Absence of Association between Methylene Blue Reduced Susceptibility and Polymorphisms in 12 Genes Involved in Antimalarial Drug Resistance in African Plasmodium falciparum

Half the human population is exposed to malaria. Plasmodium falciparum antimalarial drug resistance monitoring and development of new drugs are major issues related to the control of malaria. Methylene blue (MB), the oldest synthetic antimalarial, is again a promising drug after the break of its use as an antimalarial drug for more than 80 years and a potential partner for triple combination. Very few data are available on the involvement of polymorphisms on genes known to be associated with standard antimalarial drugs and parasite in vitro susceptibility to MB (cross-resistance). In this context, MB susceptibility was evaluated against 482 isolates of imported malaria from Africa by HRP2-based ELISA chemosusceptibility assay. A total of 12 genes involved in antimalarial drug resistance (Pfcrt, Pfdhfr, Pfmdr1, Pfmdr5, Pfmdr6, PfK13, Pfubq, Pfcarl, Pfugt, Pfact, Pfcoronin, and copy number of Pfpm2) were sequenced by Sanger method and quantitative PCR. On the Pfmdr1 gene, the mutation 86Y combined with 184F led to more susceptible isolates to MB (8.0 nM vs. 11.6 nM, p = 0.03). Concerning Pfmdr6, the isolates bearing 12 Asn repetitions were more susceptible to MB (4.6 nM vs. 11.6 nM, p = 0.005). None of the polymorphisms previously described as involved in antimalarial drug resistance was shown to be associated with reduced susceptibility to MB. Some genes (particularly PfK13, Pfugt, Pfact, Pfpm2) did not present enough genetic variability to draw conclusions about their involvement in reduced susceptibility to MB. None of the polymorphisms analyzed by multiple correspondence analysis (MCA) had an impact on the MB susceptibility of the samples successfully included in the analysis. It seems that there is no in vitro cross-resistance between MB and commonly used antimalarial drugs.

Download Full-text

Role ofPfmdr1inIn VitroPlasmodium falciparum Susceptibility to Chloroquine, Quinine, Monodesethylamodiaquine, Mefloquine, Lumefantrine, and Dihydroartemisinin

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.03494-14 ◽

2014 ◽

Vol 58 (12) ◽

pp. 7032-7040 ◽

Cited By ~ 41

Author(s):

Nathalie Wurtz ◽

Bécaye Fall ◽

Aurélie Pascual ◽

Mansour Fall ◽

Eric Baret ◽

...

Keyword(s):

Drug Resistance ◽

Plasmodium Falciparum ◽

Multidrug Resistance ◽

Antimalarial Drug ◽

Antimalarial Drugs ◽

Wild Type ◽

Antimalarial Drug Resistance ◽

Content Type ◽

Increased Susceptibility

ABSTRACTThe involvement ofPfmdr1(Plasmodium falciparummultidrug resistance 1) polymorphisms in antimalarial drug resistance is still debated. Here, we evaluate the association between polymorphisms inPfmdr1(N86Y, Y184F, S1034C, N1042D, and D1246Y) andPfcrt(K76T) andin vitroresponses to chloroquine (CQ), mefloquine (MQ), lumefantrine (LMF), quinine (QN), monodesethylamodiaquine (MDAQ), and dihydroartemisinin (DHA) in 174Plasmodium falciparumisolates from Dakar, Senegal. ThePfmdr186Y mutation was identified in 14.9% of the samples, and the 184F mutation was identified in 71.8% of the isolates. No 1034C, 1042N, or 1246Y mutations were detected. ThePfmdr186Y mutation was significantly associated with increased susceptibility to MDAQ (P= 0.0023), LMF (P= 0.0001), DHA (P= 0.0387), and MQ (P= 0.00002). The N86Y mutation was not associated with CQ (P= 0.214) or QN (P= 0.287) responses. ThePfmdr1184F mutation was not associated with various susceptibility responses to the 6 antimalarial drugs (P= 0.168 for CQ, 0.778 for MDAQ, 0.324 for LMF, 0.961 for DHA, 0.084 for QN, and 0.298 for MQ). ThePfmdr186Y-Y184 haplotype was significantly associated with increased susceptibility to MDAQ (P= 0.0136), LMF (P= 0.0019), and MQ (P= 0.0001). The additionalPfmdr186Y mutation increased significantly thein vitrosusceptibility to MDAQ (P< 0.0001), LMF (P< 0.0001), MQ (P< 0.0001), and QN (P= 0.0026) in wild-typePfcrtK76 parasites. The additionalPfmdr186Y mutation significantly increased thein vitrosusceptibility to CQ (P= 0.0179) inPfcrt76T CQ-resistant parasites.

Download Full-text

Absence of Association between Piperaquine In Vitro Responses and Polymorphisms in the pfcrt, pfmdr1, pfmrp, and pfnhe Genes in Plasmodium falciparum

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00183-10 ◽

2010 ◽

Vol 54 (9) ◽

pp. 3537-3544 ◽

Cited By ~ 31

Author(s):

Sébastien Briolant ◽

Maud Henry ◽

Claude Oeuvray ◽

Rémy Amalvict ◽

Eric Baret ◽

...

Keyword(s):

Drug Resistance ◽

Plasmodium Falciparum ◽

Confidence Interval ◽

Antimalarial Drug ◽

Significant Positive Correlation ◽

Geometric Mean ◽

Transport Protein ◽

Cross Resistance ◽

Antimalarial Drug Resistance

ABSTRACT We have analyzed the profiles of 23 of Plasmodium falciparum strains for their in vitro chemosusceptibilities to piperaquine (PPQ), dihydroartemisinin (DHA), chloroquine, monodesethylamodiaquine, quinine, mefloquine, lumefantrine, atovaquone, pyrimethamine, and doxycycline (DOX) in association with polymorphisms in genes involved in quinoline resistance (Plasmodium falciparum crt [pfcrt], pfmdr1, pfmrp, and pfnhe). The 50% inhibitory concentrations (IC50s) for PPQ ranged from 29 to 98 nM (geometric mean = 57.8 nM, 95% confidence interval [CI] = 51 to 65) and from 0.4 to 5.8 nM for DHA (geometric mean = 1.8 nM, 95% CI = 1.4 to 2.3). We found a significant positive correlation between the responses to PPQ and DHA (r 2 = 0.17; P = 0.0495) and between the responses to PPQ and DOX (r 2 = 0.41; P = 0.001). We did not find a significant association between the PPQ IC50 (0.0525 < P < 0.9247) or the DHA IC50 (0.0138 < P < 0.9018) and polymorphisms in the pfcrt, pfmdr1, pfmrp, and pfnhe-1 genes. There was an absence of cross-resistance with quinolines, and the IC50s for PPQ and DHA were found to be unrelated to mutations in the pfcrt, pfmdr1, pfmrp, and pfnhe-1 transport protein genes, which are involved in quinoline antimalarial drug resistance. These results confirm the interest in and the efficacy of the combination of PPQ and DHA for areas in which parasites are resistant to chloroquine or other quinolines.

Download Full-text

In Vitroand Molecular Surveillance for Antimalarial Drug Resistance in Plasmodium falciparum Parasites in Western Kenya Reveals Sustained Artemisinin Sensitivity and Increased Chloroquine Sensitivity

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01894-15 ◽

2015 ◽

Vol 59 (12) ◽

pp. 7540-7547 ◽

Cited By ~ 16

Author(s):

Naomi W. Lucchi ◽

Franklin Komino ◽

Sheila Akinyi Okoth ◽

Ira Goldman ◽

Philip Onyona ◽

...

