The blood-stages of Plasmodium georgesi, P. gonderi and P. petersi: course of untreated infection in their natural hosts and additional morphological distinctive features

Parasitology ◽  
1995 ◽  
Vol 111 (5) ◽  
pp. 547-554 ◽  
Author(s):  
J. Poirriez ◽  
E. Dei-Cas ◽  
L. Dujardin ◽  
I. Landau
Keyword(s):  
Surface Area ◽  
Malaria Parasite ◽  
Polarized Light ◽  
Malaria Parasites ◽  
Distinctive Features ◽  
Low Level ◽  
Mixed Blood ◽  
Natural Hosts ◽  
Round Nucleus ◽  
Chronic Course

SUMMARYIn the blood of a Cercocebus albigena and of a C. galeritus agilis monkey, the infection with Plasmodium gonderi was found to follow its well-known chronic course; P. georgesi seemed to occur as a relapsing type of malaria parasite; P. petersi was found for only a few days and at a low level in C. albigena (end of an attack?). As shown by using polarized light, the pigment granules appeared mostly as fine dots in P. georgesi, short rods in P. gonderi and long needles in P. petersi. The three species can be distinguished by the morphological appearance of the nucleus of the young trophozoites, and also by the measurement of its surface area (Sa): small round nucleus (Sa= 0·81 ± 0·06 μm2) in P. gonderi, large 2-coloured nucleus (Sa= 1·43 ± 0·21 μm2) in P. petersi, and long crescent-shaped nucleus (Sa= 2·18±0·25 μm2) in P. georgesi. The first colour illustrations of the blood-stages of P. georgesi are presented. The dynamics of single and mixed blood infections in primate malaria parasites are discussed, with a proposal to classify them into 3 types.

scholarly journals Prevalence of simian malaria parasites in macaques of Singapore

2021 ◽  
Vol 15 (1) ◽  
pp. e0009110
Author(s):  
Meizhi Irene Li ◽  
Diyar Mailepessov ◽  
Indra Vythilingam ◽  
Vernon Lee ◽  
Patrick Lam ◽  
...  
Keyword(s):  
Human Population ◽  
Malaria Parasite ◽  
Parasite Species ◽  
Plasmodium Knowlesi ◽  
Malaria Parasites ◽  
Simian Malaria ◽  
Specific Pcr ◽  
Natural Hosts ◽  
Multiple Species ◽  
Species Specific

Plasmodium knowlesi is a simian malaria parasite currently recognized as the fifth causative agent of human malaria. Recently, naturally acquired P. cynomolgi infection in humans was also detected in Southeast Asia. The main reservoir of both parasites is the long-tailed and pig-tailed macaques, which are indigenous in this region. Due to increased urbanization and changes in land use, there has been greater proximity and interaction between the long-tailed macaques and the general population in Singapore. As such, this study aims to determine the prevalence of simian malaria parasites in local macaques to assess the risk of zoonosis to the general human population. Screening for the presence of malaria parasites was conducted on blood samples from 660 peridomestic macaques collected between Jan 2008 and Mar 2017, and 379 wild macaques collected between Mar 2009 and Mar 2017, using a Pan-Plasmodium-genus specific PCR. Positive samples were then screened using a simian Plasmodium species-specific nested PCR assay to identify the species of parasites (P. knowlesi, P. coatneyi, P. fieldi, P. cynomolgi, and P. inui) present. All the peridomestic macaques sampled were tested negative for malaria, while 80.5% of the 379 wild macaques were infected. All five simian Plasmodium species were detected; P. cynomolgi being the most prevalent (71.5%), followed by P. knowlesi (47.5%), P. inui (42.0%), P. fieldi (32.5%), and P. coatneyi (28.5%). Co-infection with multiple species of Plasmodium parasites was also observed. The study revealed that Singapore’s wild long-tailed macaques are natural hosts of the five simian malaria parasite species, while no malaria was detected in all peridomestic macaques tested. Therefore, the risk of simian malaria transmission to the general human population is concluded to be low. However, this can be better demonstrated with the incrimination of the vectors of simian malaria parasites in Singapore.

scholarly journals A cornucopia of research resources for the fourth rodent malaria parasite species

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Jane M. Carlton
Keyword(s):  
Malaria Parasite ◽  
Parasite Species ◽  
First Century ◽  
Model Systems ◽  
Rodent Malaria Parasite ◽  
Malaria Parasites ◽  
Rodent Malaria ◽  
Human Malaria ◽  
Plasmodium Vinckei ◽  
Research Resources

AbstractThe study of human malaria caused by species of Plasmodium has undoubtedly been enriched by the use of model systems, such as the rodent malaria parasites originally isolated from African thicket rats. A significant gap in the arsenal of resources of the species that make up the rodent malaria parasites has been the lack of any such tools for the fourth of the species, Plasmodium vinckei. This has recently been rectified by Abhinay Ramaprasad and colleagues, whose pivotal paper published in BMC Biology describes a cornucopia of new P. vinckei ‘omics datasets, mosquito transmission experiments, transfection protocols, and virulence phenotypes, to propel this species firmly into the twenty-first century.

