Is it Reality or a Sci-fi Movie?

Evolution and the concept of the “survival of the fittest” seem to be working against humans. In fact, they are causing nearly two million people to be infected, resulting in nearly 23,000 deaths annually just in the United States, according to statistics reported by the Centers for Disease Control in 2013. This number is much higher on the global scale. How might Darwin’s theory of evolution have anything to do with these deaths? What do these numbers mean and how might we be able to prevent such deaths?

Antibiotic drug-resistant bacterial infections are the cause of such deaths. The bacteria that are resistant to one or more antibiotics are also known as “superbugs.” Superbugs evolve as a result of a four-step process:

  1. There are lots of microbes present, a few of which have developed a genetic mutation that allows them to be resistant to select drugs.
  2. Antibiotics kill most of the bacteria causing the disease, as well as other bacteria present.
  3. Only the drug-resistant bacteria remain, which can then divide and replicate.
  4. These drug-resistant bacteria can also transmit their genes to other non-resistant bacteria, allowing even more bacteria to develop resistance.

While the transmission of beneficial genes is a natural process, humans also aid the development of superbugs. Antibiotics are used frequently in the meat industry. They are given to beef cattle, chickens and other animals in order to help them grow better. Eventually, these antibiotics are excreted but not broken down, enabling them to enter the ground and water where they can affect bacteria. The bacteria that have developed antibiotic resistance due to mutations out-compete other bacteria.

While the transmission of beneficial genes is a natural process, the development of superbugs is also aided by humans.

The lack of sanitation in poorer countries is also a key factor in increasing the number of resistant bacterial strains. In many areas, the wastewater from hospitals is poorly filtered and thus contains antibiotic-resistant bacteria. Drinking this contaminated water spreads the antibiotic-resistant bacteria throughout the population. In other areas, pharmaceuticals release antibiotics into wastewater, which leads to overuse of the antibiotics and eventually leads to the growth of antibiotic-resistant bacteria.

Additionally, antibiotics in many countries are available without a prescription or are over-prescribed by doctors. Many times, antibiotics are prescribed for viral infections, in which case the antibiotics have no effect on curing the infection but simply lead to the growth and survival of antibiotic-resistant bacteria. Furthermore, for bacterial infections, multiple antibiotics are frequently prescribed. While this may be a more efficient way of curing bacterial infections, the microbes can become resistant to multiple antibiotics simultaneously. In China, for instance, hospitals receive financial incentives for prescribing medications, leading to the overuse of antibiotics. “It’s essentially destroying a valuable resource,” says Ramanan Laxminarayan, the director of the Center of Disease Dynamics, Economics & Policy.

So what must be done to combat these superbugs? In its 2013 report on antibiotic resistance threats, the CDC outlined four key steps that are required in order to fight against superbugs:

  1. Prevent infections and therefore the spread of resistance
  2. Track and gather data on resistant infections and the risk factors involved
  3. Regulate antibiotic prescriptions, use, and availability as well as the spread of antibiotics in the environment
  4. Develop new drugs, including new antibiotics as well as drugs targeting other aspects of the disease

Several methods have been identified and are being investigated to target antibiotic resistance. First, limiting the number of infections occurring is a way of controlling the spread of the disease and the antibiotic-resistant bacteria. This can be accomplished via contact tracing — identifying the people who have been in contact with the diseased patients, giving them appropriate treatment and identifying other contact points. This would help limit the spread of antibiotic-resistant bacteria.

Additionally, several labs have begun investigating other aspects of treating bacterial diseases such as cholera. These labs have been focusing on targeting quorum sensing in Vibrio cholerae bacteria. Quorum sensing is the intercellular communication of single-celled bacteria, which controls when the bacteria are virulent and when they aren’t. The development of drugs that impact this cell-to-cell communication and reduce the virulence of bacteria is a promising way of treating bacterial infections in the future.

While quorum sensing is a promising way of treating antibiotic-resistant diseases, other potential ways of treating such infections include developing new vaccines to prevent these infections (from antibiotic-resistant strains) from happening in the first place.

These methods, in addition to the regulation of antibiotic use and the development of new and more potent antibiotics, will be the first steps towards combating and overcoming these superbugs that cause so many infections and deaths in the United States and globally.

References

Antibiotic Resistance Threats in the United States, 2013. N.p.: n.p., n.d. CDC. Web. 31 Oct. 2014. .
“Fatal Superbugs: Antibiotics Losing Effectiveness, WHO Says.” National Geographic. N.p., n.d. Web. 31 Oct. 2014. .
“Rates of Antibiotic-Resistant Superbug Double over Last Decade.” Aljazeera America. N.p., n.d. Web. 31 Oct. 2014. .
Reardon, Sara. “Antibiotic Resistance Sweeping Developing World.” Nature. N.p., n.d. Web. 31 Oct. 2014.

About The Author

Aastha is a sophomore at Princeton planning to major in Molecular Biology. She is interested in pursuing certificates in Global Health and Health Policy as well as Quantitative and Computational Biology. She is very interested in healthcare related areas and plans on going to medical school. She likes writing about science news and research going on. She is part of several science and health related publications on campus in various positions. She is involved in research projects in the Princeton science departments for 2 years. She also participated in several science competitions. She is also a volunteer at the UMCPP.