No Association between the Plasmodium vivax crt-o MS334 or In9pvcrt Polymorphisms and Chloroquine Failure in a Pre-Elimination Clinical Cohort from Malaysia with a Large Clonal Expansion
Issued Date
2023-07-18
Resource Type
eISSN
10986596
Scopus ID
2-s2.0-85164845183
Pubmed ID
37314336
Journal Title
Antimicrobial agents and chemotherapy
Volume
67
Issue
7
Rights Holder(s)
SCOPUS
Bibliographic Citation
Antimicrobial agents and chemotherapy Vol.67 No.7 (2023) , e0161022
Suggested Citation
Rumaseb A., Moraes Barros R.R., Sá J.M., Juliano J.J., William T., Braima K.A., Barber B.E., Anstey N.M., Price R.N., Grigg M.J., Marfurt J., Auburn S. No Association between the Plasmodium vivax crt-o MS334 or In9pvcrt Polymorphisms and Chloroquine Failure in a Pre-Elimination Clinical Cohort from Malaysia with a Large Clonal Expansion. Antimicrobial agents and chemotherapy Vol.67 No.7 (2023) , e0161022. doi:10.1128/aac.01610-22 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/88046
Title
No Association between the Plasmodium vivax crt-o MS334 or In9pvcrt Polymorphisms and Chloroquine Failure in a Pre-Elimination Clinical Cohort from Malaysia with a Large Clonal Expansion
Author's Affiliation
Mahidol Oxford Tropical Medicine Research Unit
Menzies School of Health Research
QIMR Berghofer Medical Research Institute
Flinders University
UNC School of Medicine
National Institute of Allergy and Infectious Diseases (NIAID)
Universidade Federal de São Paulo
Nuffield Department of Medicine
Queen Elizabeth Hospital
Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit
Menzies School of Health Research
QIMR Berghofer Medical Research Institute
Flinders University
UNC School of Medicine
National Institute of Allergy and Infectious Diseases (NIAID)
Universidade Federal de São Paulo
Nuffield Department of Medicine
Queen Elizabeth Hospital
Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit
Other Contributor(s)
Abstract
Increasing reports of resistance to a frontline malaria blood-stage treatment, chloroquine (CQ), raises concerns for the elimination of Plasmodium vivax. The absence of an effective molecular marker of CQ resistance in P. vivax greatly constrains surveillance of this emerging threat. A recent genetic cross between CQ sensitive (CQS) and CQ resistant (CQR) NIH-1993 strains of P. vivax linked a moderate CQR phenotype with two candidate markers in P. vivax CQ resistance transporter gene (pvcrt-o): MS334 and In9pvcrt. Longer TGAAGH motif lengths at MS334 were associated with CQ resistance, as were shorter motifs at the In9pvcrt locus. In this study, high-grade CQR clinical isolates of P. vivax from a low endemic setting in Malaysia were used to investigate the association between the MS334 and In9pvcrt variants and treatment efficacy. Among a total of 49 independent monoclonal P. vivax isolates assessed, high-quality MS334 and In9pvcrt sequences could be derived from 30 (61%) and 23 (47%), respectively. Five MS334 and six In9pvcrt alleles were observed, with allele frequencies ranging from 2 to 76% and 3 to 71%, respectively. None of the clinical isolates had the same variant as the NIH-1993 CQR strain, and none of the variants were associated with CQ treatment failure (all P > 0.05). Multi-locus genotypes (MLGs) at 9 neutral microsatellites revealed a predominant P. vivax strain (MLG6) accounting for 52% of Day 0 infections. The MLG6 strain comprised equal proportions of CQS and CQR infections. Our study reveals complexity in the genetic basis of CQ resistance in the Malaysian P. vivax pre-elimination setting and suggests that the proposed pvcrt-o MS334 and In9pvcrt markers are not reliable markers of CQ treatment efficacy in this setting. Further studies are needed in other endemic settings, applying hypothesis-free genome-wide approaches, and functional approaches to understand the biological impact of the TGAAGH repeats linked to CQ response in a cross are warranted to comprehend and track CQR P. vivax.