Publications by authors named "Charlotte Avanzi"

21 Publications

  • Page 1 of 1

Molecular epidemiology of leprosy: An update.

Infect Genet Evol 2020 12 4;86:104581. Epub 2020 Oct 4.

Laboratory of Molecular Biology Applied to Mycobacteria - Oswaldo Cruz Institute, Fiocruz, Rio de Janeiro, Brazil. Electronic address:

Molecular epidemiology investigations are notoriously challenging in the leprosy field mainly because the inherent characteristics of the disease as well as its yet uncultivated causative agents, Mycobacterium leprae and M. lepromatosis. Despite significant developments in understanding the biology of leprosy bacilli through genomic approaches, the exact mechanisms of transmission is still unclear and the factors underlying pathological variation of the disease in different patients remain as major gaps in our knowledge about leprosy. Despite these difficulties, the last two decades have seen the development of genotyping procedures based on PCR-sequencing of target loci as well as by the genome-wide analysis of an increasing number of geographically diverse isolates of leprosy bacilli. This has provided a foundation for molecular epidemiology studies that are bringing a better understanding of strain evolution associated with ancient human migrations, and phylogeographical insights about the spread of disease globally. This review discusses the advantages and drawbacks of the main tools available for molecular epidemiological investigations of leprosy and summarizes various methods ranging from PCR-based genotyping to genome-typing techniques. We also describe their main applications in analyzing the short-range and long-range transmission of the disease. Finally, we summarise the current gaps and challenges that remain in the field of molecular epidemiology of leprosy.
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http://dx.doi.org/10.1016/j.meegid.2020.104581DOI Listing
December 2020

2000-year-old pathogen genomes reconstructed from metagenomic analysis of Egyptian mummified individuals.

BMC Biol 2020 08 28;18(1):108. Epub 2020 Aug 28.

Institute of Evolutionary Medicine, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.

Background: Recent advances in sequencing have facilitated large-scale analyses of the metagenomic composition of different samples, including the environmental microbiome of air, water, and soil, as well as the microbiome of living humans and other animals. Analyses of the microbiome of ancient human samples may provide insights into human health and disease, as well as pathogen evolution, but the field is still in its very early stages and considered highly challenging.

Results: The metagenomic and pathogen content of Egyptian mummified individuals from different time periods was investigated via genetic analysis of the microbial composition of various tissues. The analysis of the dental calculus' microbiome identified Red Complex bacteria, which are correlated with periodontal diseases. From bone and soft tissue, genomes of two ancient pathogens, a 2200-year-old Mycobacterium leprae strain and a 2000-year-old human hepatitis B virus, were successfully reconstructed.

Conclusions: The results show the reliability of metagenomic studies on Egyptian mummified individuals and the potential to use them as a source for the extraction of ancient pathogen DNA.
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http://dx.doi.org/10.1186/s12915-020-00839-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7456089PMC
August 2020

Genomic Characterization of to Explore Transmission Patterns Identifies New Subtype in Bangladesh.

Front Microbiol 2020 16;11:1220. Epub 2020 Jun 16.

Department of Infectious Diseases, Leiden University Medical Center, Leiden, Netherlands.

, the causative agent of leprosy, is an unculturable bacterium with a considerably reduced genome (3.27 Mb) compared to homologues mycobacteria from the same ancestry. In 2001, the genome of was first described and subsequently four genotypes (1-4) and 16 subtypes (A-P) were identified providing means to study global transmission patterns for leprosy. In order to understand the role of asymptomatic carriers we investigated carriage as well as infection in leprosy patients ( = 60) and healthy household contacts (HHC; = 250) from Bangladesh using molecular detection of the bacterial element RLEP in nasal swabs (NS) and slit skin smears (SSS). In parallel, to study genotype distribution in Bangladesh we explored strain diversity by whole genome sequencing (WGS) and Sanger sequencing. In the studied cohort in Bangladesh, DNA was detected in 33.3% of NS and 22.2% of SSS of patients with bacillary index of 0 whilst in HHC 18.0% of NS and 12.3% of SSS were positive. The majority of the strains detected in this study belonged to genotype 1D (55%), followed by 1A (31%). Importantly, WGS allowed the identification of a new genotype, designated 1B-Bangladesh (14%), which clustered separately between the 1A and 1B strains. Moreover, we established that the genotype previously designated 1C, is not an independent subtype but clusters within the 1D genotype. Intraindividual differences were present between the strains obtained including mutations in hypermutated genes, suggesting mixed colonization/infection or in-host evolution. In summary, we observed that is present in asymptomatic contacts of leprosy patients fueling the concept that these individuals contribute to the current intensity of transmission. Our data therefore emphasize the importance of sensitive and specific tools allowing post-exposure prophylaxis targeted at -infected or -colonized individuals.
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http://dx.doi.org/10.3389/fmicb.2020.01220DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7308449PMC
June 2020

Cell Surface Remodeling of under Cystic Fibrosis Airway Growth Conditions.

