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Gene Jan 2023The Hsp18 protein is a major T-cell antigen of Mycobacterium leprae belonging to the family of small heat-shock proteins. The protein is specifically regulated at...
The Hsp18 protein is a major T-cell antigen of Mycobacterium leprae belonging to the family of small heat-shock proteins. The protein is specifically regulated at post-translational level during the intracellular growth of M. leprae within macrophages due to auto-phosphorylation, indicating its importance in the survival of the bacterium. The promoter and regulatory sequences that control hsp18 expression are located within a 256-bp sequence upstream of the translation start site. However, there are no studies describing either characterization of the hsp18 promoter or its genetic regulation. Therefore, we constructed an hsp18-EGFP transcriptional fusion in an E. coli-Mycobacterium shuttle vector. A 168-bp sequence comprising the hsp18 promoter was cloned upstream of the EGFP gene and transformed in M. smegmatis, and the integration of the construct was confirmed by Southern hybridization. hsp18 promoter activity was measured by analyzing EGFP expression in M. smegmatis and Escherichia coli grown under different environmental stress conditions normally encountered by M. leprae in vivo. We found that the 168-bp upstream sequence of hsp18 could function as a promoter, and the regulation of hsp18 expression was host-, environmental stress-, and temperature-dependent. Appreciable EGFP expression was detected in M. smegmatis grown under normal conditions, and theexpression was significantly increased by environmental stress. However, EGFP expression was observed in E. coli only under stress conditions. Comparative sequence analysis revealed the putative sigma factor C (SigC)-binding site within the 168-bp promoter sequence of hsp18, which might be involved in the regulation of hsp18 expression during stress conditions in M. leprae. Thus, our data demonstrated the transcriptional regulation of hsp18 expression in response to different environmental stress conditions, possibly through SigC in Mycobacterium. Further, this shuttle vector could be used for the functional characterization of M. leprae genes in heterologous systems.
Topics: Mycobacterium leprae; Heat-Shock Proteins; Escherichia coli; Bacterial Proteins; Promoter Regions, Genetic; Mycobacterium
PubMed: 36371000
DOI: 10.1016/j.gene.2022.147034 -
Clinical Microbiology and Infection :... Nov 2021The fact that Mycobacterium leprae does not grow in vitro remains a challenge in the survey of its antimicrobial resistance (AMR). Mainly molecular methods are used to... (Review)
Review
BACKGROUND
The fact that Mycobacterium leprae does not grow in vitro remains a challenge in the survey of its antimicrobial resistance (AMR). Mainly molecular methods are used to diagnose AMR in M. leprae to provide reliable data concerning mutations and their impact. Fluoroquinolones (FQs) are efficient for the treatment of leprosy and the main second-line drugs in case of multidrug resistance.
OBJECTIVES
This study aimed at performing a systematic review (a) to characterize all DNA gyrase gene mutations described in clinical isolates of M. leprae, (b) to distinguish between those associated with FQ resistance or susceptibility and (c) to delineate a consensus numbering system for M. leprae GyrA and GyrB.
DATA SOURCES
Data source was PubMed.
STUDY ELIGIBILITY CRITERIA
Publications reporting genotypic susceptibility-testing methods and gyrase gene mutations in M. leprae clinical strains.
RESULTS
In 25 studies meeting our inclusion criteria, 2884 M. leprae isolates were analysed (2236 for gyrA only (77%) and 755 for both gyrA and gyrB (26%)): 3.8% of isolates had gyrA mutations (n = 110), mostly at position 91 (n = 75, 68%) and 0.8% gyrB mutations (n = 6). Since we found discrepancies regarding the location of substitutions associated with FQ resistance, we established a consensus numbering system to properly number the mutations. We also designed a 3D model of the M. leprae DNA gyrase to predict the impact of mutations whose role in FQ-susceptibility has not been demonstrated previously.
CONCLUSIONS
Mutations in DNA gyrase are observed in 4% of the M. leprae clinical isolates. To solve discrepancies among publications and to distinguish between mutations associated with FQ resistance or susceptibility, the consensus numbering system we proposed as well as the 3D model of the M. leprae gyrase for the evaluation of the impact of unknown mutations in FQ resistance, will provide help for resistance surveillance.
