scholarly journals Plasmodium Species and Drug Resistance

2021 ◽  
Author(s):  
Sintayehu Tsegaye Tseha
Keyword(s):  
Drug Resistance ◽  
Artemisinin Resistance ◽  
Plasmodium Species ◽  
Public Health Problem ◽  
Antimalarial Drugs ◽  
Chloroquine Resistance ◽  
Resistance Pattern ◽  
Malaria Parasites ◽  
Human Malaria ◽  
The World

Malaria is a leading public health problem in tropical and subtropical countries of the world. In 2019, there were an estimated 229 million malaria cases and 409, 000 deaths due malaria in the world. The objective of this chapter is to discuss about the different Plasmodium parasites that cause human malaria. In addition, the chapter discusses about antimalarial drugs resistance. Human malaria is caused by five Plasmodium species, namely P. falciparum, P. malariae, P. vivax, P. ovale and P. knowlesi. In addition to these parasites, malaria in humans may also arise from zoonotic malaria parasites, which includes P. inui and P. cynomolgi. The plasmodium life cycle involves vertebrate host and a mosquito vector. The malaria parasites differ in their epidemiology, virulence and drug resistance pattern. P. falciparum is the deadliest malaria parasite that causes human malaria. P. falciparum accounted for nearly all malarial deaths in 2018. One of the major challenges to control malaria is the emergence and spread of antimalarial drug-resistant Plasmodium parasites. The P. vivax and P. falciparum have already developed resistance against convectional antimalarial drugs such as chloroquine, sulfadoxine-pyrimethamine, and atovaquone. Chloroquine-resistance is connected with mutations in pfcr. Resistance to Sulfadoxine and pyrimethamine is associated with multiple mutations in pfdhps and pfdhfr genes. In response to the evolution of drug resistance Plasmodium parasites, artemisinin-based combination therapies (ACTs) have been used for the treatment of uncomplicated falciparum malaria since the beginning of 21th century. However, artemisinin resistant P. falciparum strains have been recently observed in different parts of the world, which indicates the possibility of the spread of artemisinin resistance to all over the world. Therefore, novel antimalarial drugs have to be searched so as to replace the ACTs if Plasmodium parasites develop resistance to ACTs in the future.

scholarly journals Replication of Plasmodium in reticulocytes can occur without hemozoin formation, resulting in chloroquine resistance

2015 ◽  
Vol 212 (6) ◽  
pp. 893-903 ◽  
Author(s):  
Jing-wen Lin ◽  
Roberta Spaccapelo ◽  
Evelin Schwarzer ◽  
Mohammed Sajid ◽  
Takeshi Annoura ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Drug Development ◽  
Antimalarial Drug ◽  
Malaria Parasite ◽  
Chloroquine Resistance ◽  
Malaria Parasites ◽  
Human Malaria ◽  
Complete Development

Most studies on malaria-parasite digestion of hemoglobin (Hb) have been performed using P. falciparum maintained in mature erythrocytes, in vitro. In this study, we examine Plasmodium Hb degradation in vivo in mice, using the parasite P. berghei, and show that it is possible to create mutant parasites lacking enzymes involved in the initial steps of Hb proteolysis. These mutants only complete development in reticulocytes and mature into both schizonts and gametocytes. Hb degradation is severely impaired and large amounts of undigested Hb remains in the reticulocyte cytoplasm and in vesicles in the parasite. The mutants produce little or no hemozoin (Hz), the detoxification by-product of Hb degradation. Further, they are resistant to chloroquine, an antimalarial drug that interferes with Hz formation, but their sensitivity to artesunate, also thought to be dependent on Hb degradation, is retained. Survival in reticulocytes with reduced or absent Hb digestion may imply a novel mechanism of drug resistance. These findings have implications for drug development against human-malaria parasites, such as P. vivax and P. ovale, which develop inside reticulocytes.

An Overview of Available Antimalarials: Discovery, Mode of Action and Drug Resistance

2020 ◽  
Vol 20 (8) ◽  
pp. 583-592 ◽  
Author(s):  
Yu-Qing Tang ◽  
Qian Ye ◽  
He Huang ◽  
Wei-Yi Zheng
Keyword(s):  
Public Health ◽  
Drug Resistance ◽  
Artemisinin Resistance ◽  
Mechanisms Of Action ◽  
Antimalarial Drugs ◽  
Public Health Burden ◽  
The Public ◽  
Health Burden ◽  
Frequent Use ◽  
The World

: Malaria is one of the three most deadly infectious diseases in the world and seriously endangers human health and life. To reduce the public health burden of this disease, scientists have focused on the discovery and development of effective antimalarial drugs, from quinine and chloroquine to antifolates and artemisinin and its derivatives, which all play a profound role in the treatment of malaria. However, drugresistant strains of Plasmodium falciparum have emerged due to frequent use of antimalarials and have become increasingly resistant to existing antimalarial drugs, causing disastrous consequences in the world. In particular, artemisinin resistance is of greatest concern which was reported in 2008. Resistance to artenisinins has been a major obstacle for malaria control, and current efforts to curb artemisinin resistance have not been successful. Based on the current situation, it is urgent to develop more effective new antimalarials with distinct targets from conventional antimalarials in the world, which could facilitate to minimize the phenomenon of drug resistance. This review aims to summarize different kinds of antimalarial therapeutic efficacy, mechanisms of action and resistance, and proposes new solutions aiming towards further improvement of malaria elimination.

scholarly journals Non-human primate and human malaria: past, present and future

2021 ◽  
Author(s):  
Spinello Antinori ◽  
Cecilia Bonazzetti ◽  
Andrea Giacomelli ◽  
Mario Corbellino ◽  
Massimo Galli ◽  
...  
Keyword(s):  
Plasmodium Knowlesi ◽  
Plasmodium Species ◽  
Molecular Techniques ◽  
Malaria Parasites ◽  
Human Malaria ◽  
Complex Interactions ◽  
Zoonotic Malaria ◽  
The Impact ◽  
Human Plasmodium ◽  
Human Primate

Abstract Background Studies of the malaria parasites infecting various non-human primates (NHPs) have increased our understanding of the origin, biology and pathogenesis of human Plasmodium parasites. This review considers the major discoveries concerning NHP malaria parasites, highlights their relationships with human malaria and considers the impact that this may have on attempts to eradicate the disease. Results The first description of NHP malaria parasites dates back to the early 20th century. Subsequently, experimental and fortuitous findings indicating that some NHP malaria parasites can be transmitted to humans have raised concerns about the possible impact of a zoonotic malaria reservoir on efforts to control human malaria. Advances in molecular techniques over the last 15 years have contributed greatly to our knowledge of the existence and geographical distribution of numerous Plasmodium species infecting NHPs, and extended our understanding of their close phylogenetic relationships with human malaria parasites. The clinical application of such techniques has also made it possible to document ongoing spillovers of NHP malaria parasites (Plasmodium knowlesi, P. cynomolgi, P. simium, P. brasilianum) in humans living in or near the forests of Asia and South America, thus confirming that zoonotic malaria can undermine efforts to eradicate human malaria. Conclusions Increasing molecular research supports the prophetic intuition of the pioneers of modern malariology who saw zoonotic malaria as a potential obstacle to the full success of malaria eradication programmes. It is, therefore, important to continue surveillance and research based on one-health approaches in order to improve our understanding of the complex interactions between NHPs, mosquito vectors and humans during a period of ongoing changes in the climate and the use of land, monitor the evolution of zoonotic malaria, identify the populations most at risk and implement appropriate preventive strategies.

scholarly journals Mammalian deubiquitinating enzyme inhibitors display in vitro and in vivo activity against malaria parasites and potentiate artemisinin action

2020 ◽  
Author(s):  
Nelson V. Simwela ◽  
Katie R. Hughes ◽  
Michael T. Rennie ◽  
Michael P. Barrett ◽  
Andrew P. Waters
Keyword(s):  
Anticancer Agents ◽  
Drug Targets ◽  
Reverse Genetics ◽  
Enzyme Inhibitors ◽  
Artemisinin Resistance ◽  
Drug Repurposing ◽  
Antimalarial Drugs ◽  
Malaria Parasites

AbstractCurrent malaria control efforts rely significantly on artemisinin combinational therapies which have played massive roles in alleviating the global burden of the disease. Emergence of resistance to artemisinins is therefore, not just alarming but requires immediate intervention points such as development of new antimalarial drugs or improvement of the current drugs through adjuvant or combination therapies. Artemisinin resistance is primarily conferred by Kelch13 propeller mutations which are phenotypically characterised by generalised growth quiescence, altered haemoglobin trafficking and downstream enhanced activity of the parasite stress pathways through the ubiquitin proteasome system (UPS). Previous work on artemisinin resistance selection in a rodent model of malaria, which we and others have recently validated using reverse genetics, has also shown that mutations in deubiquitinating enzymes, DUBs (upstream UPS component) modulates susceptibility of malaria parasites to both artemisinin and chloroquine. The UPS or upstream protein trafficking pathways have, therefore, been proposed to be not just potential drug targets, but also possible intervention points to overcome artemisinin resistance. Here we report the activity of small molecule inhibitors targeting mammalian DUBs in malaria parasites. We show that generic DUB inhibitors can block intraerythrocytic development of malaria parasites in vitro and possess antiparasitic activity in vivo and can be used in combination with additive effect. We also show that inhibition of these upstream components of the UPS can potentiate the activity of artemisinin in vitro as well as in vivo to the extent that ART resistance can be overcome. Combinations of DUB inhibitors anticipated to target different DUB activities and downstream 20s proteasome inhibitors are even more effective at improving the potency of artemisinins than either inhibitors alone providing proof that targeting multiple UPS activities simultaneously could be an attractive approach to overcoming artemisinin resistance. These data further validate the parasite UPS as a target to both enhance artemisinin action and potentially overcome resistance. Lastly, we confirm that DUB inhibitors can be developed into in vivo antimalarial drugs with promise for activity against all of human malaria and could thus further exploit their current pursuit as anticancer agents in rapid drug repurposing programs.Graphical abstract

scholarly journals Next-Generation Sequencing and Bioinformatics Protocol for Malaria Drug Resistance Marker Surveillance

2018 ◽  
Vol 62 (4) ◽  
pp. e02474-17 ◽  
Author(s):  
Eldin Talundzic ◽  
Shashidhar Ravishankar ◽  
Julia Kelley ◽  
Dhruviben Patel ◽  
Mateusz Plucinski ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Next Generation Sequencing ◽  
Deep Sequencing ◽  
Artemisinin Resistance ◽  
The United States ◽  
Imported Malaria ◽  
Chloroquine Resistance ◽  
Next Generation ◽  
Content Type ◽  
Generation Sequencing

ABSTRACT The recent advances in next-generation sequencing technologies provide a new and effective way of tracking malaria drug-resistant parasites. To take advantage of this technology, an end-to-end Illumina targeted amplicon deep sequencing (TADS) and bioinformatics pipeline for molecular surveillance of drug resistance in P. falciparum, called malaria resistance surveillance (MaRS), was developed. TADS relies on PCR enriching genomic regions, specifically target genes of interest, prior to deep sequencing. MaRS enables researchers to simultaneously collect data on allele frequencies of multiple full-length P. falciparum drug resistance genes (crt, mdr1, k13, dhfr, dhps, and the cytochrome b gene), as well as the mitochondrial genome. Information is captured at the individual patient level for both known and potential new single nucleotide polymorphisms associated with drug resistance. The MaRS pipeline was validated using 245 imported malaria cases that were reported to the Centers for Disease Control and Prevention (CDC). The chloroquine resistance crt CVIET genotype (mutations underlined) was observed in 42% of samples, the highly pyrimethamine-resistant dhps IRN triple mutant in 92% of samples, and the sulfadoxine resistance dhps mutation SGEAA in 26% of samples. The mdr1 NFSND genotype was found in 40% of samples. With the exception of two cases imported from Cambodia, no artemisinin resistance k13 alleles were identified, and 99% of patients carried parasites susceptible to atovaquone-proguanil. Our goal is to implement MaRS at the CDC for routine surveillance of imported malaria cases in the United States and to aid in the adoption of this system at participating state public health laboratories, as well as by global partners.

Prediction of human Plasmodium sex specific gene by homology search: a systematic review and meta-synthesis

2017 ◽  
Author(s):  
Mitsuhiro Odaka ◽  
Amen Sassy ◽  
Shymmaa Khatab ◽  
Linh Tran ◽  
Khaled Ismaeil ◽  
...  
Keyword(s):  
Systematic Review ◽  
Candidate Genes ◽  
Plasmodium Species ◽  
Homology Search ◽  
Specific Gene ◽  
Published Data ◽  
Malaria Parasites ◽  
Human Malaria ◽  
Search Terms ◽  
Human Plasmodium

Human Plasmodium species have a sex specific process in the life cycle namely gametocytogenesis or gametogenesis. Gametocytes production and subsequent gametes zygosis are critical for malaria parasites to link to mosquito stage and to merge to sexual reproduction. Here, we aimed at the identification of genes related to gametocytogenesis or gametogenesis in human malaria using systematic review, meta-synthesis and homology search. Based on our search terms, we conducted a systematic search of published data in nine databases resulting in 96 finally included papers with a total of 255 genes from apicomplexan species. We found more papers involved in Plasmodium than we had expected, which reflects that the extensive amount of research on Plasmodium genes have been examined. Subsequently we searched sequence homology between FASTA sequences of apicomplexan sex specific genes other than human malaria parasites and those of human malaria parasites genome on PlasmoDB. We focused on eight candidate genes of Plasmodium falciparum (PF). Finally we predicted that PRPF6, SMC1 and SMC2 can be the especially promising candidate genes.

scholarly journals Ten-Year Molecular Surveillance of Drug-Resistant Plasmodium spp. Isolated From the China–Myanmar Border

2021 ◽  
Vol 11 ◽  
Author(s):  
Tongke Tang ◽  
Yanchun Xu ◽  
Long Cao ◽  
Penghai Tian ◽  
Jiang Shao ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Low Frequency ◽  
Artemisinin Resistance ◽  
Border Region ◽  
Chloroquine Resistance ◽  
Antimalarial Drug Resistance ◽  
Molecular Surveillance ◽  
First Choice ◽  
Greater Mekong Subregion ◽  
C580y Mutation

Antimalarial drug resistance has emerged as a major threat to global malaria control efforts, particularly in the Greater Mekong Subregion (GMS). In this study, we analyzed the polymorphism and prevalence of molecular markers associated with resistance to first-line antimalarial drugs, such as artemisinin, chloroquine, and pyrimethamine, using blood samples collected from malaria patients in the China–Myanmar border region of the GMS from 2008 to 2017, including 225 cases of Plasmodium falciparum and 194 cases of Plasmodium vivax. In artemisinin resistance, only the C580Y mutation with low frequency was detected in pfk13, and no highly frequent stable mutation was found in pvk12. In chloroquine resistance, the frequency of K76T mutation in pfcrt was always high, and the frequency of double mutations in pvmdr1 of P. vivax has been steadily increasing every year. In pyrimidine resistance, pfdhfr and pvdhfr had relatively more complex mutant types associated with drug resistance sites, and the overall mutation rate was still high. Therefore, artemisinin-based combination therapies are still suitable for use as the first choice of antimalarial strategy in the China–Myanmar border region in the future.

scholarly journals Prevalence of Plasmodium falciparum Chloroquine Resistance Transporter (Pfcrt76T) Mutation Associated with Antimalarial Drug Resistance in Two Different Epidemiological Setting (Banfora and Saponé) in Burkina Faso Few Years after the Implementation of Artemisnine Based Combination Therapy (ACTs)

2020 ◽  
pp. 1-11
Author(s):  
Séni Nikiema ◽  
Samuel Sindié Sermé ◽  
Salif Sombié ◽  
Amidou Diarra ◽  
Noelie Bere Henry ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Burkina Faso ◽  
Public Health Problem ◽  
Antimalarial Drugs ◽  
Sub Saharan Africa ◽  
Chloroquine Resistance ◽  
Chloroquine Resistance Transporter ◽  
Significant Difference ◽  
Sub Saharan ◽  
Biology Laboratory

Introduction: In spite of considerable progress, malaria remains a public health problem in many areas, particularly in sub-Saharan Africa. One major complexity of malaria disease is caused by the development and the spread of vector and parasite resistance to insecticides and antimalarial drugs respectively. The Pfcrt76T gene mutation has been validated as a marker conferring resistance to chloroquine and other antimalarial drugs. The extension of Plasmodium falciparum resistance to commonly used antimalarial drugs (chloroquine, sulfadoxine-pyrimethamine) led to the adoption and the use of artemisinin-based combinations in Burkina Faso since 2005. Aims: The present study was initiated to assess the prevalence of the Pfcrt76T mutation in two different malaria epidemiological setting after a decade of introduction of artemisinin-based combination therapies (ACTs) in Burkina Faso.  Methodology:  The study population consisted of 181 uncomplicated malaria patients recruited in Banfora and Saponé health districts in 2012 and 2013. Blood samples were collected from finger prick on filter paper, dried and sent to the Molecular Biology Laboratory at Centre National de Recherche et de Formation sur le Paludisme (CNRFP) for molecular analyzes. DNA of Plasmodium falciparum was extracted with DNA extraction kit (Qiagen®) and the Pfcrt76T mutation was determined based on Polymerase Chain Reaction / Restriction Fragment Length Polymorphism technique (RFLP). Results:  The results of this study showed that the frequency of the pfcrt76T mutant allele (33.7%) was statistically lower than the Pfcrt76K wild-type allele (57.4%) in the study area. Moreover, the prevalence of Pfcrt76T mutation was neither associated with the patient age nor with the parasite density while a significant difference was observed between the two epidemiological setting, Banfora and Saponé. Conclusion: The findings of this study has shown a drop in the prevalence of mutant parasites Pfcrt76T in both the study area eight years after the introduction of ACTs compared to previous studies.

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