scholarly journals Molecular surveillance of anti-malarial resistance Pfdhfr and Pfdhps polymorphisms in African and Southeast Asia Plasmodium falciparum imported parasites to Wuhan, China

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Tingting Jiang ◽  
Weijia Cheng ◽  
Yi Yao ◽  
Huabing Tan ◽  
Kai Wu ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Migrant Workers ◽  
Nucleotide Polymorphisms ◽  
Triple Mutant ◽  
Single Nucleotide ◽  
Molecular Surveillance ◽  
High Prevalence ◽  
The Status ◽  
Quadruple Mutant ◽  
Antifolate Resistance

Abstract Background Anti-malarial drug resistance is a severe challenge for eventual control and global elimination of malaria. Resistance to sulfadoxine-pyrimethamine (SP) increases as mutations accumulate in the Pfdhfr and Pfdhps genes. This study aimed to assess the polymorphisms and prevalence of mutation in these genes in the Plasmodium falciparum infecting migrant workers returning to Wuhan, China. Methods Blood samples were collected for 9 years (2011–2019). Parasite genomic DNA was extracted from blood spots on filter paper. The mutations were evaluated by nested PCR and sequencing. The single-nucleotide polymorphisms (SNPs) and haplotypes of the Pfdhfr and Pfdhps genes were analysed. Results Pfdhfr codon 108 showed a 94.7% mutation rate, while for Pfdhps, the rate for codon 437 was 79.0%. In total, five unique haplotypes at the Pfdhfr locus and 11 haplotypes at the Pfdhps locus were found while the Pfdhfr-Pfdhps combined loci revealed 28 unique haplotypes. A triple mutant (IRNI) of Pfdhfr was the most prevalent haplotype (84.4%). For Pfdhps, a single mutant (SGKAA) and a double mutant (SGEAA) were detected at frequencies of 37.8 and 22.3%, respectively. Among the combined haplotypes, a quadruple mutant (IRNI-SGKAA) was the most common, with a 30.0% frequency, followed by a quintuplet mutant (IRNI-SGEAA) with a frequency of 20.4%. Conclusion The high prevalence and saturation of Pfdhfr haplotypes and the medium prevalence of Pfdhps haplotypes demonstrated in the present data will provide support for predicting the status and progression of antifolate resistance in malaria-endemic regions and imported malaria in nonendemic areas. Additional interventions to evaluate and prevent SP resistance should be continuously considered.

scholarly journals Molecular Surveillance of Drug Resistance of Plasmodium falciparum Isolates Imported from Angola in Henan Province, China

2019 ◽  
Vol 63 (10) ◽  
Author(s):  
Ruimin Zhou ◽  
Chengyun Yang ◽  
Suhua Li ◽  
Yuling Zhao ◽  
Ying Liu ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Plasmodium Falciparum ◽  
Antimalarial Drug ◽  
Henan Province ◽  
Nucleotide Polymorphisms ◽  
Combination Therapies ◽  
Antimalarial Drug Resistance ◽  
Single Nucleotide ◽  
Molecular Surveillance ◽  
Content Type

ABSTRACT Angola was the main origin country for the imported malaria in Henan Province, China. Antimalarial drug resistance has posed a threat to the control and elimination of malaria. Several molecular markers were confirmed to be associated with the antimalarial drug resistance, such as pfcrt, pfmdr1, pfdhfr, pfdhps, and K13. This study evaluated the drug resistance of the 180 imported Plasmodium falciparum isolates from Angola via nested PCR using Sanger sequencing. The prevalences of pfcrt C72V73M74N75K76, pfmdr1 N86Y184S1034N1042D1246, pfdhfr A16N51C59S108D139I164, and pfdhps S436A437A476K540A581 were 69.4%, 59.9%, 1.3% and 6.3%, respectively. Three nonsynonymous (A578S, M579I, and Q613E) and one synonymous (R471R) mutation of K13 were found, the prevalences of which were 2.5% and 1.3%, respectively. The single nucleotide polymorphisms (SNPs) in pfcrt, pfmdr1, pfdhfr, and pfdhps were generally shown as multiple mutations. The mutant prevalence of pfcrt reduced gradually, but pfdhfr and pfdhps still showed high mutant prevalence, while pfmdr1 was relatively low. The mutation of the K13 gene was rare. Molecular surveillance of artemisinin (ART) resistance will be used as a tool to evaluate the real-time efficacy of the artemisinin-based combination therapies (ACTs) and the ART resistance situation.

scholarly journals Prevalence of chloroquine and antifolate drug resistance alleles in Plasmodium falciparum clinical isolates from three areas in Ghana

2018 ◽  
Vol 1 ◽  
pp. 1 ◽  
Author(s):  
James Abugri ◽  
Felix Ansah ◽  
Kwaku P. Asante ◽  
Comfort N. Opoku ◽  
Lucas A. Amenga-Etego ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Plasmodium Falciparum ◽  
Chloroquine Resistance ◽  
Published Data ◽  
Nucleotide Polymorphisms ◽  
Triple Mutant ◽  
Chloroquine Resistance Transporter ◽  
Significant Difference ◽  
Quadruple Mutant ◽  
Study Sites

Background: The emergence and spread of resistance in Plasmodium falciparum to chloroquine (CQ) and the antifolate drug sulfadoxine-pyrimethamine (SP) necessitated the change from CQ to artemisinin-based combination therapies (ACTs) as first-line drug for the management of uncomplicated malaria in Ghana in 2005. Methods: To examine the prevalence of molecular markers associated with CQ and antifolate drug resistance in Ghana, we genotyped single nucleotide polymorphisms (SNPs) in the P. falciparum chloroquine resistance transporter (pfcrt, PF3D7_0709000), multidrug resistance (pfmdr1, PF3D7_0523000), bifunctional dihydrofolate reductase-thymidylate synthase (pfdhfr, PF3D7_0417200) and dihydropteroate synthase (pfdhps, PF3D7_0810800) genes in children with malaria reporting to hospitals in three different epidemiological areas of Ghana (Accra, Kintampo and Navrongo) between 2012 and 2017. Results: The overall prevalence of the CQ resistance-associated pfcrt 76T allele was 8%, whereas pfmdr1 86Y and 184F alleles were present in 10% and 65% of infections respectively. Most of the isolates harboured the antifolate resistance-associated pfdhfr 51I, 59R and 108N alleles, including 68% of them with the triple mutant pfdhfr I51R59N108 combination. Pfdhps 437G and 540E were detected in 90.6% and 0.7% of infections, respectively. We observed no significant difference across the three study sites for all the polymorphisms except for pfdhps 437G, which was more common in Accra than at the other sites. Across both pfdhfr and pfdhps genes, a large proportion (61%) of the isolates harboured the quadruple mutant combination (I51R59N108/G437). Conclusion: Comparison of the present results to previously published data shows a significant decrease in the prevalence of CQ resistance alleles during the 12 years after CQ withdrawal, but an increase in the alleles that mediate SP resistance, which could be due to the continuous use of antifolate drugs for prophylaxis.

scholarly journals Low prevalence of highly sulfadoxine‐resistant dihydropteroate synthase alleles in Plasmodium falciparum isolates in Benin

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Samaly Souza Svigel ◽  
Adicath Adeothy ◽  
Augustin Kpemasse ◽  
Ernest Houngbo ◽  
Antoine Sianou ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Intermittent Preventive Treatment ◽  
Preventive Treatment ◽  
Nucleotide Polymorphisms ◽  
Triple Mutant ◽  
Single Nucleotide ◽  
Dihydropteroate Synthase ◽  
Seasonal Malaria Chemoprevention ◽  
Study Sites ◽  
Low Prevalence