Topics: DNA Gyrase; Drug Resistance, Bacterial; Fluoroquinolones; Humans; Microbial Sensitivity Tests; Mutation; Mycobacterium leprae
PubMed: 34265461
DOI: 10.1016/j.cmi.2021.07.007 -
BMC Biology Oct 2021Hansen's disease (leprosy), widespread in medieval Europe, is today mainly prevalent in tropical and subtropical regions with around 200,000 new cases reported annually....
BACKGROUND
Hansen's disease (leprosy), widespread in medieval Europe, is today mainly prevalent in tropical and subtropical regions with around 200,000 new cases reported annually. Despite its long history and appearance in historical records, its origins and past dissemination patterns are still widely unknown. Applying ancient DNA approaches to its major causative agent, Mycobacterium leprae, can significantly improve our understanding of the disease's complex history. Previous studies have identified a high genetic continuity of the pathogen over the last 1500 years and the existence of at least four M. leprae lineages in some parts of Europe since the Early Medieval period.
RESULTS
Here, we reconstructed 19 ancient M. leprae genomes to further investigate M. leprae's genetic variation in Europe, with a dedicated focus on bacterial genomes from previously unstudied regions (Belarus, Iberia, Russia, Scotland), from multiple sites in a single region (Cambridgeshire, England), and from two Iberian leprosaria. Overall, our data confirm the existence of similar phylogeographic patterns across Europe, including high diversity in leprosaria. Further, we identified a new genotype in Belarus. By doubling the number of complete ancient M. leprae genomes, our results improve our knowledge of the past phylogeography of M. leprae and reveal a particularly high M. leprae diversity in European medieval leprosaria.
CONCLUSIONS
Our findings allow us to detect similar patterns of strain diversity across Europe with branch 3 as the most common branch and the leprosaria as centers for high diversity. The higher resolution of our phylogeny tree also refined our understanding of the interspecies transfer between red squirrels and humans pointing to a late antique/early medieval transmission. Furthermore, with our new estimates on the past population diversity of M. leprae, we gained first insights into the disease's global history in relation to major historic events such as the Roman expansion or the beginning of the regular transatlantic long distance trade. In summary, our findings highlight how studying ancient M. leprae genomes worldwide improves our understanding of leprosy's global history and can contribute to current models of M. leprae's worldwide dissemination, including interspecies transmissions.
Topics: Europe; Genome, Bacterial; Humans; Leprosy; Mycobacterium leprae; Population Dynamics
PubMed: 34610848
DOI: 10.1186/s12915-021-01120-2 -
Infectious Diseases Now Aug 2022Leprosy is one of the oldest infectious diseases, reported for more than 2000years. Leprosy elimination goal as a public health problem set by the World Health... (Review)
Review
Leprosy is one of the oldest infectious diseases, reported for more than 2000years. Leprosy elimination goal as a public health problem set by the World Health Organization, aiming for a global prevalence rate<1 patient in a population of 10,000, was achieved in 2000 mainly thanks to the worldwide use of leprosy drugs starting in the 1980s and their access at no cost for patients since 1995. However, around 200,000 new cases are still reported each year, particularly in India, Brazil, and Indonesia. As with other bacteria of medical interest, antimicrobial resistance is observed in Mycobacterium leprae strains in several parts of the world, despite multidrug therapy being the recommended standard leprosy treatment to avoid resistance selection since 1982. Therefore, identifying and monitoring resistance is necessary. We provide an overview of the historical facts that led to the current drug resistance situation, the antibiotics effective against M. leprae, their mechanisms of action and resistance, and resistance detection methods. We also discuss therapeutic management of the resistant cases, new genes with potential roles in drug resistance and bacterial adaptation, new drugs under investigation, and the risk for resistance selection with the chemoprophylaxis measures.
Topics: Drug Resistance; Drug Therapy, Combination; Humans; Leprostatic Agents; Leprosy; Mycobacterium leprae
PubMed: 35483633
DOI: 10.1016/j.idnow.2022.04.001 -
Emerging Infectious Diseases Jun 2021Mycobacterium leprae was detected by optical microscopy, fluorescent in situ hybridization, and molecular detection in feces collected for the diagnosis of Entamoeba...
Mycobacterium leprae was detected by optical microscopy, fluorescent in situ hybridization, and molecular detection in feces collected for the diagnosis of Entamoeba coli enteritis in a leprosy patient in Burkina Faso. This observation raises questions about the role of fecal excretion of M. leprae in the natural history and diagnosis of leprosy.
Topics: Burkina Faso; Humans; In Situ Hybridization, Fluorescence; Leprosy; Mycobacterium leprae
PubMed: 34013859
DOI: 10.3201/eid2706.200748 -
PLoS Neglected Tropical Diseases May 2020Leprosy urgently needs a precise and early diagnostic tool. The sensitivity of the direct (bacilli staining, Mycobacterium leprae DNA) and indirect (antibody levels, T...
Leprosy urgently needs a precise and early diagnostic tool. The sensitivity of the direct (bacilli staining, Mycobacterium leprae DNA) and indirect (antibody levels, T cell assays) diagnostics methods vary based on the clinical form. Recently, PCR-based M. leprae DNA detection has been shown to differentially diagnose leprosy from other dermatological conditions. However, accuracy can still be improved, especially for use with less invasive clinical samples. We tested different commercial DNA extraction kits: DNeasy Blood & Tissue, QIAamp DNA Microbiome, Maxwell 16 DNA Purification, PowerSoil DNA Isolation; as well as in-house phenol-chloroform and Trizol/FastPrep methods. Extraction was performed on M. leprae-infected mouse footpads and different clinical samples of leprosy patients (skin biopsies and scrapings, lesion, oral and nasal swabs, body hair, blood on FTA cards, peripheral whole blood). We observed that the Microbiome kit was able to enrich for mycobacterial DNA, most likely due the enzymatic digestion cocktail along with mechanical disruption involved in this method. Consequently, we had a significant increase in sensitivity in skin biopsies from paucibacillary leprosy patients using a duplex qPCR targeting 16S rRNA (M. leprae) and 18S rRNA (mammal) in the StepOnePlus system. Our data showed that the presence of M. leprae DNA was best detected in skin biopsies and skin scrapings, independent of the extraction method or the clinical form. For multibacillary patients, detection of M. leprae DNA in nasal swabs indicates the possibility of having a much less invasive sample that can be used for the purposes of DNA sequencing for relapse analysis and drug resistance monitoring. Overall, DNA extracted with the Microbiome kit presented the best bacilli detection rate for paucibacillary cases, indicating that investments in extraction methods with mechanical and DNA digestion should be made.
Topics: Animals; DNA, Bacterial; Humans; Mice; Mycobacterium leprae; Polymerase Chain Reaction; RNA, Bacterial; RNA, Ribosomal, 16S; Sensitivity and Specificity
PubMed: 32453754
DOI: 10.1371/journal.pntd.0008325 -
Immunological Reviews May 2021Leprosy is a chronic granulomatous infectious disease caused by the pathogen, Mycobacterium leprae, and the more recently discovered, M. lepromatosis. Described in... (Review)
Review
Leprosy is a chronic granulomatous infectious disease caused by the pathogen, Mycobacterium leprae, and the more recently discovered, M. lepromatosis. Described in 1873, M. leprae was among the first microorganisms to be proposed as a cause of a human infectious disease. As an obligate intracellular bacterium, it has still not thus far been reproducibly cultivated in axenic medium or cell cultures. Shepard's mouse footpad assay, therefore, was truly a breakthrough in leprosy research. The generation of immunosuppressed and genetically engineered mice, along with advances in molecular and cellular techniques, has since offered more tools for the study of the M. leprae-induced granuloma. While far from perfect, these new mouse models have provided insights into the immunoregulatory mechanisms responsible for the spectrum of this complex disease.
Topics: Animals; Disease Models, Animal; Leprosy; Mice; Mycobacterium leprae; Skin
PubMed: 33660297
DOI: 10.1111/imr.12960 -
Japanese Journal of Infectious Diseases Jul 2022The causative agents of leprosy are Mycobacterium leprae and M. lepromatosis. Mycobacterium lepromatosis was found in 2008 to cause diffuse lepromatous leprosy in...
The causative agents of leprosy are Mycobacterium leprae and M. lepromatosis. Mycobacterium lepromatosis was found in 2008 to cause diffuse lepromatous leprosy in Mexican patients. This study aimed to identify M. leprae and M. lepromatosis in paraffin-embedded skin samples from Caribbean patients with leprosy. A total of six skin samples were obtained from the Dominican Republic. All cases presented the multibacillary form; five were nodular lepromatous leprosy, and one was borderline lepromatous leprosy. All patients received multidrug therapy. Molecular identification was achieved using the M. leprae-specific repetitive element for M. leprae and the hemN gene for M. lepromatosis. Mycobacterium leprae was identified in two lepromatous leprosy cases, and one borderline lepromatous leprosy case; M. lepromatosis was found in one nodular lepromatous leprosy case. Both Mycobacterium species were present in two nodular lepromatous leprosy cases. This is the first report of M. lepromatosis in the Dominican Republic.
Topics: Dominican Republic; Drug Therapy, Combination; Humans; Leprostatic Agents; Leprosy; Leprosy, Lepromatous; Mycobacterium; Mycobacterium leprae
PubMed: 35354704
DOI: 10.7883/yoken.JJID.2021.709 -
Drug Discovery Today Jul 2021Hansen's disease (HD), or leprosy, continues to be endemic in many parts of the world. Although multidrug therapy (MDT) is successful in curing a large number of... (Review)
Review
Hansen's disease (HD), or leprosy, continues to be endemic in many parts of the world. Although multidrug therapy (MDT) is successful in curing a large number of patients, some of them abandon it because it is a long-term treatment. Therefore, identification of new drug targets in Mycobacterium leprae is considered of high importance. Here, we introduce an overview of in silico and in vitro studies that might be of help in this endeavor. The essentiality of M. leprae proteins is reviewed with discussion of flux balance analysis, gene expression, and knockout articles. Finally, druggability techniques are proposed for the validation of new M. leprae protein targets (see Fig. 1).
Topics: Animals; Bacterial Proteins; Computer Simulation; Drug Design; Gene Ontology; Humans; Leprostatic Agents; Leprosy; Mycobacterium leprae
PubMed: 33798649
DOI: 10.1016/j.drudis.2021.03.026 -
International Journal of Dermatology Nov 2015Leprosy is a chronic granulomatous inflammation primarily of the peripheral nervous system, skin, and reticuloendothelial system caused by Mycobacterium leprae. It... (Review)
Review
Leprosy is a chronic granulomatous inflammation primarily of the peripheral nervous system, skin, and reticuloendothelial system caused by Mycobacterium leprae. It presents clinically as an erythematous or hypopigmented anesthetic patch and a thickened and/or tender cutaneous nerve trunk. Leprosy is also called Hansen disease. Leprosy is a great imitator of other skin diseases, and it can present with different morphological lesions, which is why an expert eye is needed to diagnose it. One of the important clinical presentations of leprosy is histoid leprosy, which is very difficult to diagnose due to different clinical and histopathological findings that mimic, e.g., a fibromatous disorder. Histoid leprosy is a very rare clinicopathological variant of leprosy. It is clinically characterized by skin-colored, soft, succulent nodules, and plaques on apparently normal skin and histologically by a dense bundle of histiocytes arranged in storiform. Though histoid leprosy is a very rare type of leprosy, the higher load of lepra bacilli in these cases makes it a concern as a reservoir for leprosy.
Topics: Diagnosis, Differential; Humans; Leprosy; Mycobacterium leprae
PubMed: 26094829
DOI: 10.1111/ijd.12799