Introduction: Parasitic diseases are one of the most common problems in the world, especially in developing countries, including our country. One of the common parasitic diseases is infection with Giardia lamblia. Giardia lamblia isolates are classified into 8 groups based on the characteristics of different genes, including triosephosphate isomerase (TPI). Assemblages A and B infect humans and a broad range of other hosts. The purpose of this study was to genotype human isolates of Giardia lamblia by PCR in Dezfoul city
Methods: For this purpose, 22 positive fecal samples of G. lamblia were collected from 2022 to 2023. DNA extraction and amplification of the TPI gene by nested-PCR successfully were performed. All samples were positive. To determine the genetic differences, sequencing on three samples was conducted. Then, all PCR products were digested with Bbv1, Mnl1, and RsaI restriction enzymes.
Results: Results showed that the alignment of the TPI sequences obtained with reference sequences indicates the presence of 2 genotypes of Giardia lamblia (A and B). The results of the RFLP technique show that 14 of 22 (63.63%) isolates belonged to assemblage A and 8 of 22 (36.36%) belonged to assemblage B.
Conclusion: In general, the results obtained in the present study indicated that genotype A is the most frequent in patients of Dezfoul city, which is probably due to the leakage of sewage into the rivers of the province and the use of contaminated water, so it is used to control this disease. Hygiene principles and safe drinking water should be given more attention.