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Scientific Reports Nov 2023In recent phylogenetic studies, bat Polychromophilus and ungulate Plasmodium, two relatively understudied haemosporidian parasites within the Apicomplexa phylum, have...
In recent phylogenetic studies, bat Polychromophilus and ungulate Plasmodium, two relatively understudied haemosporidian parasites within the Apicomplexa phylum, have often been overlooked. Instead, the focus has been primarily on haemosporidian parasites in primates, rodents, and birds. Several phylogenetic analyses of bat Polychromophilus have relied on limited datasets and short informative DNA sequences. As a result of these inherent limitations, the substantiation of their evolutionary stance has encountered a diminished degree of robust validation. This study successfully obtained complete mitochondrial genome sequences from 11 Polychromophilus parasites originating from Hipposideros gentilis and Myotis siligoensis bats for the first time. Additionally, the authors have sequenced the apicoplast caseinolytic protease C genes from Polychromophilus murinus and a potentially new Polychromophilus species. These mitochondrial genomes range in length from 5994 to 6001 bp and consist of three protein-coding genes (PCGs), seven small subunit ribosomal RNA genes (SSU rRNA), 12 large subunit ribosomal RNA genes (LSU rRNA), and seven miscellaneous RNA genes. Phylogenetic analyses using Bayesian Inference and Maximum Likelihood methods indicated robust support for the grouping of ungulate Plasmodium and bat Polychromophilus in a single clade separate from other Plasmodium spp., confirming previous reports, albeit with stronger evidence in this study. The divergence between Polychromophilus in bats and Plasmodium in ungulates occurred approximately 29.61 to 55.77 million years ago (Mya), with a node age estimated at 40.63 Mya. These findings highlight that the genus Plasmodium, which includes species found in ungulates, birds, reptiles, and other mammals, does not form a monophyletic group. By incorporating Polychromophilus in bats and Plasmodium in ungulates, this study contributes significantly to understanding the phylogenetic relationships within the Haemosporida order. It provides valuable insights into the evolutionary history and interconnections among these diverse parasites, thereby expanding knowledge in this field.
Topics: Animals; Chiroptera; Phylogeny; Genome, Mitochondrial; Bayes Theorem; Plasmodium; Mammals; Haemosporida; Parasites; Rodentia; Primates
PubMed: 37985797
DOI: 10.1038/s41598-023-45551-z -
BMC Infectious Diseases Sep 2023Malaria cases in non-endemic zero-indigenous case areas are most likely to have been imported whatever of the route of importation. In countries recently declared...
BACKGROUND
Malaria cases in non-endemic zero-indigenous case areas are most likely to have been imported whatever of the route of importation. In countries recently declared malaria-free and now without local transmission, imported cases remain a threat to re-introduction of the disease and a burden on the health system.
CASE PRESENTATION
Three days after returning from a long trip to malaria- endemic countries; Abyei-Sudan, Chad and Uganda, a 41-year-old male resident from Jericho, Palestine, suffered paroxysms of fever, general fatigue, myalgia, arthralgia, headache, and a strong desire to vomit. Thin and thick Giemsa-stained blood smears were prepared and examined microscopically using oil immersion. Immature trophozoites (ring forms) were seen to parasitize approximately 10% of the erythrocytes revealing hyperparasitemia equivalent to > 100,000 parasites/ µl indicating severe malaria [1, 2]. The double chromatin configuration (headphones) and accolé (applique) position are both indicative of Plasmodium falciparum infection. The 18S rRNA- PCR targeting the rPLU6-rPLU5 region was used to confirm the diagnosis. The next-generation sequencing (NGS) method was carried out according to the manufacturer's instructions (Illumina® DNA Prep, (M) Tagmentation kit (20060060), Illumina) to identify Plasmodium spp. Furthermore, NGS produced a whole-genome sequence of 22.8Mbp of the 14 chromosomes and 25Kbp of the apicoplast. A BLAST search of the apicoplast DNA and selected chromosomal DNA revealed that P. falciparum was the causative agent. The merozoite surface protein-1 (msp-1) was used to construct a phylogenetic tree of 26 P. falciparum, including the one isolated from the patient from Jericho, which clustered with the Sudanese isolate indicating genetic relatedness between the two.
CONCLUSION
The travel history together with signs and symptoms of malaria, followed by prompt diagnosis using conventional microscopic inspection of Giemsa-stained films together with molecular DNA tracking tools like msp-1 were key means in tracking the place of origin of infection in the case of travel to multiple destination.
Topics: Humans; Adult; Plasmodium falciparum; Merozoite Surface Protein 1; Phylogeny; Malaria; Malaria, Falciparum; Azure Stains; DNA, Ribosomal
PubMed: 37723449
DOI: 10.1186/s12879-023-08583-4 -
ACS Infectious Diseases Jan 2024Replication of the malarial parasite in human erythrocytes requires massive zinc fluxes, necessitating the action of zinc transporters across the parasite plasma and...
