Novel mutations found in Mycobacterium leprae DNA repair gene nth from central India

INTRODUCTION

The importance of DNA repair enzymes in maintaining genomic integrity is highlighted by the hypothesis that DNA damage by reactive oxygen/nitrogen species produced inside the host cell is essential for the mutagenesis process. Endonuclease III (Nth), formamidopyrimide (Fpg) and endonuclease VIII (Nei) DNA glycosylases are essential components of the bacterial base excision repair process. Mycobacterium leprae lost both fpg/nei genes during the reductive evolution event and only has the nth (ML2301) gene. This study aims to characterize the mutations in the nth gene of M. leprae strains and explore its correlation with drug-resistance.

METHOD

A total of 91 M. leprae positive DNA samples extracted from skin biopsy samples of newly diagnosed leprosy patients from NSCB Hospital Jabalpur were assessed for the nth gene as well as drug resistance-associated loci of the rpoB, gyrA and folP1 genes through PCR followed by Sanger sequencing.

RESULTS

Of these 91 patients, a total of two insertion frameshift mutations, two synonymous and seven nonsynonymous mutations were found in nth in seven samples. Sixteen samples were found to be resistant to ofloxacin and one was found to be dapsone resistant as per the known DRDR mutations. No mutations were found in the rpoB region. Interestingly, none of the nth mutations were identified in the drug-resistant associated samples.

CONCLUSION

The in-silico structural analysis of the non-synonymous mutations in the Nth predicted five of them were to be deleterious. Our results suggest that the mutations in the nth gene may be potential markers for phylogenetic and epidemiological studies.

Coinfection with Leprosy and Tuberculosis: A Case Series in Malagasy Patients

Background

Leprosy and tuberculosis are two of the oldest and most common mycobacterial infections, caused by Mycobacterium leprae and Mycobacteium lepramatosis for leprosy and Mycobacterium tuberculosis for tuberculosis. Dual infections have been known since ancient times; however, cases remain rarely reported in the literature, even in countries where both diseases are endemic, such as Madagascar.

Purpose

We report a case series of simultaneous occurrence of leprosy and tuberculosis.

Patients and Methods

In this retrospective study, we reviewed the medical records of patients with leprosy registered at the Department of Dermatology, University Hospital Befelatanana, Antananarivo, Madagascar, between January 2012 and June 2021. Patients with leprosy and diagnosed as coinfected by tuberculosis were included in the study.

Results

Of the 120 leprosy cases observed during the study period, coinfection with leprosy and tuberculosis was found in five patients. The mean age was 43.4 (SD 13.2) ranging, 21-59 years. Male gender was predominant (4/5). Four patients presented with lepromatous leprosy, and one with borderline lepromatous leprosy. Three patients experienced leprosy reaction. Four cases of pulmonary tuberculosis and one case of multifocal tuberculosis were observed. The diagnosis of leprosy preceded tuberculosis in four cases, and a coinfection diagnosis was made simultaneously in one case. The average time to develop tuberculosis was 38.8 (SD 10.2) months. HIV infection, malnutrition, alcohol consumption, and long-term corticosteroid therapy were the immunosuppressive factors reported in our patients. Three patients received concomitant multidrug therapy for leprosy and tuberculosis.

Conclusion

Dermatologists should be aware of the importance of screening patients affected by leprosy for latent or active tuberculosis to prevent morbidity and mortality due to coinfection and to reduce the risk of acquired resistance to rifampicin, which is the greatest risk of this association.

CYBB-Mediated Ferroptosis Associated with Immunosuppression in Mycobacterium leprae-Infected Monocyte-Derived Macrophages

Mycobacterium leprae-infected macrophages preferentially exhibit the regulatory M2 phenotype in vitro, which helps the immune escape unabated growth of M leprae in host cells. The mechanism that triggers macrophage polarization is still unknown. In this study, we performed single-cell RNA sequencing to determine the initial responses of human monocyte-derived macrophages against M leprae infection of 4 healthy individuals and found an increase in a major alternative-activated macrophage type that overexpressed NEAT1, CCL2, and CD163. Importantly, further functional analysis showed that ferroptosis was positively correlated with M2 polarization of macrophages, and in vitro experiments have shown that inhibition of ferroptosis promotes the survival of M leprae within macrophages. In addition, further joint analysis of our results with mutisequencing data from patients with leprosy and in vitro validation identified that CYBB was the pivotal molecule for ferroptosis that could promote the M2 polarization of M leprae-infected macrophages, resulting in the immune escape and unabated growth of pathogenic bacteria. Overall, our results suggest that M leprae facilitated its survival by inducing CYBB-mediated macrophage ferroptosis leading to its alternative activation and might reveal the potential for a new therapeutic strategy of leprosy.

[Hansen's Disease: An Unusual Manifestation of an Ancient Disease]

Hansen's disease, commonly known as leprosy, is an infectious disease caused by Mycobacterium leprae. Being rare in developed countries, it is an increasingly common imported disease due to the migratory flow from countries where it is endemic. We present the case of a 21-year-old man who went to the emergency department with complaints of additive polyarthralgia involving large joints, papules, and erythematous plaques on the limbs with bullae and central necrosis and fever with chills for one week. Skin biopsy was performed revealing neutrophilic infiltrate with perineural granulomas. The bacilloscopy detected acid-alcohol resistant bacilli. The diagnosis of multibacillary HD with type 2 lepromatous reaction (erythema nodosum leprosum - ENL) was established, showing clinical improvement under corticosteroid therapy. ENL usually presents with painful lesions, being an atypical presentation of leprosy, especially in the presence of bullae and necrosis, making diagnosis difficult and challenging. Social stigma is often present making it difficult to accept the disease as well as adherence to treatment.

Unlocking Opportunities for Mycobacterium leprae and Mycobacterium ulcerans

In the recent decade, scientific communities have toiled to tackle the emerging burden of drug-resistant tuberculosis (DR-TB) and rapidly growing opportunistic nontuberculous mycobacteria (NTM). Among these, two neglected mycobacteria species of the Acinetobacter family, Mycobacterium leprae and Mycobacterium ulcerans, are the etiological agents of leprosy and Buruli ulcer infections, respectively, and fall under the broad umbrella of neglected tropical diseases (NTDs). Unfortunately, lackluster drug discovery efforts have been made against these pathogenic bacteria in the recent decade, resulting in the discovery of only a few countable hits and majorly repurposing anti-TB drug candidates such as telacebec (Q203), P218, and TB47 for current therapeutic interventions. Major ignorance in drug candidate identification might aggravate the dramatic consequences of rapidly spreading mycobacterial NTDs in the coming days. Therefore, this Review focuses on an up-to-date account of drug discovery efforts targeting selected druggable targets from both bacilli, including the accompanying challenges that have been identified and are responsible for the slow drug discovery. Furthermore, a succinct discussion of the all-new possibilities that could be alternative solutions to mitigate the neglected mycobacterial NTD burden and subsequently accelerate the drug discovery effort is also included. We anticipate that the state-of-the-art strategies discussed here may attract major attention from the scientific community to navigate and expand the roadmap for the discovery of next-generation therapeutics against these NTDs.

Molecular epidemiological characteristics of Mycobacterium leprae in highly endemic areas of China during the COVID-19 epidemic

Objectives

The present study analyzed the impact of the COVID-19 pandemic on the prevalence and incidence of new leprosy cases, as well as the diversity, distribution, and temporal transmission of Mycobacterium leprae strains at the county level in leprae-endemic provinces in Southwest China.

