Navigation Links
Tuberculosis genomes portray secrets of pathogen's success
Date:8/21/2013

MADISON, Wis. By any measure, tuberculosis (TB) is a wildly successful pathogen. It infects as many as two billion people in every corner of the world, with a new infection of a human host estimated to occur every second.

Now, thanks to a new analysis of dozens of tuberculosis genomes gathered from around the world, scientists are getting a more detailed picture of why TB is so prevalent and how it evolves to resist countermeasures. Writing today (Aug. 21, 2013) in the journal Public Library of Science (PLoS) Pathogens, a team led by University of Wisconsin-Madison researcher Caitlin Pepperell describes a bacterium that marches in lockstep with human population growth and history, evolving to take advantage of the most crowded and wretched human conditions.

"It's as though the bacterium places bets on human behavior," says Pepperell, formerly of Stanford University, and now a professor of medicine and medical microbiology at UW-Madison. "It always bets that humans will go to war, send people to refugee camps, and gather in miserable places. Historically, that's been a winning bet on the bacterium's part."

The PLoS Pathogens study, whose senior author is Marcus Feldman of Stanford, reveals that tuberculosis experienced a 25-fold expansion worldwide in the 17th century, a time when human populations underwent explosive growth and European exploration of Africa, the Americas, Asia and Oceania was at its peak.

"The timing is coincident with expansion, urbanization and colonial migrations of global human populations," Pepperell explains. "These findings suggest that much of the current TB pandemic has its origins in historical events of the last three centuries."

TB is only transmitted by people, and the organism cannot survive in the environment. It thrives, however, in the crowded conditions of prisons, refugee camps and slums, and TB populations tend to be dominated by the bacteria "lucky" enough to land in those environments.

The analysis conducted by Pepperell and her colleagues focused on the role of natural selection, looking at patterns of genetic diversity among 63 TB and related pathogenic mycobacterial genomes gathered from around the globe.

The study shows a highly constrained bacterial genome, with most deleterious mutations quickly discarded. This was especially true for genes essential for causing disease, protein translation and the trafficking and metabolism of inorganic ions, which help control the interaction between the TB pathogen and its human host.

The bacterium's "defense" genes, on the other hand, showed a high degree of tolerance for beneficial mutations, which may play a role in evolution of drug resistance and evasion of the human immune system.

Pepperell notes: "Evolutionary theory predicts that Mycobacterium tuberculosis populations should be vulnerable to extinction. Yet it is obviously highly prevalent. It must have some incredibly clever strategies and tricks to hang on."

As a result, the explosive spread of TB parallels the growth of human populations and takes every advantage of a world where most people live in crowded and impoverished conditions.

The study, according to Pepperell, should help other researchers home in on genes that may be good candidates for targeting with new drugs, and aid disease control strategies that accommodate or even co-opt the bacterium's evolution and help drive its extinction.


'/>"/>

Contact: Caitlin Pepperell
cspepper@medicine.wisc.edu
608-262-5983
University of Wisconsin-Madison
Source:Eurekalert

Related biology news :

1. Biosignatures distinguish between tuberculosis and sarcoidosis
2. Targeting tuberculosis hotspots could have widespread benefit
3. MIT-designed cooler preserves tuberculosis drugs, records doses
4. Research on improvements in diagnosing and treating tuberculosis
5. Millions of diabetics could die of tuberculosis
6. New approach of resistant tuberculosis
7. Iowa State, Ames Lab researchers study the structure of drug resistance in tuberculosis
8. High doses of Vitamin D help tuberculosis patients recover more quickly
9. Scientists reveal how natural antibiotic kills tuberculosis bacterium
10. Notre Dame research could provide new insights into tuberculosis and other diseases
11. Missing link discovered in the defence mechanism of the tuberculosis pathogen
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/28/2016)... and BANGALORE, India , April ... EdgeVerve Systems, a product subsidiary of Infosys (NYSE: ... today announced a global partnership that will provide ... to use mobile banking and payment services.      ... a key innovation area for financial services, but it also ...
(Date:4/26/2016)... , April 27, 2016 ... the  "Global Multi-modal Biometrics Market 2016-2020"  report to ... ) , The analysts forecast the ... CAGR of 15.49% during the period 2016-2020.  ... number of sectors such as the healthcare, BFSI, ...
(Date:4/15/2016)... Research and Markets has announced ... 2016-2020,"  report to their offering.  , ... global gait biometrics market is expected to grow ... 2016-2020. Gait analysis generates multiple variables ... to compute factors that are not or cannot ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... CAMBRIDGE, Mass. , June 23, 2016 /PRNewswire/ ... the development of novel compounds designed to target ... compound, napabucasin, has been granted Orphan Drug Designation ... in the treatment of gastric cancer, including gastroesophageal ... cancer stemness inhibitor designed to inhibit cancer stemness ...
(Date:6/23/2016)... June 23, 2016 A person commits a crime, ... scene to track the criminal down. An outbreak ... and Drug Administration (FDA) uses DNA evidence to track down ... Sound far-fetched? It,s not. The FDA has increasingly used ... investigations of foodborne illnesses. Put as simply as possible, whole ...
(Date:6/23/2016)... ... 2016 , ... Charm Sciences, Inc. is pleased to announce ... Research Institute approval 061601. , “This is another AOAC-RI approval of the Peel ... President of Regulatory and Industrial Affairs. “The Peel Plate methods perform comparably to ...
(Date:6/23/2016)... NEW YORK , June, 23, 2016  The ... students to envision new ways to harness living systems ... of Modern Art (MoMA) in New York ... more than 130 participating students, showcased projects at MoMA,s ... included Paola Antonelli , MoMA,s senior curator of ...
Breaking Biology Technology: