scholarly journals Thermal Asymmetric Interlaced PCR Amplification of YAC Insert End Fragments for Chromosome Walking in Plasmodium falciparum and Other A/T-Rich Genomes

BioTechniques ◽  
1999 ◽  
Vol 27 (2) ◽  
pp. 240-248
Author(s):  
Jeremy M. Foster ◽  
Zoe Christodoulou ◽  
Gill M. Cowan ◽  
Christopher I. Newbold
Keyword(s):  
Plasmodium Falciparum ◽  
Pcr Amplification ◽  
Chromosome Walking ◽  
Thermal Asymmetric Interlaced Pcr

scholarly journals Deletions of pfhrp2 and pfhrp3 genes in rapid diagnostic test-negative Plasmodium falciparum isolates from Uganda

2020 ◽  
Author(s):  
Sam L Nsobya ◽  
Andrew Walakira ◽  
Elizabeth Namirembe ◽  
Moses Kiggundu ◽  
Joaniter I Nankabirwa ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Protein Expression ◽  
False Negative ◽  
Plasmodium Species ◽  
Pcr Amplification ◽  
Rapid Diagnostic Tests ◽  
False Negatives ◽  
Cross Sectional ◽  
True Prevalence ◽  
Blood Smears

Abstract Background: Rapid diagnostic tests (RDTs) play a key role in malaria case management. The most widely used RDT identifies Plasmodium falciparum based on immunochromatographic recognition of P. falciparum histidine-rich protein 2 (PfHRP2). Deletion of the homologous pfhrp2 and pfhrp3 genes leads to false-negative PfHRP2-based RDTs, and has been reported in P. falciparum from South America and Africa. However, identification of pfhrp2/pfhrp3 deletions has usually been based only on failure to amplify these genes using PCR, without confirmation based on protein expression, and our understanding of the true prevalence of deletions is incomplete. Methods: We investigated pfhrp2 / pfhrp3 deletions in blood samples from cross-sectional surveys in 2012-13 in three regions of varied malaria transmission intensity in Uganda. We evaluated samples with positive Giemsa-stained thick blood smears and negative PfHRP2-based RDTs by PCR amplification of conserved subunit ribosomal DNA for Plasmodium species, PCR amplification of pfhrp2 and pfhrp3 genes to identify deletions, and bead-based immunoassays for expression ofPfHRP2. Results: Of 3516 samples collected in cross-sectional surveys, 1493 (42.5%) had positive blood smears, of which 96 (6.4%) were RDT-negative. Of these 96 RDT-negative samples, P. falciparum was identified in 56 (58%) and only non-falciparum plasmodial DNA in 40 (42%). In all 56 P. falciparum -positive samples there was a failure to amplify pfhrp2 or pfhrp3 :in 25 (45%) pfhrp2 was not amplified, in 39 (70%) pfhrp3 was not amplified, and in 19 (34%) neither gene was amplified. For the 39 P. falciparum -positive, RDT-negative samples available for analysis of protein expression, PfHRP2 was not identified by immunoassay in only four samples (10.3%); these four samples all had failure to amplify both pfhrp2 and pfhrp3 by PCR. Thus, only four of 96 (4.2%) smear-positive, RDT-negative samples had P. falciparum infections with deletion of pfhrp2 and pfhrp3 confirmed by failure to amplify the genes by PCR and lack of expression of PfHRP2 demonstrated by immunoassay. Conclusion: False negative RDTs were uncommon, and deletions in pfhrp2 and pfhrp3 explained some of these findings, although most false negatives were not due to deletion of the pfhrp2 and pfhrp3 genes.

scholarly journals Screening for antifolate and artemisinin resistance in Plasmodium falciparum clinical isolates from three hospitals of Eritrea

F1000Research ◽  
2021 ◽  
Vol 10 ◽  
pp. 628
Author(s):  
Harriet Natabona Mukhongo ◽  
Johnson Kang'ethe Kinyua ◽  
Yishak Gebrekidan Weldemichael ◽  
Remmy Wekesa Kasili
Keyword(s):  
Drug Resistance ◽  
Plasmodium Falciparum ◽  
Point Mutations ◽  
Artemisinin Resistance ◽  
Pcr Amplification ◽  
Clinical Isolates ◽  
Genetic Mechanism ◽  
Dried Blood Spot ◽  
Nested Polymerase Chain Reaction ◽  
Blood Spot

