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Journal of Vector Borne Diseases Jun 2010Malaria, an ancient human infectious disease caused by five species of Plasmodium, among them Plasmodium vivax is the most widespread human malaria species and causes...
BACKGROUND & OBJECTIVES
Malaria, an ancient human infectious disease caused by five species of Plasmodium, among them Plasmodium vivax is the most widespread human malaria species and causes huge morbidity to its host. Identification of genetic marker to resolve higher genetic diversity for an ancient origin organism is a crucial task. We have analyzed genetic diversity of P. vivax field isolates using highly polymorphic antigen gene merozoite surface protein-3 alpha (msp-3 alpha) and assessed its suitability as high-resolution genetic marker for population genetic studies.
METHODS
27 P. vivax field isolates collected during chloroquine therapeutic efficacy study at Chennai were analyzed for genetic diversity. PCR-RFLP was employed to assess the genetic variations using highly polymorphic antigen gene msp-3 alpha.
RESULTS
We observed three distinct PCR alleles at msp-3 alpha, and among them allele A showed significantly high frequency (53%, chi2 = 8.22, p = 0.001). PCR-RFLP analysis revealed 14 and 17 distinct RFLP patterns for Hha1 and Alu1 enzymes respectively. Further, RFLP analysis revealed that allele A at msp-3 alpha is more diverse in the population compared with allele B and C. Combining Hha1 and Alu1 RFLP patterns revealed 21 distinct genotypes among 22 isolates reflects higher diversity resolution power of msp-3 alpha in the field isolates.
INTERPRETATION & CONCLUSION
P. vivax isolates from Chennai region revealed substantial amount of genetic diversity and comparison of allelic diversity with other antigen genes and microsatellites suggesting that msp-3 alpha could be a high-resolution marker for genetic diversity studies among P. vivax field isolates.
Topics: Antigens, Protozoan; Blood; Genetic Markers; Genetic Variation; Genotype; Humans; Malaria, Vivax; Plasmodium vivax; Polymorphism, Genetic; Protozoan Proteins
PubMed: 20539045
DOI: No ID Found -
Nature Communications 2014Plasmodium vivax is the leading cause of human malaria in Asia and Latin America but is absent from most of central Africa due to the near fixation of a mutation that...
Plasmodium vivax is the leading cause of human malaria in Asia and Latin America but is absent from most of central Africa due to the near fixation of a mutation that inhibits the expression of its receptor, the Duffy antigen, on human erythrocytes. The emergence of this protective allele is not understood because P. vivax is believed to have originated in Asia. Here we show, using a non-invasive approach, that wild chimpanzees and gorillas throughout central Africa are endemically infected with parasites that are closely related to human P. vivax. Sequence analyses reveal that ape parasites lack host specificity and are much more diverse than human parasites, which form a monophyletic lineage within the ape parasite radiation. These findings indicate that human P. vivax is of African origin and likely selected for the Duffy-negative mutation. All extant human P. vivax parasites are derived from a single ancestor that escaped out of Africa.
Topics: Africa; Animals; Asia; Evolution, Molecular; Malaria; Phylogeny; Plasmodium vivax
PubMed: 24557500
DOI: 10.1038/ncomms4346 -
Methods in Molecular Biology (Clifton,... 2015Plasmodium vivax is considered as the most widely distributed human malaria parasite outside Africa. Studies of P. vivax malaria have always been limited due to the lack...
Plasmodium vivax is considered as the most widely distributed human malaria parasite outside Africa. Studies of P. vivax malaria have always been limited due to the lack of continuously in vitro-propagated parasite lines. Due to this limitation, studies on P. vivax have lagged behind that of P. falciparum, which is routinely maintained in in vitro blood-stage culture. This method allows for the short-term ex vivo culture of P. vivax blood stages and as such offers a wealth of opportunities to study the biology of the blood stages of the parasite. In this chapter we describe the in vitro erythrocyte invasion inhibition assay (IIA) for P. vivax, which can be used as a powerful tool for blood-stage vaccine screening. The major challenges of this assay are the purification of schizont-stage parasites and host reticulocytes. The purification methods for both P. vivax schizont-stage parasites and reticulocytes as detailed here have been developed and simplified. The protocols in this chapter have been optimized to ensure that IIA becomes a more feasible and reliable assay.
Topics: Africa; Animals; Erythrocytes; Humans; Malaria, Vivax; Plasmodium vivax; Reticulocytes; Schizonts; Vaccines
PubMed: 26450389
DOI: 10.1007/978-1-4939-2815-6_15 -
PLoS Neglected Tropical Diseases Feb 2016The burden of malaria in Vietnam has drastically reduced, prompting the National Malaria Control Program to officially engage in elimination efforts. Plasmodium vivax is...
