Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 19 1 2024 03 01 98 104 Elaheh Hezardastan Department of Parasitology and Mycology, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran Ali Fattahi Bafghi Department of Parasitology and Mycology, Infectious Diseases Research Center, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran Gilda Eslami Department of Parasitology and Mycology, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran Mahmoud Vakili Health Monitoring Research Center, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran 2023 09 24 2024 01 06 Background: To investigate Molecular Genotyping of Giardia duodenalis in Humans in the Yazd County, Central of Iran. Methods: Total of 35 fecal samples were collected from patients referred to Yazd central laboratory from February to July 2022. All the samples were included in this study after microscopic observation of G duodenalis. DNA samples were extracted using related kit and were analyzed by Nano Drop. The molecular assessment was carried out using semi-nested PCR using the target gene of gdh. All amplified samples were sequenced using Sanger method. The sequences were analyzed by BLAST for assemblage identification. Results: Out of 35 samples, 24 (68.57%) and 11 (31.43%) were male and female, respectively. All included samples were amplified using the specific gdh primer pair. The molecular analysis showed 17 isolates (48.57%) as assemblage BIV, 8 isolates (22.86%) as assemblage BIII, 6 isolates (17.14%) as assemblage AII and 4 isolates (11.43%) as assemblage AIII (p<0.05). Conclusion: The molecular analysis conducted in this study showed that assemblages A and B are the most prevalent in Central Iran. The molecular identification of G duodenalis isolates from animals and implementing control programs is strongly recommended as a preventive measure to limit the transmission of giardiasis to humans. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/4046 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/4046/1345