Featured Research

from universities, journals, and other organizations

Scientists track evolution and spread of deadly fungus, one of the world's major killers

Date:
May 3, 2011
Source:
Wellcome Trust
Summary:
New research has shed light on the origins of a fungal infection which is one of the major causes of death from AIDS-related illnesses. The study shows how the more virulent forms of Cryptococcus neoformans evolved and spread out of Africa and into Asia.

New research has shed light on the origins of a fungal infection which is one of the major causes of death from AIDS-related illnesses. The study, published in the journal PLoS Pathogens, funded by the Wellcome Trust and the BBSRC, shows how the more virulent forms of Cryptococcus neoformans evolved and spread out of Africa and into Asia.

Cryptococcus neoformans is a species of often highly aggressive fungi. One particular strain of the fungus -- known as Cryptococcus neoformas variety grubii (Cng) -- causes meningitis amongst patients with compromised immune systems following HIV infection. There are believed to over up to a million cases of cryptococcal meningitis each year, resulting in over 600,000 deaths. Infection with the fungus, which invades the central nervous system, is treated with a life long therapy of antifungal drugs, which can have highly unpleasant side effects.

Sitali Simwami and Dr Matthew Fisher from Imperial College London, together with colleagues from St Georges, University of London, Naresuan University, Thailand, and the CBS Fungal Biodiversity Centre, The Netherlands, used genetic sequencing techniques to compare the genetic diversity of Cng in 183 samples taken from the clinic and the environment in Thailand against the 77 samples from a global database. Thailand has an emerging HIV epidemic and nearly one in five HIV-infected patients are affected by cryptococcal infection.

"Cryptococcal meningitis kills hundreds of thousands of people each year, almost as many as malaria, yet gets little attention," explains Dr Fisher. "We know very little about where it originated from and how it evolved. If we can track its evolution and diversity, then we can begin to understand where the pathogen originates from, how it infects people and how it adapts to become more -- or less -- virulent. This information will be valuable in helping us identify potential therapeutic targets in the future."

The researchers found that Cng in Thailand exhibits significantly less genetic diversity in comparison to other areas of the world, especially Africa where many different lineages of the pathogen occur. This suggests that populations of the fungus in Africa will have a wider spectrum of virulent strains and higher rates of adaptation to antifungal treatments, implying that clinicians need to pay particular attention to the risk of drug-resistant forms of the fungus here.

Their analysis also suggested that the pathogen was introduced from Africa to Asia at some point within the last 7,000 years. Many human infectious diseases are thought to have emerged within the last 11,000 years, following the rise of agriculture and domestication of animals. In particular, it supports the idea that the pathogen was imported via infected pigeons, which were domesticated around 5,000 years ago. The common pigeon, which originated in Africa, is considered to be a carrier and potential spreader of the fungus, its faeces being a common environmental source of Cng.


Story Source:

The above story is based on materials provided by Wellcome Trust. Note: Materials may be edited for content and length.


Journal Reference:

  1. Sitali P. Simwami, Kantarawee Khayhan, Daniel A. Henk, David M. Aanensen, Teun Boekhout, Ferry Hagen, Annemarie E. Brouwer, Thomas S. Harrison, Christl A. Donnelly, Matthew C. Fisher. Low Diversity Cryptococcus neoformans Variety grubii Multilocus Sequence Types from Thailand Are Consistent with an Ancestral African Origin. PLoS Pathogens, 2011; 7 (4): e1001343 DOI: 10.1371/journal.ppat.1001343

Cite This Page:

Wellcome Trust. "Scientists track evolution and spread of deadly fungus, one of the world's major killers." ScienceDaily. ScienceDaily, 3 May 2011. <www.sciencedaily.com/releases/2011/05/110503132711.htm>.
Wellcome Trust. (2011, May 3). Scientists track evolution and spread of deadly fungus, one of the world's major killers. ScienceDaily. Retrieved September 2, 2014 from www.sciencedaily.com/releases/2011/05/110503132711.htm
Wellcome Trust. "Scientists track evolution and spread of deadly fungus, one of the world's major killers." ScienceDaily. www.sciencedaily.com/releases/2011/05/110503132711.htm (accessed September 2, 2014).

Share This




More Plants & Animals News

Tuesday, September 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

We've Got Mites Living In Our Faces And So Do You

We've Got Mites Living In Our Faces And So Do You

Newsy (Aug. 30, 2014) A new study suggests 100 percent of adult humans (those over 18 years of age) have Demodex mites living in their faces. Video provided by Newsy
Powered by NewsLook.com
Washington Wildlife Center Goes Nuts Over Baby Squirrels

Washington Wildlife Center Goes Nuts Over Baby Squirrels

Reuters - US Online Video (Aug. 30, 2014) An animal rescue in Washington state receives an influx of orphaned squirrels, keeping workers busy as they nurse them back to health. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Experimental Ebola Drug ZMapp Cures Lab Monkeys Of Disease

Experimental Ebola Drug ZMapp Cures Lab Monkeys Of Disease

Newsy (Aug. 29, 2014) In a new study, a promising experimental treatment for Ebola managed to cure a group of infected macaque monkeys. Video provided by Newsy
Powered by NewsLook.com
Killer Amoeba Found in Louisiana Water System

Killer Amoeba Found in Louisiana Water System

AP (Aug. 28, 2014) State health officials say testing has confirmed the presence of a killer amoeba in a water system serving three St. John the Baptist Parish towns. (Aug. 28) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins