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Two New Ways To Prevent Cholera: Microbes Fighting Microbes

The research has so far only been done in animals

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A woman draws water from an unprotected well in Chigwirizano, a peri-urban area hit by a Cholera outbreak in Malawi.
A woman draws water from an unprotected well in Chigwirizano, a peri-urban area hit by a Cholera outbreak in Malawi. VOA

Two promising new ways to prevent cholera are on the horizon. One is an entirely new kind of vaccine. The other is as simple as a cup of yogurt.

Both may offer fast, cheap protection from explosive outbreaks of a disease that claims tens of thousands of lives each year.

The research has so far only been done in animals. Human studies are yet to come.

Cholera declawed

Cholera causes such serious diarrhea that it can kill within hours. Current vaccines take at least 10 days to work, don’t provide complete protection and don’t work well for young children.

One group of scientists working to create a better vaccine engineered cholera bacteria that are missing the genes that make the microbe toxic.

The researchers fed the modified bacteria to rabbits. The microbes colonized the animals’ guts but did not make them sick.

When the scientists then fed rabbits normal, disease-causing cholera 24 hours later, most of the animals survived.

Those that did get sick took longer to do so than rabbits given unmodified bacteria, or modified bacteria that had been killed. Those animals died within hours.

Doctors Giving vaccines
Doctors Giving vaccines, Pixabay

The engineered cholera bacteria provided protection much faster than a conventional vaccine. They acted as a probiotic: colonized the animals’ intestines in less than a day and prevented the disease-causing microbes from getting a foothold.

The researchers expect that the modified bacteria will also act like a typical vaccine, stimulating the body’s immune system to fight a future cholera infection.

“This is a new type of therapy,” Harvard University Medical School microbiologist Matthew Waldor said. “It’s both a probiotic and a vaccine. We don’t know the right name for it yet.”

The research is published in the Science Translational Medicine journal.

Yogurt solution

In another study in the same journal, a group of researchers discovered that a microbe commonly found in yogurt, cheese and other fermented dairy products can prevent cholera infection.

Bioengineer Jim Collins at the Massachusetts Institute of Technology and colleagues had been working on genetically modifying the bacteria, known as Lactococcus lactis, to treat cholera.

It hadn’t been working.

But they accidentally discovered that unmodified L. lactis keeps cholera germs in check by producing acid that the disease-causing microbes can’t tolerate.

Feeding mice doses of L. lactis bacteria every 10 hours nearly doubled their survival rate from cholera infection.

“It was remarkably surprising and satisfying,” Colllins said. “We were really getting frustrated.”

They also designed a strain of L. lactis that turns a cholera-infected mouse’s stool red. It could be a useful diagnostic, for example, to identify those carrying the bacteria but not showing symptoms.

Collins said pills of L. lactis bacteria — or simply ample supplies of fermented milk products — could be “a very inexpensive, safe and easy-to-administer way to keep some of these outbreaks in check.”

Waldor said his group’s modified-cholera vaccine also could be grown and packaged in pills quickly and easily in case of an outbreak.

Both caution that these animal studies are a long way from new treatments for human patients. They need to be proven in clinical trials.

Microscopic Image Of a Virus
Microscopic Image Of a Virus, Pixabay

Beyond cholera

The two studies could not only have an impact on cholera, but could also influence how doctors treat other intestinal diseases and manage gut health, according to Robert Hall, who oversees research funded by the National Institute of Allergy and Infectious Diseases.

While fermented foods promising better health are widely available, “the studies with probiotics in the field have really seldom shown great effectiveness when they’re done scientifically,” Hall said.

The work Collins’s group did not only shows effectiveness, but explains how it works: by “making the intestine inhospitable” to cholera, he added.

Hall wrote a commentary accompanying the two studies.

Other gut diseases work the same way as cholera, he noted, so it’s possible that other microbes could be developed that block harmful germs from gaining a foothold while acting as vaccines at the same time.

Also read: Lack of Toilets, Clean Drinking Water Pose Cholera Threat in Rohingya Refugee Camps

“It’s a very exciting principle,” Hall said. (VOA)

Next Story

Scientists: Nations Need Stronger Pledges to Curb Climate Change

Governments are moving in the right direction, but nowhere near enough, so hopefully they will be willing to take on much stronger commitments

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Scientists, Nations, Climate Change
A woman wearing a mask walks past buildings on a polluted day in Handan, Hebei province, China, Jan. 12, 2019. China is reportedly the world's top emitter of greenhouse gases. VOA

The vast majority of national commitments in the 2015 Paris Agreement are inadequate to prevent the worst effects of global warming, scientists said on Tuesday, naming the world’s biggest greenhouse gas emitting countries as among those that must ratchet up their efforts.

“Governments are moving in the right direction, but nowhere near enough, so hopefully they will be willing to take on much stronger commitments” in next month’s United Nation’s climate summit in Spain, said Robert Watson, lead author of the report by the nonprofit Universal Ecological Fund.

The report ranked nearly 75%, or 136, of the pledges as insufficient, including ones by major carbon emitters China, the United States, and India. A dozen, by countries including Australia, Japan and Brazil, were judged only partially sufficient.

Countries at next month’s summit in Madrid will hash out some details of the international pact to curb warming. Chile withdrew as host following weeks of riots protesting inequality.

Scientists, Nations, Climate Change
A protestor holds a placard in front of the India Gate during a protest demanding government to take immediate steps to control air pollution in New Delhi, India, Nov. 5, 2019. VOA

Of the 184 pledges countries made under the climate agreement, only 36 are ambitious enough to help reach the agreement’s goal of keeping global warming less than 1.5 Celsius (2.7 F) above pre-industrial levels, the report said.

Most of those 36 are by countries in the European Union.

Watson, a former chair of the U.N. Intergovernmental Panel on Climate Change, said the report could be read two ways: “You can read ‘My God it’s hopeless’, or ‘My God this is a wake up call.'”

Watson estimated that even if all nations meet their existing pledges, the world would be headed for temperature rise of between 3 and 3.5 degrees Celsius, which could lead to more extreme weather, rising sea levels and the loss of plant and animal species.

Also Read- New WhatsApp Feature Lets Users Decide to Join a Group or Not: Tech Report

The report rated the European Union’s 28 member states as having sufficient pledges because they aim to cut emissions of greenhouse gases by at least 40% below the 1990 level by 2030.

It ranked the United States as insufficient because President Donald Trump reversed former President Barack Obama’s climate policies and yanked Washington out of the pact. The administration, which argues that Paris Agreement would cost U.S. taxpayers too much money, filed official paperwork on Monday to withdraw.

China, the world’s top emitter of greenhouse gases, and India, also came in as insufficient because their pledges focus on carbon intensity targets, which lower emissions per unit of gross domestic product, or GDP. Because those economies are growing and coal produces much of their electricity, total emissions have risen sharply even though carbon intensity levels in China and India have fallen. (VOA)