BACKGROUND
The burden of malaria in Vietnam has drastically reduced, prompting the National Malaria Control Program to officially engage in elimination efforts. Plasmodium vivax is becoming increasingly prevalent, remaining a major problem in the country's central and southern provinces. A better understanding of P. vivax genetic diversity and structure of local parasite populations will provide baseline data for the evaluation and improvement of current efforts for control and elimination. The aim of this study was to examine the population genetics and structure of P. vivax isolates from four communities in Tra Leng commune, Nam Tra My district in Quang Nam, Central Vietnam.
METHODOLOGY/PRINCIPAL FINDINGS
P. vivax mono infections collected from 234 individuals between April 2009 and December 2010 were successfully analyzed using a panel of 14 microsatellite markers. Isolates displayed moderate genetic diversity (He = 0.68), with no significant differences between study communities. Polyclonal infections were frequent (71.4%) with a mean multiplicity of infection of 1.91 isolates/person. Low but significant genetic differentiation (FST value from -0.05 to 0.18) was observed between the community across the river and the other communities. Strong linkage disequilibrium ([Formula: see text] = 0.113, p < 0.001) was detected across all communities, suggesting gene flow within and among them. Using multiple approaches, 101 haplotypes were grouped into two genetic clusters, while 60.4% of haplotypes were admixed.
CONCLUSIONS/SIGNIFICANCE
In this area of Central Vietnam, where malaria transmission has decreased significantly over the past decade, there was moderate genetic diversity and high occurrence of polyclonal infections. Local human populations have frequent social and economic interactions that facilitate gene flow and inbreeding among parasite populations, while decreasing population structure. Findings provide important information on parasites populations circulating in the study area and are relevant to current malaria elimination efforts.
Topics: Adolescent; Adult; Child; Child, Preschool; Female; Genetic Variation; Genotype; Humans; Malaria, Vivax; Male; Microsatellite Repeats; Molecular Sequence Data; Phylogeny; Plasmodium vivax; Rural Population; Vietnam; Young Adult
PubMed: 26872387
DOI: 10.1371/journal.pntd.0004434 -
Parasitology International Aug 2018Malaria parasites utilize Methylerythritol phosphate (MEP) pathway for synthesis of isoprenoid precursors which are essential for maturation and survival of parasites...
Malaria parasites utilize Methylerythritol phosphate (MEP) pathway for synthesis of isoprenoid precursors which are essential for maturation and survival of parasites during erythrocytic and gametocytic stages. The absence of MEP pathway in the human host establishes MEP pathway enzymes as a repertoire of essential drug targets. The fourth enzyme, 4-diphosphocytidyl-2C-methyl-d-erythritol kinase (IspE) has been proved essential in pathogenic bacteria, however; it has not yet been studied in any Plasmodium species. This study was undertaken to investigate genetic polymorphism and concomitant structural implications of the Plasmodium vivax IspE (PvIspE) by employing sequencing, modeling and bioinformatics approach. We report that PvIspE gene displayed six non-synonymous mutations which were restricted to non-conserved regions within the gene from seven topographically distinct malaria-endemic regions of India. Phylogenetic studies reflected that PvIspE occupies unique status within Plasmodia genus and reflects that Plasmodium vivax IspE gene has a distant and non-conserved relation with human ortholog Mevalonate Kinase (MAVK). Structural modeling analysis revealed that all PvIspE Indian isolates have critically conserved canonical galacto-homoserine-mevalonate-phosphomevalonate kinase (GHMP) domain within the active site lying in a deep cleft sandwiched between ATP and CDPME-binding domains. The active core region was highly conserved among all clinical isolates, may be due to >60% β-pleated rigid architecture. The mapped structural analysis revealed the critically conserved active site of PvIspE, both sequence, and spacially among all Indian isolates; showing no significant changes in the active site. Our study strengthens the candidature of Plasmodium vivax IspE enzyme as a future target for novel antimalarials.
Topics: Antimalarials; Catalytic Domain; Computational Biology; Drug Delivery Systems; Erythritol; Genetic Variation; Humans; India; Kinetics; Malaria, Vivax; Models, Structural; Phosphotransferases; Phosphotransferases (Alcohol Group Acceptor); Phylogeny; Plasmodium vivax; Polymorphism, Genetic; Protozoan Proteins
PubMed: 29550587
DOI: 10.1016/j.parint.2018.03.001 -
Malaria Journal Mar 2011Rhoptries are specialized organelles from parasites belonging to the phylum Apicomplexa; they secrete their protein content during invasion of host target cells and are...