Background: Antimalarial drug resistance is a major challenge hampering malaria control and elimination. Plasmodium falciparum, the leading causative parasite species, has developed resistance to basically all antimalarials. Continued surveillance of drug resistance using genetic markers provides important molecular data for treatment policies. This study sought to verify the genetic mechanism of resistance to sulfadoxine-pyrimethamine and assess the occurrence of point mutations associated with artemisinin resistance in P. falciparum clinical isolates from Eritrea. Methods: Nineteen dried blood spot samples were collected from patients visiting Adi Quala, Keren and Gash Barka Hospitals, Eritrea. The patients were followed up after receiving treatment with first line artesunate-amodiaquine. Nested polymerase chain reaction and Sanger sequencing techniques were employed to genotype point mutations in the P. falciparum bifunctional dihydrofolate reductase-thymidylate synthase (Pfdhfr, PF3D7_0417200), dihydropteorate synthase (Pfdhps, PF3D7_0810800) and kelch 13 (PfK13, PF3D7_1343700) genes. Results: Eight of nineteen (42%) of the dried blood spot samples were successful for PCR-amplification. Data analyses of the PCR-positive isolates revealed the following point mutations: Pfdhfr N51I in four isolates, C59R in one isolate, S108N in four isolates, a rare non-synonymous substitution V45A in four isolates and Pfdhps K540E in four isolates. No PfK13 point mutations were reported. Conclusions: Pfdhfr C59R and Pfdhps K540E point mutations are reliable markers for the sulfadoxine-pyrimethamine quintuple mutant haplotype combination. These findings highlight first reports in Eritrea, which verify the underlying genetic mechanism of antifolate resistance. Continuous monitoring of the PfK13 marker is recommended.

scholarly journals Deletions of pfhrp2 and pfhrp3 genes were uncommon in rapid diagnostic test-negative Plasmodium falciparum isolates from Uganda

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Sam L. Nsobya ◽  
Andrew Walakira ◽  
Elizabeth Namirembe ◽  
Moses Kiggundu ◽  
Joaniter I. Nankabirwa ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Protein Expression ◽  
Diagnostic Tests ◽  
False Negative ◽  
Pcr Amplification ◽  
Rapid Diagnostic Tests ◽  
False Negatives ◽  
Cross Sectional ◽  
True Prevalence ◽  
Blood Smears

Abstract Background Rapid diagnostic tests (RDTs) play a key role in malaria case management. The most widely used RDT identifies Plasmodium falciparum based on immunochromatographic recognition of P. falciparum histidine-rich protein 2 (PfHRP2). Deletion of the paralogous pfhrp2 and pfhrp3 genes leads to false-negative PfHRP2-based RDTs, and has been reported in P. falciparum infections from South America and Africa. However, identification of pfhrp2/pfhrp3 deletions has usually been based only on failure to amplify these genes using PCR, without confirmation based on PfHRP2 protein expression, and understanding of the true prevalence of deletions is incomplete. Methods Deletions of pfhrp2/pfhrp3 in blood samples were investigated from cross-sectional surveys in 2012-13 in three regions of varied malaria transmission intensity in Uganda. Samples with positive Giemsa-stained thick blood smears, but negative PfHRP2-based RDTs were evaluated by PCR amplification of conserved subunit ribosomal DNA for Plasmodium species, PCR amplification of pfhrp2 and pfhrp3 genes to identify deletions, and bead-based immunoassays for expression of PfHRP2. Results Of 3516 samples collected in cross-sectional surveys, 1493 (42.5%) had positive blood smears, of which 96 (6.4%) were RDT-negative. Of these 96 RDT-negative samples, P. falciparum DNA was identified by PCR in 56 (58%) and only non-falciparum plasmodial DNA in 40 (42%). In all 56 P. falciparum-positive samples there was a failure to amplify pfhrp2 or pfhrp3: in 25 (45%) pfhrp2 was not amplified, in 39 (70%) pfhrp3 was not amplified, and in 19 (34%) neither gene was amplified. For the 39 P. falciparum-positive, RDT-negative samples available for analysis of protein expression, PfHRP2 was not identified by immunoassay in only four samples (10.3%); these four samples all had failure to amplify both pfhrp2 and pfhrp3 by PCR. Thus, only four of 96 (4.2%) smear-positive, RDT-negative samples had P. falciparum infections with deletion of pfhrp2 and pfhrp3 confirmed by failure to amplify the genes by PCR and lack of expression of PfHRP2 demonstrated by immunoassay. Conclusion False negative RDTs were uncommon. Deletions in pfhrp2 and pfhrp3 explained some of these false negatives, but most false negatives were not due to deletion of the pfhrp2 and pfhrp3 genes.