Abstract Background In 2004, in response to high levels of treatment failure associated with sulfadoxine-pyrimethamine (SP) resistance, Benin changed its first-line malaria treatment from SP to artemisinin-based combination therapy for treatment of uncomplicated Plasmodium falciparum malaria. Resistance to SP is conferred by accumulation of single nucleotide polymorphisms (SNPs) in P. falciparum genes involved in folate metabolism, dihydrofolate reductase (Pfdhfr) and dihydropteroate synthase (Pfdhps), targeted by pyrimethamine and sulfadoxine, respectively. Because SP is still used for intermittent preventive treatment in pregnant women (IPTp) and seasonal malaria chemoprevention (SMCP) in Benin, the prevalence of Pfdhfr and Pfdhps SNPs in P. falciparum isolates collected in 2017 were investigated. Methods This study was carried out in two sites where the transmission of P. falciparum malaria is hyper-endemic: Klouékanmey and Djougou. Blood samples were collected from 178 febrile children 6–59 months old with confirmed uncomplicated P. falciparum malaria and were genotyped for SNPs associated with SP resistance. Results The Pfdhfr triple mutant IRN (N51I, C59R, and S108N) was the most prevalent (84.6%) haplotype and was commonly found with the Pfdhps single mutant A437G (50.5%) or with the Pfdhps double mutant S436A and A437G (33.7%). The quintuple mutant, PfdhfrIRN/PfdhpsGE (A437G and K540E), was rarely observed (0.8%). The A581G and A613S mutant alleles were found in 2.6 and 3.9% of isolates, respectively. Six isolates (3.9%) were shown to harbour a mutation at codon I431V, recently identified in West African parasites. Conclusions This study showed that Pfdhfr triple IRN mutants are near fixation in this population and that the highly sulfadoxine-resistant Pfdhps alleles are not widespread in Benin. These data support the continued use of SP for chemoprevention in these study sites, which should be complemented by periodic nationwide molecular surveillance to detect emergence of resistant genotypes.

Associations between varied susceptibilities of PfATP4 inhibitors and genotypes in Ugandan Plasmodium falciparum isolates

2021 ◽  
Author(s):  
Oriana Kreutzfeld ◽  
Stephanie A. Rasmussen ◽  
Aarti A. Ramanathan ◽  
Patrick K. Tumwebaze ◽  
Oswald Byaruhanga ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Single Nucleotide Polymorphisms ◽  
Ex Vivo ◽  
Nucleotide Polymorphisms ◽  
Wild Type ◽  
Single Nucleotide ◽  
Field Isolates ◽  
Frequent Mutations ◽  
Mixed Field ◽  
P Type

Among novel compounds under recent investigation as potential new antimalarial drugs are three independently developed inhibitors of the Plasmodium falciparum P-type ATPase (PfATP4): KAE609 (cipargamin), PA92, and SJ733. We assessed ex vivo susceptibilities to these compounds of 374 fresh P. falciparum isolates collected in Tororo and Busia districts, Uganda from 2016-2019. Median IC 50 s were 65 nM for SJ733, 9.1 nM for PA92, and 0.5 nM for KAE609. Sequencing of pfatp4 for 218 of these isolates demonstrated many non-synonymous single nucleotide polymorphisms; the most frequent mutations were G1128R (69% of isolates mixed or mutant), Q1081K/R (68%), G223S (25%), N1045K (16%) and D1116G/N/Y (16%). The G223S mutation was associated with decreased susceptibility to SJ733, PA92 and KAE609. The D1116G/N/Y mutations were associated with decreased susceptibility to SJ733, and the presence of mutations at both codons 223 and 1116 was associated with decreased susceptibility to PA92 and SJ733. In all of these cases, absolute differences in susceptibilities of wild type (WT) and mutant parasites were modest. Analysis of clones separated from mixed field isolates consistently identified mutant clones as less susceptible than WT. Analysis of isolates from other sites demonstrated presence of the G223S and D1116G/N/Y mutations across Uganda. Our results indicate that malaria parasites circulating in Uganda have a number of polymorphisms in PfATP4 and that modestly decreased susceptibility to PfATP4 inhibitors is associated with some mutations now present in Ugandan parasites.

scholarly journals Single nucleotide polymorphisms in Plasmodium falciparum V type H+ pyrophosphatase gene (pfvp2) and their associations with pfcrt and pfmdr1 polymorphisms

2014 ◽  
Vol 24 ◽  
pp. 111-115 ◽  
Author(s):  
Irina Tatiana Jovel ◽  
Pedro Eduardo Ferreira ◽  
Maria Isabel Veiga ◽  
Maja Malmberg ◽  
Andreas Mårtensson ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Single Nucleotide Polymorphisms ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide

Single nucleotide polymorphisms (SNPs) analysis of CYP2C8, GSTT1, GSTP1, MDR1(A), MDR1(B) and ERCC1 as predictor of survival after weekly paclitaxel for relapsed advanced head & neck cancer patients (AHNCP)

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 2540-2540 ◽  
Author(s):  
J. J. Grau ◽  
M. Monzo ◽  
M. Vargas ◽  
S. Jansa ◽  
m. Campayo ◽  
...  
Keyword(s):  
Cancer Patients ◽  
Phase 1 ◽  
High Rate ◽  
Weekly Paclitaxel ◽  
Head Neck Cancer ◽  
Nucleotide Polymorphisms ◽  
Wild Type ◽  
Single Nucleotide ◽  
The Status ◽  
Head Neck

2540 Background: Gene SNPs correlate with survival in cancer patients (pts) treated with chemotherapy (CHM). CYP2C8 and GSTT1, GTSP1 genes are involved in phase 1 and 2 drug cellular metabolisms respectively; MDR1(A) and MDR1(B) are involved in drug membrane transport and ERCC1 in DNA repair Methods: We evaluated the presence of SNPs of these 6 genes and the survival of AHNCP treated with weekly paclitaxel, 80 mg/m2 iv for 6 weeks. Responding pts continue CHM till progression. All pts were cisplatin resistant and no other local therapies were available. We analysed paraffin-embedded biopsies from 47 consecutive AHNCP for SNPs of the mentioned genes. The status of the alleles wild type (wt) or at least 1 SNP was compared with response rate (RR), time to progression (TTP) and overall survival (OS) Results: Of 47 pts, 43 were male and 4 female. The median of age was 57 yr (46–80). RR was 45% (21/47) and the TTP in responders was 5 months of median. OS for all pts was 5.6 months. Wild type vs at least 1 SNPs frequencies according the genes were: CYP2C8 23/24; GSTT1 45/2; GSTP1 36/11; MDR1(A) 21/28; MDR1(B) 13/34; and ERCC1 27/20. OS was significantly better in pts with 2 or more SNPs accumulated (p=0.0455). No other significant differences were observed in RR, TTP or OS in SNPs vs wild type pts. Conclusions: SNPs of CYP2C8, MDR1(A) and MDR1(B) genes were more frequent than wt in our pts. OS was significantly better in pts with 2 or more SNPs accumulated. Paclitaxel provides high rate of responses of short duration in AHNC pts No significant financial relationships to disclose.

scholarly journals Evidence of Selective Sweeps in Genes Conferring Resistance to Chloroquine and Pyrimethamine in Plasmodium falciparum Isolates in India

2009 ◽  
Vol 54 (3) ◽  
pp. 997-1006 ◽  
Author(s):  
Tonya Mixson-Hayden ◽  
Vidhan Jain ◽  
Andrea M. McCollum ◽  
Amanda Poe ◽  
Avinash C. Nagpal ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Plasmodium Falciparum ◽  
Cerebral Malaria ◽  
Direct Sequencing ◽  
Point Mutations ◽  
Drug Resistant ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Mild Malaria ◽  
Resistant Genotypes

ABSTRACT Treatment of Plasmodium falciparum is complicated by the emergence and spread of parasite resistance to many of the first-line drugs used to treat malaria. Antimalarial drug resistance has been associated with specific point mutations in several genes, suggesting that these single nucleotide polymorphisms can be useful in tracking the emergence of drug resistance. In India, P. falciparum infection can manifest itself as asymptomatic, mild, or severe malaria, with or without cerebral involvement. We tested whether chloroquine- and antifolate drug-resistant genotypes would be more commonly associated with cases of cerebral malaria than with cases of mild malaria in the province of Jabalpur, India, by genotyping the dhps, dhfr, pfmdr-1, and pfcrt genes using pyrosequencing, direct sequencing, and real-time PCR. Further, we used microsatellites surrounding the genes to determine the origins and spread of the drug-resistant genotypes in this area. Resistance to chloroquine was essentially fixed, with 95% of the isolates harboring the pfcrt K76T mutation. Resistant genotypes of dhfr, dhps, and pfmdr-1 were found in 94%, 17%, and 77% of the isolates, respectively. Drug-resistant genotypes were equally likely to be associated with cerebral malaria as with mild malaria. We found evidence of a selective sweep in pfcrt and, to a lesser degree, in dhfr, indicating high levels of resistance to chloroquine and evolving resistance to pyrimethamine. Microsatellites surrounding pfcrt indicate that the resistant genotypes (SVMNT) were most similar to those found in Papua New Guinea.

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