Replication of the malarial parasite in human erythrocytes requires massive zinc fluxes, necessitating the action of zinc transporters across the parasite plasma and organellar membranes. Although genetic knockout studies have been conducted on a few "orphan" zinc transporters in spp., none of them have been functionally characterized. We used the recombinant Zrt-/Irt-like protein (ZIP1) and specific antibodies generated against it to explore the subcellular localization, function, metal-ion selectivity, and response to cellular zinc levels. ZIP1 expression was enhanced upon the depletion of cytosolic Zn. The protein transitioned from the processed to unprocessed form through blood stages, localizing to the apicoplast in trophozoites and to the parasite plasma membrane in schizonts and gametocytes, indicating stage-specific functional role. The ZIP1 dimer mediated Zn influx in proteoliposomes. It exhibited preferential binding to Zn compared to Fe, with the selectivity for zinc being driven by a C-terminal histidine-rich region conserved only in primate-infecting species.
Topics: Animals; Humans; Plasmodium falciparum; Apicoplasts; Parasites; Cell Membrane; Erythrocytes
PubMed: 38163252
DOI: 10.1021/acsinfecdis.3c00426 -
BioRxiv : the Preprint Server For... Jan 2024Babesiosis, caused by protozoan parasites of the genus , is an emerging tick-borne disease of significance for both human and animal health. parasites infect...
Babesiosis, caused by protozoan parasites of the genus , is an emerging tick-borne disease of significance for both human and animal health. parasites infect erythrocytes of vertebrate hosts where they develop and multiply rapidly to cause the pathological symptoms associated with the disease. The identification of various species underscores the ongoing risk of new zoonotic pathogens capable of infecting humans, a concern amplified by anthropogenic activities and environmental shifts impacting the distribution and transmission dynamics of parasites, their vectors, and reservoir hosts. One such species, MO1, previously implicated in severe cases of human babesiosis in the midwestern United States, was initially considered closely related to , the predominant agent of human babesiosis in Europe. Yet, uncertainties persist regarding whether these pathogens represent distinct variants of the same species or are entirely separate species. We show that although both MO1 and share similar genome sizes, comprising three nuclear chromosomes, one linear mitochondrial chromosome, and one circular apicoplast chromosome, major differences exist in terms of genomic sequence divergence, gene functions, transcription profiles, replication rates and susceptibility to antiparasitic drugs. Furthermore, both pathogens have evolved distinct classes of multigene families, crucial for their pathogenicity and adaptation to specific mammalian hosts. Leveraging genomic information for MO1, , and other members of the Babesiidae family within Apicomplexa provides valuable insights into the evolution, diversity, and virulence of these parasites. This knowledge serves as a critical tool in preemptively addressing the emergence and rapid transmission of more virulent strains.
PubMed: 38293033
DOI: 10.1101/2024.01.17.575932 -
Frontiers in Epidemiology 2024Antimalarial drugs including artemisinin-based combination therapy (ACT) regimens and sulphadoxine-pyrimethamine (SP) are used in Ghana for malaria therapeutics and...
INTRODUCTION
Antimalarial drugs including artemisinin-based combination therapy (ACT) regimens and sulphadoxine-pyrimethamine (SP) are used in Ghana for malaria therapeutics and prophylaxis respectively. The genetic basis of development of drug resistance involves single nucleotide polymorphisms in genes encoding proteins for multiple cellular and metabolic processes. The prevalence of single nucleotide polymorphisms in nine genes linked to ACT and SP resistance in the malaria parasite population was determined.
METHODS
Archived filter paper blood blot samples from patients aged 9 years and below with uncomplicated malaria reporting at 10 sentinel sites located in three ecological zones for the Malaria Therapeutic Efficacy Studies were used. The samples used were collected from 2007-2018 malaria transmission seasons and mutations in the genes were detected using PCR and Sanger sequencing.
RESULTS
In all 1,142 samples were used for the study. For falcipain-2 gene () Sanger sequencing was successful for 872 samples and were further analysed. The prevalence of the mutants was 45% (392/872) with markers V51I and S59F occurring in 15.0% (128/872) and 3.0% (26/872) of the samples respectively. Prevalence of other gene mutations: coronin () was 44.8% (37/90); cysteine desulfurase () was 73.9% (68/92); apicoplast ribosomal protein S10 () was 36.8% (35/95); ferredoxin () was 8.8% (8/91); multidrug resistance protein-1 () was 95.2.0% (80/84); multidrug resistance protein-2 () was 91.4% (32/35); dihydrofolate reductase () was 99.0% (84/85); dihydropteroate synthase () was 72% (68/95).
DISCUSSION
The observation of numerous mutations in these genes of interest in the Ghanaian isolates, some of which have been implicated in delayed parasite clearance is of great interest. The presence of these genotypes may account for the decline in the efficacies of ACT regimens being used to treat uncomplicated malaria in the country. The need for continuous monitoring of these genetic markers to give first-hand information on parasite susceptibility to antimalarial drugs to inform policy makers and stakeholders in malaria elimination in the country is further discussed.
