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Journal of Bacteriology Dec 2015Mycobacterium leprae induces the formation of lipid droplets, which are recruited to pathogen-containing phagosomes in infected macrophages and Schwann cells....
UNLABELLED
Mycobacterium leprae induces the formation of lipid droplets, which are recruited to pathogen-containing phagosomes in infected macrophages and Schwann cells. Cholesterol is among the lipids with increased abundance in M. leprae-infected cells, and intracellular survival relies on cholesterol accumulation. The present study investigated the capacity of M. leprae to acquire and metabolize cholesterol. In silico analyses showed that oxidation of cholesterol to cholest-4-en-3-one (cholestenone), the first step of cholesterol degradation catalyzed by the enzyme 3β-hydroxysteroid dehydrogenase (3β-HSD), is apparently the only portion of the cholesterol catabolic pathway seen in Mycobacterium tuberculosis preserved by M. leprae. Incubation of bacteria with radiolabeled cholesterol confirmed the in silico predictions. Radiorespirometry and lipid analyses performed after incubating M. leprae with [4-(14)C]cholesterol or [26-(14)C]cholesterol showed the inability of this pathogen to metabolize the sterol rings or the side chain of cholesterol as a source of energy and carbon. However, the bacteria avidly incorporated cholesterol and, as expected, converted it to cholestenone both in vitro and in vivo. Our data indicate that M. leprae has lost the capacity to degrade and utilize cholesterol as a nutritional source but retains the enzyme responsible for its oxidation to cholestenone. Thus, the essential role of cholesterol metabolism in the intracellular survival of M. leprae is uncoupled from central carbon metabolism and energy production. Further elucidation of cholesterol metabolism in the host cell during M. leprae infection will establish the mechanism by which this lipid supports M. leprae intracellular survival and will open new avenues for novel leprosy therapies.
IMPORTANCE
Our study focused on the obligate intracellular pathogen Mycobacterium leprae and its capacity to metabolize cholesterol. The data make an important contribution for those interested in understanding the mechanisms of mycobacterial pathogenesis, since they indicate that the essential role of cholesterol for M. leprae intracellular survival does not rely on its utilization as a nutritional source. Our findings reinforce the complexity of cholesterol's role in sustaining M. leprae infection. Further elucidation of cholesterol metabolism in the host cell during M. leprae infection will establish the mechanism by which this lipid supports M. leprae intracellular survival and will open new avenues for novel leprosy therapies.
Topics: Carbon; Cholesterol; Energy Metabolism; Humans; Leprosy; Microbial Viability; Mycobacterium leprae
PubMed: 26391209
DOI: 10.1128/JB.00625-15 -
Microbial Drug Resistance (Larchmont,... Dec 2021Leprosy is a chronic infectious disease caused by and the treatment of choice is ofloxacin (OFX). Specific amino acid substitutions in DNA gyrase of have been...
Leprosy is a chronic infectious disease caused by and the treatment of choice is ofloxacin (OFX). Specific amino acid substitutions in DNA gyrase of have been reported leading to resistance against the drug. In our previous study, WQ-3810, a fluoroquinolone with a new R1 group (6-amino-3,5-difluoropyridin-2-yl) was shown to have a strong inhibitory activity on OFX-resistant DNA gyrases of , and the structural characteristics of its R1 group was predicted to enhance the inhibitory activity. To further understand the contribution of the R1 group, WQ-3334 with the same R1 group as WQ-3810, WQ-4064, and WQ-4065, but with slightly modified R1 group, were assessed on their activities against recombinant DNA gyrase of . An study was conducted to understand the molecular interactions between DNA gyrase and WQ compounds. WQ-3334 and WQ-3810 were shown to have greater inhibitory activity against DNA gyrase than others. Furthermore, analysis using quinolone-resistant DNA gyrases showed that WQ-3334 had greater inhibitory activity than WQ-3810. The R8 group was shown to be a factor for the linkage of the R1 groups with GyrB by an study. The inhibitory effect of WQ compounds that have a new R1 group against DNA gyrase can be enhanced by improving the binding affinity with different R8 group molecules. The information obtained by this work could be applied to design new fluoroquinolones effective for quinolone-resistant and other bacterial pathogens.
Topics: Anti-Bacterial Agents; Azetidines; DNA Gyrase; Drug Resistance, Multiple, Bacterial; Fluoroquinolones; Genes, Bacterial; Microbial Sensitivity Tests; Mycobacterium leprae; Quinolones
PubMed: 34077282
DOI: 10.1089/mdr.2020.0408 -
International Journal of Molecular... May 2023Peripheral nerves and Schwann cells (SCs) are privileged and protected sites for initial colonization, survival, and spread of leprosy bacillus. strains that survive...
Peripheral nerves and Schwann cells (SCs) are privileged and protected sites for initial colonization, survival, and spread of leprosy bacillus. strains that survive multidrug therapy show a metabolic inactivation that subsequently induces the recurrence of typical clinical manifestations of leprosy. Furthermore, the role of the cell wall phenolic glycolipid I (PGL-I) in the internalization in SCs and the pathogenicity of have been extensively known. This study assessed the infectivity in SCs of recurrent and non-recurrent and their possible correlation with the genes involved in the PGL-I biosynthesis. The initial infectivity of non-recurrent strains in SCs was greater (27%) than a recurrent strain (6.5%). In addition, as the trials progressed, the infectivity of the recurrent and non-recurrent strains increased 2.5- and 2.0-fold, respectively; however, the maximum infectivity was displayed by non-recurrent strains at 12 days post-infection. On the other hand, qRT-PCR experiments showed that the transcription of key genes involved in PGL-I biosynthesis in non-recurrent strains was higher and faster (Day 3) than observed in the recurrent strain (Day 7). Thus, the results indicate that the capacity of PGL-I production is diminished in the recurrent strain, possibly affecting the infective capacity of these strains previously subjected to multidrug therapy. The present work opens the need to address more extensive and in-depth studies of the analysis of markers in the clinical isolates that indicate a possible future recurrence.
Topics: Humans; Mycobacterium leprae; Drug Therapy, Combination; Leprostatic Agents; Leprosy; Glycolipids; Antibodies; Schwann Cells; Antigens, Bacterial
PubMed: 37240073
DOI: 10.3390/ijms24108727 -
Emerging Infectious Diseases Dec 2015Nine-banded armadillos (Dasypus novemcinctus) are naturally infected with Mycobacterium leprae and have been implicated in zoonotic transmission of leprosy. Early...
Nine-banded armadillos (Dasypus novemcinctus) are naturally infected with Mycobacterium leprae and have been implicated in zoonotic transmission of leprosy. Early studies found this disease mainly in Texas and Louisiana, but armadillos in the southeastern United States appeared to be free of infection. We screened 645 armadillos from 8 locations in the southeastern United States not known to harbor enzootic leprosy for M. leprae DNA and antibodies. We found M. leprae-infected armadillos at each location, and 106 (16.4%) animals had serologic/PCR evidence of infection. Using single-nucleotide polymorphism variable number tandem repeat genotyping/genome sequencing, we detected M. leprae genotype 3I-2-v1 among 35 armadillos. Seven armadillos harbored a newly identified genotype (3I-2-v15). In comparison, 52 human patients from the same region were infected with 31 M. leprae types. However, 42.3% (22/52) of patients were infected with 1 of the 2 M. leprae genotype strains associated with armadillos. The geographic range and complexity of zoonotic leprosy is expanding.
Topics: Animals; Armadillos; Disease Reservoirs; Humans; Leprosy; Louisiana; Mycobacterium leprae; Texas; Zoonoses
PubMed: 26583204
DOI: 10.3201/eid2112.150501 -
Infection and Immunity Jul 1995Mycobacterium leprae, the causative agent of leprosy, is an obligate intracellular pathogen. M. leprae can infect a variety of cells in vivo, including epithelial cells,... (Comparative Study)
Comparative Study
Mycobacterium leprae, the causative agent of leprosy, is an obligate intracellular pathogen. M. leprae can infect a variety of cells in vivo, including epithelial cells, muscle cells, and Schwann cells, in addition to macrophages. The ligand-receptor interactions important in the attachment and ingestion of M. leprae by these nonmacrophage cells remains unknown. Fibronectin (FN) significantly enhances both attachment and ingestion of M. leprae by epithelial and Schwann cell lines. We cloned an M. leprae FN binding protein (FN attachment protein [FAP]) distinct from the 85ABC complex which has been shown previously to bind FN. The FAP open reading frame predicts a protein of 29.5 kDa with a 39-amino-acid signal peptide and was previously described as an antigen in leprosy patients. M. leprae FAP has homologies in M. vaccae, M. avium, and M. tuberculosis, as determined by Southern blotting and direct peptide analysis. Both anti-FAP antibodies and an Escherichia coli-expressed recombinant protein significantly blocked M. leprae attachment and internalization by T-24, an epithelial cell line, and JS1, a Schwann cell line. These data suggest that FN can be a bridging opsonic ligand for attachment of mycobacteria to nonphagocytes and that FAP plays an important role in this process. This may be an important step in the initiation of M. leprae infection in vivo.
