Background: The
spread of Plasmodium vivax strains resistant to chloroquine (CQ) has
posed a challenge to control strategies aimed at eliminating malaria.
Molecular analysis of candidate resistance markers is very important for
monitoring the P. vivax resistance to CQ in different endemic regions.
In the present study, the multidrug resistance 1 (pvmdr1) gene, a
possible marker for CQ resistance in P. vivax, was evaluated by
molecular methods.
Methods: A
simple PCR-RFLP method was developed for mutation analysis in pvmdr1
gene. A number of 120 blood spots were obtained from patients with P.
vivax mono-infection in 2021. All of the samples were collected from
Pakistani patients who travelled to Iran.
Results: None
of the samples had any mutation at codon 976 of pvmdr1, while the 1076
mutation was detected in 96.2% of the examined isolates. Only two pvmdr1
haplotypes were identified, including the single mutant (Y976/1076L) as
the most prevalent haplotype (with 96.2% frequency) and the wild type
(Y976/F1076; with 3.8% frequency).
Conclusions: In
this study, the major CQ resistance-mediating mutation and multiple
mutant haplotypes of the pvmdr1 gene was not detected. However,
continuous monitoring of drug resistance markers and close supervision
of the efficacy of CQ is essential to detect the potential emergence of
CQ-resistant P. vivax isolates in Iran. This data is important for
performing future epidemiological surveillance to monitor CQ resistance
in this endemic area and the bordering regions.