Comparison of gene expression patterns among<i>Leishmania braziliensis</i>clinical isolates showing a different<i>in vitro</i>susceptibility to pentavalent antimony

Adaui, Vanessa; Schnorbusch, Kathy; Zimic, Mirko; Gutiérrez, Andres H.; Decuypere, Saskia; Vanaerschot, Manu; Doncker, Simonne De; Maes, Ilse; Llanos-Cuentas, Alejandro; Chappuis, François; Arévalo, Jorge; Dujardin, Jean‐Claude

doi:10.1017/s0031182010001095

Cited by 37 publications

(31 citation statements)

References 33 publications

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“…Overall, our results indicate that molecular resistance in Leishmania is multifactorial. These findings are generally in accordance with several multigene studies focused on other areas where leishmaniasis is endemic (45,46). …”

Section: Discussionsupporting

confidence: 92%

“…Additionally, neither amplification nor overexpression of TRYR, HSP83, SKCRP, and MDR1 was observed, although these genes have displayed differential gene numbers or mRNA levels between sensitive and resistant parasites in other studies (19,45,46,49,50). These negative results could be due to the geographical particularities of mechanisms of resistance in western Mediterranean countries.…”

Section: Discussionmentioning

confidence: 79%

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Heterogeneity of Molecular Resistance Patterns in Antimony-Resistant Field Isolates of Leishmania Species from the Western Mediterranean Area

Jeddi

Mary

Karim

et al. 2014

Antimicrob Agents Chemother

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h Antimonials remain the first-line treatment for the various manifestations of leishmaniasis in most areas where the disease is endemic, and increasing cases of therapeutic failure associated with parasite resistance have been reported. In this study, we assessed the molecular status of 47 clinical isolates of Leishmania causing visceral and cutaneous leishmaniasis from Algeria, Tunisia, and southern France. In total, we examined 14 genes that have been shown to exhibit significant variations in DNA amplification, mRNA levels, or protein expression with respect to resistance to antimonials. The gene status of each clinical isolate was assessed via qPCR and qRT-PCR. We then compared the molecular pattern against the phenotype determined via an in vitro sensitivity test of the clinical isolates against meglumine antimoniate, which is considered the reference technique. Our results demonstrate significant DNA amplification and/or RNA overexpression in 56% of the clinical isolates with the resistant phenotype. All clinical isolates that exhibited significant overexpression of at least 2 genes displayed a resistant phenotype. Among the 14 genes investigated, 10 genes displayed either significant amplification or overexpression in at least 1 clinical isolate; these genes are involved in several metabolic pathways. Moreover, various gene associations were observed depending on the clinical isolates, supporting the multifactorial nature of Leishmania resistance. Molecular resistance features were found in the 3 Leishmania species investigated (Leishmania infantum, Leishmania major, and Leishmania killicki). To our knowledge, this is the first report of the involvement of molecular resistance genes in field isolates of Leishmania major and Leishmania killicki with the resistance phenotype.

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Section: Discussionsupporting

confidence: 92%

Section: Discussionmentioning

confidence: 79%

Heterogeneity of Molecular Resistance Patterns in Antimony-Resistant Field Isolates of Leishmania Species from the Western Mediterranean Area

Jeddi

Mary

Karim

et al. 2014

Antimicrob Agents Chemother

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“…On the other hand, the emergence of multiple origins of drug resistance in this population together with different genomic signatures encountered among antimonial-resistant parasites is compatible with a pleomorphic response of L. donovani. This is supported by previous studies targeting specific genes and pointing out different patterns of overexpression in antimonial-resistant parasites (Adaui et al 2011).…”

Section: Discussionsupporting

confidence: 80%

Whole genome sequencing of multiple Leishmania donovani clinical isolates provides insights into population structure and mechanisms of drug resistance

Downing¹,

Imamura²,

Decuypere³

et al. 2011

Genome Res.

