Alleles of the Plasmodium falciparum Pfmdr1 gene appear not to be associated with chloroquine resistance in India

Bhattacharya, Pramatha R.; Biswas, Subrata; Kabilan, L

doi:10.1016/s0035-9203(97)90283-2

Cited by 26 publications

(19 citation statements)

References 12 publications

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“…The discordance between the prediction based on the allelic form of pfmdr1 and chloroquine resistance has been shown elsewhere. [19][20][21][22][23][24][25] No mutation at Asn-1042 and Asp-1246 was detected among the Thai chloroquine-resistant isolates of P. falciparum, although earlier studies have reported this. 6 Similarly, Cox-Singh and others found no mutations of this type in isolates from Malaysia.…”

Section: Discussionmentioning

confidence: 76%

Analysis of mefloquine resistance and amplification of pfmdr1 in multidrug-resistant Plasmodium falciparum isolates from Thailand.

Chaiyaroj

Buranakiti²,

Angkasekwinai³

et al. 1999

Am J Trop Med Hyg

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Abstract. Resistance to quinoline-containing compound has been associated with the Plasmodium falciparum multidrug resistance 1 (pfmdr1) gene. We analyzed wild P. falciparum isolates with high levels of chloroquine and mefloquine resistance for their macrorestriction maps of chromosome 5 and sequence of pfmdr1. Two types of chromosome 5 amplification were found. Eleven of 62 resistant isolates displayed Bgl I fragments larger than 100 kb. Twenty-nine isolates possessed multiple copies of the fragments. We failed to detect any amplification of this region on chromosome 5 in 22 mefloquine-resistant isolates, suggesting that other mechanisms can mediate the mefloquine-resistant phenotype. There was no direct association between pfmdr1 mutations and chloroquine sensitivity. Resistant lines could have Asn-86 and Tyr-184 or Phe-184, the predicted sequence of those chloroquine-sensitive isolates. No mutation at Asn-1042 and Asp-1246 was detected among these chloroquine-resistant isolates. Therefore, a few base substitutions in the pfmdr1 gene may not be sufficient to account for all chloroquine-resistant phenotypes.In Thailand, malaria continues to be a major public health problem due to the emergence of multidrug-resistant organisms. Increasing levels and prevalence of Plasmodium falciparum resistance to choloroquine 1 and mefloquine 2-4 have been reported. This has made the treatment and prophylaxis of malaria increasingly complicated. Although new drugs and several drug combinations are being introduced, it is important to elucidate the molecular mechanism of aminoquinoline drug resistance to develop the appropriate strategies for malaria therapy.A P-glycoprotein homolog (Pgh 1) has been implicated in chloroquine-and mefloquine-resistant phenotypes of P. falciparum. [5][6][7][8] It is encoded by the P. falciparum multidrug resistance 1 (pfmdr1) gene and is localized on the membrane of the digestive vacuole of this parasite. 8,9 High levels of Pgh 1 expression have been shown in drug-resistant cell lines to confer a chloroquine-sensitive phenotype and in yeast to complement the ste 6 functions, 10 suggesting a role as a drug transporter. Controversy exists regarding the pfmdr 1 gene and chloroquine resistance from the work of Wellems and others 11 in that there is no linkage between pfmdr 1 and such resistance. In addition, in vitro selection of parasites for increased chloroquine resistance resulted in parasites with higher sensitivity to mefloquine. 12 Surprisingly, chromosome 5 of these parasite clones demonstrated deamplification and the expression of Pgh 1 was also decreased. 12 In subsequent drug selection studies, the higher levels of mefloquine resistance have been associated with amplification of pfmdr1. 8,13 Data from several field isolates with mefloquine resistance suggested that the amplification of pfmdr1 and an increase in mRNA expression is associated with natural resistance. Furthermore, cross-resistance to other related drugs such as halofantrine and quinine was also observed. [13][14][15] In this s...

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Section: Discussionmentioning

confidence: 76%

Analysis of mefloquine resistance and amplification of pfmdr1 in multidrug-resistant Plasmodium falciparum isolates from Thailand.

Chaiyaroj

Buranakiti²,

Angkasekwinai³

et al. 1999

Am J Trop Med Hyg

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“…Nevertheless, in some of these epidemiological studies, the low number of CQ susceptible samples does not allow to provide a statistically meaningful analysis [55,63]. When precautions are taken into account, no relationship or only weak relationships are brought to the fore between CQ resistance and Pfmdr1 mutations in P. falciparum [54,57,[64][65][66][67]. Other polymorphism features of Pfmdr1, like point mutations at codon 184, 1034, 1042 and 1246, were identified in both CQ susceptible and resistant parasites [68,69].…”

