Development and evaluation of different PCR-based typing methods for discrimination of<i>Leishmania donovani</i>isolates from Nepal

Bhattarai, Narayan; Dujardin, Jean Claude; Rijal, Suman; Doncker, Simonne De; Boelaert, Marleen; Auwera, Geert Van Der

doi:10.1017/s0031182009991752

Cited by 26 publications

(26 citation statements)

References 31 publications

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“…1C; Supplemental Fig. S4) both revealed significant genetic differences in our population not detected by microsatellite profiling (Alam et al 2009;Bhattarai et al 2010). These distinct relationships resolved by genomic SNP data were closely mirrored by phylogenetic signals inferred from large CNVs (Supplemental Fig.…”

Section: Genomic Patterns Of Snp Diversity Within L Donovani Linesmentioning

confidence: 55%

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.

384

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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Section: Genomic Patterns Of Snp Diversity Within L Donovani Linesmentioning

confidence: 55%

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.

384

516

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“…20 Nevertheless, some degree of genetic variability has been observed using multilocus microsatellite typing and other genetic markers among isolates from the Indian subcontinent. [21][22][23] The molecular data from this preliminary study is not sufficient to identify the origin of the parasites. One of the microscopically confirmed bone marrow smears was negative for all the molecular tests used, but this is not surprising as this post-treatment specimen had a very low parasite load.…”

Section: Discussionmentioning

confidence: 86%

Endemic Transmission of Visceral Leishmaniasis in Bhutan

Yangzom

Cruz²,

Bern³

et al. 2012

The American Society of Tropical Medicine and Hygiene

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Abstract. Visceral leishmaniasis was first reported in Bhutan in 2006. We conducted studies of the parasite, possible vectors and reservoirs, and leishmanin skin test and risk factor surveys in three villages. Nineteen cases were reported from seven districts. Parasite typing yielded two novel microsatellite sequences, both related to Indian L. donovani. In one case village, 40 (18.5%) of 216 participants had positive leishmanin skin test results, compared with 3 (4.2%) of 72 in the other case village and 0 of 108 in the control village. Positive results were strongly associated with the village and increasing age. None of the tested dogs were infected. Eighteen sand flies were collected, 13 Phlebotomus species and 5 Sergentomyia species; polymerase chain reaction for leishmanial DNA was negative. This assessment suggests that endemic visceral leishmaniasis transmission has occurred in diverse locations in Bhutan. Surveillance, case investigations, and further parasite, vector, and reservoir studies are needed. The potential protective impact of bed nets should be evaluated.

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“…The obtained fragment patterns form the basis of so-called schizodeme identification (132,134,151). In our experience, such patterns are extremely difficult to reproduce, even within the same lab (152), and they have more use in strain tracking or studying intraspecies variability (e.g., see references 62, 153, and 154). Volpini et al (155) (vi) LAMP.…”

Section: Kdnamentioning

confidence: 99%

Species Typing in Dermal Leishmaniasis

2015

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SUMMARY Leishmania is an infectious protozoan parasite related to African and American trypanosomes. All Leishmania species that are pathogenic to humans can cause dermal disease. When one is confronted with cutaneous leishmaniasis, identification of the causative species is relevant in both clinical and epidemiological studies, case management, and control. This review gives an overview of the currently existing and most used assays for species discrimination, with a critical appraisal of the limitations of each technique. The consensus taxonomy for the genus is outlined, including debatable species designations. Finally, a numerical literature analysis is presented that describes which methods are most used in various countries and regions in the world, and for which purposes.

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Development and evaluation of different PCR-based typing methods for discrimination ofLeishmania donovaniisolates from Nepal

Cited by 26 publications

References 31 publications

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

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

Endemic Transmission of Visceral Leishmaniasis in Bhutan

Species Typing in Dermal Leishmaniasis

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