ACS Infect Dis 2020 08 2;6(8):2143-2154. Epub 2020 Jul 2.

Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado 80523-1682, United States.

Understanding the physiological processes underlying the ability of to become a chronic pathogen of the cystic fibrosis (CF) lung is important to the development of prophylactic and therapeutic strategies to better control and treat pulmonary infections caused by these bacteria. Gene expression profiling of a diversity of complex isolates points to amino acids being significant sources of carbon and energy for in both CF sputum and synthetic CF medium and to the bacterium undergoing an important metabolic reprogramming in order to adapt to this particular nutritional environment. Cell envelope analyses conducted on the same representative isolates further revealed unexpected structural alterations in major cell surface glycolipids known as the glycopeptidolipids (GPLs). Besides showing an increase in triglycosylated forms of these lipids, CF sputum- and synthetic CF medium-grown isolates presented as yet unknown forms of GPLs representing as much as 10% to 20% of the total GPL content of the cells, in which the classical amino alcohol located at the carboxy terminal of the peptide, alaninol, is replaced with the branched-chain amino alcohol leucinol. Importantly, both these lipid changes were exacerbated by the presence of mucin in the culture medium. Collectively, our results reveal potential new drug targets against in the CF airway and point to mucin as an important host signal modulating the cell surface composition of this pathogen.
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http://dx.doi.org/10.1021/acsinfecdis.0c00214DOI Listing
August 2020

Population Genomics of Reveals a New Genotype in Madagascar and the Comoros.

Front Microbiol 2020 11;11:711. Epub 2020 May 11.

Global Health Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.

Human settlement of Madagascar traces back to the beginning of the first millennium with the arrival of Austronesians from Southeast Asia, followed by migrations from Africa and the Middle East. Remains of these different cultural, genetic, and linguistic legacies are still present in Madagascar and other islands of the Indian Ocean. The close relationship between human migration and the introduction and spread of infectious diseases, a well-documented phenomenon, is particularly evident for the causative agent of leprosy, . In this study, we used whole-genome sequencing (WGS) and molecular dating to characterize the genetic background and retrace the origin of the strains circulating in Madagascar ( = 30) and the Comoros ( = 3), two islands where leprosy is still considered a public health problem and monitored as part of a drug resistance surveillance program. Most strains (97%) from Madagascar and Comoros belonged to a new genotype as part of branch 1, closely related to single nucleotide polymorphism (SNP) type 1D, named 1D-Malagasy. Other strains belonged to the genotype 1A (3%). We sequenced 39 strains from nine other countries, which, together with previously published genomes, amounted to 242 genomes that were used for molecular dating. Specific SNP markers for the new 1D-Malagasy genotype were used to screen samples from 11 countries and revealed this genotype to be restricted to Madagascar, with the sole exception being a strain from Malawi. The overall analysis thus ruled out a possible introduction of leprosy by the Austronesian settlers and suggests a later origin from East Africa, the Middle East, or South Asia.
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http://dx.doi.org/10.3389/fmicb.2020.00711DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7233131PMC
May 2020

Emergence of Mycobacterium leprae Rifampin Resistance Evaluated by Whole-Genome Sequencing after 48 Years of Irregular Treatment.

Antimicrob Agents Chemother 2020 06 23;64(7). Epub 2020 Jun 23.

Leprosy Laboratory, Oswaldo Cruz Institute, Fiocruz, Rio de Janeiro, Brazil

A case of rifampin resistance after irregular antileprosy treatments since 1971 is reported. Whole-genome sequencing from four longitudinal samples indicated relapse due to acquired rifampin resistance and not to reinfection with another strain. A putative compensatory mutation in was also detected. Clinical improvement was achieved using an alternative therapy.
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http://dx.doi.org/10.1128/AAC.00330-20DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7318023PMC
June 2020

The immunology of other mycobacteria: M. ulcerans, M. leprae.

Semin Immunopathol 2020 06 25;42(3):333-353. Epub 2020 Feb 25.

Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland.

Mycobacterial pathogens can be categorized into three broad groups: Mycobacterium tuberculosis complex causing tuberculosis, M. leprae and M. lepromatosis causing leprosy, and atypical mycobacteria, or non-tuberculous mycobacteria (NTM), responsible for a wide range of diseases. Among the NTMs, M. ulcerans is responsible for the neglected tropical skin disease Buruli ulcer (BU). Most pathogenic mycobacteria, including M. leprae, evade effector mechanisms of the humoral immune system by hiding and replicating inside host cells and are furthermore excellent modulators of host immune responses. In contrast, M. ulcerans replicates predominantly extracellularly, sheltered from host immune responses through the cytotoxic and immunosuppressive effects of mycolactone, a macrolide produced by the bacteria. In the year 2018, 208,613 new cases of leprosy and 2713 new cases of BU were reported to WHO, figures which are notoriously skewed by vast underreporting of these diseases.
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http://dx.doi.org/10.1007/s00281-020-00790-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7224112PMC
June 2020

Leprosy in red squirrels in the UK.

Vet Rec 2019 03;184(13):416

University of Melbourne, Parkville VIC 3010, Melbourne, Australia.

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http://dx.doi.org/10.1136/vr.l1385DOI Listing
March 2019

British Red Squirrels Remain the Only Known Wild Rodent Host for Leprosy Bacilli.

Front Vet Sci 2019 1;6. Epub 2019 Feb 1.

Global Health Institute, Federal Institute of Technology in Lausanne, Lausanne, Switzerland.

Eurasian red squirrels in the British Isles are the most recently discovered animal reservoir for the leprosy bacteria and . Initial data suggest that prevalence of leprosy infection is variable and often low in different squirrel populations. Nothing is known about the presence of leprosy bacilli in other wild squirrel species despite two others (Siberian chipmunk [], and Thirteen-lined ground squirrel []) having been reported to be susceptible to experimental infection with . Rats, a food-source in some countries where human leprosy occurs, have been suggested as potential reservoirs for leprosy bacilli, but no evidence supporting this hypothesis is currently available. We screened 301 squirrel samples covering four species [96 Eurasian red squirrels, 67 Eastern gray squirrels (), 35 Siberian chipmunks, and 103 Pallas's squirrels ()] from Europe and 72 Mexican white-throated woodrats () for the presence of and using validated PCR protocols. No DNA from leprosy bacilli was detected in any of the samples tested. Given our sample-size, the pathogen should have been detected if the prevalence and/or bacillary load in the populations investigated were similar to those found for British red squirrels.
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http://dx.doi.org/10.3389/fvets.2019.00008DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6367869PMC
February 2019

Highly Reduced Genome of the New Species , the Causative Agent of Nodular Thelitis and Tuberculoid Scrotitis in Livestock and a Close Relative of the Leprosy Bacilli.

mSphere 2018 10 3;3(5). Epub 2018 Oct 3.

Institut des Agent infectieux, Hôpital de la Croix Rousse, Hospices Civils de Lyon, Lyon, France

Nodular thelitis is a chronic enzootic infection affecting dairy cows and goats. The causative agent was recently shown to be related to the leprosy-causing bacilli and In this study, the genome of this pathogen was sequenced and analyzed. Phylogenomic analyses confirmed that the pathogen present in nodular thelitis and tuberculoid scrotitis is a distinct species related to the leprosy bacilli and Because the pathogen was originally isolated from a bovine udder, it was named "" The genome of "" is only 3.12 Mb in length, which represents the smallest mycobacterial genome identified so far but which is close to that of leprosy bacilli in size. The genome contains 1,759 protein-coding genes and 1,081 pseudogenes, indicative of extensive reductive evolution and likely the reason that cannot be grown axenically. The pseudogenization and genome reduction in seem to have been to some extent independent from the results determined for the genomes of the leprosy bacilli. is an emerging skin pathogen in dairy animals. Its genome underwent massive reduction and gene decay, leading to a minimal set of genes required for an obligatory intracellular lifestyle, which highly resembles the evolution of the leprosy agents and The genomic similarity between and the leprosy bacilli can help in identifying key virulence factors of these closely related species or in identifying genes responsible for the distinct differences between thelitis or scrotitis and leprosy with respect to clinical manifestations. Specific DNA markers can now be developed for quick detection of this pathogen.
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http://dx.doi.org/10.1128/mSphere.00405-18DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6170788PMC
October 2018

Evaluation of Auramine O staining and conventional PCR for leprosy diagnosis: A comparative cross-sectional study from Ethiopia.

