Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 11 1 2016 03 14 98 103 Somayeh MAGHSOODLOORAD Dept. of Parasitology and Mycology, School of Medicine, Golestan University of Medical Sciences, Gorgan, Iran Ali HAGHIGHI Dept. of Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran Khojasteh SHARIFI SARASIABI Paramedical Faculty, Hormozgan University of Medical Sciences, Bandar Abbas, Iran Niloofar TAGHIPOOR Dept. of Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran Nahid HOSSEINZADEH Dept. of Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran Latif GACHKAR Tropical and Infectious Diseases Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran Ehsan NAZEMALHOSSEINI MOJARRAD Research Center for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran Elham MAGHSOODLOORAD Sayyad Shirazi Hospital, Golestan University of Medical Sciences, Gorgan, Iran 2016 03 14 2016 03 14 Background: The present study was formulated in order to determine pol­ymorphism of dihydropteroate synthetase gene (dhps) of Plasmodium vivax (P. vivax) in Hormozgan Province, southern Iran and mutations at codons 382, 383, 512, 553, and 585 associated with resistance of P. vivax to sulfadoxine. Method: One-hundred eighteen isolates of P. vivax were prepared within 2007-2008 to determine dihydrofolate reductase-thymidylate synthase (dhfr-ts) gene. The isolates were determined in the study of genetic diversity of dihy­dropteroate synthetase gene (dhps) of P. vivax. The study was performed via PCR test and nucleotide sequencing. Results: Of 118 blood samples infected by P. vivax, 46 and 72 samples be­longed to Minab and Jask, respectively. No mutation was detected at 5 target codons. However, among these 118 samples, three isolates (2.54%) were found to have a mutation at the new codon 421. Conclusion: Since mutation was detected in dihydrofolate reductase (Pvdhfr) gene in the same samples but no mutation was found at five main codons of Pvdhps gene, it can be concluded that P. vivax, considering their mutations in Pvdhfr, is still susceptible to sulfadoxine and therefore, to fansidar in Hor­mozgan Province, Southern Iran. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/816 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/816/660