Topics: Adhesins, Bacterial; Amino Acid Sequence; Antigens, Bacterial; Bacterial Adhesion; Bacterial Proteins; Base Sequence; Cloning, Molecular; Epithelium; Fibronectins; Gene Expression; Genes, Bacterial; Molecular Sequence Data; Mycobacterium leprae; Oligonucleotide Probes; RNA, Messenger; Schwann Cells; Sequence Alignment; Sequence Homology, Amino Acid
PubMed: 7790081
DOI: 10.1128/iai.63.7.2652-2657.1995 -
Scientific Reports May 2021Leprosy, a progressive, mutilating and highly stigmatized disease caused by Mycobacterium leprae (ML), continues to prevail in the developing world. This is due to the... (Observational Study)
Observational Study
Leprosy, a progressive, mutilating and highly stigmatized disease caused by Mycobacterium leprae (ML), continues to prevail in the developing world. This is due to the absence of rapid, specific and sensitive diagnostic tools for its early detection since the disease gets notified only with the advent of physical scarring in patients. This study reports the development of a Loop-mediated isothermal amplification (LAMP) technique for fast, sensitive and specific amplification of 16S rRNA gene of ML DNA for early detection of leprosy in resource-limited areas. Various parameters were optimized to obtain robust and reliable amplification of ML DNA. Blind clinical validation studies were performed which showed that this technique had complete concurrence with conventional techniques. Total absence of amplification of negative control DNA confirmed the specificity of this test. Various visual detection methods viz. colorimetric, turbidity differentiation and bridge flocculation were standardized to establish easy-to-read and rapid diagnosis. This technique eliminates the lack of accuracy and sensitivity in skin smear tests in patients and the requirement for expensive lab equipments and trained technicians. The technique holds promise for further expansion and has the potential to cater to the unmet needs of society for a cheap, highly-sensitive and robust rapid diagnosis of ML.
Topics: DNA, Bacterial; Feasibility Studies; Female; Humans; Leprosy; Male; Molecular Diagnostic Techniques; Mycobacterium leprae; Nucleic Acid Amplification Techniques; RNA, Ribosomal, 16S; Sensitivity and Specificity; Validation Studies as Topic
PubMed: 33972644
DOI: 10.1038/s41598-021-89304-2 -
Clinical Microbiology and Infection :... Nov 2011Leprosy is an important health problem in Brazil despite extensive use of multidrug therapy. The nasal mucosa is the preferential site of entry and exit of Mycobacterium...
Leprosy is an important health problem in Brazil despite extensive use of multidrug therapy. The nasal mucosa is the preferential site of entry and exit of Mycobacterium leprae, and although lesions have been found in the oral mucosa, its potential involvement in the transmission of leprosy bacilli has never been investigated. We investigated the presence of the M. leprae DNA in buccal swabs of leprosy patients (334) and household contacts (1288) through polymerase chain reaction (PCR), and correlated this with clinical and laboratorial evaluations. The overall positivity for patients and contacts was 18.26% and 6.83%, respectively. Subclinical infection among contacts was considered when PCR and anti-PGL-1 ELISA presented positive results. This study provides evidence that the oral mucosa may be a secondary site of M. leprae transmission and infection, and contacts with bacillary DNA may be actively involved in transmission. We have also shown that bacilli DNA is more frequently found in the oral mucosa of PB patients. Our findings have great epidemiological relevance and indicate an additional strategy for leprosy control programmes and dental clinics.
Topics: Adult; Antibodies, Bacterial; Brazil; Cross-Sectional Studies; DNA, Bacterial; Enzyme-Linked Immunosorbent Assay; Female; Humans; Leprosy; Male; Middle Aged; Mouth Mucosa; Mycobacterium leprae; Polymerase Chain Reaction
PubMed: 21199152
DOI: 10.1111/j.1469-0691.2010.03453.x -
Brazilian Journal of Medical and... Feb 2012Leprosy is an infectious disease caused by Mycobacterium leprae. The polymerase chain reaction (PCR) has been applied to detect M. leprae in different clinical samples...
