Travis North

Biology 1610

Antibiotics: Talking, not Fighting

Although not as controversial as vaccines, many adult Americans have some preliminary knowledge of antibiotics and have likely formed their own opinion as to the benefits or detriments from using or misusing antibiotics. I have benefited from antibiotics personally and value them when I'm sick; however, in preparing for this assignment, I realized my knowledge of antibiotics was somewhat superficial, as I did not have a in depth understanding of how antibiotics interact with our anatomy.  As a result, I was intrigued by the 2009 Scientific American Article, "Antibiotics, These wonder-drug molecules might have evolved to help bacteria speak with their neighbors, not kill them" by Jessica Snyder Sachs.[1]

First, it is important to understand where antibiotics come from. The majority of antibiotics used in modern medicine are derived from soil bacteria. The standard thinking in microbiology is that dirt microbes contributed to the evolution of antibiotic compounds into "lethal weapons" which could be used on each other as the microbes fought over food and territory.  These microbes are much smarter than people realize.

A common misconception about antibiotics is that it kills the "bad" bacteria within your body. Most people seem to think antibiotics go to the bacteria and kill it. Most people don’t know how it is done. For more than fifteen years microbiologist, Dr. Julian Davies of the University of British Columbia, has argued otherwise. His research supports the proposition that antibiotics are “talking, not fighting,” Dr. Davies is well respected within the microbiology community. He claims that bacteria use most of the small molecules we call antibiotics to communicate. As evidence, he looks to nature, and argues that because soil bacteria secretes antibiotics at trace levels, levels which are so insignificant that they do not adversely affect, let alone kill their microbial neighbors, the soil bacteria must be aware of their neighbor plants presence. "Only when we use them at unnaturally high concentrations do we find that these chemicals inhibit bacteria."

During his research, Dr. Davies identified a way to observe the communication between bacteria as they used antibiotics. Since then, Dr. Davies staff has been "eavesdropping on the flurry of gene activity in bacteria exposed to low-dose antibiotics." The researchers equip their bacteria with glow-in-the-dark lux genes that provide a fluorescent signal when other linked genes are active. The researchers then watched those genetic “switchboards” light up in a chorus of responses to antibiotic exposure. These results led Dr. Davies to ascertain that a gram of soil contains more than 1,000 different types of bacteria. He proposes that many antibiotics may help coordinate bacterial activities. Dr. Davies concluded, “They’re all thriving there together and clearly not killing one another.”

Dr. Davies’s theory implies both good and bad news for the world of antibiotics and its application within the medical community. Observing the communication within bacterial communities may lead pharmaceutical companies to increase the amount of antibiotics communicating with a specific microbe, increasing its potential to kill.  Regardless, understanding how bacteria use antibiotics to communicate could to more efficient medications.

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[1]https://www.scientificamerican.com/index.cfm/_api/render/file/?method=attachment&fileID=5B5836C3-6630-45C9-A6454224F0CD5124