Related Experiment Video
Updated: May 10, 2026
Laboratory Protocol for Genetic Gut Content Analyses of Aquatic Macroinvertebrates Using Group-specific rDNA Primers
Published on: October 5, 2017
Molecular identification of Giardia duodenalis in Ecuador by polymerase chain reaction-restriction fragment length
Richard Atherton1, Darlene Bhavnani, Manuel Calvopiña
1Centro de Biomedicina, Universidad Central del Ecuador, Quito, Pichincha, Ecuador. richard.atherton@hotmail.co.uk
Abstract:
The aim of this study was to determine the genetic diversity of Giardia duodenalis present in a human population living in a northern Ecuadorian rain forest. All Giardia positive samples (based on an ELISA assay) were analysed using a semi-nested polymerase chain reaction-restriction fragment length polymorphism assay that targets the glutamate dehydrogenase (gdh) gene; those amplified were subsequently genotyped using NlaIV and RsaI enzymes. The gdh gene was successfully amplified in 74 of 154 ELISA positive samples; 69 of the 74 samples were subsequently genotyped. Of these 69 samples, 42 (61%) were classified as assemblage B (26 as BIII and 16 as BIV), 22 (32%) as assemblage A (3 as AI and 19 as AII) and five (7%) as mixed AII and BIII types. In this study site we observe similar diversity in genotypes to other regions in Latin America, though in contrast to some previous studies, we found similar levels of diarrheal symptoms in those individuals infected with assemblage B compared with those infected with assemblage A.