scholarly journals Deletions of pfhrp2 and pfhrp3 genes were uncommon in rapid diagnostic test-negative Plasmodium falciparum isolates from Uganda

2020 ◽  
Author(s):  
Sam L Nsobya ◽  
Andrew Walakira ◽  
Elizabeth Namirembe ◽  
Moses Kiggundu ◽  
Joaniter I Nankabirwa ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Protein Expression ◽  
Diagnostic Tests ◽  
False Negative ◽  
Pcr Amplification ◽  
Rapid Diagnostic Tests ◽  
False Negatives ◽  
Cross Sectional ◽  
True Prevalence ◽  
Blood Smears

Abstract BackgroundRapid diagnostic tests (RDTs) play a key role in malaria case management. The most widely used RDT identifies Plasmodium falciparum based on immunochromatographic recognition of P. falciparum histidine-rich protein 2 (PfHRP2). Deletion of the paralogous pfhrp2 and pfhrp3 genes leads to false-negative PfHRP2-based RDTs, and has been reported in P. falciparum infections from South America and Africa. However, identification of pfhrp2/pfhrp3 deletions has usually been based only on failure to amplify these genes using PCR, without confirmation based on PfHRP2 protein expression, and understanding of the true prevalence of deletions is incomplete.MethodsDeletions of pfhrp2/pfhrp3 in blood samples were investigated from cross-sectional surveys in 2012-13 in three regions of varied malaria transmission intensity in Uganda. Samples with positive Giemsa-stained thick blood smears, but negative PfHRP2-based RDTs were evaluated by PCR amplification of conserved subunit ribosomal DNA for Plasmodium species, PCR amplification of pfhrp2 and pfhrp3 genes to identify deletions, and bead-based immunoassays for expression of PfHRP2.ResultsOf 3516 samples collected in cross-sectional surveys, 1493 (42.5%) had positive blood smears, of which 96 (6.4%) were RDT-negative. Of these 96 RDT-negative samples, P. falciparum DNA was identified by PCR in 56 (58%) and only non-falciparum plasmodial DNA in 40 (42%). In all 56 P. falciparum-positive samples there was a failure to amplify pfhrp2 or pfhrp3: in 25 (45%) pfhrp2 was not amplified, in 39 (70%) pfhrp3 was not amplified, and in 19 (34%) neither gene was amplified. For the 39 P. falciparum-positive, RDT-negative samples available for analysis of protein expression, PfHRP2 was not identified by immunoassay in only four samples (10.3%); these four samples all had failure to amplify both pfhrp2 and pfhrp3 by PCR. Thus, only four of 96 (4.2%) smear-positive, RDT-negative samples had P. falciparum infections with deletion of pfhrp2 and pfhrp3 confirmed by failure to amplify the genes by PCR and lack of expression of PfHRP2 demonstrated by immunoassay.ConclusionFalse negative RDTs were uncommon. Deletions in pfhrp2 and pfhrp3 explained some of these false negatives, but most false negatives were not due to deletion of the pfhrp2 and pfhrp3 genes.

Significant Differences in FcγRIIa, FcγRIIa and FcγRIIIb Genes Polymorphism and Anti-malarial IgG Subclass Pattern are Associated with Severe Malaria in Saudi Children

2021 ◽  
Author(s):  
Amre Nasr ◽  
Ahmad Aljada ◽  
Osama Hamid ◽  
Hatim A. Elsheikh ◽  
Emad Masuadi ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Clinical Outcome ◽  
Severe Malaria ◽  
Malaria Infection ◽  
Pcr Amplification ◽  
Igg Subclass ◽  
Gene Variants ◽  
Disease Outcomes ◽  
Cellular And Humoral Immunity ◽  
Increased Susceptibility

Abstract Background: The FcyRs genotypes have been reported to play a key role in the defence against malaria parasites through both cellular and humoral immunity. This study aimed to investigate the possible correlation between FcγR (IIa, IIIa, and IIIb) genes polymorphism and the clinical outcome for anti‐malarial antibody response of Plasmodium falciparum infection among Saudi children. Material and methods: A 600 volunteers have been enrolled in this study, including 200 malaria-free control (MFC) subjects, 218 patients with uncomplicated malaria (UM) and 182 patients with severe malaria (SM). The FcγR genotypes was analysed using PCR amplification methods, and measurement of immunoglobulins were determine using ELISA. Results: The data revealed the FcγRIIa-R/R131 showed a statistically association with the increased susceptibility to SM when compared to UM patients. Furthermore, higher levels of IgG1, IgG2, and IgG4 were associated with the FcγRIIa-H/H131 genotypes among UM patients. Although the FcγRIIa-F/V176 genotype was not associated with UM, it showed a significant association with severe malaria. Interestingly, the FcγRIIa-V/V176 genotype was This study aimed to associated with protection against SM. Moreover, severe malaria patients carrying the FcγRIIa-F/F genotype showed higher levels of AMA-1-specific IgG2 and IgG4 antibodies. The FcγRIIIb NA1/NA1 and FcγRIIIb NA2/NA2 genotypes did not show significant differences between UM and the MFC. However, the genotype FcγRIIIb-NA2/NA2 was statistically associated with severe malaria. Conclusions: The data presented in this study strongly suggest the possible impact of FcyR (IIa, RIIIa and RIIIb) gene variants and anti-malaria IgG subclasses play a role in susceptibility to malaria infection and disease outcomes in Saudi children.

scholarly journals Prevalence of pfk13 and pfmdr1 polymorphisms in Bounkiling, Southern Senegal

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0249357
Author(s):  
Ambroise Ahouidi ◽  
Rafael Oliveira ◽  
Lis Lobo ◽  
Cyrille Diedhiou ◽  
Souleymane Mboup ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Plasmodium Falciparum ◽  
Pcr Amplification ◽  
Parasite Clearance ◽  
Dried Blood Spots ◽  
Multi Drug Resistance ◽  
Nucleotide Polymorphisms ◽  
Wild Type ◽  
Multidrug Resistance Gene ◽  
Filter Papers

Background Delayed Plasmodium falciparum parasite clearance has been associated with Single Nucleotide Polymorphisms (SNPs) in the kelch protein propeller domain (coded by pfk13 gene). SNPs in the Plasmodium falciparum multidrug resistance gene 1 (pfmdr1) are associated with multi-drug resistance including the combination artemether-lumefantrine. To our knowledge, this is the first work providing information on the prevalence of k13-propeller and pfmdr1 mutations from Sédhiou, a region in the south of Senegal. Methods 147 dried blood spots on filter papers were collected from symptomatic patients attending a hospital located in Bounkiling City, Sédhiou Region, Southern Senegal. All samples were collected between 2015–2017 during the malaria transmission season. Specific regions of the gene pfk13 and pfmdr1 were analyzed using PCR amplification and Sanger sequencing. Results The majority of parasites (92.9%) harboured the pfk13 wild type sequence and 6 samples harboured synonymous changes. Regarding pfmdr1, wild-type alleles represented the majority except at codon 184. Overall, prevalence of 86Y was 11.9%, 184F was 56.3% and 1246Y was 1.5%. The mutant allele 184F decreased from 73.7% in 2015 to 40.7% in 2017. The prevalence of haplotype NFD decreased from 71.4% in 2015 to 20.8% in 2017. Conclusions This study provides the first description of pfk13 and pfmdr1 genes variations in Bounkiling, a city in the Sédhiou Region of Senegal, contributing to closing the gap of information on anti-malaria drug resistance molecular markers in southern Senegal.

scholarly journals Molecular identification and anti-malarial drug resistance profile of Plasmodium falciparum from patients attending Kisoro Hospital, southwestern Uganda

