymorphisms).

Multiple loci variable number tandem repeat (VNTR) analysis (MLVA) of Mycobacterium leprae isolates amplified from European archaeological human remains with lepromatous leprosy

Molecular typing methods based on polymorphisms in single nucleotides and short tandem repeat motifs have been developed as epidemiological typing tools for Mycobacterium leprae. We have used a variable number tandem repeat method based on three variable loci to identify strain variation in archaeological cases of lepromatous leprosy. The panel of polymorphic loci used revealed unique profiles in five cases of leprosy, including those with identical SNP type and subtype. These were also different from profiles of three previously studied lepromatous skeletons. Whilst examination with SNP typing provides evidence for disease origins, dissemination and phylogeny, tandem repeat typing may be useful for studying cases from within a defined area or community where SNP types may be identical due to geographical constraints. We envisage the technique may be useful in studying contemporaneous burials such as those associated with leprosaria and will prove invaluable in authentication of ancient DNA analyses.

VNTR typing of Mycobacterium leprae in South Indian leprosy patients

To study the suitability, stability and diversity of short tandem repeat (STR) genomic markers to elicit strain variation in the Mycobacterium leprae isolates within leprosy patients from Andhra Pradesh and Tamil Nadu states in South India. Slit skin smear (SSS) samples were collected from lesions and various body sites of newly diagnosed leprosy patients. The SSSs from each patient were pooled, except in the case of five patients. Total DNA was extracted from SSS samples. M. leprae STRs were amplified from the DNA either by multiplex PCR (MP) or single PCR methods. The number of repeats for each STR locus (the STR allele) was obtained either by fragment length analysis (FLA) or by DNA sequencing of the PCR amplicons. Multiplex PCR minimised the use of DNA and reagents, and together with FLA, was time and cost effective for STR strain typing. After examination of the isolates of South Indian origin at 13 STR loci, it was determined that the alleles for (AC)8b, (GGT)5, 6-3a (rpoT), 21-3, 27-5, and 23-3 were conserved in two study populations. In a family from Andhra Pradesh, the M. leprae STR patterns in two patients were identical in 16 of 18 loci which indicate a common source of infection. Fourteen of 15 STR loci showed no intra-patient variation in the five patients tested in Tamil Nadu. Altogether, these studies indicate the suitability of STR strain typing for assessing short-range transmission chains.

Genetic diversity of Mycobacterium leprae isolates from Brazilian leprosy patients

Leprosy is a chronic disease caused by infection with Mycobacterium leprae, an obligate intracellular parasite. A problem in studying the transmission of leprosy is the small amount of variation in bacterial genomic DNA. The discovery of variable number of tandem repeats (VNTRs) allowed the detection of strain variation in areas with a high prevalence of leprosy. Four genotypes of M. leprae based on three single-nucleotide polymorphism (SNPs) were also discovered to be useful for analysis of the global spread of leprosy. In this present study, we examined the allelic diversity of M. leprae at 16 select VNTR and three SNP loci using 89 clinical isolates obtained from patients mainly from the neighbouring states of São Paulo and Rio de Janeiro Brazil. By use of a PCR-RFLP-based procedure that allows the recognition of SNP types 3 and 4 without the need for the more expensive DNA sequencing steps, characterisation of the main M. leprae genotypes was easy. When applied on the study population, it was found that the SNP type 3 is most frequent in these two states of Brazil, and that VNTRs provided further discrimination of the isolates. Two Short Tandem Repeats (STRs) were monomorphic, with the remaining 14 STRs represented by two to 18 alleles. Epidemiological associations with township or state were not evident in this random collection and require further investigations. In phylogenetic trees, branches formed by all 16 STRs clearly separated SNP type 3 organisms from the other types while the allelic patterns of two minisatellite loci 27-5 and 12-5 were highly correlated with SNP type 3. This strain typing study provide the basis for comparison of M. leprae strain types within Brazil and with those from other countries, and informed selection of genomic markers and methods for future studies.

