Dataset Information

A dual colour fluorescence in situ hybridization (FISH) assay for identifying the zoonotic malaria parasite Plasmodium knowlesi with a potential application for the specific diagnosis of knowlesi malaria in peripheral-level laboratories of Southeast Asia.

ABSTRACT: Plasmodium knowlesi is primarily responsible for zoonotic malaria in several Southeast Asian countries. Precise identification of the parasite in the blood of patients presently relies on an expensive and elaborate PCR procedure because microscopic examination of blood and other available field identification techniques lack adequate specificity. Therefore, the use of a simple and inexpensive dual-colour fluorescence in situ hybridization (FISH) assay, analogous to FISH assays recently described for Plasmodium falciparum and Plasmodium vivax, was investigated as a potential tool for identifying P. knowlesi.A P. knowlesi 18S rDNA sequence-based DNA probe was used to test thin blood smears of P. knowlesi by FISH, and fluorescence viewed in a light microscope fitted with a light emitting diode light source and appropriate emission and barrier filters. The limit of detection in the P. knowlesi FISH assay was 84 parasites per μl in infected monkey blood and 61 parasites per μl for P. knowlesi cultured in human blood. The P. knowlesi-specific FISH probe detected only P. knowlesi and not P. falciparum, Plasmodium malariae, Plasmodium ovale, P. vivax or a panel of other human blood-borne pathogens. A previously described Plasmodium genus-specific probe used simultaneously in the P. knowlesi FISH assay reacted with all tested Plasmodium species.To our knowledge, this is the first description of a FISH assay for P. knowlesi that is potentially useful for diagnosing infections in remote laboratories in endemic countries.

SUBMITTER: Shah J

PROVIDER: S-EPMC5517825 | biostudies-other | 2017 Jul

REPOSITORIES: biostudies-other

ACCESS DATA

Similar Datasets

Project description:BackgroundPlasmodium knowlesi is a significant cause of human malaria in Sarawak, Malaysian Borneo. Only one study has been previously undertaken in Sarawak to identify vectors of P. knowlesi, where Anopheles latens was incriminated as the vector in Kapit, central Sarawak. A study was therefore undertaken to identify malaria vectors in a different location in Sarawak.MethodsMosquitoes found landing on humans and resting on leaves over a 5-day period at two sites in the Lawas District of northern Sarawak were collected and identified. DNA samples extracted from salivary glands of Anopheles mosquitoes were subjected to nested PCR malaria-detection assays. The small subunit ribosomal RNA (SSU rRNA) gene of Plasmodium was sequenced, and the internal transcribed spacer 2 (ITS2) and mitochondrial cytochrome c oxidase subunit 1 (cox1) gene of the mosquitoes were sequenced from the Plasmodium-positive samples for phylogenetic analysis.ResultsTotals of 65 anophelines and 127 culicines were collected. By PCR, 6 An. balabacensis and 5 An. donaldi were found to have single P. knowlesi infections while 3 other An. balabacensis had either single, double or triple infections with P. inui, P. fieldi, P. cynomolgi and P. knowlesi. Phylogenetic analysis of the Plasmodium SSU rRNA gene confirmed 3 An. donaldi and 3 An. balabacensis with single P. knowlesi infections, while 3 other An. balabacensis had two or more Plasmodium species of P. inui, P. knowlesi, P. cynomolgi and some species of Plasmodium that could not be conclusively identified. Phylogenies inferred from the ITS2 and/or cox1 sequences of An. balabacensis and An. donaldi indicate that they are genetically indistinguishable from An. balabacensis and An. donaldi, respectively, found in Sabah, Malaysian Borneo.ConclusionsPreviously An. latens was identified as the vector for P. knowlesi in Kapit, central Sarawak, Malaysian Borneo, and now An. balabacensis and An. donaldi have been incriminated as vectors for zoonotic malaria in Lawas, northern Sarawak.

Dataset Information

A dual colour fluorescence in situ hybridization (FISH) assay for identifying the zoonotic malaria parasite Plasmodium knowlesi with a potential application for the specific diagnosis of knowlesi malaria in peripheral-level laboratories of Southeast Asia.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets