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
OCT 17, 2019
Microbiology
OCT 17, 2019
Developing a Framework for Microbiome Research
Scientists and clinicians are beginning to recognize the power of the microbiome - the microbes that we carry in and on our bodies....
OCT 17, 2019
Genetics & Genomics
OCT 17, 2019
Rearranging Whole Chromosomes with CRISPR
CRISPR/Cas9 was developed as a gene-editing tool and now it's going beyond small, targeted changes in the genome....
OCT 17, 2019
Microbiology
OCT 17, 2019
Dengue Virus Changes According to the Temperature
Four related types of dengue virus are common in at least 100 countries and threaten around three billion people....
OCT 17, 2019
Microbiology
OCT 17, 2019
A Mosquito-borne Disease Called EEE is Spreading This Year
Massachusetts health officials confirmed yesterday that a third person has died from Eastern Equine Encephalitis this year....
OCT 17, 2019
Immunology
OCT 17, 2019
Your Immune Response Varies from AM to PM
“My biological clock is ticking.” We’ve heard people say this phrase - maybe even said it ourselves - but what do we mean exactly? Often...
OCT 17, 2019
Microbiology
OCT 17, 2019
A Bacterial Pathogen Can Steal Huge Chunks of DNA From Other Microbes
Microorganisms are everywhere, and they are often engaged in a fight for resources with other microbes....
Loading Comments...