Methods

A total of 219 new leprosy cases during two periods, 2018-2019 and 2020-2021, were compared. We genetically characterized 83 clinical isolates of M. leprae in Guizhou using variable number tandem repeats (VNTRs) and single nucleotide polymorphisms (SNPs). The obtained genetic profiles and cluster consequences of M. leprae were compared between the two periods.

Results

There was an 18.97% decrease in the number of counties and districts reporting cases. Considering the initial months (January-March) of virus emergence, the number of new cases in 2021 increased by 167% compared to 2020. The number of patients with a delay of >12 months before COVID-19 (63.56%) was significantly higher than that during COVID-19 (48.51%). Eighty-one clinical isolates (97.60%) were positive for all 17 VNTR types, whereas two (2.40%) clinical isolates were positive for 16 VNTR types. The (GTA)9, (TA)18, (TTC)21 and (TA)10 loci showed higher polymorphism than the other loci. The VNTR profile of these clinical isolates generated five clusters, among which the counties where the patients were located were adjacent or relatively close to each other. SNP typing revealed that all clinical isolates possessed the single SNP3K.

Conclusion

COVID-19 may have a negative/imbalanced impact on the prevention and control measures of leprosy, which could be a considerable fact for official health departments. Isolates formed clusters among counties in Guizhou, indicating that the transmission chain remained during the epidemic and was less influenced by COVID-19 preventative policies.

Description of electroneuromiographic and laboratorial findings in leprosy neuropathy, according to its clinical forms: the confirmation of a spectral disease

Introduction

Leprosy is one of the most common infectious cause of peripheral neuropathy in the world and can lead to sequelae and physical disabilities. Electroneuromyography (ENMG) is the gold-standard test for evaluating neural impairment, detecting from subclinical abnormalities to advanced lesions. This study aims to describe the electroneuromyographic findings in patients with leprosy, according to their clinical forms.

Methods

The study is a retrospective observational analysis of the medical records of patients with leprosy, of a National Reference Center of Sanitary Dermatology and Leprosy in Brazil between 2014 and 2022. 513 patients underwent ENMG at leprosy diagnosis and also underwent a clinical, serological and molecular evaluation of the disease.

Results

The electroneuromyographic findings showed 2,671 altered nerves, with an average of 6.9 (±5.1) altered nerves per patient. The most affected sensory nerves were the superficial peroneal (25.0%; 413/1649), sural (15.1%; 397/2627) and ulnar (13.8%; 363/2627), with average of 4.3 (±3.2) affected sensory nerves per patient. The most affected motor nerves were the ulnar (33.1%; 338/1022) and common peroneal (12.1%; 319/2627), with average of 2.6 (±2.5) motor nerves affected per patient. 126 patients presented normal ENMG and, among the 387 with abnormalities in the exam, 13.2% (51/387) had mononeuropathy and 86.8% (336/387) had multiple mononeuropathy. Axonal involvement was more frequent in primary neural leprosy, borderline-tuberculoid, borderline-lepromatous and lepromatous forms.

Discussion

Our findings support that leprosy is a spectral disease, characterized by a balance between host immunity and bacillary load. Therefore, the impairment and electroneuromyographic characteristics are distinct and may vary according to the clinical form.

Pre- and post-surgical evaluation of the impact on Hansen disease sequealae patients' quality of life submitted to orthopedic surgery for closure of chronic plantar ulcers

INTRODUCTION

Leprosy is a chronic infectious disease that still persists as a public health problem in Brazil. Plantar ulcers are serious complications due to leprosy neuropathy and intensify the isolation and stigma of these individuals. The difficulty in closing these lesions associated with the fetid odor negatively impact the quality of life of people with these lesions.

OBJECTIVE

To evaluate the clinical, socioeconomic conditions, degree of satisfaction and quality of life (QoL) of patients after healing of chronic ulcers on feet submitted to orthopedic surgery.

METHODOLOGY

This is a qualitative, exploratory, descriptive and observational study carried out with 92 people after surgical treatment of chronic leprosy plantar ulcers. These patients were submitted to a semi-structured questionnaire raising questions of an epidemiological, socioeconomic and perception of quality-of-life order, comparing before and after the surgical procedure.

RESULTS

Decrease in indicators - alcohol consumption, tobacco consumption, average monthly cost of analgesic medications, fetid wound odor, foot pain and number of dressings performed weekly; Recurrence of lesions in 55.4 % of cases, related to irregular use or lack of shoes and insoles; Improvement in self-perception of Quality of Life (QoL) in 89.1 % of patients after surgery.

CONCLUSION

Orthopedic surgical treatment with resection of plantar bony prominences and skin grafting is an effective therapeutic method for closing chronic plantar ulcers in leprosy, resulting in a decrease in the financial costs employed and in an important improvement in the Quality-of-Life parameters of the individuals undergoing to this procedure. The availability and regular use of shoes and insoles is crucial to prevent recurrence of these injuries.

Antimicrobial Stewardship Program: Time to be Focused in Speciality Settings of Leprosy Institute and Related Health Care Setup

Leprosy, often known as Hansen's disease is a contagious chronic infectious disease caused by Mycobacterium leprae (M. leprae). Our methodology is easily repeatable in tertiary care settings with diagnostic accuracy resources and staff capable of building a stewardship team. Comprehensive antimicrobial policies and programmes are required to properly alleviate the initial issue.

Exploring the Cell Wall and Secretory Proteins of Mycobacterium leprae as Biomarkers

The bacterial cell wall is composed of a wide variety of intricate proteins in addition to lipids, glycolipids, and polymers. Given the diversity of cell wall proteins among bacterial species, they are a feasible target for biomarker identification and characterization in clinical research and diagnosis of the disease. The slow growth rate of Mycobacterium leprae poses a major hurdle in the accurate diagnosis of leprosy before the onset of peripheral neuropathy. The use of biomarker- based diagnostic methods can help in preventing the spread and manifestation of leprosy. Despite many advances in research methods and techniques, there remains a knowledge gap regarding the cell wall proteomes of M. leprae that can be used as biomarkers. The cell wall and secretory proteins of M. leprae are the major focus of this review article. This article enfolds the characteristics and functions of M. leprae cell wall proteins and gives an insight into those cell wall proteins that are yet to be established as biomarkers. Tools and techniques used in cell wall extraction and biomarker identification can also be explored in this article.

Xenophagy as a Strategy for Mycobacterium leprae Elimination during Type 1 or Type 2 Leprosy Reactions: A Systematic Review

BACKGROUND

Mycobacterium leprae is an intracellular bacillus that causes leprosy, a neglected disease that affects macrophages and Schwann cells. Leprosy reactions are acute inflammatory responses to mycobacterial antigens, classified as type1 (T1R), a predominant cellular immune response, or type2 (T2R), a humoral phenomenon, leading to a high number of bacilli in infected cells and nerve structures. Xenophagy is a type of selective autophagy that targets intracellular bacteria for lysosomal degradation; however, its immune mechanisms during leprosy reactions are still unclear. This review summarizes the relationship between the autophagic process and M. leprae elimination during leprosy reactions.

METHODS

Three databases, PubMed/Medline (n = 91), Scopus (n = 73), and ScienceDirect (n = 124), were searched. After applying the eligibility criteria, articles were selected for independent peer reviewers in August 2023.

RESULTS

From a total of 288 studies retrieved, eight were included. In multibacillary (MB) patients who progressed to T1R, xenophagy blockade and increased inflammasome activation were observed, with IL-1β secretion before the reactional episode occurrence. On the other hand, recent data actually observed increased IL-15 levels before the reaction began, as well as IFN-γ production and xenophagy induction.

