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Clinical Infectious Diseases : An... Dec 2012
Topics: Female; Humans; Malaria, Vivax; Male; Plasmodium vivax
PubMed: 22911647
DOI: 10.1093/cid/cis709 -
Journal of Vector Borne Diseases 2019Molecular analysis of antifolate resistance-associated genes-dihydrofolate reductase (dhfr) and dihydropteroate synthetase (dhps) of Plasmodium vivax is important in...
Molecular analysis of antifolate resistance-associated genes-dihydrofolate reductase (dhfr) and dihydropteroate synthetase (dhps) of Plasmodium vivax is important in predicting the emergence of drug resistance to sulphadoxine-pyrimethamine (SP). The present study aimed to determine the polymorphism of dhfr and dhps genes in P. vivax field isolates. Samples from 80 microscopically diagnosed vivax malaria cases were collected from endemic areas of malaria in Hormozgan Province of Iran, from June 2010 to November 2015. The two sets of codons at position 33, 57, 58, 117, 173 of dhfr and 382, 383, and 553 of dhps genes were analysed by direct sequencing of PCR products. The majority of the isolates (70%) harboured a wild-type allele for P. vivax dhfr (Pvdhfr) and P. vivax dhps (Pvdhps). Mutations were detected in three codons of Pvdhfr (P33L, S58R and S117N) and single codon in Pvdhps (A383G). Novel mutations that have not been identified previously at codon 459 (D459A) of Pvdhps were also observed. The high prevalence of point mutation as well as the rising triple mutation of Pvdhfr and Pvdhps genotypes necessitate change in programmes and guidelines to eliminate P. vivax in future.
Topics: Antimalarials; Dihydropteroate Synthase; Drug Resistance, Multiple; Genotype; Haplotypes; Iran; Plasmodium vivax; Point Mutation; Polymorphism, Restriction Fragment Length; Protozoan Proteins; Tetrahydrofolate Dehydrogenase
PubMed: 31397394
DOI: 10.4103/0972-9062.263716 -
Antimicrobial Agents and Chemotherapy May 2010The novel organometallic chloroquine analog ferroquine (SSR 97193) is effective against chloroquine-resistant Plasmodium falciparum. The ex vivo efficacy of ferroquine...
The novel organometallic chloroquine analog ferroquine (SSR 97193) is effective against chloroquine-resistant Plasmodium falciparum. The ex vivo efficacy of ferroquine against Plasmodium vivax isolates was tested. Ferroquine has a potent ex vivo effect on P. vivax schizont maturation (median 50% inhibitory concentration, 15 nM; n = 42). No significant cross-sensitivity between ferroquine and other antimalarials was detected. This drug may be a suitable replacement for chloroquine in the treatment of drug-resistant P. vivax malaria.
Topics: Aminoquinolines; Antimalarials; Dose-Response Relationship, Drug; Drug Resistance, Bacterial; Ferrous Compounds; Humans; In Vitro Techniques; Malaria, Vivax; Metallocenes; Microbial Sensitivity Tests; Plasmodium vivax; Thailand
PubMed: 20308387
DOI: 10.1128/AAC.01572-09 -
Malaria Journal Feb 2016Knowledge of the population genetics and transmission dynamics of Plasmodium vivax is crucial in predicting the emergence of drug resistance, relapse pattern and novel...
BACKGROUND
Knowledge of the population genetics and transmission dynamics of Plasmodium vivax is crucial in predicting the emergence of drug resistance, relapse pattern and novel parasite phenotypes, all of which are relevant to the control of vivax infections. The aim of this study was to analyse changes in the genetic diversity of P. vivax genes from field isolates collected at different times along the Thai-Myanmar border.
METHODS
Two hundred and fifty-four P. vivax isolates collected during two periods 10 years apart along the Thai-Myanmar border were analysed. The parasites were genotyped by nested-PCR and PCR-RFLP targeting selected polymorphic loci of Pvmsp1, Pvmsp3α and Pvcsp genes.
RESULTS
The total number of distinguishable allelic variants observed for Pvcsp, Pvmsp1, and Pvmsp3α was 17, 7 and 3, respectively. High genetic diversity was observed for Pvcsp (H E = 0.846) and Pvmsp1 (H E = 0.709). Of the 254 isolates, 4.3 and 14.6 % harboured mixed Pvmsp1 and Pvcsp genotypes with a mean multiplicity of infection (MOI) of 1.06 and 1.15, respectively. The overall frequency of multiple genotypes was 16.9 %. When the frequencies of allelic variants of each gene during the two distinct periods were analysed, significant differences were noted for Pvmsp1 (P = 0.018) and the Pvcsp (P = 0.033) allelic variants.
CONCLUSION
Despite the low malaria transmission levels in Thailand, P. vivax population exhibit a relatively high degree of genetic diversity along the Thai-Myanmar border of Thailand, in particular for Pvmsp1 and Pvcsp, with indication of geographic and temporal variation in frequencies for some variants. These results are of relevance to monitoring the emergence of drug resistance and to the elaboration of measures to control vivax malaria.
Topics: Adolescent; Adult; Female; Genetic Variation; Genotype; Humans; Malaria, Vivax; Male; Middle Aged; Plasmodium vivax; Polymerase Chain Reaction; Protozoan Proteins; Thailand; Young Adult
PubMed: 26858120
DOI: 10.1186/s12936-016-1136-6 -
Malaria Journal Nov 2018Malaria in Nigeria is principally due to Plasmodium falciparum and, to a lesser extent to Plasmodium malariae and Plasmodium ovale. Plasmodium vivax is thought to be...
BACKGROUND
Malaria in Nigeria is principally due to Plasmodium falciparum and, to a lesser extent to Plasmodium malariae and Plasmodium ovale. Plasmodium vivax is thought to be absent in Nigeria in particular and sub-Saharan Africa in general, due to the near fixation of the Duffy negative gene in this population. Nevertheless, there are frequent reports of P. vivax infection in Duffy negative individuals in the sub-region, including reports from two countries sharing border with Nigeria to the west (Republic of Benin) and east (Cameroon). Additionally, there were two cases of microscopic vivax-like malaria from Nigerian indigenous population. Hence molecular surveillance of the circulating Plasmodium species in two states (Lagos and Edo) of southwestern Nigeria was carried out.
METHODS
A cross-sectional survey between September 2016 and March 2017 was conducted. 436 febrile patients were included for the present work. Venous blood of these patients was subjected to RDT as well as microscopy. Further, parasite DNA was isolated from positive samples and PCR diagnostic was employed followed by direct sequencing of the 18S rRNA of Plasmodium species as well as sequencing of a portion of the promoter region of the Duffy antigen receptor for chemokines. Samples positive for P. vivax were re-amplified several times and finally using the High Fidelity Taq to rule out any bias introduced.
RESULTS
Of the 256 (58.7%) amplifiable malaria parasite DNA, P. falciparum was, as expected, the major cause of infection, either alone 85.5% (219/256; 97 from Edo and 122 from Lagos), or mixed with P. malariae 6.3% (16/256) or with P. vivax 1.6% (4/256). Only one of the five P. vivax isolates was found to be a single infection. DNA sequencing and subsequent alignment of the 18S rRNA of P. vivax with the reference strains displayed very high similarities (100%). Remarkably, the T-33C was identified in all P. vivax samples, thus confirming that all vivax-infected patients in the current study are Duffy negative.
CONCLUSION
The present study gave the first molecular evidence of P. vivax in Nigeria in Duffy negative individuals. Though restricted to two states; Edo in South-South and Lagos in South-west Nigeria, the real burden of this species in Nigeria and sub-Saharan Africa might have been underestimated, hence there is need to put in place a country-wide, as well as a sub-Saharan Africa-wide surveillance and appropriate control measures.
Topics: Child, Preschool; Cross-Sectional Studies; DNA, Protozoan; DNA, Ribosomal; Duffy Blood-Group System; Female; Humans; Infant; Infant, Newborn; Malaria, Vivax; Male; Nigeria; Plasmodium vivax; RNA, Ribosomal, 18S; Receptors, Cell Surface; Sequence Analysis, DNA
PubMed: 30486887
DOI: 10.1186/s12936-018-2588-7 -
Bulletin of the World Health... 1977The understanding of clinico-epidemiological phenomena of tertian malaria has been the subject of controversy. The authors suggest a system of postulates which give a... (Review)
Review
The understanding of clinico-epidemiological phenomena of tertian malaria has been the subject of controversy. The authors suggest a system of postulates which give a non-contradictory explanation of the phenomena of relapses and long incubation. The main idea is that the duration of exoerythrocytic development of Plasmodium vivax is a polymorphic characteristic controlled by a set of genes. According to these postulates sporozoites may be subdivided into two groups designated as tachysporozoites and bradysporozoites, responsible for early and late manifestations, respectively. The logical analysis of the system suggests that it does not contradict the experimental facts. Moreover, the theory of polymorphic sporozoites permits an explanation and quantification of interrelations between different phenomena. The authors stress that the variation of genes is much greater in natural populations of parasites than in individual isolates and strains and therefore that the features of strains do not fully reflect the features of populations. Classical laboratory experiments should be combined with epidemiological experiments which allow a study of the population as a whole. The methodology of experiments to be undertaken in further investigations of the long latency period is discussed.
Topics: Animals; Erythrocytes; Malaria; Phenotype; Plasmodium vivax; Polymorphism, Genetic
PubMed: 338188
DOI: No ID Found -
Zhongguo Xue Xi Chong Bing Fang Zhi Za... Jun 2014Malaria remains a serious public health problem, especially in developing countries. With the deepening of the understanding of vivax malaria, Plasmodium vivax is also... (Review)
Review
Malaria remains a serious public health problem, especially in developing countries. With the deepening of the understanding of vivax malaria, Plasmodium vivax is also attracting more and more attention. An effective drug treatment is the foundation of controlling or even eliminating malaria. In recent years, more and more reports of chloroquine-resistance Plasmodium vivax have been reported. Plasmodium vivax chloroquine resistance has been a focus problem in vivax malaria prevention and treatment. In this paper, the research progress on distribution situation, detection methods and molecular markers of Plasmodium vivax chloroquine resistance is summarized.