Various genotypes of Mycobacterium leprae from Mexico reveal distinct geographic distribution

To classify Mycobacterium leprae isolates from multiple areas in Mexico based on variable number of tandem repeats of 6 base within the rpoT gene and three single nucleotide polymorphism (SNP), and to analyse their geographic distribution in the context of the origin of leprosy in Mexico. Analysis for rpoT genotyping of 64 samples collected in the west and southwestern areas revealed that 46 isolates were of the 4 copy type and 18 isolates were of the 3 copy type. All samples from the eastern coastal area (n = 24) and from the Yucatan peninsula (n = 12) were of the 3 copy type. Six isolates from the west and southwestern area were SNP-type 1, 13 isolates were SNP-type 2 and 45 isolates were SNP-type 3. Nineteen of 24 isolates from the eastern coastal area were SNP-type 3 and one was SNP-type 4. Seven isolates from the Yucatan peninsula were SNP-type 3 and one was SNP-type 4. The difference of the proportion of each genotype between the western areas and the eastern areas indicated the expansion of leprosy through different paths in Mexico.

The frequency of drug resistance mutations in Mycobacterium leprae isolates in untreated and relapsed leprosy patients from Myanmar, Indonesia and the Philippines

The magnitude of drug resistance in Mycobacterium leprae to dapsone, rifampicin, and ofloxacin was studied in three Southeast Asian countries with a high prevalence of leprosy. M. leprae from the skin of leprosy patients was collected in North Maluku and North Sulawesi in Indonesia, Yangon in Myanmar, and Cebu in the Philippines. Mutations in the drug resistance determining regions in the folP1, rpoB, and gyrA genes, which have been proven to confer resistance, were analysed. In addition, samples from 51 newly diagnosed cases and 13 patients with leprosy relapse in Cebu were submitted for susceptibility testing in the mouse footpad. Of 252 isolates obtained from new cases, 3% were dapsone resistant and 2% were rifampicin resistant. In samples taken from patients with relapsed leprosy (n = 53), significantly more resistance mutations were detected: 15% had dapsone resistance mutations, and 8% had rifampicin resistance mutations. Two patients with relapsed leprosy had mutations for both dapsone and rifampicin resistance. No mutations conferring quinolone resistance were detected. No mutations were detected in the folP1 gene of M. leprae isolates with a low degree of resistance to dapsone. Detection of drug-resistant cases by mutation detection in the drug resistance determining region of the genome is a practical method for monitoring resistance. A comparison of the results obtained in this study with previous data obtained prior to the use of multidrug therapy (MDT), does not indicate clearly whether the magnitude of drug resistance has changed. Larger studies of resistance mutations in M. leprae isolated from patients with relapsed leprosy are needed to confirm our results. We recommend monitoring the magnitude of drug resistance globally, by testing M. leprae DNA from relapse cases and a representative sample of new cases.

Polymorphism in the rpoT gene in Mycobacterium leprae isolates obtained from Latin American countries and its possible correlation with the spread of leprosy

The genotypes of Mycobacterium leprae isolates originating from Mexico, Peru and Paraguay were analysed for the polymorphism of short tandem repeats in the rpoT gene. The genotype with four copies of the six-base tandem repeats in the rpoT gene was prominently predominant in Mexico, but the genotype of all isolates from Peru and Paraguay contained three copies of the six-base tandem repeats. These obvious different distributions might reflect the spread of leprosy by the different strains of M. leprae harboured by the various human races that moved to the American continent, as has been demonstrated in other infectious diseases.