CONCLUSION

Our search results showed a dichotomy in the T1R development and their relationship with xenophagy. No T2R studies were found.

Whole mitogenome sequencing uncovers a relation between mitochondrial heteroplasmy and leprosy severity

BACKGROUND

In recent years, the mitochondria/immune system interaction has been proposed, so that variants of mitochondrial genome and levels of heteroplasmy might deregulate important metabolic processes in fighting infections, such as leprosy.

METHODS

We sequenced the whole mitochondrial genome to investigate variants and heteroplasmy levels, considering patients with different clinical forms of leprosy and household contacts. After sequencing, a specific pipeline was used for preparation and bioinformatics analysis to select heteroplasmic variants.

RESULTS

We found 116 variants in at least two of the subtypes of the case group (Borderline Tuberculoid, Borderline Lepromatous, Lepromatous), suggesting a possible clinical significance to these variants. Notably, 15 variants were exclusively found in these three clinical forms, of which five variants stand out for being missense (m.3791T > C in MT-ND1, m.5317C > A in MT-ND2, m.8545G > A in MT-ATP8, m.9044T > C in MT-ATP6 and m.15837T > C in MT-CYB). In addition, we found 26 variants shared only by leprosy poles, of which two are characterized as missense (m.4248T > C in MT-ND1 and m.8027G > A in MT-CO2).

CONCLUSION

We found a significant number of variants and heteroplasmy levels in the leprosy patients from our cohort, as well as six genes that may influence leprosy susceptibility, suggesting for the first time that the mitogenome might be involved with the leprosy process, distinction of clinical forms and severity. Thus, future studies are needed to help understand the genetic consequences of these variants.

ncRNAs: an unexplored cellular defense mechanism in leprosy

Leprosy is an infectious disease primarily caused by the obligate intracellular parasite Mycobacterium leprae. Although it has been considered eradicated in many countries, leprosy continues to be a health issue in developing nations. Besides the social stigma associated with it, individuals affected by leprosy may experience nerve damage leading to physical disabilities if the disease is not properly treated or early diagnosed. Leprosy is recognized as a complex disease wherein socioenvironmental factors, immune response, and host genetics interact to contribute to its development. Recently, a new field of study called epigenetics has emerged, revealing that the immune response and other mechanisms related to infectious diseases can be influenced by noncoding RNAs. This review aims to summarize the significant advancements concerning non-coding RNAs in leprosy, discussing the key perspectives on this novel approach to comprehending the pathophysiology of the disease and identifying molecular markers. In our view, investigations on non-coding RNAs in leprosy hold promise and warrant increased attention from researches in this field.

Multiplex PCR-based RFLP assay for early identification of prevalent Mycobacterium leprae genotypes

Mycobacterium leprae is classified into four SNP genotypes and 16 subtypes (from 1A to 4P) that exhibit phylogeographical association reported from around the world. Among them, genotypes 1D and 3I represent more than 60% of M. leprae strains. Here, we report a new method for M. leprae genotyping which identifies the genotypes 1D and 3I by combining multiplex PCR amplification and restriction fragment length polymorphism (RFLP) of a M. leprae DNA amplicons using AgeI restriction enzyme. Agarose gel electrophoresis showed a deletion of 11 bp only among 3I genotypes by electrophoresis. When this multiplex PCR reaction is subjected to AgeI digestion, successful restriction digestion shows three bands for all the genotypes except 1D where only two bands were observed due to loss of restriction site. This method gives us the advantage of 1-step identification of the two most prevalent strains of M. leprae without using specialized equipments such as the Sanger sequencing system or quantitative PCR.

What happens when Schwann cells are exposed to Mycobacterium leprae - A systematic review

Mycobacterium leprae, the pathogen that causes human leprosy, has a unique affinity for infecting and persisting inside Schwann cells, the principal glia of the peripheral nervous system. Several studies have focused on this intricate host-pathogen interaction as an attempt to advance the current knowledge of the mechanisms governing nerve destruction and disease progression. However, during the chronic course of leprosy neuropathy, Schwann cells can respond to and internalize both live and dead M. leprae and bacilli-derived antigens, and this may result in divergent cellular pathobiological responses. This may also distinctly contribute to tissue degeneration, failure to repair, inflammatory reactions, and nerve fibrosis, hallmarks of the disease. Therefore, the present study systematically searched for published studies on M. leprae-Schwann cell interaction in vitro to summarize the findings and provide a focused discussion of Schwann cell dynamics following challenge with leprosy bacilli.

Leprosy with type 1 reaction in a patient from Ontario, Canada without recent travel misdiagnosed as vasculitic neuropathy: a case report

BACKGROUND

Leprosy is rare within non-endemic countries such as Canada, where cases are almost exclusively imported from endemic regions, often presenting after an incubation period of as many as 20 years. Due to its rarity and prolonged incubation period, diagnosis is often delayed, which may result in neurologic impairment prior to the initiation of treatment. In this report we describe a case that is novel in its incubation period, which is the longest reported to-date and may have contributed to diagnostic delay. The case also uniquely demonstrates the challenges of distinguishing leprosy reactions from new rheumatologic manifestations in a patient with established autoimmune disease.

CASE PRESENTATION

We describe an 84-year-old male patient with rheumatoid arthritis on methotrexate and hydroxychloroquine, with no travel history outside Canada for 56 years, who presented in 2019 with new-onset paresthesias and rash. His paresthesias persisted despite a short course of prednisone, and his rash recurred after initial improvement. He underwent skin biopsy in May 2021, which eventually led to the diagnosis of leprosy. He was diagnosed with type 1 reaction and was started on rifampin, dapsone, clofazimine and prednisone, with which his rash resolved but his neurologic impairment remained.

CONCLUSION

This case report serves to highlight the potential for leprosy to present after markedly prolonged incubation periods. This is especially relevant in non-endemic countries that is home to an aging demographic of individuals who migrated decades ago from endemic countries. The importance of this concept is emphasized by the persistent neurologic impairment suffered by our case due to untreated type 1 reaction. We also demonstrate the necessity of skin biopsy in distinguishing this diagnosis from other autoimmune mimics in a patient with known autoimmune disease.

Trend of pediatric leprosy in an endemic area in Northeast of Brazil, 2008-2018

BACKGROUND

The incidence of leprosy in children is an important indicator of the disease's tendency in the general population and suggests intense circulation and transmission of Mycobacterium leprae.

OBJECTIVES

To describe the clinical, epidemiological characteristics and temporal dynamics of leprosy cases in children under 15 years of age from 2008 to 2018 in an endemic municipality.

METHODS

A descriptive study with an analytical approach was carried out with data from leprosy cases registered in the Brazilian Information System on Notifiable Diseases for the municipality of Cabo de Santo Agostinho, Pernambuco, Brazil.

RESULTS

Between 2008 and 2018, 112 new cases of leprosy were registered. Most cases were classified as paucibacillary leprosy and occurred in children living in urban areas. There was no significant difference in the incidence of leprosy during the study period. Only 4.5% of the sample presented reactional episodes, but a high number of cases were not evaluated for the occurrence of reactions.

CONCLUSIONS

The findings of this study show a high incidence of paucibacillary leprosy in children and adolescents, which reveals active transmission in the community and failures in the detection of new multibacillary cases among adults. Children between 10 and 14 years old are more vulnerable to M. leprae infection and mainly develop paucibacillary leprosy.

