Fighting fire with fire

The past few blog posts have been all about information and awareness about a growing health concern: antibiotic resistance. After all the facts and examples have been considered, it is clear that this phenomenon cannot be ignored any longer. However, is it a lost cause or an inevitable fight against organisms that will just continue to evolve against anything we throw at them?

In order to come up with innovative solutions we must examine what bacteria are and what they can do to survive. Pathogenic or disease-causing bacteria are parasites. They invade the host, prey upon and colonize healthy tissue. Antibiotics can help fight these infections but overuse of them results in these predators evolving resistance. How do we work around this?

Researchers came up with a very unique solution for this conundrum. They reasoned that the only way to defeat a predator is with a higher predator, namely viruses. 

There are viruses in nature that prey on very specific bacterial hosts. These species are classified as bacteriophages. Biologists are convinced that these species are the key to a new solution for bacterial infections. They believe this approach can be ideal because bacteriophages are host specific parasites that can only attack the species of bacteria that they are compatible with. Essentially, each phage species have only one species of bacteria as a host. They are incapable of invading any other types of cells because of this specificity.

A recent study published in 2014 investigates the possibility of using these bacteriophages to target infectious Escherichia coli. E. coli is a fairly common species found in a wide range of hosts including humans, however, there are several highly pathogenic strains that infect cows, sheep and other livestock. These pathogens can be found in beef, poultry, and dairy. To prevent the cases of these infections food manufacturers have to resort to the overuse of antibiotics on farm animals.

The researchers injected a cocktail of designed bacteriophages that target E. coli into white mice in order to see if there was a reduction in level of the bacteria present in the mice. The results showed that the bacteriophages were effective in reducing the level of E. coli exponentially. The authors state they saw the lowest levels of E.coli in the mice on the 7^th and 8^th day after the injection. They stress that this method can be beneficial in the agriculture industry as a form of biocontrol used to prevent the growth of E.coli in livestock and processed food. This solution is also promising because 70 percent of antibiotics in the U.S. are used up by the agricultural industry. Cutting this number down will mean that antibiotic exposure will reduce to a level that will ensure that they won’t become obsolete before people are ready for them to be.

The study that was cited in this post was not the only approach being considered. Several studies have been done over the years to examine bacteriophages that target pneumonia, salmonella, and tuberculosis to name a few. It is possible that within the next few decades these bacteriophages will make using antibiotics an old fashioned remedy.  

References

Abdulamir, A. S., Jassim, S. A., & Abu Bakar, F. (2014). Novel approach of using a cocktail of designed bacteriophages against gut pathogenic E. coli for bacterial load biocontrol. Annals of Clinical Microbiology and Antimicrobials, 13, 39. doi:http://dx.doi.org.mutex.gmu.edu/10.1186/s12941-014-0039-z