PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Scientists unlock evolution of cholera, identify strain responsible for early pandemics

2014-01-09
(Press-News.org) Contact information: Michelle Donovan
donovam@mcmaster.ca
905-525-9140
McMaster University
Scientists unlock evolution of cholera, identify strain responsible for early pandemics

Working with a nearly 200-year-old sample of preserved intestine, researchers at McMaster University and the University of Sydney have traced the bacterium behind a global cholera pandemic that killed millions – a version of the same bug that continues to strike vulnerable populations in the world's poorest regions.

Using sophisticated techniques, the team has mapped the entire genome of the elusive 19th century bacterium. The findings are significant because, until now, researchers had not identified the early strains of cholera, a water-borne pathogen. The discovery significantly improves understanding of the pathogen's origin and creates hope for better treatment and possible prevention.

Researchers have now confirmed the first of two types of cholera, known as classical, was likely responsible for five of the seven devastating outbreaks in the 1800s, all of which most likely originated in waters of the Bay of Bengal.

That strain of cholera had remained a mystery because researchers were unable to examine samples from early victims. The pathogen thrives in the intestines, never reaching teeth or bones, so remnants of its DNA do not exist in skeletal remains. Despite many known cholera burials, access to historical cholera DNA had seemed impossible since it can only be found in soft-tissue remains.

But graduate student Alison Devault and evolutionary geneticists Hendrik Poinar, Brian Golding and Eddie Holmes—working with a team of other scientists—learned that a remarkable collection of tissue specimens was housed at a medical history museum. The Mütter Museum was established by the College of Physicians of Philadelphia in 1858, after the city itself was devastated by cholera earlier in the century.

Researchers carefully sampled a preserved intestine from a male victim of the 1849 pandemic and extracted information from tiny DNA fragments to reconstruct the Vibrio cholera genome.

The results, currently published in The New England Journal of Medicine, could lead to a better understanding of cholera and its modern-day strain known as El Tor, which replaced the classical strain in the 1960s for unknown reasons and is responsible for recent epidemics, including the devastating post-earthquake outbreak in Haiti.

"Understanding the evolution of an infectious disease has tremendous potential for understanding its epidemiology, how it changes over time, and what events play a role in its jump into humans," explains Poinar, associate professor and director of the McMaster Ancient DNA Centre and an investigator with the Michael G. DeGroote Institute of Infectious Disease Research, also at McMaster University.

"We need to understand the selective pressures on the pathogen which in turn is driving its evolution, its virulence and hopefully use that information to develop better treatments," he says. Using a sophisticated technique to extract, purify and enrich fragments of the pathogen's DNA, the team collected precious genomic data, which answered many unresolved questions.

The researchers identified "novel genomic islands", or genome regions that don't occur in current strains. In addition, a well-known genic region involved in toxicity of the pathogen (a sequence called "CTX") occurs more times in the ancient strain than in its modern descendants.

This may mean that this strain was more virulent, say researchers, but further testing will be needed.

Regarding the origins, the team's calculations show that the classical strain and El Tor co-existed in humans and estuaries for many centuries, potentially thousands of years prior to the 19th century pandemics, and emerged as a full-blown infection in humans in the early 1800's.

The ancestor of both the classical and El Tor strain likely circulated together in the waters of the Bay of Bengal for several thousand years before emerging in humans during what is known as the first epidemiological transition, or a time of great agricultural revolution and human settlement.

The World Health Organization estimates there are three to five million new cholera cases every year. Of those, 100,000 to 120,000 people typically die from the disease. But with access to historical collections and samples, scientists hope to gain a better understanding of how pandemics arise, spread and ultimately how they might be better controlled or stopped.

"The genomes of ancestral pathogens that have descendants today reside in these archival medical collections all over the world," says Poinar. "We have access to hundreds of thousands of ancient specimens, which hold tremendous potential to determine the origins of past epidemics." Thus these collections represent a treasure trove and should be carefully preserved and maintained.



INFORMATION:

The research was funded by the Natural Sciences and Engineering Research Council, the Social Sciences and Humanities Research Council, an NHMRC Australia Fellowship and an Ontario Graduate Scholarship.

Attention Editors: A full suite of multimedia material, including high def footage, high res photos and graphics is available at: https://www.dropbox.com/sh/wbs6oh726zre5og/DJmZ_ykSzU

For more information please contact:

Michelle Donovan
Public Relations Manager
McMaster University
905-525-9140, ext. 22869
donovam@mcmaster.ca

Wade Hemsworth
Public Relations Manager
McMaster University
905-525-9140, ext. 27988
hemswor@mcmaster.ca



ELSE PRESS RELEASES FROM THIS DATE:

Organic mega flow battery promises breakthrough for renewable energy

2014-01-09
Organic mega flow battery promises breakthrough for renewable energy Harvard technology could economically store energy for use when the wind doesn't blow and the sun doesn't shine Cambridge, Mass. – January 8, 2014 – A team of Harvard scientists and engineers has demonstrated ...

Researchers unveil rich world of fish biofluorescence

2014-01-09
Researchers unveil rich world of fish biofluorescence Technology-driven study finds about 180 glowing species, highlights new potential source for biomedical fluorescent proteins A team of researchers led by scientists from the American Museum of Natural ...

Simple test can indicate cervical cancer

2014-01-09
Simple test can indicate cervical cancer LOUISVILLE, Ky. – Researchers at the University of Louisville have confirmed that using the heat profile from a person's blood, called a plasma thermogram, can serve as an indicator for the presence or absence of cervical ...

On-field blood test can diagnose sports concussions

2014-01-09
On-field blood test can diagnose sports concussions A brain protein, S100B, which may soon be detected by a simple finger-stick blood test, accurately distinguishes a sports-related concussion from sports exertion, according to a study of college ...

Fungi may determine the future of soil carbon

2014-01-09
Fungi may determine the future of soil carbon When scientists discuss global change, they often focus on the amount of carbon in the atmosphere and vegetation. But soil contains more carbon than air and plants combined. This means that even a minor ...

A 1-percent measure of galaxies half the universe away

2014-01-09
A 1-percent measure of galaxies half the universe away Researchers from the Baryon Oscillation Spectroscopic Survey (BOSS) today announced that they have measured the distance to galaxies more than six billion light years away to an ...

Molecular engines star in new model of DNA repair

2014-01-09
Molecular engines star in new model of DNA repair Study reveals major role of RNA polymerase and other enzymes in DNA repair Our health depends in large part upon the ability of specialized enzymes to find and repair ...

International Tree Nut Council funded study links nut intake with lower risks of obesity

2014-01-09
International Tree Nut Council funded study links nut intake with lower risks of obesity New Findings on tree nuts, metabolic syndrome and obesity in PlosOne A new study , published today in the online journal PLOS ONE, looks at the association between tree nuts (almonds, ...

Marine bacteria to fight tough infections

2014-01-09
Marine bacteria to fight tough infections Aggressive infections are a growing health problem all over the world. The development of resistant bacteria is rampant and, in the United States, resistant staphylococci cause more deaths than AIDS on an annual basis. Researchers ...

Controlling blood sugar levels in critically ill children could save NHS £12 million per year

2014-01-09
Controlling blood sugar levels in critically ill children could save NHS £12 million per year A major UK-wide study (The CHiP trial) led by Royal Brompton & Harefield NHS Foundation Trust in partnership with the London School of Hygiene & Tropical ...

LAST 30 PRESS RELEASES:

Less intensive works best for agricultural soil

Arctic rivers project receives “national champion” designation from frontiers foundation

Computational biology paves the way for new ALS tests

Study offers new hope for babies born with opioid withdrawal syndrome

UT, Volkswagen Group of America celebrate research partnership

New Medicare program could dramatically improve affordability for cancer drugs – if patients enroll

Are ‘zombie’ skin cells harmful or helpful? The answer may be in their shapes

University of Cincinnati Cancer Center presents research at AACR 2025

Head and neck, breast, lung and survivorship studies headline Dana-Farber research at AACR Annual Meeting 2025

AACR: Researchers share promising results from MD Anderson clinical trials

New research explains why our waistlines expand in middle age

Advancements in muon detection: Taishan Antineutrino Observatory's innovative top veto tracker

Chips off the old block

Microvascular decompression combined with nerve combing for atypical trigeminal neuralgia

Cutting the complexity from digital carpentry

Lung immune cell type “quietly” controls inflammation in COVID-19

Fiscal impact of expanded Medicare coverage for GLP-1 receptor agonists to treat obesity

State and sociodemographic trends in US cigarette smoking with future projections

Young adults drive historic decline in smoking

NFCR congratulates Dr. Robert C. Bast, Jr. on receiving the AACR-Daniel D. Von Hoff Award for Outstanding Contributions to Education and Training in Cancer Research

Chimpanzee stem cells offer new insights into early embryonic development

This injected protein-like polymer helps tissues heal after a heart attack

FlexTech inaugural issue launches, pioneering interdisciplinary innovation in flexible technology

In Down syndrome mice, 40Hz light and sound improve cognition, neurogenesis, connectivity

Methyl eugenol: potential to inhibit oxidative stress, address related diseases, and its toxicological effects

A vascularized multilayer chip reveals shear stress-induced angiogenesis in diverse fluid conditions

AI helps unravel a cause of Alzheimer's disease and identify a therapeutic candidate

Coalition of Autism Scientists critiques US Department of Health and Human Services Autism Research Initiative

Structure dictates effectiveness, safety in nanomedicine

Mission accomplished for the “T2T” Hong Kong Bauhinia Genome Project

[Press-News.org] Scientists unlock evolution of cholera, identify strain responsible for early pandemics