Tapan Bhattacharyya

Tapan Bhattacharyya
London School of Hygiene and Tropical Medicine | LSHTM · Faculty of Infectious and Tropical Diseases

About

75
Publications
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Publications

Publications (75)
Article
Full-text available
Background Chagas disease remains a significant public health problem in Latin America. There are only two chemotherapy drugs, nifurtimox and benznidazole, and both may have severe side effects. After complete chemotherapy of acute cases, seropositive diagnosis may revert to negative. However, there are no definitive parasitological or serological...
Article
Full-text available
Background: Visceral leishmaniasis (VL) is a zoonotic protozoal vector-borne disease that is a major public health challenge. In Argentina, canine (CVL) and human visceral leishmaniasis (HVL) have recently emerged. There is a lack of standardised diagnostic tests for CVL, which hinders control of CVL and HVL. Methodology/principal findings: Samp...
Article
Background: This study identified Trypanosoma cruzi discrete typing units (DTUs) in maternal and infant specimens collected from two hospitals in Bolivia, using conventional genotyping and DTU-specific serotyping. Methods: Specimens from 142 mothers were used, including 24 seronegative and 118 seropositive individuals; 29 women transmitted T. cruz...
Article
Full-text available
Diagnosis of visceral leishmaniasis (VL) relies on invasive and risky aspirate procedures, and confirmation of cure after treatment is unreliable. Detection of Leishmania donovani antigens in urine has the potential to provide both a non-invasive diagnostic and a test of cure. We searched for L. donovani antigens in urine of VL patients from India...
Article
Full-text available
Ergosterol biosynthesis inhibitors, such as posaconazole and ravuconazole, have been proposed as drug candidates for Chagas disease, a neglected infectious tropical disease caused by the protozoan parasite Trypanosoma cruzi. To understand better the mechanism of action and resistance to these inhibitors, a clone of the T. cruzi Y strain was culture...
Article
Full-text available
Protozoan parasites of the Leishmania donovani complex – L. donovani and L. infantum – cause the fatal disease visceral leishmaniasis. We present the first comprehensive genome-wide global study, with 151 cultured field isolates representing most of the geographical distribution. L. donovani isolates separated into five groups that largely coincide...
Article
Full-text available
Protozoan parasites of the Leishmania donovani complex – L. donovani and L. infantum – cause the fatal disease visceral leishmaniasis. We present the first comprehensive genome-wide global study, with 151 cultured field isolates representing most of the geographical distribution. L. donovani isolates separated into five groups that largely coincide...
Article
Full-text available
Protozoan parasites of the Leishmania donovani complex – L. donovani and L. infantum – cause the fatal disease visceral leishmaniasis. We present the first comprehensive genome-wide global study, with 151 cultured field isolates representing most of the geographical distribution. L. donovani isolates separated into five groups that largely coincide...
Article
Full-text available
Trypanosoma cruzi, the protozoan agent of Chagas disease in the Americas, is comprised of six genetic lineages (TcI-TcVI) and a possible seventh (TcBat, related to TcI). Identification of T. cruzi lineages infecting reservoir mammalian species is fundamental to resolving transmission cycles. However, this is hindered by the limited sensitivity and...
Article
Full-text available
Background: Trypanosoma cruzi, the protozoan agent of Chagas disease, is comprised of at least 6 genetic lineages (TcI-TcVI). Their geographical distribution, clinical associations and reservoir hosts are not fully elucidated, as genotyping is hampered due to the difficulty in isolating representative populations of organisms. Lineage-specific ser...
Article
Full-text available
Background: Visceral leishmaniasis (VL), caused by the Leishmania donovani complex, is a fatal, neglected tropical disease that is targeted for elimination in India, Nepal, and Bangladesh. Improved diagnostic tests are required for early case detection and for monitoring the outcomes of treatments. Previous investigations using Leishmania lysate a...
Article
Full-text available
Objectives: Local health personnel have drawn attention to an apparent increase in incidence and severity of cutaneous leishmaniasis (CL) in Sudan. The objective of this study was to investigate CL burden and surveillance. Methods: Surveillance data were compiled from the KalaCORE programme, Leishmania coordinators in Northern Kordofan and South...