Effective amelioration of the Lucio phenomenon with adjuvant tofacitinib therapy in a patient with dual infection of Mycobacterium leprae and Mycobacterium lepromatosis: a case report from India

Introduction

The Lucio phenomenon (LP) is a characteristic reaction pattern seen in patients with diffuse lepromatous leprosy (DLL). Dual infection with Mycobacterium leprae and Mycobacterium lepromatosis in DLL has been confirmed from other endemic countries but not previously documented from India. Conventionally, LP is treated with a high dose of systemic glucocorticoid (GC) and anti-leprosy treatment (ALT). Here we report a case of leprosy lymphadenitis at initial presentation in a patient with LP and DLL due to dual infection with M. leprae and M. lepromatosis who responded favourably to tofacitinib as adjuvant to ALT and systemic GC therapy.

Case report

A 20- to 30-year-old man presented with swelling over the bilateral inguinal region, pus-filled skin lesions with multiple ulcers, fever and joint pain. Post-hospitalization investigations showed the presence of anaemia, leukocytosis, and elevated acute and chronic inflammatory markers. Skin and lymph node biopsies were suggestive of LP and leprosy lymphadenitis. The presence of M. leprae and M. lepromatosis was confirmed by PCR followed by DNA sequencing of PCR amplicons from tissue. Despite anti-leprosy treatment, oral GC and thalidomide therapy, the patient continued to develop new lesions. One month after the commencement of adjuvant tofacitinib, the patient showed excellent clinical improvement with healing of all existing lesions and cessation of new LP lesions.

Conclusion

Our case confirms the presence of dual infection with M. leprae and lepromatosis in India. Lymph node involvement as an initial presentation of DLL should be considered in endemic areas. Tofacitinib may be a promising new adjuvant therapy for recalcitrant lepra reactions.

Biosensor-Based Multiple Cross Displacement Amplification for the Rapid Detection of Mycobacterium leprae

Leprosy is an ancient disease caused by Mycobacterium leprae (ML) that remains a public health problem in poverty-stricken areas worldwide. Although many ML detection techniques have been used, a rapid and sensitive tool is essential for the early detection and treatment of leprosy. Herein, we developed a rapid ML detection technique by combining multiple cross displacement amplification (MCDA) with a nanoparticle-based lateral flow biosensor (LFB), termed ML-MCDA-LFB. MCDA induced a rapid isothermal reaction using specific primers targeting the RLEP gene, and the LFB enabled instant visual amplicon detection. The pure genomic DNA of ML and nucleic acids from various pathogens were employed to evaluate and optimize the ML-MCDA-LFB assay. The optimal conditions for ML-MCDA-LFB were 68 °C and 35 min, respectively. The limit of detection for pure ML genomic DNA was 150 fg per vessel, and the specificity of detection was 100% for the experimental strains. Additionally, the entire detection process could be performed within 40 min, including the isothermal amplification (35 min) and result confirmation (1-2 min). Hence, the ML-MCDA-LFB assay was shown to be a rapid, sensitive, and visual method for detecting ML and could be used as a potential tool for early clinical diagnosis and field screening of leprosy.

Ticks are unlikely to play a role in leprosy transmission in the Comoros (East Africa) as they do not harbour M. leprae DNA

Introduction

Leprosy, one of the oldest known human diseases, continues to pose a global challenge for disease control due to an incomplete understanding of its transmission pathways. Ticks have been proposed as a potential contributor in leprosy transmission due to their importance as vectors for other infectious diseases.

Methods

In 2010, a sampling of ticks residing on cattle was conducted on the islands Grande Comore, Anjouan, and Mohéli which constitute the Union of the Comoros where leprosy remains endemic. To investigate the potential role of ticks as a vector in transmission of leprosy disease, molecular analyses were conducted.

Results

Out of the 526 ticks analysed, none were found to harbour Mycobacterium leprae DNA, as determined by a quantitative polymerase chain reaction (qPCR) assay targeting a family of dispersed repeats (RLEP) specific to M. leprae.

Discussion

Therefore, our results suggest that in the Union of the Comoros, ticks are an unlikely vector for M. leprae.

Highly sensitive and rapid determination of Mycobacterium leprae based on real-time multiple cross displacement amplification

BACKGROUND

Mycobacterium leprae (ML) is the pathogen that causes leprosy, which has a long history and still exists today. ML is an intracellular mycobacterium that dominantly induces leprosy by causing permanent damage to the skin, nerves, limbs and eyes as well as deformities and disabilities. Moreover, ML grows slowly and is nonculturable in vitro. Given the prevalence of leprosy, a highly sensitive and rapid method for the early diagnosis of leprosy is urgently needed.

RESULTS

In this study, we devised a novel tool for the diagnosis of leprosy by combining restriction endonuclease, real-time fluorescence analysis and multiple cross displacement amplification (E-RT-MCDA). To establish the system, primers for the target gene RLEP were designed, and the optimal conditions for E-RT-MCDA at 67 °C for 36 min were determined. Genomic DNA from ML, various pathogens and clinical samples was used to evaluate and optimize the E-RT-MCDA assay. The limit of detection (LoD) was 48.6 fg per vessel for pure ML genomic DNA, and the specificity of detection was as high as 100%. In addition, the detection process could be completed in 36 min by using a real-time monitor.

CONCLUSION

The E-RT-MCDA method devised in the current study is a reliable, sensitive and rapid technique for leprosy diagnosis and could be used as a potential tool in clinical settings.

Leprosy - neglected tropical disease in Pygmies inhabiting Central African Republic

Leprosy is a neglected tropical disease that is still present worldwide despite efforts aimed at elimination of the disease. The BaAka Pygmy community inhabiting rural areas in the Central African Republic is one of the most leprosy-vulnerable populations. The aim of the study was to assess the prevalence of leprosy in the BaAka Pygmy population. People living in the Dzanga Sangha protected area were regularly visited by a mobile clinic in 2019/2020. The diagnosis was based on the clinical manifestation of the disease. Deformations of skin and extremities were assessed. In a 12-month period 26 cases of leprosy were diagnosed and 25 patients received treatment. 24 of those patients were BaAka Pygmies, 10 were women, 7 were children under 15 years old and 8 were diagnosed with grade 2 disability. Presented data shows that leprosy in Dzanga Sangha region is not well controlled due to the high transmission rate. Efforts to diagnose and report new leprosy cases should be intensified.

New insights at the interface between leprosy and immune-mediated rheumatic diseases

Leprosy is an infectious and contagious disease of slow evolution, triggered by Mycobacterium leprae. Arthritis is its third most common manifestation, after cutaneous and peripheral nerve involvement. Since musculoskeletal symptoms may be the initial presentation of the disease, it is important for health professionals to recognize its rheumatic manifestations for early diagnosis and appropriate treatment, especially in endemic areas. In addition, cases of leprosy have increased globally, notably in patients undergoing treatment with TNF-α blockers and due to the increase in migration and travel of people from developing countries to developed countries. This review proposes to discuss the main scenarios of mimicry of different rheumatic diseases by leprosy, as well as the role of immunosuppressive drugs used in rheumatology practice in the treatment of reactional states and in the risk of developing the infection.

Specialized active leprosy search strategies in an endemic area of the Brazilian Amazon identifies a hypermutated Mycobacterium leprae strain causing primary drug resistance

Introduction

Leprosy, an infectious disease caused by Mycobacterium leprae, remains a public health concern in endemic countries, particularly in Brazil. In this study, we conducted an active surveillance campaign in the hyperendemic city of Castanhal in the northeastern part of the state of Pará using clinical signs and symptoms combined with serological and molecular tools to diagnose new cases and to identify drug resistance of circulating M. leprae strains and their distribution in the community.