PubMed: 38456076
DOI: 10.3389/fepid.2024.1279835 -
Nucleic Acids Research Jun 2024The human malaria parasite Plasmodium falciparum genome is among the most A + T rich, with low complexity regions (LCRs) inserted in coding sequences including those...
The human malaria parasite Plasmodium falciparum genome is among the most A + T rich, with low complexity regions (LCRs) inserted in coding sequences including those for proteins targeted to its essential relict plastid (apicoplast). Replication of the apicoplast genome (plDNA), mediated by the atypical multifunctional DNA polymerase PfPrex, would require additional enzymatic functions for lagging strand processing. We identified an apicoplast-targeted, [4Fe-4S]-containing, FEN/Exo (PfExo) with a long LCR insertion and detected its interaction with PfPrex. Distinct from other known exonucleases across organisms, PfExo recognized a wide substrate range; it hydrolyzed 5'-flaps, processed dsDNA as a 5'-3' exonuclease, and was a bipolar nuclease on ssDNA and RNA-DNA hybrids. Comparison with the rodent P. berghei ortholog PbExo, which lacked the insertion and [4Fe-4S], revealed interspecies functional differences. The insertion-deleted PfExoΔins behaved like PbExo with a limited substrate repertoire because of compromised DNA binding. Introduction of the PfExo insertion into PbExo led to gain of activities that the latter initially lacked. Knockout of PbExo indicated essentiality of the enzyme for survival. Our results demonstrate the presence of a novel apicoplast exonuclease with a functional LCR that diversifies substrate recognition, and identify it as the candidate flap-endonuclease and RNaseH required for plDNA replication and maintenance.
PubMed: 38888125
DOI: 10.1093/nar/gkae512 -
Proceedings of the National Academy of... Feb 2024is an emerging zoonosis and widely distributed veterinary infection caused by 100+ species of parasites. The diversity of parasites and the lack of specific drugs...
is an emerging zoonosis and widely distributed veterinary infection caused by 100+ species of parasites. The diversity of parasites and the lack of specific drugs necessitate the discovery of broadly effective antibabesials. Here, we describe a comparative chemogenomics (CCG) pipeline for the identification of conserved targets. CCG relies on parallel in vitro evolution of resistance in independent populations of spp. ( and ). We identified a potent antibabesial, MMV019266, from the Malaria Box, and selected for resistance in two species of . After sequencing of multiple independently derived lines in the two species, we identified mutations in a membrane-bound metallodependent phosphatase (). In both species, the mutations were found in the phoD-like phosphatase domain. Using reverse genetics, we validated that mutations in confer resistance to MMV019266 in . We have also demonstrated that BdPhoD localizes to the endomembrane system and partially with the apicoplast. Finally, conditional knockdown and constitutive overexpression of BdPhoD alter the sensitivity to MMV019266 in the parasite. Overexpression of BdPhoD results in increased sensitivity to the compound, while knockdown increases resistance, suggesting BdPhoD is a pro-susceptibility factor. Together, we have generated a robust pipeline for identification of resistance loci and identified BdPhoD as a resistance mechanism in species.
Topics: Humans; Babesia; Alkaline Phosphatase; Antiparasitic Agents; Babesiosis; Genomics; Anti-Infective Agents
PubMed: 38377214
DOI: 10.1073/pnas.2312987121 -
Scientific Reports May 2024Plasmodium falciparum, the causative agent of malaria, poses a significant global health challenge, yet much of its biology remains elusive. A third of the genes in the...
Plasmodium falciparum, the causative agent of malaria, poses a significant global health challenge, yet much of its biology remains elusive. A third of the genes in the P. falciparum genome lack annotations regarding their function, impeding our understanding of the parasite's biology. In this study, we employ structure predictions and the DALI search algorithm to analyse proteins encoded by uncharacterized genes in the reference strain 3D7 of P. falciparum. By comparing AlphaFold predictions to experimentally determined protein structures in the Protein Data Bank, we found similarities to known domains in 353 proteins of unknown function, shedding light on their potential functions. The lowest-scoring 5% of similarities were additionally validated using the size-independent TM-align algorithm, confirming the detected similarities in 88% of the cases. Notably, in over 70 P. falciparum proteins the presence of domains resembling heptatricopeptide repeats, which are typically involvement in RNA binding and processing, was detected. This suggests this family, which is important in transcription in mitochondria and apicoplasts, is much larger in Plasmodium parasites than previously thought. The results of this domain search provide a resource to the malaria research community that is expected to inform and enable experimental studies.
Topics: Plasmodium falciparum; Protozoan Proteins; Algorithms; Protein Domains; Databases, Protein; Models, Molecular
PubMed: 38719885
DOI: 10.1038/s41598-024-60058-x