A Simple Isothermal DNA Amplification Method to Screen Black Flies for <i>Onchocerca volvulus</i> Infection



Alhassan, Andy, Makepeace, Benjamin L ORCID: 0000-0002-6100-6727, LaCourse, Elwyn James, Osei-Atweneboana, Mike Y and Carlow, Clotilde KS
(2014) A Simple Isothermal DNA Amplification Method to Screen Black Flies for <i>Onchocerca volvulus</i> Infection. PLOS ONE, 9 (10). e108927-.

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Abstract

Onchocerciasis is a debilitating neglected tropical disease caused by infection with the filarial parasite Onchocerca volvulus. Adult worms live in subcutaneous tissues and produce large numbers of microfilariae that migrate to the skin and eyes. The disease is spread by black flies of the genus Simulium following ingestion of microfilariae that develop into infective stage larvae in the insect. Currently, transmission is monitored by capture and dissection of black flies and microscopic examination of parasites, or using the polymerase chain reaction to determine the presence of parasite DNA in pools of black flies. In this study we identified a new DNA biomarker, encoding O. volvulus glutathione S-transferase 1a (OvGST1a), to detect O. volvulus infection in vector black flies. We developed an OvGST1a-based loop-mediated isothermal amplification (LAMP) assay where amplification of specific target DNA is detectable using turbidity or by a hydroxy naphthol blue color change. The results indicated that the assay is sensitive and rapid, capable of detecting DNA equivalent to less than one microfilaria within 60 minutes. The test is highly specific for the human parasite, as no cross-reaction was detected using DNA from the closely related and sympatric cattle parasite Onchocerca ochengi. The test has the potential to be developed further as a field tool for use in the surveillance of transmission before and after implementation of mass drug administration programs for onchocerciasis.

Item Type: Article
Uncontrolled Keywords: Animals, Cattle, Humans, Simuliidae, Onchocerca volvulus, Onchocerciasis, Cattle Diseases, Glutathione Transferase, Nucleic Acid Amplification Techniques, Sequence Alignment, Insect Vectors, Base Sequence, Larva, Molecular Sequence Data, Microfilariae
Depositing User: Symplectic Admin
Date Deposited: 17 Mar 2015 15:01
Last Modified: 05 Oct 2023 09:26
DOI: 10.1371/journal.pone.0108927
Publisher's Statement : © 2014 Alhassan et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/2008205