Preprint
Full-text available
Protozoan parasites of the Leishmania donovani complex, L. donovani and L. infantum, cause the fatal disease visceral leishmaniasis. We present the first comprehensive genome-wide global study, with 151 cultured field isolates representing most of the geographical distribution. L. donovani isolates separated into five groups that largely coincide w...
Article
Full-text available
Background The search for diagnostic biomarkers has been profiting from a growing number of high quality sequenced genomes and freely available bioinformatic tools. These can be combined with wet lab experiments for a rational search. Improved, point-of-care diagnostic tests for visceral leishmaniasis (VL), early case detection and surveillance are...
Article
Full-text available
Background Hosts repeatedly bitten by sand flies develop antibodies against sand fly saliva and screening of these immunoglobulins can be employed to estimate the risk of Leishmania transmission, to indicate the feeding preferences of sand flies, or to evaluate the effectiveness of vector control campaigns. Previously, antibodies to sand fly saliva...
Data
S1 Table. Dilutions in ELISA experiments. Host species, used blocking media and conju- gates, sera and conjugate dilutions are indicated in this table. (DOCX)
Data
Dilutions in ELISA experiments. Host species, used blocking media and conjugates, sera and conjugate dilutions are indicated in this table. (DOCX)
Data
Images of VL Sero K-SeT and western blots for Indian PKDL samples.
Data
Spreadsheet with ELISA, RDT & blot results for Indian cured paired, PKDL and relapse samples.
Data
Images of VL Sero K-SeT and western blots for Indian asymptomatic progressors and non-progressors.
Data
Images of western blots for Indian paired cured samples.
Data
Images of VL Sero K-SeT and western blots for Indian and Sudanese relapsed samples.
Data
Images of VL Sero K-SeT for Indian paired cured samples, corresponding to those in S3.
Article
Full-text available
Background: There is a recognized need for an improved diagnostic test to assess post-chemotherapeutic treatment outcome in visceral leishmaniasis (VL) and to diagnose post kala-azar dermal leishmaniasis (PKDL). We previously demonstrated by ELISA and a prototype novel rapid diagnostic test (RDT), that high anti-Leishmania IgG1 is associated with p...
Article
Full-text available
Background: Trypanosoma cruzi causes Chagas disease in the Americas. Outcome of infection ranges from lifelong asymptomatic status to severe disease. Understanding how history of T. cruzi lineage (TcI-TcVI) infection relates to clinical prognosis is challenging. We previously described peptide-based lineage-specific ELISA with Trypomastigote Small...
Article
Full-text available
Background Stimulated by the increasing recent use of ‘K’ or ‘rK’ nomenclature for antigens reported for visceral leishmaniasis (VL) diagnostic serology, we wished to give a chronological synopsis of their reporting and the potentially confusing terminology. Methods The literature was examined for ‘K' or ‘rK’ terminology for VL diagnostic antigens...
Article
Full-text available
: Trypanosoma cruzi, the agent of Chagas disease in humans, has a vast reservoir of mammalian hosts in the Americas, and is classified into six genetic lineages, TcI-TcVI, with a possible seventh, TcBat. Elucidating enzootic cycles of the different lineages is important for understanding the ecology of this parasite, the emergence of new outbreaks...
Article
Full-text available
Trypanosoma cruzi, causative agent of Chagas disease, displays high intraspecific genetic diversity: six genetic lineages or discrete typing units (DTUs) are currently recognized, termed TcI through TcVI. Each DTU presents a particular distribution pattern across the Americas, and is loosely associated with different transmission cycles and hosts....
Article
Sequence diversity in the Trypanosoma cruzi small surface molecule TSSA has yielded antigens for serology to investigate the T. cruzi lineage-specific infection history of patients with Chagas disease. Synthetic peptides can be used as the lineage-specific antigens. Here we consider the rationale, feasibility and potential of applying peptide-based...