Mutations in genes related to drug resistance in Mycobacterium leprae isolates from leprosy patients in Korea

Objective. Identification of the presence and drug resistance of Mycobacterium leprae is key to the diagnosis and treatment of leprosy in non-endemic country like Korea. The aim of this study was to screen the drug target DNA such as folP, rpoB, gyr, and 23S rRNA of drug resistance strain of M. leprae. Patients and methods. Sequences of those genes were analyzed for the 104 bacterial index positive cases out of 171 leprosy patients in Korea using touchdown PCR, single stranded conformational polymorphism. Results. Twenty (19.2%) cases have shown the mutations in folP gene of dapsone-resistant M. leprae in which three (2.89%) cases were mutations in two genes, folP and rpoB, of multidrugs resistant strains to dapsone and rifampin, and two (1.92%) cases in folP and gyr genes of resistance to dapsone and oflaxacin, respectively. Besides double mutation for folP gene was one case (0.96%) and for rpoB gene one case, respectively. There was no mutant isolates in 23S rRNA gene against clarithromycin. Conclusions. This result should leads to a better understanding of the status of multidrug resistant leprosy in Korea and may assist in the rapid diagnosis of drug resistant M. leprae and the choice of the appropriate treatment regimens.

Mutations in genes related to drug resistance in Mycobacterium leprae isolates from leprosy patients in Korea

<h2>Abstract</h2> <i>Objective</i>. Identification of the presence and drug resistance of <i>Mycobacterium leprae</i> is key to the diagnosis and treatment of leprosy in non-endemic country like Korea. The aim of this study was to screen the drug target DNA such as <i>folP</i>, <i>rpoB</i>, <i>gyr</i>, and 23S rRNA of drug resistance strain of <i>M. leprae</i>. <i>Patients and methods</i>. Sequences of those genes were analyzed for the 104 bacterial index positive cases out of 171 leprosy patients in Korea using touchdown PCR, single stranded conformational polymorphism. <i>Results</i>. Twenty (19.2%) cases have shown the mutations in <i>folP</i> gene of dapsone-resistant <i>M. leprae</i> in which three (2.89%) cases were mutations in two genes, <i>folP</i> and <i>rpoB</i>, of multidrugs resistant strains to dapsone and rifampin, and two (1.92%) cases in <i>folP</i> and <i>gyr</i> genes of resistance to dapsone and oflaxacin, respectively. Besides double mutation for <i>folP</i> gene was one case (0.96%) and for <i>rpoB</i> gene one case, respectively. There was no mutant isolates in 23S rRNA gene against clarithromycin. <i>Conclusions</i>. This result should leads to a better understanding of the status of multidrug resistant leprosy in Korea and may assist in the rapid diagnosis of drug resistant <i>M. leprae</i> and the choice of the appropriate treatment regimens.

らい菌のダプソン耐性変異

The relation between diaminodiphenylsulfone (called dapsone)-resistance and point mutations of the dihydropteroate synthase (DHPS) gene was analyzed using dapsone resistant Mycobacterium leprae isolates derived from Japanese leprosy patients. The mutation was found at amino acid residues 53 or 55 of the DHPS. This finding suggests that two specific mutations in the DHPS gene involved in dapsone resistance of M. leprae.

Typing of clinical isolates of Mycobacterium leprae and their distribution in Korea

Although there is no genetic diversity in isolates of Mycobacterium leprae, the variance of tandem repeats in the rpoT gene was recently demonstrated. We have typed clinical isolates of M. leprae in Korea using difference of the tandem repeats in the rpoT gene. Among 69 patients, 65 Korean isolates (94.2%) demonstrated four copies of the 6 bp tandem repeat (GACATC) in the rpoT gene, and incidences of three copies were found in only two Koreans and two foreigners (2.9%, respectively).

Multidrug resistant Mycobacterium leprae from patients with leprosy.

Sequences of the folP1, rpoB, and gyrA genes were analyzed for 88 isolates of Mycobacterium leprae from leprosy patients in Japan, Haiti, Indonesia, Pakistan, and the Philippines. Thirteen isolates (14.8%) showed representative mutations in more than two genes, suggesting the emergence of multidrug-resistant M. leprae.

The prevalence of folP1 mutations associated with clinical resistance to dapsone, in Mycobacterium leprae isolates from South Korea.

(2001). The prevalence of folP1 mutations associated with clinical resistance to dapsone, in Mycobacterium leprae isolates from South Korea. Annals of Tropical Medicine & Parasitology: Vol. 95, No. 4, pp. 429-432.