PLoS Negl Trop Dis 2018 09 4;12(9):e0006706. Epub 2018 Sep 4.

Armauer Hansen Research Institute, Addis Ababa, Ethiopia.

Background: Diagnosis of leprosy mainly relies on clinical examination due to the inconsistent sensitivity and poor reproducibility of the current laboratory tests. Utilisation of alternative methods to the standard Ziehl Neelsen (ZN), Fite-Faraco (FF) and Haematoxylin and Eosin (H&E) staining procedures may eventually improve leprosy diagnosis.

Methodology/principal Findings: In this comparative study, the performance of the fluorescent Auramine O (AO) staining and polymerase chain reaction (PCR) was assessed with different skin samples using a combination of ZN, FF and H&E staining as the gold standard. AO, ZN, FF, H&E and PCR tests were performed on slit skin smears (SSS) and/or punch biopsies collected from 141 clinically confirmed leprosy cases and 28 non-leprosy skin samples. DNA was extracted from punch biopsies using two different methods with or without mechanical lysis. Sensitivities were 87.6%, 59.3% and 77% for H&E, ZN and FF, respectively, whereas it reached 65.5% and 77.9% for AO in SSS and tissue sections and 91.1% for PCR in tissue samples. Morover, samples with low bacillary index, sensitivity of AO staining (61.8%) was similar to FF (60%, p>0.05) and lower than PCR (86.6%, p<0.05). Sensitivity of PCR also increased (96.8%, p<0.05) when mechanical lysis was used during DNA extraction compared to enzymatic treatment alone (84.6%).

Conclusions/significance: Our results showed that for diagnostic purposes, analysis of skin section is more sensitive than SSS, especially for samples with low bacillary load. AO staining on SSS and tissue sections was not significantly better than other routine diagnostic tests but considerably more user friendly. The sensitivity of PCR was higher than current standard methods and increased when combined with more efficient DNA extraction using mechanical and chemical lysis. Therefore, we recommend AO staining for the diagnosis of leprosy in lower health facilities such as health centres and district hospitals and PCR diagnosis at referral level and research centres.
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http://dx.doi.org/10.1371/journal.pntd.0006706DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6138420PMC
September 2018

Evidence of zoonotic leprosy in Pará, Brazilian Amazon, and risks associated with human contact or consumption of armadillos.

PLoS Negl Trop Dis 2018 06 28;12(6):e0006532. Epub 2018 Jun 28.

Department of Microbiology, Immunology, and Pathology, Mycobacteria Research Laboratories, Colorado State University, Fort Collins, Colorado, United States of America.

Mycobacterium leprae (M. leprae) is a human pathogen and the causative agent for leprosy, a chronic disease characterized by lesions of the skin and peripheral nerve damage. Zoonotic transmission of M. leprae to humans by nine-banded armadillos (Dasypus novemcinctus) has been shown to occur in the southern United States, mainly in Texas, Louisiana, and Florida. Nine-banded armadillos are also common in South America, and residents living in some areas in Brazil hunt and kill armadillos as a dietary source of protein. This study examines the extent of M. leprae infection in wild armadillos and whether these New World mammals may be a natural reservoir for leprosy transmission in Brazil, similar to the situation in the southern states of the U.S. The presence of the M. leprae-specific repetitive sequence RLEP was detected by PCR amplification in purified DNA extracted from armadillo spleen and liver tissue samples. A positive RLEP signal was confirmed in 62% of the armadillos (10/16), indicating high rates of infection with M. leprae. Immunohistochemistry of sections of infected armadillo spleens revealed mycobacterial DNA and cell wall constituents in situ detected by SYBR Gold and auramine/rhodamine staining techniques, respectively. The M. leprae-specific antigen, phenolic glycolipid I (PGL-I) was detected in spleen sections using a rabbit polyclonal antibody specific for PGL-I. Anti-PGL-I titers were assessed by ELISA in sera from 146 inhabitants of Belterra, a hyperendemic city located in western Pará state in Brazil. A positive anti-PGL-I titer is a known biomarker for M. leprae infection in both humans and armadillos. Individuals who consumed armadillo meat most frequently (more than once per month) showed a significantly higher anti-PGL-I titer than those who did not eat or ate less frequently than once per month. Armadillos infected with M. leprae represent a potential environmental reservoir. Consequently, people who hunt, kill, or process or eat armadillo meat are at a higher risk for infection with M. leprae from these animals.
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http://dx.doi.org/10.1371/journal.pntd.0006532DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6023134PMC
June 2018

Ancient genomes reveal a high diversity of Mycobacterium leprae in medieval Europe.

PLoS Pathog 2018 05 10;14(5):e1006997. Epub 2018 May 10.

Institute for Archaeological Sciences, University of Tübingen, Tübingen, Germany.

Studying ancient DNA allows us to retrace the evolutionary history of human pathogens, such as Mycobacterium leprae, the main causative agent of leprosy. Leprosy is one of the oldest recorded and most stigmatizing diseases in human history. The disease was prevalent in Europe until the 16th century and is still endemic in many countries with over 200,000 new cases reported annually. Previous worldwide studies on modern and European medieval M. leprae genomes revealed that they cluster into several distinct branches of which two were present in medieval Northwestern Europe. In this study, we analyzed 10 new medieval M. leprae genomes including the so far oldest M. leprae genome from one of the earliest known cases of leprosy in the United Kingdom-a skeleton from the Great Chesterford cemetery with a calibrated age of 415-545 C.E. This dataset provides a genetic time transect of M. leprae diversity in Europe over the past 1500 years. We find M. leprae strains from four distinct branches to be present in the Early Medieval Period, and strains from three different branches were detected within a single cemetery from the High Medieval Period. Altogether these findings suggest a higher genetic diversity of M. leprae strains in medieval Europe at various time points than previously assumed. The resulting more complex picture of the past phylogeography of leprosy in Europe impacts current phylogeographical models of M. leprae dissemination. It suggests alternative models for the past spread of leprosy such as a wide spread prevalence of strains from different branches in Eurasia already in Antiquity or maybe even an origin in Western Eurasia. Furthermore, these results highlight how studying ancient M. leprae strains improves understanding the history of leprosy worldwide.
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http://dx.doi.org/10.1371/journal.ppat.1006997DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5944922PMC
May 2018

Phylogenomics and antimicrobial resistance of the leprosy bacillus Mycobacterium leprae.

Nat Commun 2018 01 24;9(1):352. Epub 2018 Jan 24.

Global Health Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, 1015, Switzerland.

Leprosy is a chronic human disease caused by the yet-uncultured pathogen Mycobacterium leprae. Although readily curable with multidrug therapy (MDT), over 200,000 new cases are still reported annually. Here, we obtain M. leprae genome sequences from DNA extracted directly from patients' skin biopsies using a customized protocol. Comparative and phylogenetic analysis of 154 genomes from 25 countries provides insight into evolution and antimicrobial resistance, uncovering lineages and phylogeographic trends, with the most ancestral strains linked to the Far East. In addition to known MDT-resistance mutations, we detect other mutations associated with antibiotic resistance, and retrace a potential stepwise emergence of extensive drug resistance in the pre-MDT era. Some of the previously undescribed mutations occur in genes that are apparently subject to positive selection, and two of these (ribD, fadD9) are restricted to drug-resistant strains. Finally, nonsense mutations in the nth excision repair gene are associated with greater sequence diversity and drug resistance.
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http://dx.doi.org/10.1038/s41467-017-02576-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5783932PMC
January 2018

Insights from the Genome Sequence of : Massive Gene Decay and Reductive Evolution.

mBio 2017 10 17;8(5). Epub 2017 Oct 17.