Thesis
Trypanosoma cruzi and the Leishmania donovani complex are parasitic protozoa that, respectively, cause Chagas disease in the Americas, and visceral leishmaniasis, predominantly in South Asia, East Africa, and Brazil. T. cruzi is divided into the lineages TcI-TcVI. The relationship between infecting lineage(s) and spectrum of clinical presentations...
Article
Full-text available
Background Visceral leishmaniasis (VL), caused by protozoa of the Leishmania donovani complex, is a widespread parasitic disease of great public health importance; without effective chemotherapy symptomatic VL is usually fatal. Distinction of asymptomatic carriage from progressive disease and the prediction of relapse following treatment are hamper...
Article
Full-text available
Background: Chagas disease, caused by infection with the protozoan Trypanosoma cruzi, remains a serious public health issue in Latin America. Genetically diverse, the species is sub-divided into six lineages, known as TcI-TcVI, which have disparate geographical and ecological distributions. TcII, TcV, and TcVI are associated with severe human dise...
Article
Full-text available
Background: Visceral leishmaniasis (VL), a widely distributed systemic disease caused by infection with the Leishmania donovani complex (L. donovani and L. infantum), is almost always fatal if symptomatic and untreated. A rapid point-of-care diagnostic test for anti-Leishmania antibodies, the rK39-immunochromatographic test (rK39-ICT), has high se...
Article
Full-text available
Background: Visceral leishmaniasis (VL), caused by infection with Leishmania donovani complex, remains a major public health problem in endemic regions of South Asia, East Africa, and Brazil. If untreated, symptomatic VL is usually fatal. Rapid field diagnosis relies principally on demonstration of anti-Leishmania antibodies in clinically suspect...
Data
Panel of reference strains from the six T. cruzi DTUs. (DOCX)
Data
Heteroplasmic sites in the Sylvio X10/1 maxicircle genome. (DOCX)
Data
Microsatellite loci and primer sequences. (DOCX)
Data
Additional T. cruzi TcIII and TcIV isolates used in selected analyses. (DOCX)
Data
Concatenated nuclear dataset spreadsheet. Individual Neighbour-Joining trees were constructed for both nuclear genes (SL-IR and GPI) and the 25 microsatellite loci. Once all trees were visualized independently to confirm congruent topologies, nuclear SNPs were re-coded numerically and concatenated with microsatellite data in this spreadsheet. DAS v...
Article
Full-text available
Mitochondrial DNA is a valuable taxonomic marker due to its relatively fast rate of evolution. In Trypanosoma cruzi, the causative agent of Chagas disease, the mitochondrial genome has a unique structural organization consisting of 20-50 maxicircles (?20 kb) and thousands of minicircles (0.5-10 kb). T. cruzi is an early diverging protist displaying...
Article
Full-text available
PHD2 serves as an oxygen sensor that rescues blood supply by regulating vessel formation and shape in case of oxygen shortage. However, it is unknown whether PHD2 can influence arteriogenesis. Here we studied the role of PHD2 in collateral artery growth by using hindlimb ischaemia as a model, a process that compensates for the lack of blood flow in...
Data
Concatenation and lineage assignment. Unrooted neighbor-joining diplotypic tree showing p-distance for 9 concatenated gene fragments (A). Concatenation of LYT1 and DHFR-TS discriminate between DTUs V and VI (inset). Concatenated diplotypic tree using a reduced panel of 4 gene fragments (B). Concatenation of Met-III, RB19, and TcGPXII assign isolate...
Article
Full-text available
Multilocus sequence typing (MLST) is a powerful and highly discriminatory method for analysing pathogen population structure and epidemiology. Trypanosoma cruzi, the protozoan agent of American trypanosomiasis (Chagas disease), has remarkable genetic and ecological diversity. A standardised MLST protocol that is suitable for assignment of T. cruzi...
Article
Chagas disease, marked by life-long chronic infection with Trypanosoma cruzi, remains a major parasitic disease in Latin America. Genetically heterogeneous, T. cruzi is divided into six discrete typing units (DTUs), most recently grouped as TcI-VI. The trypomastigote small surface antigen (TSSA) of T. cruzi has been described as the only known sero...