ISSN 2736-173X
Research Article
African Journal of Malaria and Tropical Diseases ISSN 4123-0981 Vol. 8 (1), pp. 001-010, January, 2020. © International Scholars Journals
Full Length Research Paper
The Hsp40-Hsp70 chaperone machinery of Plasmodium falciparum
Eva-Rachele Pesce* and Gregory L. Blatch
Biomedical Biotechnology Research Unit, Department of Biochemistry, Microbiology and Biotechnology, Rhodes University, Grahamstown 6140, South Africa.
Accepted 14 December, 2019
Abstract
Plasmodium falciparum is the protozoan parasite responsible for the most virulent form of malaria. The majority of the asexual stages of its life cycle occur in the human erythrocyte. Since the infected erythrocytes undergo dramatic structural and functional changes upon parasite infection, malaria research has been focusing on investigating the proteins potentially involved in host cell modifications. Molecular chaperones are believed to play an important role in erythrocyte remodelling as many of these proteins are predicted to be exported into the erythrocyte cytoplasm. A family of molecular chaperones that has recently received much attention is the heat shock protein family (Hsps), and in particular members belonging to the 40 and 70 kDa heat shock proteins classes (Hsp40s and Hsp70s). This review summarises the latest in silico and in vivo data available on P. falciparum Hsp40s and Hsp70s.
Key words: Plasmodium falciparum, malaria, Hsp40s, Hsp70.
Gregory L. Blatch, Eva-Rachele Pesce*
Page: 1 - 10
Research Article
African Journal of Malaria and Tropical Diseases ISSN 4123-0981 Vol. 8 (1), pp. 001-007, January, 2020. © International Scholars Journals
Full Length Research Paper
Optimization of a protocol for extraction of Plasmodium falciparum RNA from infected whole blood samples for use in DNA microarrays
Jaffu Chilongola1*, Sakurani Balthazary2 and Erasto Mbugi3
1Faculty of Medicine, Kilimanjaro Christian Medical College, Tumaini University, Tanzania.
2Department of, Physiology, Biochemistry, Pharmacology and Toxicology, Faculty of Veterinary Medicine, Sokoine University of Agriculture, Tanzania.
3Department of Biochemistry, School of Medicine, Muhimbili University of Health and Allied Sciences (MUHAS), P.O. Box 65001, Dar es Salaam, Tanzania.
Accepted 28 October, 2019
Abstract
This study was carried out to determine the efficiency of two reagents, RNAlater and RNAwiz, for their ability to stabilize Plasmodium falciparum RNA in infected whole blood and saponin lysed parasite pellets for use in DNA microarrays. Eight infected blood samples were stored in each of the reagents, and RNA extracted at days 0 and 56 post collection. RNA yields and quality were compared at the different time points between the two test reagents. We show that for both reagents, higher RNA yields and quality is obtained when RNA is isolated immediately after sample collection (day 0), however, results show that RNAwiz storage provides a marginally higher RNA yield compared to RNAlater storage. Our results indicate that whole blood gave slightly higher RNA yields with superior quality as compared to saponin lysed samples when such whole blood samples are stored in RNA wiz, but not in RNAlater. From our results, we recommend RNAwiz as a better reagent for use in storage of whole infected blood intended for extraction of P. falciparum RNA for DNA microarrays and other sensitive techniques.
Key words: RNAwiz, RNAlater, RNA extraction, Plasmodium falciparum, DNA microarrays.
Sakurani Balthazary and Erasto Mbugi, Jaffu Chilongola*
Page: 1 - 7
Research Article
African Journal of Malaria and Tropical Diseases ISSN 4123-0981 Vol. 8 (1), pp. 001-005, January, 2020. © International Scholars Journals
Full Length Research Paper
Influence of the asexual parasite biomass on in vitro susceptibility of Plasmodium falciparum to antimalarial drugs in Abidjan
Bla Kouakou Brice1, Yavo William2, Ouattara Lacinan1, Basco Leonardo3 and Djaman Allico Joseph1, 4*
1Laboratoire de Pharmacodynamie-biochimique, Université de Cocody, 22 BP 582 Abidjan 22, Côte d’Ivoire.
2Laboratoire de microbiologie de l’Institut National de Santé Publique (INSP), BP V47 Abidjan, Côte d’Ivoire.
3Unité de Recherche Paludologie Afro-tropicale, Institut de recherche pour le développement (IRD) – Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), BP 288 Yaoundé, Cameroun.
4Département de Biochimie, Institut Pasteur de Côte d’Ivoire, 01 BP 490 Abidjan, Côte d’Ivoire.
Accepted 16 March, 2019
Abstract
The in vitro activities of artemisinin, dihydroartemisinin (the biologically active metabolite of artemisinin derivatives), chloroquine and pyronaridine were assessed in 32 isolates of Plasmodium falciparum from Abobo in the northern of Abidjan district (Côte d’Ivoire) using a test based on the standard microtechnique recommended by the World Health Organization (WHO). The parasites densities were ranged between 8,000 and 540,000 rings/µl of blood. The geometric means 50% inhibitory concentration (GMIC50) values for chloroquine, pyronaridine and artemisinin were 145.5 nM (95% confidence interval (CI) =65-226 nM), 17.69 nM (95% CI=9.1-26.3 nM) and 5.72 nM (95% CI=2.3-9.1 nM), respectively. Dihydroartemisinin was the most potent drug against chloroquine-sensitive and chloroquine-resistant isolates with a geometric mean of 2.72 nM. There was no correlation between the parasite densities and the responses to chloroquine (r2=0.01, p<0.5), pyronaridine (r2=0.13, p<0.05), artemisinin (r2=0.13, p<0.05) and dihydroartemisinin (r2=0.07, p<0.1).
Key words: Artemisinin, chloroquine, dihydroartemisinin, in vitro test, parasite biomass, pyronaridine.
Basco Leonardo and Djaman Allico Joseph*, Bla Kouakou Brice, Ouattara Lacinan, Yavo William
Page: 1 - 5
Research Article
African Journal of Malaria and Tropical Diseases ISSN 4123-0981 Vol. 8 (1), pp. 001-004, January, 2020. © International Scholars Journals
Full Length Research Paper
Variation of nitric oxide levels in imported Plasmodium falciparum malaria episodes
De Sousa, Karina*, Silva, Marcelo S. and Tavira, Luís T.
Instituto de Higiene e Medicina Tropical, Centro de Malária e outras Doenças Tropicais, Unidade de Ensino e Investigação da Clínica das Doenças Tropicais – Rua da Junqueira, 96, 1349-008 Lisboa Portugal.
Accepted 12 November, 2019
Abstract
Nitric oxide (NO) has been recognized during the past two decades as one of the most versatile players in the immune system. Even though the molecular mechanisms responsible by the naturally acquired immunity against malaria are still to be clarified, the production of NO seems to play an important role as a marker for the severity of the disease. In this study we assess the level of nitric oxide in the serum of subjects exposed to malarial settings but who have not become clinically infected by plasmodia parasites. We conclude that NO is in fact a marker of clinical infections but cannot be used as an indicator of the disease’s severity.
Key words: Nitric oxide, malaria, Plasmodium falciparum, imported malaria.
LuÃs T., Karina* , De Sousa, Silva , Marcelo S. and Tavira
Page: 1 - 4
Research Article
African Journal of Malaria and Tropical Diseases ISSN 4123-0981 Vol. 8 (1), pp. 001-011, January, 2020. © International Scholars Journals
Full Length Research Paper
Limited variation of the 5’cis-control region of the transmission blocking vaccine candidate Pfs25 amid great genetic diversity of Plasmodium falciparum in Cameroon
Wilfred Fon Mbacham1*, Patrice Nsangou Mimche1, Palmer Masumbe Netongo1, Evehe Bebandoue Marie-Solange1, Akindeh Nji1, Immaculate Amunom1, Johanna Daily2, Valerie Makoge1, Kayla Laserson2, Songmbe Michael Yong3, Nicoline Lomah3, Peter Enyong4, Vincent P. Titanji3 and Dyann F. Wirth2
1The Biotechnology Center, University of Yaounde I, Cameroon.
2Department of Immunology and Infectious Diseases, Harvard School of Public Health, U.S.A.
3Biotechnology Unit, University of Buea, Cameroon.
4Center for Medical and Medicinal Plant Research, Ministry of Scientific Research, Kumba, SWP, Cameroon.
Accepted 16 September, 2019
Abstract
Genetic recombination during sexual reproduction within Plasmodium sp. contributes to parasite diversity and altered gene expression of certain surface markers. The pfs25 gene involved in the upset of gametocytogenesis is a candidate antigen in transmission blocking vaccine. This study investigated the polymorphism of Pfs25 within its 5’cis-control region in field isolates from different ecotypes in Cameroon. Symptomatic patients and asymptomatic healthy school children with a positive smear and from different ecozones were included. Parasite DNA was extracted and polymorphisms within pfs25, cg2-ω, msp-1, msp-2 and glurp genes were investigated by PCR-RFLP and DNA sequencing. Putative control elements of the 5’cis control regions of Pfs25 were identified by PCGENE software and enzymes were selected whose sequences produced or abolished restriction sites by mutations. Malaria infection was mainly caused by Plasmodium falciparum with sporadic occurrence of Plasmodium malariae and Plasmodium ovale. Analysis of the Pfs25 5’ cis-control region identified only one polymorphism (0.002%) that abolished an RsaI restriction site as part of the sequence TTTCTGTAC, located 40 bp downstream of the promoter and found at – 478 bp of the ATG. Analysis of the 5’ cis-control sequence of Pfs25 revealed minimal variation of the promoter region amid great zonal differences in parasite population. Altitudinal differences in parasite populations were not easily discernable.
Key words: Plasmodium falciparum, Pfs25, cis-control elements, genetic polymorphism.
Evehe Bebandoue Marie-Solange, Kayla Laserson Songmbe Michael Yong, Wilfred Fon Mbacham*, Akindeh Nji, Patrice Nsangou Mimche, Valerie Makoge, Immaculate Amunom, Johanna Daily, Palmer Masumbe Netongo
Page: 1 - 11
Research Article
African Journal of Malaria and Tropical Diseases ISSN 4123-0981 Vol. 7 (5), pp. 001-011, May, 2019. © International Scholars Journals
Full Length Research Paper
Plasmodium falciparum multidrug resistance protein (MRP) gene expression under chloroquine and mefloquine challenge
Fátima Nogueira*, Dinora Lopes, Ana Catarina Alves and Virgílio Estólio do Rosário
Centro de Malária e Outras Doenças Tropicais/IHMT/UEI Malária, Rua da Junqueira 96, 1349-008, Lisbon, Portugal.
Accepted 13 January 2019
Abstract
The present investigation was carried out to identify and study the gene expression patterns of two novel Plasmodium falciparum Multidrug Resistance associated Protein (MRP) transporters belonging to the ABC protein family coded by the genes pfmrp1 and pfmrp2 in P. falciparum. Full sequencing resulted in the identification of four SNPs in pfmrp1 and eight SNPs and three insertions/deletions in pfmrp2. Both genes showed different patterns of expression along the intraerythrocytic cycle, pfmrp1 peaks at the late trophozoites/early schizont stage, while pfmrp2 is transcribed, mostly during the ring stage and peaks again towards the end of the cycle, suggesting different parasite physiological functions. Higher levels of pfmrp1 and pfmrp2 gene expression were observed in chloroquine and mefloquine treated cultures, more visible with mefloquine. These results suggest a possible involvement of pfmrp1 and pfmrp2 genes in P. falciparum drug response.
Key words: Efflux pumps, drug resistance, gene expression, MRP, Plasmodium falciparum, polymorphism.
Fátima Nogueira*, Dinora Lopes, Ana Catarina Alves and VirgÃlio Estólio do Rosário
Page: 1 - 11