Section: Abc Transportersmentioning

confidence: 99%

Chloroquine Resistance Reversal Agents as Promising Antimalarial Drugs

Henry¹,

Alibert²,

Orlandi-Pradines³

et al. 2006

CDT

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The development and spread of resistance to antimalarial drugs poses a severe and increasing public health threat. Failures of prophylaxis or treatment with quinolines, hydroxynaphthoquinones, sesquiterpene lactones, antifolate drugs and sulfamides are involved in a return malaria-related morbidity and mortality. Resistance is associated with a decrease in accumulation of drugs into the vacuole, which results from a reduced uptake of the drug, an increased efflux or a combination of both. A number of candidate genes in P. falciparum have been proposed to be involved in antimalarial resistance, each concerned in membrane transport. Weaker or stronger associations are seen in P. falciparum between the resistance to quinolines or artemisinin derivatives and codon changes in Pfmdr1, a gene which encodes Pgh-1, an ortholog of one of the P-glycoproteins expressed in multi-drug resistant human cancer cells (ABC transporter). Further analysis has revealed a new gene, Pfcrt, encoding a PfCRT protein, which resembles an anion channel. Codon changes found in the Pfcrt sequence in drug resistant isolates could facilitate the drug efflux through a putative channel. It has been proposed that the reversal of quinoline resistance by verapamil is due to hydrophobic binding to the mutated PfCRT protein. Several compounds have demonstrated in the past decade a promising capability to reverse the antimalarial drug resistance in vitro in parasite isolates, in animal models and in human malaria. These drugs belong to different pharmacological classes such as calcium channel blockers, tricyclic antidepressants, antipsychotic calmodulin antagonists, histamine H1-receptor antagonists, analgesic and antipyretic drugs, non-steroidal anti-inflammatory drugs, and to different chemical classes such as synthetic surfactants, alkaloids from plants used in traditional medicine, pyrrolidinoaminoalkanes and anthracenic derivatives. Here we summarize the progress made in biochemical and genetic basis of antimalarial resistance, emphasizing the recent developments on drugs, which interfere with trans membrane proteins involved in drug efflux or uptake.

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“…No obstante, algunos autores reportan falta de asociación entre la falla terapéutica o la resistencia y la presencia de mutaciones en el gen pfmdr1 (10)(11)(12)(13)(14). La mutación 86 Tir en pfmdr1 asociada con resistencia a la cloroquina, también puede incrementar la sensibilidad a mefloquina y halofantrina (15), mientras que la presencia del alelo silvestre Asn 86 se ha correlacionado con resistencia a la mefloquina (16,17).…”

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Polimorfismos del gen pfmdr1 en muestras clínicas de Plasmodium falciparum y su relación con la respuesta terapéutica a antipalúdicos y paludismo grave en Colombia

et al. 2007

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Polimorfismos del gen pfmdr1 en muestras clínicas de Plasmodium falciparum y su relación con la respuesta terapéutica a antipalúdicos y paludismo grave en Colombia Paula Montoya, Alberto Tobón, Silvia Blair, Jaime Carmona, Amanda Maestre Grupo de Malaria, Sede de Investigación Universitaria, Universidad de Antioquia, Medellín, ColombiaIntroducción. El gen pfmdr1 de Plasmodium falciparum se describió como un gen de resistencia a diversos antipalúdicos. Sin embargo, no se han estudiado el papel de su polimorfismo en la respuesta terapéutica al tratamiento con antipalúdicos en Colombia, ni su relación con paludismo grave. Objetivos. Este trabajo determinó la asociación entre los polimorfismos Asn 86 Tir y Asp 1246 Tir del gen pfmdr1 con la respuesta terapéutica a cloroquina, amodiaquina y mefloquina, en tres municipios antioqueños, y la asociación de estos polimorfismos con paludismo grave en muestras de pacientes del municipio de Tumaco. Materiales y métodos. Los polimorfismos del gen pfmdr1 se determinaron mediante amplificación de ácidos nucleicos y análisis con enzimas de restricción. Resultados. El alelo silvestre Asn 86 se encontró en 97% (137/141) de las muestras en el estudio de respuesta terapéutica a cloroquina, amodiaquina y mefloquina; no se observó ninguna asociación entre su presencia y la falla terapéutica como sí lo reportan otros autores. El alelo 1246 Tir se encontró en una alta proporción en el estudio de respuesta terapéutica, tanto en las muestras del día cero como en los del día de la falla después del tratamiento con los antipalúdicos. Conclusiones. Los polimorfismos 86 Tir y 1246 Tir en el gen pfmdr1 no son útiles como factores de predicción de falla terapéutica o paludismo grave en los municipios estudiados. Este estudio describe por primera vez la presencia del alelo 86 Tir en cuatro muestras clínicas de Suramérica.Palabras clave: Plasmodium falciparum/efectos de drogas, antipalúdicos/uso terapéutico, malaria, cloroquina, amodiaquina, mefloquina. Polymorphisms of the pfmdr1 gene in field samples of Plasmodium falciparum and their association with therapeutic response to antimalarial drugs and severe malaria in ColombiaIntroduction. The pfmdr1 gene of Plasmodium falciparum has been described as a gene conferring resistance to several antimalarial drugs. In particular, polymorphisms on specific codons have been associated with resistance and treatment failure with cloroquine, amodiaquine and mefloquine. However, the role of these polymorphisms in treatment response to antimalarials remains unexplored in Colombia. Furthermore, the relationship of these polymorphisms to severe malaria is unknown. Objective. This work studied the association of the Asn 86 Tyr and Asp 1246 Tyr pfmdr1 polymorphisms with response to cloroquine, amodiaquine and mefloquine treatment in three municipalities of Antioquia, and severe malaria cases from the municipality Tumaco. Materials and methods.The polymorphisms were assessed by nucleic acid amplification followed by restriction length polymorphism analysis. Result...

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Alleles of the Plasmodium falciparum Pfmdr1 gene appear not to be associated with chloroquine resistance in India

Cited by 26 publications

References 12 publications

Analysis of mefloquine resistance and amplification of pfmdr1 in multidrug-resistant Plasmodium falciparum isolates from Thailand.

Analysis of mefloquine resistance and amplification of pfmdr1 in multidrug-resistant Plasmodium falciparum isolates from Thailand.

Chloroquine Resistance Reversal Agents as Promising Antimalarial Drugs

Polimorfismos del gen pfmdr1 en muestras clínicas de Plasmodium falciparum y su relación con la respuesta terapéutica a antipalúdicos y paludismo grave en Colombia

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