Methods

During an active surveillance of one week, we enrolled 318 individuals using three different strategies to enroll subjects for this study: (i) an active survey of previously treated cases from 2006 to 2016 found in the Brazil National Notifiable Disease Information System database (n = 23) and their healthy household contacts (HHC) (n = 57); (ii) an active survey of school children (SC) from two primary public schools in low-income neighborhoods (n = 178), followed by visits to the houses of these newly diagnosed SC (n = 7) to examine their HHC (n = 34) where we diagnosed additional new cases (n = 6); (iii) and those people who spontaneously presented themselves to our team or the local health center with clinical signs and/or symptoms of leprosy (n = 6) with subsequent follow-up of their HHC when the case was confirmed (n = 20) where we diagnosed two additional cases (n = 2). Individuals received a dermato-neurological examination, 5 ml of peripheral blood was collected to assess the anti-PGL-I titer by ELISA and intradermal earlobe skin scrapings were taken from HHC and cases for amplification of the M. leprae RLEP region by qPCR.

Results

Anti-PGL-I positivity was highest in the new leprosy case group (52%) followed by the treated group (40.9%), HHC (40%) and lowest in SC (24.6%). RLEP qPCR from SSS was performed on 124 individuals, 22 in treated cases, 24 in newly diagnosed leprosy cases, and 78 in HHC. We detected 29.0% (36/124) positivity overall in this sample set. The positivity in treated cases was 31.8% (7/22), while in newly diagnosed leprosy cases the number of positives were higher, 45.8% (11/23) and lower in HHC at 23.7% (18/76). Whole genome sequencing of M. leprae from biopsies of three infected individuals from one extended family revealed a hypermutated M. leprae strain in an unusual case of primary drug resistance while the other two strains were drug sensitive.

Discussion

This study represents the extent of leprosy in an active surveillance campaign during a single week in the city of Castanhal, a city that we have previously surveyed several times during the past ten years. Our results indicate the continuing high transmission of leprosy that includes fairly high rates of new cases detected in children indicating recent spread by multiple foci of infection in the community. An unusual case of a hypermutated M. leprae strain in a case of primary drug resistance was discovered. It also revealed a high hidden prevalence of overt disease and subclinical infection that remains a challenge for correct clinical diagnosis by signs and symptoms that may be aided using adjunct laboratory tests, such as RLEP qPCR and anti-PGL-I serology.

A Review of Software and Mobile Apps to Support the Clinical Diagnosis of Hansen Disease

This scoping review indicates a lack of scientific articles that specifically explore software and mobile applications designed to assist in the clinical diagnosis of leprosy, and our findings have provided insights into the available tools, their usage methods, and the benefits offered by health technologies.

Case Report of Leprosy in Central Florida, USA, 2022

Florida, USA, has witnessed an increased incidence of leprosy cases lacking traditional risk factors. Those trends, in addition to decreasing diagnoses in foreign-born persons, contribute to rising evidence that leprosy has become endemic in the southeastern United States. Travel to Florida should be considered when conducting leprosy contact tracing in any state.

Analysis of socioeconomic condition and bacillary index with respect to the development of Hansen's disease

Background

Leprosy is a chronic granulomatous infection caused by Mycobacterium leprae or Mycobacterium lepromatosis and mainly affects the skin and peripheral nerves. Although treatable, its early intervention can significantly reduce the occurrence of disability. India accounts for more than half of new cases globally. This study was undertaken to better understand the clinical traits of newly diagnosed cases in a tertiary facility of Western Uttar Pradesh, and a few from Madhya Pradesh and Uttarakhand.

Methods

The observational prospective study was carried out on all the newly diagnosed leprosy cases who visited the Outpatient Department of ICMR-National JALMA Institute for Leprosy and Other Mycobacterial Diseases, Agra, during October 2019-December 2022. After obtaining answers to a prestructured questionnaire with their consent, participants were enrolled in the study and underwent clinical examination and a slit-skin smear test.

Results

A total of 56 cases were investigated, and among them, 20 (35.7%) and 36 (64.3%) women and men, respectively, had positive contact with persons affected by leprosy either within family, friends, or neighbors. It is observed that due to the delayed detection of leprosy cases, paucibacillary (PB) patients converted into multibacillary (MB) patients, and the number of MB cases is much higher compared to PB cases.

Conclusion

Leprosy instances continue to spread frequently from sick to healthy people indicating continued transmission of leprosy in society. Multidrug therapy in the management of leprosy cases is effective; however, early diagnosis of PB cases is still a challenge and needs to be addressed on priority.

Hi-plex deep amplicon sequencing for identification, high-resolution genotyping and multidrug resistance prediction of Mycobacterium leprae directly from patient biopsies by using Deeplex Myc-Lep

BACKGROUND

Expansion of antimicrobial resistance monitoring and epidemiological surveillance are key components of the WHO strategy towards zero leprosy. The inability to grow Mycobacterium leprae in vitro precludes routine phenotypic drug susceptibility testing, and only limited molecular tests are available. We evaluated a culture-free targeted deep sequencing assay, for mycobacterial identification, genotyping based on 18 canonical SNPs and 11 core variable-number tandem-repeat (VNTR) markers, and detection of rifampicin, dapsone and fluoroquinolone resistance-associated mutations in rpoB/ctpC/ctpI, folP1, gyrA/gyrB, respectively, and hypermutation-associated mutations in nth.

METHODS

The limit of detection (LOD) was determined using DNA of M. leprae reference strains and from 246 skin biopsies and 74 slit skin smears of leprosy patients, with genome copies quantified by RLEP qPCR. Sequencing results were evaluated versus whole genome sequencing (WGS) data of 14 strains, and versus VNTR-fragment length analysis (FLA) results of 89 clinical specimens.

FINDINGS

The LOD for sequencing success ranged between 80 and 3000 genome copies, depending on the sample type. The LOD for minority variants was 10%. All SNPs detected in targets by WGS were identified except in a clinical sample where WGS revealed two dapsone resistance-conferring mutations instead of one by Deeplex Myc-Lep, due to partial duplication of the sulfamide-binding domain in folP1. SNPs detected uniquely by Deeplex Myc-Lep were missed by WGS due to insufficient coverage. Concordance with VNTR-FLA results was 99.4% (926/932 alleles).

INTERPRETATION

Deeplex Myc-Lep may help improve the diagnosis and surveillance of leprosy. Gene domain duplication is an original putative drug resistance-related genetic adaptation in M. leprae.

FUNDING

EDCTP2 programme supported by the European Union (grant number RIA2017NIM-1847 -PEOPLE). EDCTP, R2Stop: Effect:Hope, The Mission To End Leprosy, the Flemish Fonds Wetenschappelijk Onderzoek.

CD11b+Gr-1low cells that accumulate in M.leprae-induced granulomas of the footpad skin of nude mice have the characteristics of monocytic-myeloid-derived suppressor cells

CD11b⁺Gr-1^low cells that are increased in the lungs of a Mycobacterium (M) tuberculosis-infection mouse model have the characteristics of monocytic (M)-myeloid-derived suppressor cells (MDSCs) and harbor M.tuberculosis. Interestingly, a high number of M-MDSCs have also been observed in skin lesions of patients with lepromatous leprosy. We hypothesized that CD11b⁺Gr-1^low cells might be involved in the pathogenesis of leprosy, as they are in tuberculosis. In the current study, we investigated the issue of whether CD11b⁺Gr-1^low cells accumulate in Mycobacterium (M) leprae-induced granulomas of the footpad skin of nude mice. Our results show that CD11b⁺Gr-1^low cells began to accumulate in the 7-month-old M.leprae-induced granulomas and were replaced by other leukocytes, including CD11b⁺Gr-1^high over time during M.leprae infections. CD11b ⁺ Gr-1^low cells expressed the surface markers of M-MDSC, Ly6C^high and Ly6G^low. In addition, CD11b⁺Gr-1^low cells have the nuclei of a mononuclear cell type and expressed higher levels of arginase 1 (Arg1) and inducible NO synthetase (iNOS). Furthermore, they showed a higher infection rate by M.leprae. Taken together, our results indicate that the inoculation with M.leprae induced an accumulation of CD11b ⁺ Gr-1^low at a relatively early stage, 7-month-old M.leprae-induced granulomas, and that CD11b⁺Gr-1^low have the characteristics of M-MDSC and may act as a reservoir for M.leprae.

Genotyping of Mycobacterium leprae strains in south central coast and central highlands of Vietnam

Background and Objectives

Leprosy remains an important health problem worldwide. It is one of the oldest recorded diseases of humankind. In this study, we expanded the analysis of the geographic distribution of Mycobacterium leprae by investigating SNPs and rpoT genotypes in South Central Coast and Central Highlands clinical isolates, providing insights into the distribution and transmission of leprosy in Vietnam and in this geographic region.

Materials and Methods

27 clinical isolates from the patients, determined the genotypes of M. leprae by SNP and rpoT polymorphism. SNP genotyping was performed by PCR amplification and sequencing, rpoT genotyping by PCR amplification and electrophoresis.

Results

All of 27 DNA samples (100%) were positive with RLEP TaqMan PCR (Ct value range is 18-32 on 3 replicates). SNP type 1 was identified in 15 isolates (56%), while SNP type 3 was detected in 12 samples (44%). SNP type 2 and type 4, were not detected. The 6-base repeat region of the rpoT gene was amplified by PCR and analyzed by 4% MetaPhor™ agarose gel electrophoresis. All isolates yielded amplification products of 91-bp, but not 97-bp.

Conclusion

This study showed that 56% of isolates belonged to type 1, 44% to type 3. In addition, all samples have the 3-copy hexamer genotype in the rpoT gene.

Mycobacterium leprae in Armadillo Tissues from Museum Collections, United States

We examined armadillos from museum collections in the United States using molecular assays to detect leprosy-causing bacilli. We found Mycobacterium leprae bacilli in samples from the United States, Bolivia, and Paraguay; prevalence was 14.8% in nine-banded armadillos. US isolates belonged to subtype 3I-2, suggesting long-term circulation of this genotype.

A perspective into"TEL" - Tenofovir, Emtricitabine, and Lamivudine antileprotic activities by drug repurposing and exploring the possibility of combination chemotherapy with drug rescued molecules for a leprosy free mankind

BACKGROUND

Since leprosy bacilli cannot grow in vitro, testing for antimicrobial resistance against Mycobacterium leprae or assessing the anti-leprosy activity of new drugs remains hard. Furthermore, developing a new leprosy drug through the traditional drug development process is not economically captivating for pharmaceutical companies. As a result, repurposing existing drugs/approved medications or their derivatives to test their anti-leprotic potency is a promising alternative. It is an accelerated method to uncover different medicinal and therapeutic properties in approved drug molecules.

AIM

The study aims to explore the binding potential of anti-viral drugs such as Tenofovir, Emtricitabine, and Lamivudine (TEL) against Mycobacterium leprae using molecular docking.

METHODS

The current study evaluated and confirmed the possibility of repurposing anti-viral drugs such as TEL (Tenofovir, Emtricitabine, and Lamivudine) by transferring the graphical window of the BIOVIA DS2017 with the Crystal Structure of a phosphoglycerate mutase gpm1 from Mycobacterium leprae (PDB ID:4EO9). Utilizing the smart minimizer algorithm, the protein's energy was reduced in order to achieve a stable local minima conformation.

RESULTS

The protein and molecule energy minimization protocol generated stable configuration energy molecules. The protein 4EO9 energy was reduced from 14264.5 kcal/mol to -17588.1 kcal/mol.

CONCLUSION

The CHARMm algorithm-based CDOCKER run docked all three molecules (TEL) inside the 4EO9 protein binding pocket (Mycobacterium leprae). The interaction analysis revealed that tenofovir had a better binding molecule with a score of -37.7297 kcal/mol than the other molecules.

Seventy years of evidence on the efficacy and safety of drugs for treating leprosy: a network meta-analysis

OBJECTIVE

The World Health Organization (WHO) recommends multidrug therapy (MDT) with rifampicin, dapsone, and clofazimine for treating leprosy, which is based on very low-quality evidence. Here, we performed a network meta-analysis (NMA) to produce quantitative evidence to strengthen current WHO recommendations.

METHOD

All studies were obtained from Embase and PubMed from the date of establishment to October 9, 2021. Data were synthesized with frequentist random-effects network meta-analyses. Outcomes were assessed using odds ratios (ORs), 95% confidence intervals (95% CIs), and P score.

RESULTS

Sixty controlled clinical trials and 9256 patients were included. MDT was effective (range of OR: 1.06-1255584.25) for treating leprosy and multibacillary leprosy. Six treatments (Range of OR: 1.199-4.50) were more effective than MDT. Clofazimine (P score=0.9141) and dapsone+rifampicin (P score=0.8785) were effective for treating type 2 leprosy reaction. There were no significant differences in the safety of any of the tested drug regimens.

CONCLUSIONS

The WHO MDT is effective for treating leprosy and multibacillary leprosy, but it may not be effective enough. Pefloxacin and ofloxacin may be good adjunct drugs for increasing MDT efficacy. Clofazimine and dapsone+rifampicin can be used in the treatment of a type 2 leprosy reaction. Single-drug regimens are not efficient enough to treat leprosy, multibacillary leprosy, or a type 2 leprosy reaction.

AVAILABILITY OF DATA AND MATERIALS

All data generated or analyzed during this study are included in this published article [and its supplementary information files].

Leprosy in an Adopted Woman Diagnosed by Molecular Tools: A Case Report from a Non-Endemic Area

Coupled with its rarity in non-endemic areas, the clinical heterogeneity of leprosy makes diagnosis very challenging. We report a diagnosis of multibacillary leprosy in a 22-year-old Indian woman, adopted at the age of 10 and living in Italy. The patient presented with painful skin lesions on the face, trunk, and lower and upper extremities, associated with dysesthesia and a motor deficit in her left leg following corticosteroid therapy interruption. Histopathology results from the skin lesions suggested leprosy, but no acid-fast bacilli were identified. Molecular biology in a center specializing in tropical diseases confirmed the diagnosis, allowing prompt and adequate treatment. Genotype analysis allowed the identification of a genotype 1D of M. leprae, facilitating the epidemiological investigation of the plausible infection origin. No resistances to rifampicin, dapsone, or ofloxacin were detected. Leprosy will continue to exist in high-income nations, and the incidence may rise over time due to increasing migration and globalization. CARE guidelines were followed.

Changes in plasma levels of endocrine hormones in lepromatous leprosy patients

Background

Leprosy affects various endocrine glands and causes disorders in internal organs in addition to the skin and peripheral nerves. These disorders are often silent and remain undiagnosed or underreported. In particular, patterns of hormone changes during leprosy, especially in lepromatous leprosy (LL) patients, are often associated with dysregulation of different endocrine and sex hormones. The aim of this study was to assess changes in four endocrine hormones - namely cortisol, dehydroepiandrosterone (DHEA), growth hormone (GH), and leptin - among LL patients compared with apparently healthy controls.

