Download Full Text (1.1 MB)


Zoonotic diseases are transmitted to humans from wildlife and often pose serious health risks. One such disease, gnathostomiasis, is caused by parasitic nematodes in the genus Gnathostoma, commonly transmitted by consumption of infected undercooked freshwater fish. Lately, movement of animals over international borders has increased, leading to emerging zoonotic diseases (2018; CDC – One Health Basics). Human gnathostomiasis is just one example.

This project expands on previous research (Cole et al.) which identified Gnathostoma in invasive eels and imported eels from food markets, using morphological features and DNA sequences of the ribosomal RNA gene array’s ITS-2 (intergenic transcribed spacer-2) region. DNA barcoding is a system used to identify species by using short DNA sequences of a common region of the genome, often a particular gene, that can distinguish between species. The cytochrome ‘c’ oxidase subunit 1 (CO1) gene is one such common barcoding gene, along with the 28s and CO2 genes. The method uses universal primers to amplify this barcoding gene.

From 20 extracted DNA samples provided by Dr. Rebecca Cole, 8 were selected as an overall representation for this project. 4 G. spinigerum, 3 G. turgidum, and 1 G. lamothei were selected to present on. PCR amplification was done to amplify the 28s, CO1, and CO2 genes. Amplified products were purified and sent to MCLabs (South San Francisco, CA) for sequencing and DNA sequences were assembled, (, followed by (phylo)genetic analyses. This study provides the first comprehensive multi-gene characterization of these nematodes.


Dr. Anindo Choudhury, Biology and Environmental Science

Publication Date



biology, environmental science, gnathostomiasis

Genetic Characterization and DNA Barcoding of the Zoonotic Parasite Gnathostoma

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.