BACKGROUND
Rhoptries are specialized organelles from parasites belonging to the phylum Apicomplexa; they secrete their protein content during invasion of host target cells and are sorted into discrete subcompartments within rhoptry neck or bulb. This distribution is associated with these proteins' role in tight junction (TJ) and parasitophorous vacuole (PV) formation, respectively.
METHODS
Plasmodium falciparum RON2 amino acid sequence was used as bait for screening the codifying gene for the homologous protein in the Plasmodium vivax genome. Gene synteny, as well as identity and similarity values, were determined for ron2 and its flanking genes among P. falciparum, P. vivax and other malarial parasite genomes available at PlasmoDB and Sanger Institute databases. Pvron2 gene transcription was determined by RT-PCR of cDNA obtained from the P. vivax VCG-1 strain. Protein expression and localization were assessed by Western blot and immunofluorescence using polyclonal anti-PvRON2 antibodies. Co-localization was confirmed using antibodies directed towards specific microneme and rhoptry neck proteins.
RESULTS AND DISCUSSION
The first P. vivax rhoptry neck protein (named here PvRON2) has been identified in this study. PvRON2 is a 2,204 residue-long protein encoded by a single 6,615 bp exon containing a hydrophobic signal sequence towards the amino-terminus, a transmembrane domain towards the carboxy-terminus and two coiled coil α-helical motifs; these are characteristic features of several previously described vaccine candidates against malaria. This protein also contains two tandem repeats within the interspecies variable sequence possibly involved in evading a host's immune system. PvRON2 is expressed in late schizonts and localized in rhoptry necks similar to what has been reported for PfRON2, which suggests its participation during target cell invasion.
CONCLUSIONS
The identification and partial characterization of the first P. vivax rhoptry neck protein are described in the present study. This protein is homologous to PfRON2 which has previously been shown to be associated with PfAMA-1, suggesting a similar role for PvRON2.
Topics: Antigens, Protozoan; Blotting, Western; Gene Expression Profiling; Microscopy, Fluorescence; Plasmodium falciparum; Plasmodium vivax; Protozoan Proteins; Reverse Transcriptase Polymerase Chain Reaction; Sequence Homology, Amino Acid; Synteny
PubMed: 21401956
DOI: 10.1186/1475-2875-10-60 -
Journal of Medical Entomology Nov 1996In total, 414 anophelines, consisting of Anopheles karwari (James), An. splendidus Koidzumi, An. dirus Peyton & Harrison, and An. barbirostris Van der Wulp were...
In total, 414 anophelines, consisting of Anopheles karwari (James), An. splendidus Koidzumi, An. dirus Peyton & Harrison, and An. barbirostris Van der Wulp were collected in 2 provinces in eastern Thailand and tested by enzyme-linked immunosorbent assay for the presence of circumsporozoite proteins. Plasmodium vivax CS protein was detected in 3.4% (2/54) of An. karwari and 4.8% (2/42) of An. barbirostris specimens. Both P. vivax phenotypes, Pv247 and Pv210, were found in An. karwari, whereas only Pv247 was detected in An. barbirostris. Plasmodium falciparum CS protein was detected only in 0.3% (1/276) of An. dirus. Results indicate that An. barbirostris may play a role in the transmission of P. vivax in Chanthaburi Province, Thailand.
Topics: Animals; Anopheles; Antigens, Protozoan; Humans; Plasmodium falciparum; Plasmodium vivax; Protozoan Proteins; Thailand
PubMed: 8961653
DOI: 10.1093/jmedent/33.6.990 -
Malaria Journal Jan 2013Plasmodium vivax is the prevalent malarial species accounting for 70% of malaria burden in Pakistan; however, there is no baseline data on the circulating genotypes....
BACKGROUND
Plasmodium vivax is the prevalent malarial species accounting for 70% of malaria burden in Pakistan; however, there is no baseline data on the circulating genotypes. Studies have shown that polymorphic loci of gene encoding antigens pvcsp and pvmsp1 can be used reliably for conducting molecular epidemiological studies. Therefore, this study aimed to bridge the existing knowledge gap on population structure on P. vivax from Pakistan using these two polymorphic genes.
METHODS
During the period January 2008 to May 2009, a total of 250 blood samples were collected from patients tested slide positive for P. vivax, at the Aga Khan University Hospital, Karachi, or its collection units located in Baluchistan and Sindh Province. Nested PCR/RFLP was performed, using pvcsp and pvmsp1 markers to detect the extent of genetic diversity in clinical isolates of P. vivax from southern Pakistan.
RESULTS
A total of 227/250 (91%) isolates were included in the analysis while the remainder were excluded due to negative PCR outcome for P.vivax. Pvcsp analysis showed that both VK 210 (85.5%, 194/227) and VK 247 type (14.5%, 33/227) were found to be circulating in P. vivax isolates from southern Pakistan. A total of sixteen and eighty-seven genotypes of pvcsp and pvmsp-1 were detected respectively.
CONCLUSION
This is the first report from southern Pakistan on characterization of P. vivax isolates confirming that extensively diverse pvcsp and pvmsp1 variants are present within this region. Results from this study provide valuable data on genetic diversity of P. vivax that will be helpful for further epidemiological studies.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Child; Child, Preschool; DNA, Protozoan; Female; Genetic Markers; Genetic Variation; Genotype; Humans; Malaria, Vivax; Male; Merozoite Surface Protein 1; Middle Aged; Pakistan; Plasmodium vivax; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length; Protozoan Proteins; Young Adult
PubMed: 23311628
DOI: 10.1186/1475-2875-12-16 -
Parasitology May 2012Plasmodium rhoptry neck protein 2 (RON2), which is released from the neck portion of the merozoite rhoptries and interacts with the microneme protein Apical Membrane...
Plasmodium rhoptry neck protein 2 (RON2), which is released from the neck portion of the merozoite rhoptries and interacts with the microneme protein Apical Membrane Antigen 1 (AMA1), plays a crucial role in erythrocyte invasion. In this study, we sequenced the Plasmodium vivax RON2 gene from 19 P. vivax isolates collected in central China in order to establish whether this protein is under positive diversifying selection, which may occur as a result of protective host immune pressure†. In comparison with the P. vivax Sal-1 reference line, we found 10 amino acid substitutions dispersed throughout the open reading frame as well as indels caused by polymorphism in a repeat unit (21-23 repeats of (Q/E/K/N/H)(G/D)G(H/L/Y/P)G) in the second tandem repeat region located at amino acid positions 541-650. A McDonald-Kreitman test with RON2 sequences from the primate malaria parasite Plasmodium knowlesi, detected significant departure from neutrality in the PvRON2 3' region (nucleotide positions 2668-6609). These results suggest that the PvRON2 gene has evolved under positive diversifying selection.
Topics: Amino Acid Sequence; Amino Acid Substitution; Animals; China; Evolution, Molecular; Humans; Malaria, Vivax; Molecular Sequence Data; Plasmodium vivax; Polymorphism, Genetic; Protozoan Proteins; Selection, Genetic; Sequence Analysis, DNA
PubMed: 22321319
DOI: 10.1017/S0031182011002447 -
Lancet (London, England) Mar 1993There are four species of human malarial parasite and several monkey ones, and in evolutionary terms the human and non-human primate plasmodia may be related. The tools...
There are four species of human malarial parasite and several monkey ones, and in evolutionary terms the human and non-human primate plasmodia may be related. The tools of molecular biology have lately pointed to the existence of two types of Plasmodium vivax. Using specific oligonucleotides we have identified a human malaria parasite resembling P vivax under the microscope but with circumsporozoite (CS) protein differing from those of P vivax types 1 and 2. The CS protein of this "P vivax-like" malaria parasite is identical to that of P simiovale, a monkey parasite resembling P ovale, a human one, morphologically. Polyclonal serum raised against a partial repeat sequence of the P vivax-like malaria parasite specifically reacted with P simiovale sporozoites but not with those of P vivax types 1 and 2, P ovale, or P simium. Sera collected from people living in malaria endemic regions of Papua New Guinea and Brazil contained antibodies that specifically reacted with the synthetic peptides representing the repeat sequences of CS protein of this P vivax-like parasite. A comparison of the CS protein gene sequences of P simiovale and the P vivax-like malaria parasites with those of other primate parasites, data on serological cross-reactivity, and 18S ribosomal DNA analyses suggest that the new human malaria parasite described here is distinct from P falciparum, P malariae, P vivax, and P ovale, the four known species of human parasite.
Topics: Animals; Antibodies, Protozoan; Antigens, Protozoan; Base Sequence; Cross Reactions; DNA, Protozoan; Haplorhini; Humans; Malaria, Vivax; Molecular Sequence Data; Papua New Guinea; Plasmodium; Plasmodium vivax; Protozoan Proteins
PubMed: 8095999
DOI: 10.1016/0140-6736(93)90559-y