390

516

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Visceral leishmaniasis is a potentially fatal disease endemic to large parts of Asia and Africa, primarily caused by the protozoan parasite Leishmania donovani. Here, we report a high-quality reference genome sequence for a strain of L. donovani from Nepal, and use this sequence to study variation in a set of 16 related clinical lines, isolated from visceral leishmaniasis patients from the same region, which also differ in their response to in vitro drug susceptibility. We show that wholegenome sequence data reveals genetic structure within these lines not shown by multilocus typing, and suggests that drug resistance has emerged multiple times in this closely related set of lines. Sequence comparisons with other Leishmania species and analysis of single-nucleotide diversity within our sample showed evidence of selection acting in a range of surface-and transport-related genes, including genes associated with drug resistance. Against a background of relative genetic homogeneity, we found extensive variation in chromosome copy number between our lines. Other forms of structural variation were significantly associated with drug resistance, notably including gene dosage and the copy number of an experimentally verified circular episome present in all lines and described here for the first time. This study provides a basis for more powerful molecular profiling of visceral leishmaniasis, providing additional power to track the drug resistance and epidemiology of an important human pathogen.[Supplemental material is available for this article.]Leishmaniases are a complex of diseases that range from self-curing lesions to gross disfigurations and potentially deadly visceral disease. The diseases are caused by protozoan parasites that are transmitted by sandflies in 88 countries and infect an estimated 12 million people (www.who.int/leishmaniasis/en/). Parasites of the Leishmania genus are remarkably biologically, clinically, and epidemiologically diverse and present enormous differences in disease tropism. The mildest form is cutaneous leishmaniasis, which is caused by Leishmania major and other species, and is largely limited to lesions around the area of a sandfly bite-though a diffuse form can also occur. Disfiguring mucocutaneous leishmaniasis is due to the destruction of nasopharyngeal tissue by parasites such as L. braziliensis. More significantly, visceral leishmaniasis is caused by parasites of the L. donovani species complex that can spread to internal organs and cause death.In 2005, sequencing the genome of L. major identified 8311 protein-coding genes and provided a framework for future comparative genomic studies (Ivens et al. 2005). The genome elucidated the full structural architecture of Leishmania chromosomes, which includes an unusual pattern of genes distributed in large directional clusters. Subsequently, the genomes of L. braziliensis and L. infantum were described-the latter is a member of the L. donovani complex (Peacock et al. 2007). A detailed comparison of these first three Leishmania genomes re...

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“…Data from in vitroselected antimony-resistant parasites revealed that one or more simultaneously present mechanisms including loss in metal reduction, overexpression of thiol biosynthetic enzymes [γ-glutamylcysteine synthetase (γ-GCS), ornithine decaboxylase (ODC) and trypanothione reductase (TR)] and multidrug resistance-associated protein A (MRPA), and the decreased Sb(III) uptake due to lower level of expression of the gene aquaporin-1 (AQP1) ) may be responsible for the phenotype. Targeted gene expression profiling in Leishmania guyanensis parasites isolated from SAG nonresponsive patients revealed that γ-GCS overexpression is linked with therapeutic failure while ODC and TR were preferentially expressed in nonresponsive Leishmania brazileinsis (Torres et al 2010;Adaui et al 2011). These markers have been studied in very few Indian L. donovani clinical isolates making it difficult to establish correlation with therapeutic response of patients (Mukherjee et al 2007;Mittal et al 2007).…”

Section: Introductionmentioning

confidence: 99%

Biomarkers of antimony resistance: need for expression analysis of multiple genes to distinguish resistance phenotype in clinical isolates of Leishmania donovani

et al. 2012

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Resistance to antimony is a major cause of failure to therapy in a large proportion of visceral leishmaniasis cases. Methods to distinguish resistant and sensitive parasite are urgently needed as the standard in vitro intracellular drug susceptibility assays are cumbersome and time consuming. Differential expression profiling studies have led to the identification of several antimony resistance-associated genes; however, their efficacy as a potential biomarker for monitoring antimony resistance remains imprecise. We analysed the expression of eight genes [antimony metabolism-associated genes - multidrug resistance protein A (MRPA), γ-glutamylcysteine synthetase (γ-GCS) and aquaporin-1 (AQP1) - and genes identified by proteome/transcriptome profiling—heat shock protein 83, mitogen-activated protein kinase 1 and histones H1, H2A and H4) in antimony-resistant (n=10) and antimony-sensitive (n=4) clinical isolates of Leishmania donovani by quantitative real-time PCR, in comparison with a lab-generated resistant and a standard sensitive isolate. We observed a significant differential expression of MRPA, histone H1 (p<0.01), γ-GCS, HSP83 (p<0.005) and histone H2A and H4 (p<0.0001) in a group of sodium antimony gluconate-resistant isolates compared to sensitive isolates. Preferential AQP1 expression was observed in all the sensitive isolates (p<0.0001). Overall, expression profile in field isolates for all the genes studied showed altered expression in majority of isolates, while in some, the expression was static. All the isolates showed a mosaic of expression pattern of the genes analysed indicating constellation of genes contributes towards the drug susceptibility of parasite. As none of the genes exhibit an absolute correlation with phenotype, targeted expression analysis of a set of genes should be considered as biomarker for distinguishing the antimony-resistant and antimony-sensitive parasite.

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Comparison of gene expression patterns amongLeishmania braziliensisclinical isolates showing a differentin vitrosusceptibility to pentavalent antimony

Cited by 37 publications

References 33 publications

Heterogeneity of Molecular Resistance Patterns in Antimony-Resistant Field Isolates of Leishmania Species from the Western Mediterranean Area

Heterogeneity of Molecular Resistance Patterns in Antimony-Resistant Field Isolates of Leishmania Species from the Western Mediterranean Area

Whole genome sequencing of multiple Leishmania donovani clinical isolates provides insights into population structure and mechanisms of drug resistance

Biomarkers of antimony resistance: need for expression analysis of multiple genes to distinguish resistance phenotype in clinical isolates of Leishmania donovani

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