Global Health Institute, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland

is the causative agent of murine leprosy, a chronic, granulomatous disease similar to human leprosy. Due to the similar clinical manifestations of human and murine leprosy and the difficulty of growing both bacilli axenically, and were once thought to be closely related, although it was later suggested that might be related to In this study, the complete genome of was sequenced using a combination of PacBio and Illumina sequencing. Phylogenomic analyses confirmed that is a distinct species within the complex (MAC). The genome is 4.05 Mb in length, which is considerably smaller than other MAC genomes, and it comprises 2,682 functional genes and 1,139 pseudogenes, which indicates that has undergone genome reduction. An error-prone repair homologue of the DNA polymerase III α-subunit was found to be nonfunctional in , which might contribute to pseudogene formation due to the accumulation of mutations in nonessential genes. has retained the functionality of several genes thought to influence virulence among members of the MAC. seems to be evolving toward a minimal set of genes required for an obligatory intracellular lifestyle within its host, a niche seldom adopted by most mycobacteria, as they are free-living. could be used as a model to elucidate functions of genes shared with other members of the MAC. Its reduced gene set can be exploited for studying the essentiality of genes in related pathogenic species, which might lead to discovery of common virulence factors or clarify host-pathogen interactions. can be cultivated only under specific conditions and even then with difficulty. Elucidating the metabolic (in)capabilities of will help develop suitable axenic media and facilitate genetic studies.
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http://dx.doi.org/10.1128/mBio.01283-17DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5646247PMC
October 2017

Whole genome sequencing distinguishes between relapse and reinfection in recurrent leprosy cases.

PLoS Negl Trop Dis 2017 Jun 15;11(6):e0005598. Epub 2017 Jun 15.

Tropical Medicine Centre, University of Brasília, Brasília DF, Brazil.

Background: Since leprosy is both treated and controlled by multidrug therapy (MDT) it is important to monitor recurrent cases for drug resistance and to distinguish between relapse and reinfection as a means of assessing therapeutic efficacy. All three objectives can be reached with single nucleotide resolution using next generation sequencing and bioinformatics analysis of Mycobacterium leprae DNA present in human skin.

Methodology: DNA was isolated by means of optimized extraction and enrichment methods from samples from three recurrent cases in leprosy patients participating in an open-label, randomized, controlled clinical trial of uniform MDT in Brazil (U-MDT/CT-BR). Genome-wide sequencing of M. leprae was performed and the resultant sequence assemblies analyzed in silico.

Principal Findings: In all three cases, no mutations responsible for resistance to rifampicin, dapsone and ofloxacin were found, thus eliminating drug resistance as a possible cause of disease recurrence. However, sequence differences were detected between the strains from the first and second disease episodes in all three patients. In one case, clear evidence was obtained for reinfection with an unrelated strain whereas in the other two cases, relapse appeared more probable.

Conclusions/significance: This is the first report of using M. leprae whole genome sequencing to reveal that treated and cured leprosy patients who remain in endemic areas can be reinfected by another strain. Next generation sequencing can be applied reliably to M. leprae DNA extracted from biopsies to discriminate between cases of relapse and reinfection, thereby providing a powerful tool for evaluating different outcomes of therapeutic regimens and for following disease transmission.
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http://dx.doi.org/10.1371/journal.pntd.0005598DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5498066PMC
June 2017

Red squirrels in the British Isles are infected with leprosy bacilli.

Science 2016 11;354(6313):744-747

Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush Campus, Roslin, Scotland, UK.

Leprosy, caused by infection with Mycobacterium leprae or the recently discovered Mycobacterium lepromatosis, was once endemic in humans in the British Isles. Red squirrels in Great Britain (Sciurus vulgaris) have increasingly been observed with leprosy-like lesions on the head and limbs. Using genomics, histopathology, and serology, we found M. lepromatosis in squirrels from England, Ireland, and Scotland, and M. leprae in squirrels from Brownsea Island, England. Infection was detected in overtly diseased and seemingly healthy animals. Phylogenetic comparisons of British and Irish M. lepromatosis with two Mexican strains from humans show that they diverged from a common ancestor around 27,000 years ago, whereas the M. leprae strain is closest to one that circulated in Medieval England. Red squirrels are thus a reservoir for leprosy in the British Isles.
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http://dx.doi.org/10.1126/science.aah3783DOI Listing
November 2016

Transmission of Drug-Resistant Leprosy in Guinea-Conakry Detected Using Molecular Epidemiological Approaches.

Clin Infect Dis 2016 Dec 23;63(11):1482-1484. Epub 2016 Aug 23.

Centre InterFacultaire de Formation et de Recherche en Environnement pour le Développement Durable University of Abomey-Calavi, Cotonou, Benin.

