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De Silva NL, De Silva VNH, Weerasooriya MV, Takagi H, Itoh M, Kato H, Yahathugoda TC. A real-time PCR for quantification of parasite burden and its correlations with clinical characteristics and anti-rKRP42 IgG level in cutaneous leishmaniasis in Sri Lanka. Parasitol Int 2024; 100:102865. [PMID: 38341021 DOI: 10.1016/j.parint.2024.102865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 02/05/2024] [Accepted: 02/06/2024] [Indexed: 02/12/2024]
Abstract
In visceral and mucocutaneous leishmaniasis, humoral immune response can reflect disease severity and parasite burden. Cutaneous leishmaniasis (CL) in Sri Lanka is caused by a usually visceralizing parasite, Leishmania donovani. We assessed the parasite burden (relative quantity-RQ) in 190 CL patients using quantitative real-time PCR (qPCR-with primers designed for this study) and smear microscopy, then correlated it with clinical parameters and IgG response. RQ of parasite DNA was determined with human-specific glyceraldehyde 3-phosphate dehydrogenase (GAPDH) as the internal control. The qPCR sensitivity was tested with serially diluted DNA from cultured L. donovani parasites. Smears were assigned a score based on number of parasites per high power field. Data from previous studies were used for comparison and correlation; nested Internal Transcribed Spacer 1 (ITS1) PCR as reference standard (RS) and IgG antibody titers to the Leishmania rKRp42 antigen as the immune response. The qPCR amplified and quantified 86.8% of the samples while demonstrating a fair and significant agreement with ITS1-PCR and microscopy. Parasite burden by qPCR and microscopy were highly correlated (r = 0.76; p = 0.01) but showed no correlation with the IgG response (r = 0.056; p = 0.48). Corresponding mean RQs of IgG titers grouped by percentiles, showed no significant difference (p = 0.93). Mean RQ was higher in early lesions (p = 0.04), decreased with lesion size (p = 0.12) and slightly higher among papules, nodules and wet ulcers (p = 0.72). Our study established qPCR's efficacy in quantifying parasite burden in Sri Lankan CL lesions but no significant correlation was observed between the parasite burden and host IgG response to the Leishmania rKRP42 antigen.
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Affiliation(s)
| | | | | | - Hidekazu Takagi
- Department of Microbiology and Immunology, Aichi Medical University School of Medicine, Aichi 480-1195, Japan.
| | - Makoto Itoh
- Department of Microbiology and Immunology, Aichi Medical University School of Medicine, Aichi 480-1195, Japan
| | - Hirotomo Kato
- Division of Medical Zoology, Department of Infection and Immunity, Jichi Medical University, Tochigi 329-0498, Japan.
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Kariyawasam R, Lau R, Valencia BM, Llanos-Cuentas A, Boggild AK. Novel detection of Leishmania RNA virus-1 (LRV-1) in clinical isolates of Leishmania Viannia panamensis. Parasitology 2024; 151:151-156. [PMID: 38031433 PMCID: PMC10941039 DOI: 10.1017/s0031182023001221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 11/16/2023] [Accepted: 11/26/2023] [Indexed: 12/01/2023]
Abstract
American tegumentary leishmaniasis comprises a discrete set of clinical presentations endemic to Latin America. Leishmania RNA virus-1 (LRV-1) is a double-stranded RNA virus identified in 20–25% of the Leishmania Viannia braziliensis and L. V. guyanensis, however not in L. V. panamensis. This is the first report of LRV-1 in L. V. panamensis and its associations with clinical phenotypes of ATL. Unique surplus discard clinical isolates of L. V. panamensis were identified from the Public Health Ontario Laboratory (PHOL) and the Leishmania Clinic of the Instituto de Medicina Tropical ‘Alexander von Humboldt’ between 2012 and 2019 and screened for LRV-1 by real-time polymerase chain reaction. Patient isolates were stratified according to clinical phenotype. Of 30 patients with L. V. panamensis, 14 (47%) and 16 (53%) patients had severe and non-severe ATL, respectively. Five (36%) of 14 severe cases and 2 (12%) of 16 non-severe cases were positive for LRV-1, respectively. No differences in sex were observed for clinical phenotype and LRV-1 status. Although an association between LRV-1 status and clinical phenotype was not demonstrated, this is the first description of the novel detection of LRV-1 in L. V. panamensis, a species that has been documented predominantly in Central America.