2022 ◽  
Vol 21 (1) ◽  
Author(s):  
Godfrey Manirakiza ◽  
Kennedy Kassaza ◽  
Ivan Mugisha Taremwa ◽  
Joel Bazira ◽  
Fredrick Byarugaba
Keyword(s):  
Drug Resistance ◽  
Plasmodium Falciparum ◽  
Molecular Identification ◽  
Plasmodium Species ◽  
Pcr Amplification ◽  
Plasmodium Malariae ◽  
Dried Blood Spots ◽  
Resistance Profile ◽  
Drug Resistance Profile ◽  
Southwestern Uganda

Abstract Background The evolution of malaria infection has necessitated the development of highly sensitive diagnostic assays, as well as the use of dried blood spots (DBS) as a potential source of deoxyribonucleic acid (DNA) yield for polymerase chain reaction (PCR) assays. This study identified the different Plasmodium species in malaria-positive patients, and the anti-malarial drug resistance profile for Plasmodium falciparum using DBS samples collected from patients attending Kisoro Hospital in Kisoro district, Southwestern Uganda. Methods The blood samples were prospectively collected from patients diagnosed with malaria to make DBS, which were then used to extract DNA for real-time PCR and high-resolution melting (HRM) analysis. Plasmodium species were identified by comparing the control and test samples using HRM-PCR derivative curves. Plasmodium falciparum chloroquine (CQ) resistance transporter (pfcrt) and kelch13 to screen the samples for anti-malarial resistance markers. The HRM-PCR derivative curve was used to present a summary distribution of the different Plasmodium species as well as the anti-malarial drug profile. Results Of the 152 participants sampled, 98 (64.5%) were females. The average age of the participants was 34.9 years (range: 2 months–81 years). There were 134 samples that showed PCR amplification, confirming the species as Plasmodium. Plasmodium falciparum (N = 122), Plasmodium malariae (N = 6), Plasmodium ovale (N = 4), and Plasmodium vivax (N = 2) were the various Plasmodium species and their proportions. The results showed that 87 (71.3%) of the samples were sensitive strains/wild type (CVMNK), 4 (3.3%) were resistant haplotypes (SVMNT), and 31 (25.4%) were resistant haplotypes (CVIET). Kelch13 C580Y mutation was not detected. Conclusion The community served by Kisoro hospital has a high Plasmodium species burden, according to this study. Plasmodium falciparum was the dominant species, and it has shown that resistance to chloroquine is decreasing in the region. Based on this, molecular identification of Plasmodium species is critical for better clinical management. Besides, DBS is an appropriate medium for DNA preservation and storage for future epidemiological studies.

scholarly journals Genetic Diversity of Polymorphic Marker Merozoite Surface Protein 1 (Msp-1) and 2 (Msp-2) Genes of Plasmodium falciparum Isolates From Malaria Endemic Region of Pakistan

2021 ◽  
Vol 12 ◽  
Author(s):  
Shahid Niaz Khan ◽  
Rehman Ali ◽  
Sanaullah Khan ◽  
Muhammad Rooman ◽  
Sadia Norin ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Plasmodium Falciparum ◽  
Pcr Amplification ◽  
Surface Protein ◽  
Polymorphic Marker ◽  
Merozoite Surface Protein ◽  
Drug Formulation ◽  
Effective Control ◽  
Endemic Region ◽  
Khyber Pakhtunkhwa

Background: Understanding the genetic diversity of Plasmodium species through polymorphic studies can assist in designing more effective control strategies of malaria like new drug formulation and development of a vaccine. Pakistan is moderate endemic for Plasmodium falciparum, but little is known about the genetic diversity of this parasite. This study aimed to investigate the molecular diversity of P. falciparum based on msp-1 and msp-2 genes in the malaria-endemic regions of Khyber Pakhtunkhwa, Pakistan.Methods: A total of 199/723 blood samples, tested positive by microscopy for falciparum malaria, were collected from four districts (Dera Ismail Khan, Karak, Mardan, and Peshawar) of Khyber Pakhtunkhwa. Nested PCR amplification technique was employed to target block 2 of msp-1 and the central domain of msp-2 genes, including their respective allelic families K1, MAD20, RO33, FC27, and 3D7/IC, and to detect the extent of genetic diversity of P. falciparum clinical isolates.Results: Among the 199 microscopy-positive P. falciparum samples, a total of 192 were confirmed using PCR. Ninety-seven amplicons were observed for msp-1 and 95 for msp-2. A total of 33 genotypes, 17 for msp-1 (eight K1, six MAD20, and three RO33) and 16 for msp-2 (nine FC27 and seven 3D7/IC), were identified. The specific allelic frequency of the K1 family was higher (44.3%) than that of MAD20 (33.0%) and RO33 (23.0%) for msp-1, while the FC27 allelic family was dominant (60.0%) compared with 3D7/IC (40.0%) for msp-2. No polyclonal infection was observed in msp-1 and msp-2. The expected heterozygosity was 0.98 and 0.97 for msp-1 and msp-2, respectively.Conclusion: It was concluded that the P. falciparum populations are highly polymorphic, and diverse allelic variants of msp-1 and msp-2 are present in Khyber Pakhtunkhwa, Pakistan.