Molecular drug susceptibility testing was performed on skin biopsies from 24 leprosy patients from Guinea-Conakry for the first time. We identified primary drug resistance in 4 cases and a dapsone-resistant cluster caused by the same strain. Primary transmission of drug-resistant Mycobacterium leprae, including a rifampicin-resistant strain, is reported.
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http://dx.doi.org/10.1093/cid/ciw572DOI Listing
December 2016

Insight into the evolution and origin of leprosy bacilli from the genome sequence of Mycobacterium lepromatosis.

Proc Natl Acad Sci U S A 2015 Apr 23;112(14):4459-64. Epub 2015 Mar 23.

Global Health Institute, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland;

Mycobacterium lepromatosis is an uncultured human pathogen associated with diffuse lepromatous leprosy and a reactional state known as Lucio's phenomenon. By using deep sequencing with and without DNA enrichment, we obtained the near-complete genome sequence of M. lepromatosis present in a skin biopsy from a Mexican patient, and compared it with that of Mycobacterium leprae, which has undergone extensive reductive evolution. The genomes display extensive synteny and are similar in size (∼3.27 Mb). Protein-coding genes share 93% nucleotide sequence identity, whereas pseudogenes are only 82% identical. The events that led to pseudogenization of 50% of the genome likely occurred before divergence from their most recent common ancestor (MRCA), and both M. lepromatosis and M. leprae have since accumulated new pseudogenes or acquired specific deletions. Functional comparisons suggest that M. lepromatosis has lost several enzymes required for amino acid synthesis whereas M. leprae has a defective heme pathway. M. lepromatosis has retained all functions required to infect the Schwann cells of the peripheral nervous system and therefore may also be neuropathogenic. A phylogeographic survey of 227 leprosy biopsies by differential PCR revealed that 221 contained M. leprae whereas only six, all from Mexico, harbored M. lepromatosis. Phylogenetic comparisons indicate that M. lepromatosis is closer than M. leprae to the MRCA, and a Bayesian dating analysis suggests that they diverged from their MRCA approximately 13.9 Mya. Thus, despite their ancient separation, the two leprosy bacilli are remarkably conserved and still cause similar pathologic conditions.
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http://dx.doi.org/10.1073/pnas.1421504112DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4394283PMC
April 2015

Mycobacterium lepromatosis Infections in Nuevo León, Mexico.

J Clin Microbiol 2015 Jun 25;53(6):1945-6. Epub 2015 Mar 25.

Global Health Institute, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.

The frequency of infection caused by the recently described pathogen Mycobacterium lepromatosis is unknown. Here, we describe the demographics, clinical characteristics, and therapeutic outcomes of five lepromatous leprosy patients suffering from M. lepromatosis infection in Nuevo Léon, Mexico. Diagnosis was facilitated by a new highly specific PCR procedure.
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http://dx.doi.org/10.1128/JCM.03667-14DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4432033PMC
June 2015

Herbal tea extracts inhibit Cytochrome P450 3A4 in vitro.

J Pharm Pharmacol 2014 Oct 13;66(10):1478-90. Epub 2014 May 13.

Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong.

Objectives: Ciclosporin and sirolimus, two immunosuppressive agents with narrow therapeutic windows, are mainly metabolized by Cytochrome 3A4 (CYP3A4). A clinical case of toxic blood levels of these drugs after the consumption of a '24-flavours' tea was reported. This study aims to identify the causative ingredients of the 24-flavour herbal tea in the inhibition of CYP3A4 metabolism.

Methods: Two commercially available 24-flavour tea products purchased in Hong Kong and the six plant constituents were tested for their CYP3A4 inhibitory effects utilizing an in-vitro fluorometric assay.

Key Findings: Of the commercially available teas available in Hong Kong, the most potent inhibitory effect was observed with the tea consumed in the initial clinical case. Of the six universal constituents, chrysanthemum exhibited the greatest inhibitory effect, with an IC50 of 95.7 μg/ml. Dandelion, liquorice and bishop's weed have IC50 of 140.6, 148.4 and 185.5 μg/ml, respectively. Field mint and Japanese honeysuckle have weaker inhibitory effect on CYP3A4 with IC50 of 1153.3 and 1466.3 μg/ml.

Conclusions: This study confirms the possible implication of herbal tea constituents in the inhibition of ciclosporin and sirolimus' CYP3A4 metabolism. Combined usage of herbal teas with drug should be closely monitored.
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http://dx.doi.org/10.1111/jphp.12270DOI Listing
October 2014