Detection and genetic characterization of Giardia intestinalis in children with gastrointestinal symptoms by PCR RFLP in Sikkim, India

Abstract

Background: This study is aimed to detect Giardia and genetically characterize Giardia intestinalis among children in Sikkim, India. Materials and Methods: A total of 400 stool samples were collected from the children (<15 years) with gastrointestinal symptoms, who attended Central Referral Hospital and Sir Thodup Namgyal Memorial Hospital. Giardia cysts were detected by microscopy from the stool samples and were genetically characterized by polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) targeting glutamate dehydrogenase gene (gdh). Results: Giardia cysts were detected in 20/400 (5% incidence rate). Out of 20 samples, 13 (65%) were successfully assayed by PCR-RFLP. The PCR product of gdh gene was digested by BsPL1 and RsaI and isolated 53.7% of BIV, 38.5% of AII and B mixed, and 7.8% of BIII assemblages. There was no AI assemblage found in this study. Diarrhea and abdominal pain were the common complaints associated with giardiasis. Conclusions: PCR-RFLP targeting gdh gene locus is a reliable, easy, and cost-effective method to identify G. intestinalis and its assemblages. This is the first report on the prevalence and genetic variability of human giardiasis in symptomatic children in Sikkim, India.