Nav: Home

New assay detects patients' resistance to antimalarial drugs from a drop of blood

June 13, 2019

Philadelphia, June 13, 2019 - Antimalarial drugs appear to follow a typical pattern, with early effectiveness eventually limited by the emergence of drug resistance. A report in the Journal of Molecular Diagnostics, published by Elsevier, describes a new assay using whole blood that simplifies the genetic analysis of malarial parasites by completely eliminating processing steps. This provides rapid access to critical information associated with resistance to antimalarials at the point of care, avoiding the time, expense, and effort of having the sample sent to a central laboratory and allowing clinicians to quickly re-evaluate treatment options.

Blood contains a wealth of genetic information, but currently must undergo significant processing to remove components that interfere with molecular analyses. Although an exciting prospect, gathering genetic information from a single drop of blood has proved elusive. This study, which analyzed a single mutation in a malaria parasite, provides the first steps to do just that: a drop of blood can be used directly, without any additional processing, to assess a range of genetic data.

"Monitoring of antimalarial resistance is important to prevent its further spread, but the available options for assessing resistance are less than ideal for field settings. Although molecular detection is perhaps the most efficient method, it is also the most complex because it requires DNA extraction and PCR instrumentation," noted co-lead investigator Mindy Leelawong, PhD, Research Assistant Professor of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA. "Our strategy eliminates the most time- and labor-intensive step: DNA extraction. By creating a procedure that overcomes the obstacles presented by blood, we have developed a simple method to quickly identify mutations associated with drug resistance. As a consequence, higher throughput testing and more rapid sample-to-result turnaround will be possible."

"To mitigate the inhibition by blood components, we redesigned the molecular tools used for DNA analysis. We utilized reporter dyes that are more optically compatible with blood, which were combined with a specific type of DNA subunit to accurately pinpoint mutations. The end result is an assay in which blood is directly added to a reaction tube to detect mutations associated with antimalarial drug resistance," explained co-lead investigator Frederick R. Haselton, PhD, of the Departments of Biomedical Engineering and Chemistry at Vanderbilt University.

Dr. Leelawong and Dr. Haselton, along with co-lead investigator David W. Wright, PhD, of the Department of Chemistry at Vanderbilt, anticipate that the technique can be modified for assessing resistance to artemisinin, the current first-line therapy for malarial infection, or future drugs as they become available. The technique may also become a platform for evaluating other molecular targets found in blood.

The technology detailed in this study offers a potential platform to manage the spread of drug resistance on the ground. According to Dr. Wright, "These drug-resistant parasites must not spread; we know from previous generations of drugs that the consequences can be catastrophic. To prevent further spread, the geographic location of drug-resistant parasites must be known."

Malaria is a serious, sometimes fatal disease caused by a parasite that commonly infects a certain type of mosquito that feeds on humans and infects red blood cells. People who contract malaria typically become very sick with high fevers, shaking chills, and flu-like illness. According to the World Malaria Report 2018, there were 219 million cases of malaria globally in 2017 resulting in 435,000 malaria deaths. Although antimalarial drugs are often effective, outcomes are worse for those who are drug resistant.
-end-


Elsevier

Related Malaria Articles:

Could there be a 'social vaccine' for malaria?
Malaria is a global killer and a world health concern.
Transgenic plants against malaria
Scientists have discovered a gene that allows to double the production of artemisinin in the Artemisia annua plant.
Fighting malaria through metabolism
EPFL scientists have fully modeled the metabolism of the deadliest malaria parasite.
Should we commit to eradicate malaria worldwide?
Should we commit to eradicate malaria worldwide, asks a debate article published by The BMJ today?
Investigational malaria vaccine shows considerable protection in adults in malaria season
An investigational malaria vaccine given intravenously was well-tolerated and protected a significant proportion of healthy adults against infection with Plasmodium falciparum malaria -- the deadliest form of the disease -- for the duration of the malaria season, according to new findings published in the Feb.
Why malaria mosquitoes like people with malaria
Malaria mosquitoes prefer to feed -- and feed more -- on blood from people infected with malaria.
Malaria superbugs threaten global malaria control
A lineage of multidrug resistant P. falciparum malaria superbugs has widely spread and is now established in parts of Thailand, Laos and Cambodia, causing high treatment failure rates for the main falciparum malaria medicines, artemisinin combination therapies (ACTs), according to a study published today in The Lancet Infectious Diseases.
Considering cattle could help eliminate malaria in India
The goal of eliminating malaria in countries like India could be more achievable if mosquito-control efforts take into account the relationship between mosquitoes and cattle, according to an international team of researchers.
Seasonal malaria chemoprevention in Senegalese children lowers overall malaria burden
Giving preventive antimalarial drugs to children up to age 10 during active malaria season reduced the cases of malaria in that age group and lowered the malaria incidence in adults, according to a randomized trial carried out in Senegal and published in PLOS Medicine by researchers from the Université Cheikh Anta Diop, Senegal, the London School of Hygiene & Tropical Medicine, UK, and other collaborators.
How malaria fools our immune system
OIST researchers reconstruct the 3-D structure of a malaria protein in combination with human antibodies.

Related Malaria Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Anthropomorphic
Do animals grieve? Do they have language or consciousness? For a long time, scientists resisted the urge to look for human qualities in animals. This hour, TED speakers explore how that is changing. Guests include biological anthropologist Barbara King, dolphin researcher Denise Herzing, primatologist Frans de Waal, and ecologist Carl Safina.
Now Playing: Science for the People

#SB2 2019 Science Birthday Minisode: Mary Golda Ross
Our second annual Science Birthday is here, and this year we celebrate the wonderful Mary Golda Ross, born 9 August 1908. She died in 2008 at age 99, but left a lasting mark on the science of rocketry and space exploration as an early woman in engineering, and one of the first Native Americans in engineering. Join Rachelle and Bethany for this very special birthday minisode celebrating Mary and her achievements. Thanks to our Patreons who make this show possible! Read more about Mary G. Ross: Interview with Mary Ross on Lash Publications International, by Laurel Sheppard Meet Mary Golda...