Leprosy is an infectious disease caused by Mycobacterium leprae. The polymerase chain reaction (PCR) has been applied to detect M. leprae in different clinical samples and urine seems to be attractive for this purpose. PCR was used to improve the sensitivity for diagnosing leprosy by amplifying a 151-bp PCR fragment of the M. leprae pra gene (PCR-Pra) in urine samples. Seventy-three leprosy patients (39 males and 34 females, 14 to 78 years old) were selected for leprosy diagnosis at a reference laboratory in Maringá, PR, Brazil. Of these, 36 were under anti-leprosy multidrug therapy with dapsone and rifampicin for tuberculoid (TT) and dapsone, rifampicin and clofazimine for borderline (BB) and lepromatous (LL) forms. The control group contained 50 healthy individuals without any clinical history of leprosy. DNA isolated from leprosy patients' urine samples was successfully amplified by PCR-Pra in 46.6% (34/73) of the cases. The positivity of PCR-Pra for patients with the TT form was 75% for both patients under treatment and non-treated patients (P = 0.1306). In patients with the LL form, PCR-Pra positivity was 52 and 30% for patients under treatment and non-treated patients, respectively (P = 0.2386). PCR-Pra showed a statistically significant difference in detecting M. leprae between the TT and LL forms of leprosy in patients under treatment (P = 0.0033). Although the current study showed that the proposed PCR-Pra has some limitations in the detection of M. leprae, this method has the potential to be a useful tool for leprosy diagnosis mainly in TT leprosy where the AFB slit-skin smear is always negative.
Topics: Adolescent; Adult; Aged; Biomarkers; Case-Control Studies; DNA, Bacterial; Female; Humans; Leprosy, Borderline; Leprosy, Lepromatous; Male; Middle Aged; Mycobacterium leprae; Polymerase Chain Reaction; Sensitivity and Specificity; Young Adult
PubMed: 22286535
DOI: 10.1590/s0100-879x2012007500011 -
Journal of Bacteriology Jun 2000The RecA proteins from Mycobacterium tuberculosis and Mycobacterium leprae contain inteins. In contrast to the M. tuberculosis RecA, the M. leprae RecA is not spliced in...
The RecA proteins from Mycobacterium tuberculosis and Mycobacterium leprae contain inteins. In contrast to the M. tuberculosis RecA, the M. leprae RecA is not spliced in Escherichia coli. We demonstrate here that M. leprae RecA is functionally spliced in Mycobacterium smegmatis and produces resistance toward DNA-damaging agents and homologous recombination.
Topics: Mycobacterium leprae; Mycobacterium smegmatis; Protein Splicing; Rec A Recombinases; Recombination, Genetic
PubMed: 10852894
DOI: 10.1128/JB.182.12.3590-3592.2000 -
International Journal of... 2023The lepromatous leprosy (LL) disease is caused by Mycobacterium leprae and Mycobacterium lepromatosis which is characterized by inadequate response to treatment, a...
BACKGROUND
The lepromatous leprosy (LL) disease is caused by Mycobacterium leprae and Mycobacterium lepromatosis which is characterized by inadequate response to treatment, a propensity to drug resistance, and patient disability. We aimed to evaluate current immunomodulatory medicines and their target proteins collectively as a drug repurposing strategy to decipher novel uses for LL.
METHODS
A dataset of human genes associated with LL-immune response was retrieved from public health genomic databases including the Human Genome Epidemiology Navigator and DisGeNET. Retrieved genes were filtered and enriched to set a robust network (≥10, up to 21 edges) and analyzed in the Cytoscape program (v3.9). Drug associations were obtained in the NDEx Integrated Query (v1.3.1) coupled with drug databases such as ChEMBL, BioGRID, and DrugBank. These networks were analyzed in Cytoscape with the CyNDEx-2 plugin and STRING protein network database.
RESULTS
Pathways analyses resulted in 100 candidate drugs organized into pharmacological groups with similar targets and filtered on 54 different drugs. Gene-target network analysis showed that the main druggable targets associated with LL were tumoral necrosis factor-alpha, interleukin-1B, and interferon-gamma. Consistently, glucosamine, binimetinib, talmapimod, dilmapimod, andrographolide, and VX-702 might have a possible beneficial effect coupled with LL treatment.
CONCLUSION
Based on our drug repurposing analysis, immunomodulatory drugs might have a promising potential to be explored further as therapeutic options or to alleviate symptoms in LL patients.
Topics: Humans; Leprosy, Lepromatous; Drug Repositioning; Mycobacterium leprae; Interferon-gamma
PubMed: 38149532
DOI: 10.4103/ijmy.ijmy_105_23