Keyword(s):

Drug Resistance ◽

Plasmodium Falciparum ◽

Antimalarial Drug ◽

Mutant Allele ◽

Surveillance Program ◽

Wild Type ◽

Antimalarial Drug Resistance ◽

Western Kenya ◽

Content Type

ABSTRACTMalaria control is hindered by the evolution and spread of resistance to antimalarials, necessitating multiple changes to drug policies over time. A comprehensive antimalarial drug resistance surveillance program is vital for detecting the potential emergence of resistance to antimalarials, including current artemisinin-based combination therapies. An antimalarial drug resistance surveillance study involving 203Plasmodium falciparummalaria-positive children was conducted in western Kenya between 2010 and 2013. Specimens from enrolled children were analyzedin vitrofor sensitivity to chloroquine (CQ), amodiaquine (AQ), mefloquine (MQ), lumefantrine, and artemisinin derivatives (artesunate and dihydroartemisinin) and for drug resistance allele polymorphisms inP. falciparum crt(Pfcrt),Pfmdr-1, and the K13 propeller domain (K13). We observed a significant increase in the proportion of samples with thePfcrtwild-type (CVMNK) genotype, from 61.2% in 2010 to 93.0% in 2013 (P< 0.0001), and higher proportions of parasites with elevated sensitivity to CQin vitro. The majority of isolates harbored the wild-type N allele inPfmdr-1codon 86 (93.5%), with only 7 (3.50%) samples with the N86Ymutant allele (the mutant nucleotide is underlined). Likewise, most isolates harbored the wild-typePfmdr-1D1246 allele (79.8%), with only 12 (6.38%) specimens with the D1246Ymutant allele and 26 (13.8%) with mixed alleles. All the samples had a single copy of thePfmdr-1gene (mean of 0.907 ± 0.141 copies). None of the sequenced parasites had mutations in K13. Our results suggest that artemisinin is likely to remain highly efficacious and that CQ sensitivity appears to be on the rise in western Kenya.

Download Full-text

Evaluation of antimalarial prescription pattern and susceptibility of Plasmodium falciparum isolates in Kaduna, Nigeria

International Journal of Biological and Chemical Sciences ◽

10.4314/ijbcs.v13i7.34 ◽

2020 ◽

Vol 13 (7) ◽

pp. 3398-3410

Author(s):

O. Ifeoluwa Akanni ◽

J.O. Ehinmidu ◽

R.O. Bolaji

Keyword(s):

Plasmodium Falciparum ◽

Combination Therapy ◽

Antimalarial Drug ◽

Drug Prescription ◽

Artemisinin Combination Therapy ◽

Therapy Resistance ◽

Antimalarial Drugs ◽

In Vitro Susceptibility

Nigeria carries the highest burden of malaria in terms of morbidity and mortality. This is compounded by continuous resistance of Plasmodium falciparum to antimalarial drugs. This study was designed to evaluate the profile of malaria patients’ antimalarial drug prescription and in vitro susceptibility of P. falciparum isolates to commonly prescribed antimalarial drugs in Kaduna, Nigeria. Three years’ records of patients antimalarial drug prescriptions were collated (2013 to 2015) and the in vitro antimalarial agent susceptibility was determined for 28 clinical isolates using WHO Mark III microtest. Artemisinin-based combination therapy (ACT) was the most prescribed antimalarial for the period under review (92.3-93.7%). Among the ACTs, Artemether-lumefantrine was most prescribed. Of the 28 P. falciparum isolates evaluated, 3 (10.71%) were resistant to chloroquine with a median IC50 of 4.82μM (4.60-8.14μM), while five (17.86%) were resistant to mefloquine with a median IC50 of 25μM (10.3-41μM), 7(25.00%) to artemether with a median IC50 of 2.69μM (2.09-8.77μM), 9 (32.14%) to artesunate-mefloquine combination with a median IC50 of 9.0μM (7.98-35μM) and to artesunate, 11(39.29%) were resistant with a median IC50 of 2.4μM (1.56-5.65μM). This result shows a decline in resistance of P. falciparum to chloroquine compared to period prior to artemisinin-combination therapy as well as reduced susceptibility to artesunate and artemether. Further in vitro and in vivo monitoring will be required to inform antimalarial drug policy change.Keywords: Antimalarial, Artemisinin-combination therapy, resistance, susceptibility, microtest.

Download Full-text

Atorvastatin Is a Promising Partner for Antimalarial Drugs in Treatment of Plasmodium falciparum Malaria

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01462-08 ◽

2009 ◽

Vol 53 (6) ◽

pp. 2248-2252 ◽

Cited By ~ 22

Author(s):

Véronique Parquet ◽

Sébastien Briolant ◽

Marylin Torrentino-Madamet ◽

Maud Henry ◽

Lionel Almeras ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Malaria Parasite ◽

Reductase Inhibitor ◽

Significant Positive Correlation ◽

Plasmodium Falciparum Malaria ◽

Antimalarial Drugs ◽

Transport Proteins ◽

Cross Resistance ◽

Antimalarial Drug Resistance

ABSTRACT Atorvastatin (AVA) is a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor. AVA exposure resulted in the reduced in vitro growth of 22 Plasmodium falciparum strains, with the 50% inhibitory concentrations (IC50s) ranging from 2.5 μM to 10.8 μM. A significant positive correlation was found between the strains’ responses to AVA and mefloquine (r = 0.553; P = 0.008). We found no correlation between the responses to AVA and to chloroquine, quinine, monodesethylamodiaquine, lumefantrine, dihydroartemisinin, atovaquone, or doxycycline. These data could suggest that the mechanism of AVA uptake and/or the mode of action of AVA is different from those for other antimalarial drugs. The IC50s for AVA were unrelated to the occurrence of mutations in the transport protein genes involved in quinoline antimalarial drug resistance, such as the P. falciparum crt, mdr1, mrp, and nhe-1 genes. Therefore, AVA can be ruled out as a substrate for the transport proteins (CRT, Pgh1, and MRP) and is not subject to the pH modification induced by the P. falciparum NHE-1 protein. The absence of in vitro cross-resistance between AVA and chloroquine, quinine, mefloquine, monodesethylamodiaquine, lumefantrine, dihydroartemisinin, atovaquone, and doxycycline argues that these antimalarial drugs could potentially be paired with AVA as a treatment for malaria. In conclusion, the present observations suggest that AVA is a good candidate for further studies on the use of statins in association with drugs known to have activities against the malaria parasite.

Download Full-text

Diagnostic accuracy of molecular methods for detecting markers of antimalarial drug resistance in clinical samples of Plasmodium falciparum: protocol for an update to a systematic review and meta-analysis

Systematic Reviews ◽

10.1186/s13643-018-0891-6 ◽

2018 ◽

Vol 7 (1) ◽

Cited By ~ 1

Author(s):

Rebekah Burrow ◽

Thomas R. Fanshawe ◽

Georgina S. Humphreys

Keyword(s):

Systematic Review ◽

Drug Resistance ◽

Plasmodium Falciparum ◽

Diagnostic Accuracy ◽

Antimalarial Drug ◽

Meta Analysis ◽

Molecular Methods ◽

Clinical Samples ◽

Antimalarial Drug Resistance

Download Full-text

History and current status of Plasmodium falciparum antimalarial drug resistance in Madagascar

Scandinavian Journal of Infectious Diseases ◽

10.3109/00365540903289670 ◽

2010 ◽

Vol 42 (1) ◽

pp. 22-32 ◽

Cited By ~ 9

Author(s):

Valérie Andriantsoanirina ◽

Didier Ménard ◽

Luciano Tuseo ◽

Rémy Durand

Keyword(s):

Drug Resistance ◽

Plasmodium Falciparum ◽

Antimalarial Drug ◽

Current Status ◽

Antimalarial Drug Resistance

Download Full-text

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

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00552-19 ◽

2019 ◽

Vol 63 (10) ◽

Cited By ~ 1

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.

Download Full-text