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Affiliation(s)
- Ruwandi Kariyawasam
- Department of Laboratory Medicine & Pathology, University of Alberta, Edmonton, AB T6G 2R3, Canada
- Alberta Precision Laboratories-Public Health, Edmonton, AB T6G 2J2, Canada
| | - Rachel Lau
- Public Health Ontario Laboratory, Toronto, ON M5G 1M1 Canada
| | - Braulio M. Valencia
- Instituto de Medicina Tropical ‘Alejandro von Humboldt’, Lima, Peru
- Kirby Institute, University of New South Wales, Sydney, Australia
| | | | - Andrea K. Boggild
- Department of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
- Tropical Disease Unit, Toronto General Hospital, Toronto, ON M5G 2C4, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON M5S 1A8, Canada
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3
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Lau R, Mukkala AN, Kariyawasam R, Clarke S, Valencia BM, Llanos-Cuentas A, Boggild AK. Comparison of Whole Genome Sequencing versus Standard Molecular Diagnostics for Species Identification in the Leishmania Viannia Subgenus. Am J Trop Med Hyg 2021; 105:660-669. [PMID: 34270450 PMCID: PMC8592345 DOI: 10.4269/ajtmh.21-0273] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 05/04/2021] [Indexed: 11/07/2022] Open
Abstract
The prognosis and treatment of New World tegumentary leishmaniasis is dependent on the infecting species, yet such species identification in the Leishmania Viannia subgenus poses a diagnostic challenge. Currently, speciation relies on standard molecular techniques such as restriction fragment length polymorphism (RFLP) analysis, and Sanger sequencing (SS). Whole-genome sequencing (WGS) is a robust and increasingly cost-efficient tool that may improve Leishmania species identification. We evaluated WGS versus standard RFLP-SS for species identification in three reference and five clinical strains of Leishmania Viannia spp. Internal transcribed spacer1 (its1), cysteine proteinase b (cpb), and heat shock protein 70 (hsp70) polymerase chain reaction-restriction fragment length polymorphism (RFLP) was performed, followed by SS of the its2, cpb, hsp70, and mannose phosphate isomerase (mpi) loci. After de novo assembly, sequences were mapped, and homology compared with both reference strains and reference genomes on National Center for Biotechnology Information. All American Type Culture Collection strains were confirmed to be single-species of L. V. braziliensis, L. V. guyanensis, or L. V. panamensis by WGS. Conversely, RFLP-SS was able to definitively identify one of three isolates to the species level. Clinical samples were identified as either single-species (N = 3), mixed (N = 1), or hybrid (N = 1) infections by WGS, while standard molecular diagnosis required multi-target composite analysis for identification due to loci-dependent results by RFLP-SS. We have corroborated the utility of WGS as a diagnostic tool to speciate members of the L. Viannia subgenus and to discriminate between mixed and hybrid infections. WGS is a potentially useful complement to multistaged RFLP-SS for species identification in Leishmania infections.
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Affiliation(s)
- Rachel Lau
- Public Health Ontario Laboratory, Toronto, Ontario, Canada
| | - Avinash N. Mukkala
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Ruwandi Kariyawasam
- Division of Diagnostic and Applied Microbiology, Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada
- Alberta Precision Laboratories–Public Health, Edmonton, Alberta, Canada
| | - Shareese Clarke
- Faculty of Nursing, University of Toronto, Toronto, Ontario, Canada
| | - Braulio M. Valencia
- Kirby Institute, University of New South Wales, Sydney, Australia
- Instituto de Medicina Tropical Alejandro von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Alejandro Llanos-Cuentas
- Public Health Ontario Laboratory, Toronto, Ontario, Canada
- Facultad de Salud Pública y Administración, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Andrea K. Boggild
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
- Tropical Disease Unit, Toronto General Hospital, Toronto, Canada
- Department of Medicine, University of Toronto, Toronto, Ontario, Canada
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4
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Reimão JQ, Coser EM, Lee MR, Coelho AC. Laboratory Diagnosis of Cutaneous and Visceral Leishmaniasis: Current and Future Methods. Microorganisms 2020; 8:E1632. [PMID: 33105784 PMCID: PMC7690623 DOI: 10.3390/microorganisms8111632] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 10/19/2020] [Accepted: 10/20/2020] [Indexed: 02/03/2023] Open
Abstract
Leishmaniasis is a neglected tropical disease with two main clinical forms: cutaneous and visceral leishmaniasis. Diagnosis of leishmaniasis is still a challenge, concerning the detection and correct identification of the species of the parasite, mainly in endemic areas where the absence of appropriate resources is still a problem. Most accessible methods for diagnosis, particularly in these areas, do not include the identification of each one of more than 20 species responsible for the disease. Here, we summarize the main methods used for the detection and identification of leishmaniasis that can be performed by demonstration of the parasite in biological samples from the patient through microscopic examination, by in vitro culture or animal inoculation; by molecular methods through the detection of parasite DNA; or by immunological methods through the detection of parasite antigens that may be present in urine or through the detection of specific antibodies against the parasite. Potential new methods that can be applied for laboratory diagnosis of leishmaniasis are also discussed.
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Affiliation(s)
- Juliana Quero Reimão
- Departamento de Morfologia e Patologia Básica, Faculdade de Medicina de Jundiaí, Jundiaí 13202-550, Brazil; (J.Q.R.); (M.R.L.)
| | - Elizabeth Magiolo Coser
- Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas 13083-862, Brazil;
| | - Monica Ran Lee
- Departamento de Morfologia e Patologia Básica, Faculdade de Medicina de Jundiaí, Jundiaí 13202-550, Brazil; (J.Q.R.); (M.R.L.)
| | - Adriano Cappellazzo Coelho
- Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas 13083-862, Brazil;
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Kariyawasam R, Lau R, Valencia BM, Llanos-Cuentas A, Boggild AK. Leishmania RNA Virus 1 (LRV-1) in Leishmania ( Viannia) braziliensis Isolates from Peru: A Description of Demographic and Clinical Correlates. Am J Trop Med Hyg 2020; 102:280-285. [PMID: 31837129 DOI: 10.4269/ajtmh.19-0147] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
RNA virus 1-1 (LRV-1-1) is a dsRNA virus identified in isolates of Leishmania (Viannia) braziliensis and thought to advance localized cutaneous leishmaniasis (LCL) to mucocutaneous or mucosal leishmaniasis (MCL/ML). We examined the prevalence of LRV-1 and its correlation to phenotypes of American tegumentary leishmaniasis caused by L. (V.) braziliensis from Peru to better understand its epidemiology. Clinical isolates of L. (V.) braziliensis were screened for LRV-1 by real-time polymerase chain reaction (PCR) and stratified according to the phenotype: LCL (< 4 ulcers in number) MCL/ML; inflammatory ulcers (erythematous, purulent, painful ulcers with or without lymphatic involvement) or multifocal ulcers (≥ 4 in ≥ 2 anatomic sites). Proportionate LRV-1 positivity was compared across phenotypes. Of 78 L. (V.) braziliensis isolates, 26 (54.2%) had an inflammatory phenotype, 22 (28%) had the MCL/ML phenotype, whereas 30 (38.5%) had LCL. Mucocutaneous or mucosal leishmaniasis was found exclusively in adult male enrollees. Leishmania RNA virus 1 positivity by phenotype was as follows: 9/22 (41%) with MCL/ML; 5/26 (19%) with an inflammatory/multifocal cutaneous leishmaniasis phenotype; and 7/30 (23%) with LCL (P = 0.19). Leishmania RNA virus 1 positivity was not associated with age (P = 0.55) or gender (P = 0.49). Relative LRV-1 copy number was greater in those with MCL/ML than those with inflammatory/multifocal CL (P = 0.02). A direct association between LRV-1 status and clinical phenotype was not demonstrated; however, relative LRV-1 copy number was highest in those with MCL/ML. Future analyses to understand the relationship between viral burden and pathogenesis are required to determine if LRV-1 is truly a contributor to the MCL/ML phenotype.
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Affiliation(s)
| | - Rachel Lau
- Public Health Ontario Laboratory, Toronto, Canada
| | - Braulio M Valencia
- Viral Immunology Systems Program, Kirby Institute, University of New South Wales, Australia
| | | | - Andrea K Boggild
- Public Health Ontario Laboratory, Toronto, Canada.,Institute of Medical Sciences, University of Toronto, Toronto, Canada.,Department of Medicine, University of Toronto, Toronto, Canada.,Tropical Disease Unit, Toronto General Hospital, Toronto, Canada
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Gianchecchi E, Montomoli E. The enemy at home: leishmaniasis in the Mediterranean basin, Italy on the focus. Expert Rev Anti Infect Ther 2020; 18:563-577. [DOI: 10.1080/14787210.2020.1751611] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
| | - Emanuele Montomoli
- VisMederi S.r.l, Siena, Italy
- Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
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Boggild AK, Caumes E, Grobusch MP, Schwartz E, Hynes NA, Libman M, Connor BA, Chakrabarti S, Parola P, Keystone JS, Nash T, Showler AJ, Schunk M, Asgeirsson H, Hamer DH, Kain KC. Cutaneous and mucocutaneous leishmaniasis in travellers and migrants: a 20-year GeoSentinel Surveillance Network analysis. J Travel Med 2019; 26:5540646. [PMID: 31553455 PMCID: PMC7353840 DOI: 10.1093/jtm/taz055] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 07/24/2019] [Accepted: 07/24/2019] [Indexed: 11/13/2022]
Abstract
BACKGROUND Cutaneous leishmaniasis (CL) may be emerging among international travellers and migrants. Limited data exist on mucocutaneous leishmaniasis (MCL) in travellers. We describe the epidemiology of travel-associated CL and MCL among international travellers and immigrants over a 20-year period through descriptive analysis of GeoSentinel data. METHODS Demographic and travel-related data on returned international travellers diagnosed with CL or MCL at a GeoSentinel Surveillance Network site between 1 September 1997 and 31 August 2017 were analysed. RESULTS A total of 955 returned travellers or migrants were diagnosed with travel-acquired CL (n = 916) or MCL during the study period, of whom 10% (n = 97) were migrants. For the 858 non-migrant travellers, common source countries were Bolivia (n = 156, 18.2%) and Costa Rica (n = 97, 11.3%), while for migrants, they were Syria (n = 34, 35%) and Afghanistan (n = 22, 22.7%). A total of 99 travellers (10%) acquired their disease on trips of ≤ 2 weeks. Of 274 cases for which species identification was available, Leishmania Viannia braziliensis was the most well-represented strain (n = 117, 42.7%), followed by L. major (n = 40, 14.6%) and L. V. panamensis (n = 38, 13.9%). Forty cases of MCL occurred, most commonly in tourists (n = 29, 72.5%) and from Bolivia (n = 18, 45%). A total of 10% of MCL cases were acquired in the Old World. CONCLUSIONS Among GeoSentinel reporting sites, CL is predominantly a disease of tourists travelling mostly to countries in Central and South America such as Bolivia where risk of acquiring L. V. braziliensis and subsequent MCL is high. The finding that some travellers acquired leishmaniasis on trips of short duration challenges the common notion that CL is a disease of prolonged travel. Migrants from areas of conflict and political instability, such as Afghanistan and Syria, were well represented, suggesting that as mass migration of refugees continues, CL will be increasingly encountered in intake countries.
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Affiliation(s)
- Andrea K Boggild
- Tropical Disease Unit, Division of Infectious Diseases, University Health Network-Toronto General Hospital, Toronto, Canada.,Public Health Ontario Laboratory, Public Health Ontario, Toronto, Canada.,Department of Medicine, University of Toronto, Toronto, Canada
| | - Eric Caumes
- Sorbonne Université, AP-HP, Hôpitaux Universitaires Pitié-Salpêtrière Charles Foix, Service de Maladies infectieuses et Tropicales, INSERM, Institut Pierre Louis d'Épidémiologie et de Santé Publique (IPLESP), 75013, Paris, France
| | - Martin P Grobusch
- Center of Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Amsterdam Academic Medical Centers, University of Amsterdam, Amsterdam, The Netherlands.,Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany.,Centre de Recherches Médicales en Lambaréné (CERMEL), Lambaréné, Gabon
| | - Eli Schwartz
- Institute of Geographic Medicine and Tropical Diseases, Sheba Medical Center Tel Hashomer and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Noreen A Hynes
- School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA.,Bloomberg School Public Health, Johns Hopkins University, Baltimore, Maryland, USA
| | - Michael Libman
- J.D. MacLean Centre for Tropical Diseases, McGill University Health Centre, Montreal Canada
| | - Bradley A Connor
- Department of Medicine, Weill Cornell Medical College, New York, USA
| | - Sumontra Chakrabarti
- Tropical Disease Unit, Division of Infectious Diseases, University Health Network-Toronto General Hospital, Toronto, Canada.,Department of Medicine, University of Toronto, Toronto, Canada.,Trillium Health Partners, Mississauga, Canada
| | - Philippe Parola
- Aix Marseille Univ, IRD, AP-HM, SSA, VITROME, Marseille, France.,IHU-Méditerranée Infection, Marseille, France
| | - Jay S Keystone
- Tropical Disease Unit, Division of Infectious Diseases, University Health Network-Toronto General Hospital, Toronto, Canada.,Department of Medicine, University of Toronto, Toronto, Canada
| | - Theodore Nash
- Clinical Parasitology Section, Laboratory of Parasitic Diseases, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Adrienne J Showler
- Tropical Disease Unit, Division of Infectious Diseases, University Health Network-Toronto General Hospital, Toronto, Canada.,Georgetown University, Washington, DC
| | - Mirjam Schunk
- Division of Infectious Diseases and Tropical Medicine, University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Hilmir Asgeirsson
- Department of Infectious Diseases, Karolinska University Hospital, Stockholm, Sweden.,Unit of Infectious Diseases, Department of Medicine Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - Davidson H Hamer
- Department of Global Health, Boston University School of Public Health, Boston, MA, USA.,Section of Infectious Diseases, Boston University School of Medicine, Boston, MA, USA
| | - Kevin C Kain
- Tropical Disease Unit, Division of Infectious Diseases, University Health Network-Toronto General Hospital, Toronto, Canada.,Department of Medicine, University of Toronto, Toronto, Canada.,SAR Laboratories, Sandra Rotman Centre for Global Health, Toronto, Canada
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Tracking of quiescence in Leishmania by quantifying the expression of GFP in the ribosomal DNA locus. Sci Rep 2019; 9:18951. [PMID: 31831818 PMCID: PMC6908629 DOI: 10.1038/s41598-019-55486-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 11/27/2019] [Indexed: 01/22/2023] Open
Abstract
Under stressful conditions some microorganisms adopt a quiescent stage characterized by a reversible non or slow proliferative condition that allows their survival. This adaptation was only recently discovered in Leishmania. We developed an in vitro model and a biosensor to track quiescence at population and single cell levels. The biosensor is a GFP reporter gene integrated within the 18S rDNA locus, which allows monitoring the expression of 18S rRNA (rGFP expression). We showed that rGFP expression decreased significantly and rapidly during the transition from extracellular promastigotes to intracellular amastigotes and that it was coupled in vitro with a decrease in replication as measured by BrdU incorporation. rGFP expression was useful to track the reversibility of quiescence in live cells and showed for the first time the heterogeneity of physiological stages among the population of amastigotes in which shallow and deep quiescent stages may coexist. We also validated the use of rGFP expression as a biosensor in animal models of latent infection. Our models and biosensor should allow further characterization of quiescence at metabolic and molecular level.
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Moreira OC, Yadon ZE, Cupolillo E. The applicability of real-time PCR in the diagnostic of cutaneous leishmaniasis and parasite quantification for clinical management: Current status and perspectives. Acta Trop 2018; 184:29-37. [PMID: 28965842 DOI: 10.1016/j.actatropica.2017.09.020] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 08/11/2017] [Accepted: 09/24/2017] [Indexed: 01/10/2023]
Abstract
Cutaneous leishmaniasis (CL) is spread worldwide and is the most common manifestation of leishmaniasis. Diagnosis is performed by combining clinical and epidemiological features, and through the detection of Leishmania parasites (or DNA) in tissue specimens or trough parasite isolation in culture medium. Diagnosis of CL is challenging, reflecting the pleomorphic clinical manifestations of this disease. Skin lesions vary in severity, clinical appearance, and duration, and in some cases, they can be indistinguishable from lesions related to other diseases. Over the past few decades, PCR-based methods, including real-time PCR assays, have been developed for Leishmania detection, quantification and species identification, improving the molecular diagnosis of CL. This review provides an overview of many real-time PCR methods reported for the diagnostic evaluation of CL and some recommendations for the application of these methods for quantification purposes for clinical management and epidemiological studies. Furthermore, the use of real-time PCR for Leishmania species identification is also presented. The advantages of real-time PCR protocols are numerous, including increased sensitivity and specificity and simpler standardization of diagnostic procedures. However, despite the numerous assays described, there is still no consensus regarding the methods employed. Furthermore, the analytical and clinical validation of CL molecular diagnosis has not followed international guidelines so far. A consensus methodology comprising a DNA extraction protocol with an exogenous quality control and an internal reference to normalize parasite load is still needed. In addition, the analytical and clinical performance of any consensus methodology must be accurately assessed. This review shows that a standardization initiative is essential to guide researchers and clinical laboratories towards the achievement of a robust and reproducible methodology, which will permit further evaluation of parasite load as a surrogate marker of prognosis and monitoring of aetiological treatment, particularly in multi-centric observational studies and clinical trials.
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10
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Jara M, Berg M, Caljon G, de Muylder G, Cuypers B, Castillo D, Maes I, Orozco MDC, Vanaerschot M, Dujardin JC, Arevalo J. Macromolecular biosynthetic parameters and metabolic profile in different life stages of Leishmania braziliensis: Amastigotes as a functionally less active stage. PLoS One 2017; 12:e0180532. [PMID: 28742826 PMCID: PMC5526552 DOI: 10.1371/journal.pone.0180532] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Accepted: 05/26/2017] [Indexed: 12/04/2022] Open
Abstract
It was recently hypothesized that Leishmania amastigotes could constitute a semi-quiescent stage characterized by low replication and reduced metabolic activity. This concept developed with Leishmania (Leishmania) mexicana and Leishmania (Leishmania) major models might explain numerous clinical and sub-clinical features of Leishmania (Viannia) braziliensis infections, like reactivation of the disease, non-response to chemotherapy or asymptomatic infections. We compared here in vitro the proliferative capability of L. (V.) braziliensis amastigotes and promastigotes, assessed the expression of key molecular parameters and performed metabolomic analysis. We found that contrary to the highly proliferative promastigotes, amastigotes (axenic and intracellular) do not show evidence of extensive proliferation. In parallel, amastigotes showed a significant decrease of (i) the kDNA mini-circle abundance, (ii) the intracellular ATP level, (iii) the ribosomal components: rRNA subunits 18S and 28S α and ribosomal proteins RPS15 and RPL19, (iv) total RNA and protein levels. An untargeted metabolomic study identified clear differences between the different life stages: in comparison to logarithmic promastigotes, axenic amastigotes showed (a) a strong decrease of 14 essential and non-essential amino acids and eight metabolites involved in polyamine synthesis, (b) extensive changes in the phospholipids composition and (c) increased levels of several endogenous and exogenous sterols. Altogether, our results show that L. (V.) braziliensis amastigotes can show a phenotype with negligible rate of proliferation, a lower capacity of biosynthesis, a reduced bio-energetic level and a strongly altered metabolism. Our results pave the way for further exploration of quiescence among amastigotes of this species.
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Affiliation(s)
- Marlene Jara
- Instituto de Medicina Tropical “Alexander von Humboldt”, Universidad Peruana Cayetano Heredia, Lima, Perú
- Institute of Tropical Medicine Antwerp, Molecular Parasitology Unit, Antwerp, Belgium
| | - Maya Berg
- Institute of Tropical Medicine Antwerp, Molecular Parasitology Unit, Antwerp, Belgium
| | - Guy Caljon
- Institute of Tropical Medicine Antwerp, Molecular Parasitology Unit, Antwerp, Belgium
| | - Geraldine de Muylder
- Institute of Tropical Medicine Antwerp, Molecular Parasitology Unit, Antwerp, Belgium
| | - Bart Cuypers
- Institute of Tropical Medicine Antwerp, Molecular Parasitology Unit, Antwerp, Belgium
- University of Antwerp, Antwerp, Belgium
| | - Denis Castillo
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Ilse Maes
- Institute of Tropical Medicine Antwerp, Molecular Parasitology Unit, Antwerp, Belgium
| | - María del Carmen Orozco
- Instituto de Medicina Tropical “Alexander von Humboldt”, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Manu Vanaerschot
- Institute of Tropical Medicine Antwerp, Molecular Parasitology Unit, Antwerp, Belgium
| | - Jean-Claude Dujardin
- Institute of Tropical Medicine Antwerp, Molecular Parasitology Unit, Antwerp, Belgium
- University of Antwerp, Antwerp, Belgium
| | - Jorge Arevalo
- Instituto de Medicina Tropical “Alexander von Humboldt”, Universidad Peruana Cayetano Heredia, Lima, Perú
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
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