The Fight Against Superbugs

While the term “superbugs” sounds like a concept from a science fiction novel, it is far from fiction. This phenomenon is in fact a dangerous reality of our times. Various types of bacteria have become immune to the antibiotics that are used to treat them, leading to the spread of diseases, thousands of deaths, and monumental financial costs to health care systems around the world. The fight against these superbugs has become tougher as bacteria continue to develop resistance to existing antibiotics faster than humans can invent or discover new remedies. According to the Center for Disease Control, these bacteria cause an average of 94,000 deaths yearly in the U.S. alone,1 and the Institute of Medicine has estimated that antibiotic resistance generates up to $26 billion per year in extra costs to the U.S. healthcare system.2

There are several methods used by bacteria for acquiring and propagating antibiotic resistance. In order to prevent the initial perpetration of antibiotics into the bacterial cell, many bacteria either excrete or completely destroy the drug, or replace the drug’s original target. These methods are commonly used by the dangerous Methicillin-resistant Staphyloccocus aureus (MRSA), Streptococcos pneumoniae, and certain strains of Escherichia coli as well. Specifically, bacteria fight off the antibiotics by preventing them from reaching their target cells (e.g., changing the permeability of cell walls or pumping the drugs out of the cells), changing the structure of target cells, or producing enzymes that destroy the antibiotic introduced.2

Once a certain bacterium has been exposed to the drug, it develops a type of “memory” that uses one of these procedures to prevent its own destruction. Bacteria may gain resistance by obtaining copies of resistance genes from other bacteria, a process called conjugation. Once a resistance gene is picked up and added to a bacterium’s DNA, the bacterium can dominate other bacteria and pass the resistance gene on to all of its descendants. Since bacteria multiply rapidly, a single resistant bacterium quickly transforms into entire strains of antibiotic resistant bacteria.

Although the process of natural selection leads to drug immunity in bacteria over time, the introduction of foreign antibiotics in bacterial cells predominantly results from improper industrial and human practices. For instance, in order to promote the growth of livestock, farmers treat the animals with antibiotics that may not be regulated in quality or dosage. Subsequently, resistance traits may be retained by certain bacteria and passed on to others, thus fostering the growth of large communities of drug resistant strains. When people consume meat that may be improperly prepared, these mutated bacteria are passed onto humans, spreading diseases that are difficult to cure with regularly available drugs. In addition, humans may encounter these superbugs solely by breathing air from concentrated animal housings or during transportation of infected livestock. It is estimated that over 70% of all antibiotics produced in the United States are given to animal farms, indicating the gargantuan nature of the problem at hand.3,5

Another example of human practices leading to superbug population growth is based on a lack of health education as well as on socio-economic dynamics. Antibiotics work against bacteria, not viruses, yet many patients push their doctors to prescribe drugs for virus-related illnesses, such as the common cold. These patients, who are unnecessarily overexposed to antibiotics, then act as breeding grounds for resistant bacteria, further facilitating the spread of the pathogenic bugs. Similarly, patients who do not complete their antibiotic courses or take diluted doses can unknowingly aid in the growth of resistant bacteria. This problem is particularly significant in countries where drugs can be obtained over the counter without a doctor’s prescription. According to an article by James Hughes of Emory University, published by the Journal of the American Medical Association, as much as 50% of antibiotic use for humans is unnecessary and inappropriate.4

Improper sterilization of hospital tools is yet another substantial source of superbug growth. When the bacteria-infested implements are exposed to light antibiotic doses through improper sterilization, the lingering bacteria develop immunity and are easily passed onto patients. Eventually, these patients suffer through the use of the infected tools for their surgeries and other medical procedures. Simple lapses in hospital sterilization processes have become major causes of superbug spread.

The pressing issue of superbug development requires the cooperation of a large number of scientists and companies from around the world to find solutions and perhaps a panacea. Currently, the scientific community is pursuing a two-pronged approach of developing new drugs and increasing awareness of the issue. The current strategies for developing new drugs fall into two categories: modifying existing antibiotics or manufacturing entirely novel ones. Searching for microbial genomes in exotic environments is among the innovative strategies being applied to the problem, and new approaches that target individual bacteria may be the key to breaking the vicious cycle of resistance. Programs such as the 10×20 plan by the Infectious Diseases Society of America (ISDA), which calls for the development of ten new and effective antibiotics by 2020, are strong motivations for an increase in research against superbugs.4

In addition to increasing research investment, widespread awareness is required to fight the challenge posed by superbugs. Propagation can be reduced by implementing careful procedures for antibiotic distribution and consumption for humans and animals, as well as by developing and monitoring effective hygiene policies for public settings such as hospitals and animal farms. On Earth Day 2011, the World Health Organization used the theme “resistance to antibiotics,” with the slogan: “No action today, no cure tomorrow”—an appropriate one considering the enormity of the issue of superbugs.6

References

  1. Associated Press. “Superbug deaths could surpass aids.” MSNBC. Last modified October 16, 2007.
  2. Walsh CT, and Fischbach MA. New ways to squash superbugs. Scientific American. 2009 Jul: 44-51.
  3. Antibiotic resistance: An ecological perspective on an old problem. American Academy of Microbiology. 2008.
  4. The spread of superbugs. The Economist. 2011 Mar 31: 70-72.
  5. Rogers L, Wenderoff J. Human health and industrial farming. Accessed April 12, 2011.
  6. Park A. How to stop the superbugs. Time. 2011 Jun 20: 34-36.
  7. Image credit (public domain): CDC. MRSA7820. Wikimedia Commons. Last modified October 5, 2005.

Anika Gupta is a student at The Harker School in San Jose, California. Follow The Triple Helix Online on Twitter and join us on Facebook.

You May Also Like