Genetic Markers

Publication Title: 
Malaria Journal

BACKGROUND: This study aimed to explore Plasmodium falciparum population dynamics during the early phase of anti-malarial drug treatment with artemisinin-based combination therapy in children with clinical malaria in a high transmission area in Africa. METHODS: A total of 50 children aged 1-10 years with acute uncomplicated P. falciparum malaria in Bagamoyo District, Tanzania, were enrolled. Participants were hospitalized and received supervised standard treatment with artemether-lumefantrine according to body weight in six doses over 3 days. Blood samples were collected 11 times, i.e.

Author(s): 
Carlsson, Anja M.
Ngasala, Billy E.
Dahlstrom, Sabina
Membi, Christopher
Veiga, Isabel M.
Rombo, Lars
Abdulla, Salim
Premji, Zul
Gil, J. Pedro
Björkman, Anders
Mårtensson, Andreas
Publication Title: 
The American Journal of Tropical Medicine and Hygiene

As a result of widespread antimalarial drug resistance, all African countries with endemic malaria have, in recent years, changed their malaria treatment policy. In Senegal, the health authorities changed from chloroquine (CQ) to a combination of sulfadoxine-pyrimethamine (SP) plus amodiaquine (AQ) in 2003. Since 2006, the artemisinin combination therapies (ACTs) artemether-lumefantrine (AL) and artesunate plus amodiaquine (AS/AQ) were adopted for uncomplicated malaria treatment.

Author(s): 
Ndiaye, Magatte
Faye, Babacar
Tine, Roger
Ndiaye, Jean Louis
Lo, Aminata
Abiola, Annie
Dieng, Yémou
Ndiaye, Daouda
Hallett, Rachel
Alifrangis, Michael
Gaye, Oumar
Publication Title: 
Proceedings of the National Academy of Sciences of the United States of America

The recent emergence of artemisinin-resistant Plasmodium falciparum malaria in western Cambodia could threaten prospects for malaria elimination. Identification of the genetic basis of resistance would provide tools for molecular surveillance, aiding efforts to contain resistance. Clinical trials of artesunate efficacy were conducted in Bangladesh, in northwestern Thailand near the Myanmar border, and at two sites in western Cambodia. Parasites collected from trial participants were genotyped at 8,079 single nucleotide polymorphisms (SNPs) using a P. falciparum-specific SNP array.

Author(s): 
Takala-Harrison, Shannon
Clark, Taane G.
Jacob, Christopher G.
Cummings, Michael P.
Miotto, Olivo
Dondorp, Arjen M.
Fukuda, Mark M.
Nosten, François
Noedl, Harald
Imwong, Mallika
Bethell, Delia
Se, Youry
Lon, Chanthap
Tyner, Stuart D.
Saunders, David L.
Socheat, Duong
Ariey, Frédéric
Phyo, Aung Pyae
Starzengruber, Peter
Fuehrer, Hans-Peter
Swoboda, Paul
Stepniewska, Kasia
Flegg, Jennifer
Arze, Cesar
Cerqueira, Gustavo C.
Silva, Joana C.
Ricklefs, Stacy M.
Porcella, Stephen F.
Stephens, Robert M.
Adams, Matthew
Kenefic, Leo J.
Campino, Susana
Auburn, Sarah
MacInnis, Bronwyn
Kwiatkowski, Dominic P.
Su, Xin-Zhuan
White, Nicholas J.
Ringwald, Pascal
Plowe, Christopher V.
Publication Title: 
Malaria Journal

BACKGROUND: Development and spread of Plasmodium falciparum resistance to artemisinin-based combination therapy (ACT) constitutes a major threat to recent global malaria control achievements. Surveillance of molecular markers could act as an early warning system of ACT-resistance before clinical treatment failures are apparent. The aim of this study was to analyse temporal trends of established genotypes associated with artemether-lumefantrine tolerance/resistance before and after its deployment as first-line treatment for uncomplicated malaria in Tanzania 2006.

Author(s): 
Malmberg, Maja
Ngasala, Billy
Ferreira, Pedro E.
Larsson, Erik
Jovel, Irina
Hjalmarsson, Angelica
Petzold, Max
Premji, Zul
Gil, José P.
Björkman, Anders
Mårtensson, Andreas
Publication Title: 
Malaria Journal

BACKGROUND: The control of malaria, caused by Plasmodium falciparum, is hampered by the relentless evolution of drug resistance. Because artemisinin derivatives are now used in the most effective anti-malarial therapy, resistance to artemisinin would be catastrophic. Indeed, studies suggest that artemisinin resistance has already appeared in natural infections. Understanding the mechanisms of resistance would help to prolong the effective lifetime of these drugs. Genetic markers of resistance are therefore required urgently.

Author(s): 
Henriques, Gisela
Martinelli, Axel
Rodrigues, Louise
Modrzynska, Katarzyna
Fawcett, Richard
Houston, Douglas R.
Borges, Sofia T.
D'Alessandro, Umberto
Tinto, Halidou
Karema, Corine
Hunt, Paul
Cravo, Pedro
Publication Title: 
The American Journal of Tropical Medicine and Hygiene

Standard therapy for malaria in Uganda changed from chloroquine to chloroquine + sulfadoxine-pyrimethamine in 2000, and artemether-lumefantrine in 2004, although implementation of each change was slow. Plasmodium falciparum genetic polymorphisms are associated with alterations in drug sensitivity. We followed the prevalence of drug resistance-mediating P. falciparum polymorphisms in 982 samples from Tororo, a region of high transmission intensity, collected from three successive treatment trials conducted during 2003-2012, excluding samples with known recent prior treatment.

Author(s): 
Mbogo, George W.
Nankoberanyi, Sheila
Tukwasibwe, Stephen
Baliraine, Frederick N.
Nsobya, Samuel L.
Conrad, Melissa D.
Arinaitwe, Emmanuel
Kamya, Moses
Tappero, Jordan
Staedke, Sarah G.
Dorsey, Grant
Greenhouse, Bryan
Rosenthal, Philip J.
Publication Title: 
The American Journal of Tropical Medicine and Hygiene

Adequate clinical and parasitologic cure by artemisinin combination therapies relies on the artemisinin component and the partner drug. Polymorphisms in the Plasmodium falciparum chloroquine resistance transporter (pfcrt) and P. falciparum multidrug resistance 1 (pfmdr1) genes are associated with decreased sensitivity to amodiaquine and lumefantrine, but effects of these polymorphisms on therapeutic responses to artesunate-amodiaquine (ASAQ) and artemether-lumefantrine (AL) have not been clearly defined.

Author(s): 
Venkatesan, Meera
Gadalla, Nahla B.
Stepniewska, Kasia
Dahal, Prabin
Nsanzabana, Christian
Moriera, Clarissa
Price, Ric N.
Mårtensson, Andreas
Rosenthal, Philip J.
Dorsey, Grant
Sutherland, Colin J.
Guérin, Philippe
Davis, Timothy M. E.
Ménard, Didier
Adam, Ishag
Ademowo, George
Arze, Cesar
Baliraine, Frederick N.
Berens-Riha, Nicole
Björkman, Anders
Borrmann, Steffen
Checchi, Francesco
Desai, Meghna
Dhorda, Mehul
Djimde, Abdoulaye A.
El-Sayed, Badria B.
Eshetu, Teferi
Eyase, Frederick
Falade, Catherine
Faucher, Jean-François
Fröberg, Gabrielle
Grivoyannis, Anastasia
Hamour, Sally
Houzé, Sandrine
Johnson, Jacob
Kamugisha, Erasmus
Kariuki, Simon
Kiechel, Jean-René
Kironde, Fred
Kofoed, Poul-Erik
LeBras, Jacques
Malmberg, Maja
Mwai, Leah
Ngasala, Billy
Nosten, François
Nsobya, Samuel L.
Nzila, Alexis
Oguike, Mary
Otienoburu, Sabina Dahlström
Ogutu, Bernhards
Ouédraogo, Jean-Bosco
Piola, Patrice
Rombo, Lars
Schramm, Birgit
Somé, A. Fabrice
Thwing, Julie
Ursing, Johan
Wong, Rina P. M.
Zeynudin, Ahmed
Zongo, Issaka
Plowe, Christopher V.
Sibley, Carol Hopkins
ASAQ Molecular Marker Study Group
WWARN AL
Publication Title: 
Malaria Journal

BACKGROUND: Anti-malarial resistance in Plasmodium falciparum remains an obstacle for malaria control. Resistance-associated genes were analysed in Brazilian samples over four decades to evaluate the impact of different treatment regimens on the parasite genetic profile. METHODS: Samples were collected on filter paper from patients infected in the Amazon region from 1984 to 2011. DNA was extracted with Chelex® 100 and monoinfection confirmed by PCR. SNPs in the pfcrt, pfmdr1, pfdhfr and pfdhps genes were assessed by PCR-RFLP.

Author(s): 
Inoue, Juliana
Lopes, Dinora
do Rosário, Virgílio
Machado, Marta
Hristov, Angélica D.
Lima, Giselle Fmc
Costa-Nascimento, Maria J.
Segurado, Aluísio C.
Di Santi, Silvia M.
Publication Title: 
Malaria Journal

BACKGROUND: Plasmodium falciparum and Plasmodium vivax are endemic in Vanuatu and the Solomon Islands. While both countries have introduced artemether-lumefantrine (AL) as first-line therapy for both P. falciparum and P. vivax since 2008, chloroquine and sulphadoxine-pyrimethamine (SP) were used as first-line therapy for many years prior to the introduction of AL. Limited data are available on the extent of SP resistance at the time of policy change.

Author(s): 
Gresty, Karryn J.
Gray, Karen-Ann
Bobogare, Albino
Wini, Lyndes
Taleo, George
Hii, Jeffrey
Cheng, Qin
Waters, Norman C.
Publication Title: 
Biological & Pharmaceutical Bulletin

Correct genotype identification of medicinal plant material remains important for botanical drug industry. Limitations of chemical and morphological approaches for authentication have generated need for newer methods in quality control of botanicals. The present study was carried out to develop DNA based marker for identification of Phyllanthus emblica LINN. A putative marker (1.1 kb) specific for P. emblica was identified by Random Amplified Polymorphic DNA (RAPD) technique. Sequence Characterized Amplified Region (SCAR) marker was developed from the RAPD amplicon.

Author(s): 
Dnyaneshwar, Warude
Preeti, Chavan
Kalpana, Joshi
Bhushan, Patwardhan

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