Method

In total, 80 plasma samples were systematically retrieved from a biorepository at the Armauer Hansen Research Institute (AHRI), based on quality, adequacy of sample volume, and appropriateness of linked clinical and sociodemographic data. Forty of the samples were obtained from LL patients (cases) and the remaining 40 from apparently healthy controls. Enzyme-linked immunosorbant assay (ELISA) was used to quantify levels of DHEA, cortisol, GH, and leptin hormones in the plasma samples. Data were analyzed using non-parametric statistics and the Mann-Whitney U-test (GraphPad Prism version 7.01). A p-value < 0.05 was considered statistically significant.

Results

Plasma levels of cortisol concentration were significantly higher in LL cases (median = 111.4 ng/ml, range = 20.54-525.7) compared with healthy controls (median = 51.98 ng/ml, range = 3.805-328.4) (p = 0.003). Levels of GH and leptin were significantly lower in LL cases compared with healthy controls (median values for GH = 1.01 µIU/ml, range = 0.4625-86.82 and 2 µIU/ml, range = 0.5838-63.36, respectively (p = 0.022); median values for leptin = 891 pg/ml, range = 728.4-21816 and 5147 pg/ml, range = 730.4-52747, respectively (p < 0.0001)). There was an apparent reduction in the plasma levels of DHEA among LL cases compared with healthy controls (p = 0.297), although this difference was not statistically significant.

Conclusion

Alterations in levels of endocrine hormones seen in LL patients reflect clinical and immunological conditions during lepromatous leprosy. However, large-scale studies are warranted to determine how leprosy causes such alterations in hormones and the interplay between endocrine hormones and the immune system during leprosy disease.

Pathogenicity and virulence of Mycobacterium leprae

Leprosy is caused by Mycobacterium leprae (M. leprae) and M. lepromatosis, an obligate intracellular organism, and over 200,000 new cases occur every year. M. leprae parasitizes histiocytes (skin macrophages) and Schwann cells in the peripheral nerves. Although leprosy can be treated by multidrug therapy, some patients relapse or have a prolonged clinical course and/or experience leprosy reaction. These varying outcomes depend on host factors such as immune responses against bacterial components that determine a range of symptoms. To understand these host responses, knowledge of the mechanisms by which M. leprae parasitizes host cells is important. This article describes the characteristics of leprosy through bacteriology, genetics, epidemiology, immunology, animal models, routes of infection, and clinical findings. It also discusses recent diagnostic methods, treatment, and measures according to the World Health Organization (WHO), including prevention. Recently, the antibacterial activities of anti-hyperlipidaemia agents against other pathogens, such as M. tuberculosis and Staphylococcus aureus have been investigated. Our laboratory has been focused on the metabolism of lipids which constitute the cell wall of M. leprae. Our findings may be useful for the development of future treatments.

Global prevalence of resistance to rifampicin in Mycobacterium leprae: A meta-analysis

OBJECTIVES

As the only bactericidal drug in multidrug therapy is rifampicin, monitoring of antimicrobial resistance is important in leprosy patients. Therefore, we conducted a meta-analysis on the resistance of Mycobacterium leprae (M. leprae) to rifampicin and estimated drug resistance in different therapeutic states and regions.

METHODS

Embase, Medline, PubMed, and Web of Science were searched to identify studies between 1 January 1993 and 1 January 2022. Two independent reviewers extracted study data. Pooled cumulative incidences were computed using random-effects meta-analyses.

RESULTS

We included 32 papers describing the resistance of M. leprae to rifampicin (pooled cumulative incidences, 11% [95% confidence interval {CI}, 7% to 15%]). Therapeutic states and regional distribution were obtained for subgroup analyses. A total of 51 of 1135 new cases (pooled incidence, 10% [95% CI, 5% to 16%]) and 81 of 733 relapsed cases (pooled incidence, 20% [95% CI, 13% to 27%]) had rifampicin resistance. A total of 139 participants, including 11 patients with rifampicin resistance (pooled incidence, 42% [95% CI, -21% to 105%]), were nonresponsive and intractable cases. The incidence of rifampicin resistance was highest in the Western Pacific (pooled incidence, 21% [95% CI, 13% to 29%]) and lowest in the Americas (pooled incidence, 4% [95% CI, 1% to 7%]).

CONCLUSIONS

Drug resistance testing and a robust and rigorous surveillance system are recommended to detect the prevalence of drug resistance in leprosy.

In vivo partial reprogramming by bacteria promotes adult liver organ growth without fibrosis and tumorigenesis

Ideal therapies for regenerative medicine or healthy aging require healthy organ growth and rejuvenation, but no organ-level approach is currently available. Using Mycobacterium leprae (ML) with natural partial cellular reprogramming capacity and its animal host nine-banded armadillos, we present an evolutionarily refined model of adult liver growth and regeneration. In infected armadillos, ML reprogram the entire liver and significantly increase total liver/body weight ratio by increasing healthy liver lobules, including hepatocyte proliferation and proportionate expansion of vasculature, and biliary systems. ML-infected livers are microarchitecturally and functionally normal without damage, fibrosis, or tumorigenesis. Bacteria-induced reprogramming reactivates liver progenitor/developmental/fetal genes and upregulates growth-, metabolism-, and anti-aging-associated markers with minimal change in senescence and tumorigenic genes, suggesting bacterial hijacking of homeostatic, regeneration pathways to promote de novo organogenesis. This may facilitate the unraveling of endogenous pathways that effectively and safely re-engage liver organ growth, with broad therapeutic implications including organ regeneration and rejuvenation.

Central nervous system, spinal root ganglion and brachial plexus involvement in leprosy: A prospective study

Background

Leprosy is primarily a disease of peripheral nerves. Some isolated case reports and case series have communicated imaging changes in the central nervous system (CNS) and brachial plexus in patients with leprosy.

Objectives

To study the neuroimaging abnormalities in patients with lepra bacilli-positive neuropathy in the context of CNS, spinal root ganglion, and brachial plexus.

Design

Prospective observational study

Methods

We screened newly-diagnosed patients with multibacillary leprosy presenting with neuropathy. Patients with bacilli-positive sural nerve biopsies were included in the study and subjected to magnetic resonance imaging (MRI) of the brain and spinal cord.

Results

A total of 54 patients with bacteriologically confirmed multibacillary leprosy were screened; Mycobacterium leprae was demonstrated in the sural nerve biopsies of 29 patients. Five patients (5/29; 17.24%) had MRI abnormalities in CNS, spinal root ganglion, and/or brachial plexus. Three patients had MRI changes suggestive of either myelitis or ganglionitis. One patient had T2/FLAIR hyperintensity in the middle cerebellar peduncle while 1 had T2/FLAIR hyperintensity in the brachial plexus.

Conclusion

CNS, spinal root ganglion, and brachial plexus are involved in patients with leprous neuropathy. Immunological reaction against M leprae antigen might be a plausible pathogenetic mechanism for brachial plexus and CNS imaging abnormalities.

Social school contacts of multibacillary leprosy cases in children living in the hyperendemic region of the Midwest of Brazil

OBJECTIVE

To analyze the prevalence of Mycobacterium leprae detection and the associated factors among social contacts in the school environment of multibacillary cases living in a hyperendemic municipality of the state of Mato Grosso.

METHODS

Cross-sectional study with 236 social contacts of multibacillary leprosy from public schools and residents in Cuiabá (Mato Grosso) in 2018. The sources of information were interviews and nasal swab tests for molecular analysis by polymerase chain reaction - PCR. For the prevalence ratio estimates, crude and adjusted analyses were performed using robust Poisson regression and their respective confidence intervals (95% CI). The ArcGIS 9.1 software was used for the geographic distribution analyses.

