QNRF Newsletter Archive

Brain disease links with toxic bacteria from Qatar’s deserts

A team of researchers is studying the ecology and toxin production of cyanobacteria, an ancient form of life that produces toxins linked to neurodegenerative diseases such as Amyotrophic Lateral Sclerosis (ALS), Parkinson’s disease and Alzheimer’s.

Cyanobacteria are one of the largest and most important groups of bacteria on earth. Referred to as ‘the plants of the bacterial world’ – with the oldest known fossils being at least 3.5 billion years old – they are the only bacteria that can perform photosynthesis like plants. They also contribute to maintaining the health of the environment, and produce compounds that can treat diseases such as cancer. However, despite all these benefits, cyanobacteria are also known to produce poisonous toxins. They represent a global health risk, and more specifically (due to their proliferation in desert environments), a significant risk to residents in Qatar.

Now, a team of QNRF-funded researchers are conducting a study that examines the basic ecology of cyanobacteria, the toxins they produce, and the effect that these toxins may have on humans. The study is being led by Dr. Renee Richer and Dr. Aspasia Chatziefthimiou. Dr. Richer is the lead principal investigator and visiting associate professor in biology in the pre-medical programme at Weill Cornell Medical College in Qatar, while Dr. Chatziefthimiou is a postdoctoral associate in microbial ecology.

Image
Black 'mats' of cyanobacteria on dried mud.

While the project focuses on Qatar, Dr. Richer and Dr. Chatziefthimiou are collaborating with Dr. Paul Cox, Dr. James Metcalf and Dr. Sandra Banack, from the Institute for Ethnomedicine in Jackson, Wyoming, USA.“As an ecologist I think that people should have a continuous interaction with their environment,” says Dr. Chatziefthimiou. “Cyanobacteria are organisms that were in this earth long before we were, so we want to try to answer questions like, ‘What makes them produce toxins?’ ‘What purpose do they serve for the organism?’ Answering these questions will help us better understand when toxins are produced, and under what conditions they are produced. Ultimately the idea is to protect people from potential exposure.”

Cyanobacteria are found in almost every terrestrial and aquatic habitat on Earth, including oceans, fresh water, and deserts. However, Qatar is one of the best places in the world to study them because they abound in desert ecosystems. Cyanobacterial mats are also easily identifiable by the naked eye. In the desert they resemble cracked mud, the difference being that cracked mud crumbles when handled, but cyanobacterial mats remain intact, and turn green when exposed to water.

The research team is examining a number of toxins, also known as bioactive compounds or cyanotoxins, produced by cyanobacteria. This includes BMAA (an amino acid produced by cyanobacteria), which has been linked to neurodegenerative conditions such as ALS, Parkinson’s disease and Alzheimer’s.

A study conducted in 2009 by Dr. Richer in collaboration with Dr. Paul Cox, Dr. James Metcalf and Dr. Sandra Banack, explored the relationship between ALS and veterans of the 1990-1991 Gulf War. The research idea stemmed from the fact that the Gulf War veterans have twice the rate of ALS in comparison to personnel who were not deployed, and that a disproportionately high number of veterans, younger than 45 years of age, were diagnosed with ALS during the decade following the Gulf War. The study focused on inhalation of cyanobacteria and cyanotoxins carried by dust in the Gulf region, particularly Qatar, and indicated that a number of cyanotoxins are produced by cyanobacteria in Qatar.

“If we want to understand the health and well-being not only of Qataris, but of people all over the world, we have to understand our interaction with other organisms in the environment,” says Dr. Richer. “Evidence linking BMMA to neurodegenerative disease is mounting and our goal is to identify why these organisms are producing these toxins.”

Image
Photomicrograph of cyanobacteria, Cylindrospermum sp. By Matthewjparker (Own work) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

Dr. Richer and Dr. Chatziefthimiou are conducting a number of experiments in the field to see how cyanobacteria respond to disturbance and whether this increases or decreases toxin production. In lab-based experiments, they manipulate a number of environmental factors such as nitrogen and phosphorus at varying light levels. “We study every single ecosystem within the desert environment. Everything from marine intertidal communities, terrestrial, air and rain,” says Dr. Chatziefthimiou. “There is a pressing need to carry out this sort of research in Qatar because of the rate of industrialisation, and we need to understand ecologically why toxin production is happening.” At present they are looking into particular routes of exposure such as water, air and food.

“Cyanobacteria toxin exposure often happens through water and food. Some of these toxins have been shown to accumulate in marine organisms, so we are investigating marine organisms that are used as a food source. We are also doing comprehensive air sampling to see whether we can pick up cyanobacteria and cyanotoxins in the air,” says Dr. Richer.

Another aspect of the study will examine whether traditional forms of dress can potentially protect people from exposure. Dr. Richer and Dr. Chatziefthimiou have been testing the male ghutra and the female nikab to see if these garments essentially act as air quality filters.

Dr. Richer and Dr. Chatziefthimiou’s work has been published in many scientific journals including Amyotrophic Lateral Sclerosis, The Journal of Arid Environments and Science of the Total Environment. QNRF’s grant has helped establish the Toxins in Desert Environments’ (TiDE) network, and as part of the network they will host a two-day conference in Qatar. The purpose of this event is to gather scientists and governmental figures from a wide range of disciplines that share an interest in toxin production in desert environments.

The third annual TiDE conference will be held in December 2014, and will cover topics pertaining to toxin production in cyanobacterial crusts, poisonous plants and animals, the food we eat, the water we drink, and the air we breathe.

For more information on this research project visit: www.tidenetwork.org


NPRP 4-775-1-116
Toxin Production by Desert Cyanobacteria

Print

Number of views (4599)

Please login or register to post comments.

Theme picker