Topics: Animals; Antimalarials; Biomarkers; Chloroquine; Drug Resistance; Humans; Malaria, Vivax; Plasmodium vivax
PubMed: 25345166
DOI: No ID Found -
Proceedings of the National Academy of... Oct 2002
Comparative Study Review
Topics: Animals; Antimalarials; Drug Resistance; Folic Acid Antagonists; Humans; Malaria, Vivax; Mutation; Plasmodium vivax; Tetrahydrofolate Dehydrogenase
PubMed: 12374849
DOI: 10.1073/pnas.232483699 -
Parasitology International Jun 2019Malaria is a sterning public health concern in India and contribute to a major part of malaria burden in Southeast Asia. Being more populated and diverse geographic...
Malaria is a sterning public health concern in India and contribute to a major part of malaria burden in Southeast Asia. Being more populated and diverse geographic conditions makes more suitable place for sustaining malaria parasite in India. Anti-malarial resistance is a major concern in the battle against malaria, and the identified molecular markers will aid us to monitor the drug resistance in endemic areas. The aim of the current study is to determine the genotype of drug resistance associated genes pvmdr-1 and pvcrt-o from four different regions of India. Especially from Puducherry and Jodhpur, there were no prior studies focused on screening of drug resistance genes in P. vivax parasite. A total of 240 positive P. vivax infected patient samples were collected from four tertiary care hospitals from four different regions of India, namely, Puducherry (PDY), Mangaluru (MAQ), Cuttack (CTC), Jodhpur (JDH). All samples were screened by microscopy, RDT, QBC, and further DNA was extracted and vivax mono-infection was confirmed by nested PCR. Randomly selected amplicons were further subjected to nucleotide sequencing. The prevalence of K10 insertion in pvcrt-o gene was detected with 18.8% in PDY, 12.5% in MAQ and 6.3% in CTC P. vivax isolates, whereas no change in nucleotide was identified in P. vivax isolates collected from JDH region. Based on the F1076L mutation in pvmdr-1 gene, resistant P. vivax isolates was highly predominant in both the regions, JDH and CTC, with 100%, followed by MAQ with 93.3% and PDY with 73.3%. This study showed less frequency of pvcrt-o and high frequency of pvmdr-1 gene variants associated with CQ resistance, which act as an indicator and the onset of P. vivax drug resistance trend in four different regions of India. Due to the poor phenotypic studies available for P. vivax parasite, the present study data for CQ resistance based on pvcrt-o and pvmdr-1 markers should assist by providing base-line data for future monitoring of drug resistance.
Topics: Antimalarials; Drug Resistance; Genetic Markers; Genotype; Humans; India; Malaria, Vivax; Mutation; Plasmodium vivax; Polymorphism, Single Nucleotide; Protozoan Proteins; Tertiary Care Centers
PubMed: 30836136
DOI: 10.1016/j.parint.2019.03.001 -
Malaria Journal Jun 2017The current trend of Plasmodium vivax cases imported from Southeast Asia into China has sharply increased recently, especially from the China-Myanmar border (CMB) area....
BACKGROUND
The current trend of Plasmodium vivax cases imported from Southeast Asia into China has sharply increased recently, especially from the China-Myanmar border (CMB) area. High recombination rates of P. vivax populations associated with varied transmission intensity might cause distinct local selective pressures. The information on the genetic variability of P. vivax in this area is scant. Hence, this study assessed the genetic diversity of P. vivax genome sequence in CMB area and aimed to provide information on the positive selection of new gene loci.
RESULTS
This study reports a genome-wide survey of P. vivax in CMB area, using blood samples from local patients to identify population-specific selective processes. The result showed that considerable genetic diversity and mean pair-wise divergence among the sequenced P. vivax isolates were higher in some important gene families. Using the standardized integrated haplotype score (|iHS|) for all SNPs in chromosomal regions with SNPs above the top 1% distribution, it was observed that the top score locus involved 356 genes and most of them are associated with red blood cell invasion and immune evasion. The XP-EHH test was also applied and some important genes associated with anti-malarial drug resistance were observed in high positive scores list. This result suggests that P. vivax in CMB area is facing more pressure to survive than any other region and this has led to the strong positive selection of genes that are associated with host-parasite interactions.
CONCLUSIONS
This study suggests that greater genetic diversity in P. vivax from CMB area and positive selection signals in invasion and drug resistance genes are consistent with the history of drug use during malaria elimination programme in CMB area. Furthermore, this result also demonstrates that haplotype-based detecting selection can assist the genome-wide methods to identify the determinants of P. vivax diversity.
Topics: Antimalarials; China; Drug Resistance; Genes, Protozoan; Genetic Variation; Genome, Protozoan; Malaria, Vivax; Plasmodium vivax
PubMed: 28587615
DOI: 10.1186/s12936-017-1882-0