scholarly journals Genetic polymorphism of the N-terminal region in circumsporozoite surface protein of Plasmodium falciparum field isolates from Sudan

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Nouh S. Mohamed ◽  
Musab M. Ali Albsheer ◽  
Hanadi Abdelbagi ◽  
Emanuel E. Siddig ◽  
Mona A. Mohamed ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Plasmodium Falciparum ◽  
Balancing Selection ◽  
Pcr Amplification ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Molecular Study ◽  
Terminal Region ◽  
Sub Saharan Africa ◽  
Cross Sectional

Abstract Background Malaria caused by Plasmodium falciparum parasite is still known to be one of the most significant public health problems in sub-Saharan Africa. Genetic diversity of the Sudanese P. falciparum based on the diversity in the circumsporozoite surface protein (PfCSP) has not been previously studied. Therefore, this study aimed to investigate the genetic diversity of the N-terminal region of the pfcsp gene. Methods A cross-sectional molecular study was conducted; 50 blood samples have been analysed from different regions in Sudan. Patients were recruited from the health facilities of Khartoum, New Halfa, Red Sea, White Nile, Al Qadarif, Gezira, River Nile, and Ad Damazin during malaria transmission seasons between June to October and December to February 2017–2018. Microscopic and nested PCR was performed for detection of P. falciparum. Merozoite surface protein-1 was performed to differentiate single and multiple clonal infections. The N-terminal of the pfcsp gene has been sequenced using PCR-Sanger dideoxy method and analysed to sequences polymorphism including the numbers of haplotypes (H), segregating sites (S), haplotypes diversity (Hd) and the average number of nucleotide differences between two sequences (Pi) were obtained using the software DnaSP v5.10. As well as neutrality testing, Tajima’s D test, Fu and Li’s D and F statistics. Results PCR amplification resulted in 1200 bp of the pfcsp gene. Only 21 PCR products were successfully sequenced while 29 were presenting multiple clonal P. falciparum parasite were not sequenced. The analysis of the N-terminal region of the PfCSP amino acids sequence compared to the reference strains showed five different haplotypes. H1 consisted of 3D7, NF54, HB3 and 13 isolates of the Sudanese pfcsp. H2 comprised of 7G8, Dd2, MAD20, RO33, Wellcome strain, and 5 isolates of the Sudanese pfcsp. H3, H4, and H5 were found in 3 distinct isolates. Hd was 0.594 ± 0.065, and S was 12. The most common polymorphic site was A98G; other sites were D82Y, N83H, N83M, K85L, L86F, R87L, R87F, and A98S. Fu and Li’s D* test value was − 2.70818, Fu and Li’s F* test value was − 2.83907, indicating a role of negative balancing selection in the pfcsp N-terminal region. Analysis with the global pfcsp N-terminal regions showed the presence of 13 haplotypes. Haplotypes frequencies were 79.4%, 17.0%, 1.6% and 1.0% for H1, H2, H3 and H4, respectively. Remaining haplotypes frequency was 0.1% for each. Hd was 0.340 ± 0.017 with a Pi of 0.00485, S was 18 sites, and Pi was 0.00030. Amino acid polymorphisms identified in the N-terminal region of global pfcsp were present at eight positions (D82Y, N83H/M, K85L/T/N, L86F, R87L/F, A98G/V/S, D99G, and G100D). Conclusions Sudanese pfcsp N-terminal region was well-conserved with only a few polymorphic sites. Geographical distribution of genetic diversity showed high similarity to the African isolates, and this will help and contribute in the deployment of RTS,S, a PfCSP-based vaccine, in Sudan.

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