RESULTS

The prevalence of detection of M. leprae in social contacts was 14%. A total of 63.6% of the schools surveyed had 5.1% to 50% of the social contacts of leprosy with positive PCR. The analysis of the geographic distribution in the neighborhoods showed a high prevalence of infection, being higher than 50% in some localities. The highest proportion of positive results occurred in the northern region of the city and from a precarious socioeconomic class.

CONCLUSION

The results showed a high prevalence of detection of M. leprae among social contacts in areas with poor socioeconomic conditions. In these regions, there is a greater risk of infection and of getting sick.

Construction and Analysis of the Complete Genome Sequence of Leprosy Agent Mycobacterium lepromatosis

Leprosy is caused by Mycobacterium leprae and Mycobacterium lepromatosis. We report construction and analyses of the complete genome sequence of M. lepromatosis FJ924. The genome contained 3,271,694 nucleotides to encode 1,789 functional genes and 1,564 pseudogenes. It shared 1,420 genes and 885 pseudogenes (71.4%) with M. leprae but differed in 1,281 genes and pseudogenes (28.6%). In phylogeny, the leprosy bacilli started from a most recent common ancestor (MRCA) that diverged ~30 million years ago (Mya) from environmental organism Mycobacterium haemophilum. The MRCA then underwent reductive evolution with pseudogenization, gene loss, and chromosomal rearrangements. Analysis of the shared pseudogenes estimated the pseudogenization event ~14 Mya, shortly before species bifurcation. Afterwards, genomic changes occurred to lesser extent in each species. Like M. leprae, four major types of highly repetitive sequences were detected in M. lepromatosis, contributing to chromosomal rearrangements within and after MRCA. Variations in genes and copy numbers were noted, such as three copies of the gene encoding bifunctional diguanylate cyclase/phosphodiesterase in M. lepromatosis, but single copy in M. leprae; 6 genes encoding the TetR family transcriptional regulators in M. lepromatosis, but 11 such genes in M. leprae; presence of hemW gene in M. lepromatosis, but absence in M. leprae; and others. These variations likely aid unique pathogenesis, such as diffuse lepromatous leprosy associated with M. lepromatosis, while the shared genomic features should explain the common pathogenesis of dermatitis and neuritis in leprosy. Together, these findings and the genomic data of M. lepromatosis may facilitate future research and care for leprosy. IMPORTANCE Leprosy is a dreaded infection that still affects millions of people worldwide. Mycobacterium lepromatosis is a recently recognized cause in addition to the well-known Mycobacterium leprae. M. lepromatosis is likely specific for diffuse lepromatous leprosy, a severe form of the infection and endemic in Mexico. This study constructed and annotated the complete genome sequence of M. lepromatosis FJ924 and performed comparative genomic analyses with related mycobacteria. The results afford new and refined insights into the genome size, gene repertoire, pseudogenes, phylogenomic relationship, genome organization and plasticity, process and timing of reductive evolution, and genetic and proteomic basis for pathogenesis. The availability of the complete M. lepromatosis genome may prove to be useful for future research and care for the infection.

Neuropathic ulcers in leprosy: clinical features, diagnosis and treatment

Leprosy is a neglected disease caused by Mycobacterium leprae and Mycobacterium lepromatosis, and is related to significant disabilities resulting from the neural damage generated by this mycobacteria. Neuropathic ulcers-lesions that can appear at the plantar and extra-plantar levels-are one such disability, and diagnosis requires an adequate dermatological, neurological and microbiological evaluation. The treatment of these lesions is based on a multidisciplinary approach that includes debridement of the necrotic tissue, controlling infections, reducing pressure areas, optimising blood flow, and nerve decompression. This review aims to describe the clinical features, diagnostic methods and treatment of neuropathic ulcers in leprosy. The diagnostic methods and medical management used in leprosy ulcers are based on those used for diabetic foot. This requires radical change as these diseases are immunologically and physiologically very different.

Mycobacterium lepromatosis as Cause of Leprosy, Colombia

Leprosy is a granulomatous infection caused by infection with Mycobacterium leprae or M. lepromatosis. We evaluated skin biopsy and slit skin smear samples from 92 leprosy patients in Colombia by quantitative PCR. Five (5.4%) patients tested positive for M. lepromatosis, providing evidence of the presence of this pathogen in Colombia.

A report of six multibacillary cases of leprosy in Dominican Republic

The causative agents of leprosy are Mycobacterium leprae and Mycobacterium lepromatosis. M. lepromatosis was found in 2008 to cause diffuse lepromatous leprosy in Mexican patients. The objective of this work was to identify M. leprae and M. lepromatosis in paraffin-embedded skin samples from Caribbean leprosy patients. A total of 6 skin samples were obtained from the Dominican Republic. All cases presented the multibacillary form; 5 cases were nodular lepromatous leprosy, and 1 case was borderline lepromatous leprosy. All patients received multidrug therapy. Molecular identification was achieved using the M. leprae-specific repetitive element (RLEP) for M. leprae and the hemN gene for M. lepromatosis. Mycobacterium leprae was identified in two lepromatous leprosy cases and 1 borderline lepromatous leprosy case; M. lepromatosis was found in 1 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.

Mycobacterium leprae induces Schwann cell proliferation and migration in a denervated milieu following intracutaneous excision axotomy in nine-banded armadillos

Nine-banded armadillos develop peripheral neuropathy after experimental Mycobacterium leprae infection that recapitulates human disease. We used an intracutaneous excision axotomy model to assess the effect of infection duration by M. leprae on axonal sprouting and Schwan cell density. 34 armadillos (17 naïve and 17 M. leprae-infected) underwent 3 mm skin biopsies to create an intracutaneous excision axotomy followed by a concentric 4-mm overlapping biopsy 3 and 12-months post M. leprae inoculation. A traditional distal leg biopsy was obtained at 15mo for intraepidermal nerve fiber (IENF) density. Serial skin sections were immunostained against a axons (PGP9.5, GAP43), and Schwann cells (p75, s100) to visualize regenerating nerves. Regenerative axons and proliferation of Schwann cells was measured and the rate of growth at each time point was assessed. Increasing anti-PGL antibody titers and intraneural M. leprae confirmed infection. 15mo following infection, there was evidence of axon loss with reduced distal leg IENF versus naïve armadillos, p < 0.05. This was associated with an increase in Schwann cell density (11,062 ± 2905 vs. 7561 ± 2715 cells/mm³, p < 0.01). Following excisional biopsy epidermal reinnervation increased monotonically at 30, 60 and 90 days; the regeneration rate was highest at 30 days, and decreased at 60 and 90 days. The reinnervation rate was highest among animals infected for 3mo vs those infected for 12mo or naïve animals (mean ± SD, 27.8 ± 7.2 vs.16.2 ± 5.8vs. 15.3 ± 6.5 mm/mm³, p < 0.05). The infected armadillos displayed a sustained Schwann cell proliferation across axotomy time points and duration of infection (3mo:182 ± 26, 12mo: 256 ± 126, naive: 139 ± 49 cells/day, p < 0.05). M. leprae infection is associated with sustained Schwann cell proliferation and distal limb nerve fiber loss. Rates of epidermal reinnervation were highest 3mo after infection and normalized by 12 mo of infection. We postulate that excess Schwann cell proliferation is the main pathogenic process and is deleterious to sensory axons. There is a compensatory initial increase in regeneration rates that may be an attempt to compensate for the injury, but it is not sustained and eventually followed by axon loss. Aberrant Schwann cell proliferation may be a novel therapeutic target to interrupt the pathogenic cascade of M. leprae.