scholarly journals Malaria parasite detection in thick blood smear microscopic images using modified YOLOV3 and YOLOV4 models

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Fetulhak Abdurahman ◽  
Kinde Anlay Fante ◽  
Mohammed Aliy
Keyword(s):  
Object Detection ◽  
Malaria Parasite ◽  
Blood Smear ◽  
Clustering Algorithm ◽  
State Of The Art ◽  
Detection Accuracy ◽  
Small Object ◽  
Thick Blood Smear ◽  
Malaria Parasites ◽  
Microscopic Images

Abstract Background Manual microscopic examination of Leishman/Giemsa stained thin and thick blood smear is still the “gold standard” for malaria diagnosis. One of the drawbacks of this method is that its accuracy, consistency, and diagnosis speed depend on microscopists’ diagnostic and technical skills. It is difficult to get highly skilled microscopists in remote areas of developing countries. To alleviate this problem, in this paper, we propose to investigate state-of-the-art one-stage and two-stage object detection algorithms for automated malaria parasite screening from microscopic image of thick blood slides. Results YOLOV3 and YOLOV4 models, which are state-of-the-art object detectors in accuracy and speed, are not optimized for detecting small objects such as malaria parasites in microscopic images. We modify these models by increasing feature scale and adding more detection layers to enhance their capability of detecting small objects without notably decreasing detection speed. We propose one modified YOLOV4 model, called YOLOV4-MOD and two modified models of YOLOV3, which are called YOLOV3-MOD1 and YOLOV3-MOD2. Besides, new anchor box sizes are generated using K-means clustering algorithm to exploit the potential of these models in small object detection. The performance of the modified YOLOV3 and YOLOV4 models were evaluated on a publicly available malaria dataset. These models have achieved state-of-the-art accuracy by exceeding performance of their original versions, Faster R-CNN, and SSD in terms of mean average precision (mAP), recall, precision, F1 score, and average IOU. YOLOV4-MOD has achieved the best detection accuracy among all the other models with a mAP of 96.32%. YOLOV3-MOD2 and YOLOV3-MOD1 have achieved mAP of 96.14% and 95.46%, respectively. Conclusions The experimental results of this study demonstrate that performance of modified YOLOV3 and YOLOV4 models are highly promising for detecting malaria parasites from images captured by a smartphone camera over the microscope eyepiece. The proposed system is suitable for deployment in low-resource setting areas.

scholarly journals Genome sequence, transcriptome, and annotation of rodent malaria parasite Plasmodium yoelii nigeriensis N67

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Cui Zhang ◽  
Cihan Oguz ◽  
Sue Huse ◽  
Lu Xia ◽  
Jian Wu ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Malaria Parasite ◽  
Vaccine Development ◽  
De Novo ◽  
Gene Families ◽  
Plasmodium Yoelii ◽  
Control Measures ◽  
Effective Control ◽  
Malaria Parasites ◽  
Rodent Malaria

Abstract Background Rodent malaria parasites are important models for studying host-malaria parasite interactions such as host immune response, mechanisms of parasite evasion of host killing, and vaccine development. One of the rodent malaria parasites is Plasmodium yoelii, and multiple P. yoelii strains or subspecies that cause different disease phenotypes have been widely employed in various studies. The genomes and transcriptomes of several P. yoelii strains have been analyzed and annotated, including the lethal strains of P. y. yoelii YM (or 17XL) and non-lethal strains of P. y. yoelii 17XNL/17X. Genomic DNA sequences and cDNA reads from another subspecies P. y. nigeriensis N67 have been reported for studies of genetic polymorphisms and parasite response to drugs, but its genome has not been assembled and annotated. Results We performed genome sequencing of the N67 parasite using the PacBio long-read sequencing technology, de novo assembled its genome and transcriptome, and predicted 5383 genes with high overall annotation quality. Comparison of the annotated genome of the N67 parasite with those of YM and 17X parasites revealed a set of genes with N67-specific orthology, expansion of gene families, particularly the homologs of the Plasmodium chabaudi erythrocyte membrane antigen, large numbers of SNPs and indels, and proteins predicted to interact with host immune responses based on their functional domains. Conclusions The genomes of N67 and 17X parasites are highly diverse, having approximately one polymorphic site per 50 base pairs of DNA. The annotated N67 genome and transcriptome provide searchable databases for fast retrieval of genes and proteins, which will greatly facilitate our efforts in studying the parasite biology and gene function and in developing effective control measures against malaria.

scholarly journals Adaptive Drug Resistance in Malaria Parasite: A Threat to Malaria Elimination Agenda?

2021 ◽  
Author(s):  
Moses Okpeku
Keyword(s):  
Drug Resistance ◽  
Malaria Elimination ◽  
Malaria Parasite ◽  
Disease Burden ◽  
Drug Application ◽  
African Region ◽  
Malaria Parasites ◽  
Sub Saharan ◽  
Host Development

Malaria is a global disease of importance, especially in the sub-Saharan African region, where malaria accounts for great losses economically and to life. Fight to eliminate this disease has resulted in reduced disease burden in many places where the diseases is endemic. Elimination strategies in most places is focus on the use of treated nets and drug application. Exposure of malaria parasites to anti-malaria drugs have led to the evolution of drug resistance in both parasites and host. Development of drug resistance vary but, studies on adaptive drug resistance has implications and consequences. Our knowledge of this consequences are limited but important for the pursuit of an uninterrupted malaria elimination agenda. This chapter draws our attention to this risks and recommends interventions.

scholarly journals OVERVIEW OF MALARIA PARASITE AND ITS PREVENTION IN INDIA

2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Adil Raza ◽  
Megha Chaudhary ◽  
Sonika Devi
Keyword(s):  
Red Blood Cells ◽  
Peripheral Blood ◽  
Blood Cells ◽  
Malaria Parasite ◽  
Plasmodium Species ◽  
Peripheral Blood Smear ◽  
Infected Mosquito ◽  
Protozoan Parasites ◽  
Malaria Parasites ◽  
Genus Plasmodium

Background: Malaria is a systematic disease caused by a parasite called Plasmodium which is transmitted into the human blood via female Anopheles mosquito. Malaria in humans is caused by four species of protozoan parasites of the genus Plasmodium: P. falciparum, P. vivax, P. ovale, and P. malariae. The parasite enters the human body through a mosquito bite and travel to the very crucial organ, the liver, where they multiply and come back to the bloodstream and destroy red blood cells. Malaria causes symptoms that typically include fever, tiredness, vomiting, and headaches. In severe cases it can cause yellow skin, seizures, coma, or death. Symptoms usually begin ten to fifteen days after being bitten by an infected mosquito. In those who have recently survived an infection, reinfection usually causes milder symptoms. Objectives: Isolation of different species of malaria parasites. The prevalence of malaria parasite in India. Methods: The procedure follows these steps: collection of peripheral blood, staining of smear with Leishman’s stain and examination of red blood cells for malaria parasites under the microscope. Results: We observed the plasmodium species in peripheral blood smear. Conclusion: Worldwide, the number of cases of malaria caused by Plasmodium falciparum, the most dangerous species of the parasite, is on the rise.

scholarly journals Wild African great apes as natural hosts of malaria parasites: current knowledge and research perspectives

2017 ◽  
Vol 4 (1) ◽  
pp. 47-59 ◽  
Author(s):  
Hélène Marie De Nys ◽  
Therese Löhrich ◽  
Doris Wu ◽  
Sébastien Calvignac-Spencer ◽  
Fabian Hubertus Leendertz
Keyword(s):  
Current Knowledge ◽  
Great Apes ◽  
Future Research ◽  
Human Populations ◽  
Great Ape ◽  
Malaria Parasites ◽  
Research Perspectives ◽  
Parasite Ecology ◽  
Natural Hosts ◽  
African Great Apes

Abstract. Humans and African great apes (AGAs) are naturally infected with several species of closely related malaria parasites. The need to understand the origins of human malaria as well as the risk of zoonotic transmissions and emergence of new malaria strains in human populations has markedly encouraged research on great ape Plasmodium parasites. Progress in the use of non-invasive methods has rendered investigations into wild ape populations possible. Present knowledge is mainly focused on parasite diversity and phylogeny, with still large gaps to fill on malaria parasite ecology. Understanding what malaria infection means in terms of great ape health is also an important, but challenging avenue of research and has been subject to relatively few research efforts so far. This paper reviews current knowledge on African great ape malaria and identifies gaps and future research perspectives.

scholarly journals PlasmoTron: an open-source platform for automated culture of malaria parasites

2017 ◽  
Author(s):  
Theo Sanderson ◽  
Julian C. Rayner
Keyword(s):  
Open Source ◽  
Genetic Modification ◽  
Malaria Parasite ◽  
Scale Up ◽  
Malaria Parasites ◽  
Parasite Culture ◽  
Liquid Handling ◽  
Liquid Handling Robot

We have created a system which allows an inexpensive opensource liquid-handling robot to automate most aspects of bloodstage malaria parasite culture. Parasites are cultured in multiwell microplates, with their details recorded in a database. Information in the database is used to generate commands for the robot to feed, monitor and passage parasite cultures. We show that the system is capable of raising cultures after transfection and then maintaining them at desired parasitaemias, facilitiating significant scale up of both routine culture and experimental genetic modification. The PlasmoTron software is available at plasmotron.org.

