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Friday, 12 December 2014

Gene mutation behind malaria drug resistance................

WASHINGTON: A new study has discovered reasons for malaria's drug resistance. 

Scientists from Nanyang Technological University (NTU), using a cost effective micro array technique, analysed 1,000 malaria samples taken from patients in the area of the Greater Mekong Subregion that includes countries such as Cambodia, Thailand, Vietnam, Laos and Myanmar. 

Team leader Zbynek Bozdech said the surprising find was that almost all the malaria parasites found in Cambodia and nearby regions had mutated and developed resistance to Artemisinin, the main drug used in combination therapies to treat malaria. 

This is a stark difference when compared to malaria parasites from the Congo and other African countries, where only one to three per cent of the malaria parasites had mutated and drug resistance has not yet been detected in the rest. 

Bozdech added that doctors in the Greater Mekong Subregion are finding that Artemisinin based treatment, the wonder drug cocktail that can treat patients in three days, is now taking twice as long to work, and in some rare cases, has little to no effect. 

Bozdech said that to find out exactly what the parasite cell is doing to protect itself against Artemisinin, they correlated the clinical data of the 1,000 samples with functional genomics results using their own customised techniques. 

First author Sachel Mok said they found the malaria parasite's two major ways by which it becomes resistant to Artemisinin. First, the malaria parasite increased its capacity to repair the damage caused by the anti-malarial drug which gives it a higher chance of survival and second, because the drug is more effective against the parasite at its later stage of its development, the parasite slowed down its growth so it could survive longer in the younger stages. 

Mok added that using methods like gene expression analysis, they linked these two phenomena to a gene named K13, which was previously suggested to be associated with drug resistance but it was not clear how. 

The findings of this study will also give scientists and government valuable data on how to better monitor the drug resistance of the malaria parasite and develop more effective ways of combating it.