FEB 01, 2017 11:18 AM PST

Viruses cure cholera

WRITTEN BY: Kerry Evans

Phage therapy may finally be gaining ground in the United States. Researchers from Tufts University just reported that a virus cocktail effectively prevents cholera in an animal model.

According to study author Andrew Camilli, “while phage therapy has existed for decades, our study is proof-of-principle that it can be used to protect against infection and intervene in the transmission of disease. We are hopeful that phages can someday be a tool in the public health arsenal that helps decrease the global burden of cholera, which affects up to four million people around the world each year."

Vibrio cholerae causes cholera.

Cholera is caused by the bacterium Vibrio cholerae. V. cholerae is a Gram-negative, comma-shaped, facultative anaerobe that hangs out in brackish water or saltwater. The symptoms of cholera - diarrhea, vomiting, dehydration, and weight loss - are caused by cholera toxin. The toxin causes cells in the intestine to expel chloride ions - this causes fluid loss (diarrhea) and eventually dehydration.

The researchers identified three phages (ICP 1, 2, and 3) that kill V. cholerae more effectively when combined as a cocktail than when applied in isolation. Next, they wanted to know if the same was true in vivo.

To test this, they measured how well the ICP cocktail reduced the number of V. cholerae bacteria in the small intestines of mice. They found that all of the phages reduced the number of bacteria by at least two orders of magnitude. Interestingly, ICP3 alone and the ICP cocktail were equally effective in reducing bacterial colonization.

Because some phages remained in the intestines after the experiment, they wondered if they could treat the animals with the cocktail at an even earlier time point (up to 24 hours before inoculating the mice with the bacteria) and still decrease bacterial colonization. They found that prophylaxis with the phage cocktail was most effective when given 6 hours before inoculating the animals with V. cholerae.

Finally, they validated their findings in a rabbit model. Rabbits, as opposed to mice, develop the symptoms associated with cholera - diarrhea, dehydration, and weight loss. They gave the rabbits the phage cocktail either 3 or 24 hours before inoculating them with V. cholerae. When the cocktail was given 3 hours before inoculation, no V. cholerae bacteria could be detected in four of seven rabbits!

Does this mean there’s hope for phage therapy? We’ll have to wait and see.

Sources: Nature Communications, EurekAlert, Wikipedia

 
About the Author
  • Kerry received a doctorate in microbiology from the University of Arkansas for Medical Sciences.
You May Also Like
APR 27, 2020
Microbiology
APR 27, 2020
CDC Adds to the List of COVID-19 Symptoms
The pandemic virus that causes COVID-19 has now infected nearly 3 million people, and killed over 200,000.
MAY 09, 2020
Microbiology
MAY 09, 2020
Mysterious Illness in Children May be Related to COVID-19
Once thought to be mostly unaffected by the virus, rare cases of an inflammatory syndrome are emerging in some kids that ...
MAY 23, 2020
Microbiology
MAY 23, 2020
The FDA Yanks Some COVID-19 Antibody Tests From the Market
The massive demand for diagnostic testing led the FDA to open a short window for many testing products to go to market w ...
MAY 25, 2020
Microbiology
MAY 25, 2020
Assessing the Risk of COVID-19 Posed by Various Summer Activities
While we know a lot more about the pandemic virus SARS-CoV-2 and the illness it causes, COVID-19, there are still many u ...
JUN 02, 2020
Chemistry & Physics
JUN 02, 2020
How Can Far-Ultraviolet Light Help Us in a Pandemic?
Ultraviolet (UV) (10-400 nm) light is everywhere. It constitutes 10 percent of the total electromagnetic radiation in th ...
JUN 21, 2020
Microbiology
JUN 21, 2020
Poor Oral Hygiene May Worsen Gut Inflammation
Good dental hygiene benefits more than just the teeth and gums; researchers have found that poor oral health can contrib ...
Loading Comments...