scholarly journals Large Variations in Malaria Parasite Carriage by Afebrile School Children Living in Nearby Communities in the Central Region of Ghana

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Evans K. Obboh ◽  
Ruth E. Okonu ◽  
Linda E. Amoah
Keyword(s):  
Malaria Transmission ◽  
Central Region ◽  
Malaria Control ◽  
Filter Paper ◽  
Malaria Parasite ◽  
Molecular Evidence ◽  
Asymptomatic Malaria ◽  
Cape Coast ◽  
Malaria Parasites ◽  
Asymptomatic Infections

Background. Indicators of successful malaria control interventions include a reduction in the prevalence and densities of malaria parasites contained in both symptomatic and asymptomatic infections as well as a reduction in malaria transmission. Individuals harboring malaria parasites in asymptomatic infections serve as reservoirs for malaria transmission. This study determined the prevalence of asymptomatic malaria parasite carriage in afebrile children attending six different schools in two districts, the Cape Coast Metropolitan Assembly (CCMA) and the Komenda Edina Eguafo Abirem (KEEA) of the Central Region of Ghana. Methods. This cross sectional study recruited afebrile children aged between 3 and 15 years old from six randomly selected schools in the Central Region of Ghana. Finger-pricked blood was collected and used to prepare thick and thin blood smears as well as spot a strip of filter paper (Whatman #3). Nested PCR was used to identify Plasmodium falciparum, Plasmodium malariae, Plasmodium ovale, and Plasmodium vivax in DNA extracted from the filter paper spots. The multiplicity of P. falciparum infection was determined using merozoite surface protein 2 genotyping. Results. Out of the 528 children sampled, PCR identified 27.1% to harbor Plasmodium parasites in asymptomatic infections, whilst microscopy identified malaria parasites in 10.6% of the children. The overall PCR estimated prevalence of P. falciparum and P. malariae was 26.6% and 1.3%, respectively, with no P. ovale or P. vivax identified by PCR or microscopy. The RDT positivity rate ranged from 55.8% in Simiw to 4.5% in Kuful. Children from the Simiw Basic School accounted for 87.5% of all the asymptomatic infections. The multiplicity of P. falciparum infection was predominantly monoclonal and biclonal. Conclusions. The low prevalence of asymptomatic malaria parasite carriage by the children living in the Cape Coast Metropolis suggests that the malaria control interventions in place in CCMA are highly effective and that additional malaria control interventions are required for the KEEA district to reduce the prevalence of asymptomatic malaria parasite carriers. No molecular evidence of P. ovale and P. vivax was identified in the afebrile children sampled from the selected schools.

scholarly journals Malaria Parasites Can Develop Stable Resistance to Artemisinin but Lack Mutations in Candidate Genes atp6 (Encoding the Sarcoplasmic and Endoplasmic Reticulum Ca2+ ATPase), tctp, mdr1, and cg10

2006 ◽  
Vol 50 (2) ◽  
pp. 480-489 ◽  
Author(s):  
A. Afonso ◽  
P. Hunt ◽  
S. Cheesman ◽  
A. C. Alves ◽  
C. V. Cunha ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasmodium Falciparum ◽  
Copy Number ◽  
Malaria Parasite ◽  
Field Studies ◽  
Rodent Malaria Parasite ◽  
Malaria Parasites ◽  
Rodent Malaria ◽  
First Time ◽  
Genetic Modulators

ABSTRACT Resistance of Plasmodium falciparum to drugs such as chloroquine and sulfadoxine-pyrimethamine is a major problem in malaria control. Artemisinin (ART) derivatives, particularly in combination with other drugs, are thus increasingly used to treat malaria, reducing the probability that parasites resistant to the components will emerge. Although stable resistance to artemisinin has yet to be reported from laboratory or field studies, its emergence would be disastrous because of the lack of alternative treatments. Here, we report for the first time, to our knowledge, genetically stable and transmissible ART and artesunate (ATN)-resistant malaria parasites. Each of two lines of the rodent malaria parasite Plosmodium chabaudi chabaudi, grown in the presence of increasing concentrations of ART or ATN, showed 15-fold and 6-fold increased resistance to ART and ATN, respectively. Resistance remained stable after cloning, freeze-thawing, after passage in the absence of drug, and transmission through mosquitoes. The nucleotide sequences of the possible genetic modulators of ART resistance (mdr1, cg10, tctp, and atp6) of sensitive and resistant parasites were compared. No mutations in these genes were identified. In addition we investigated whether changes in the copy number of these genes could account for resistance but found that resistant parasites retained the same number of copies as their sensitive progenitors. We believe that this is the first report of a malaria parasite with genetically stable and transmissible resistance to artemisinin or its derivatives.

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