Antibiotic Resistance

Antibiotics

Antibiotics are life-saving drugs. Ever since Alexander Fleming accidentally discovered penicillin from a mold-contaminated growth plate, millions have been saved and cured of bacterial infections. While penicillin and its family members act only on bacterial cell walls, we have since developed many more methods of action to manage and cure bacterial infections. For example, we have antibiotics that inhibit prokaryotic transcription, prokaryotic translation, and even specific metabolic pathways in bacteria, such as folate production. However, as much as these drugs have served us, they are losing their efficacy at an increasingly alarming rate.

Antibiotic Resistance: The Emergence of “SuperBugs”

Bacteria replicate very quickly. Just a few E. coli cells can divide into millions in a short time under the proper conditions. Each time a cell divides, it must replicate its genome. While this task is incredibly accurate, errors are made. Most of the time, these errors are deleterious to the effected bacterium. Sometimes, however, these mutations may provide an advantage, such as an amino acid change that disallows ampicillin to bind its target molecule. This renders the bacterium (which can then divide into millions more clones) resistant to one or more antibiotics. While these mutations are inevitable, improper use of antibiotics can exacerbate their effects. What’s more, many bacteria also posses the ability to share antibiotic resistance genes via a R plasmid. These bacteria can pass on resistance code during conjugation through a special sex pilus. Not only do we see this within species, but species have been known to pass on resistance genes to other completely other species. This has led to the emergence of “superbugs”, or bacteria that are resistant to some or all of the medications used to kill them. For example, XDR-TB is a strain of Mycobacterium tuberculosis (the pathogen that causes tuberculosis) that is resistant to first-line antibiotics in addition to even more toxic last-resort drugs. According to a Medical New Today article, superbugs like these are the cause of 35,000 deaths in the United States alone, a figure that will continue to grow if we continue are poor use of antibiotics discussed later. In fact, we are on the horizon of an era where our life-saving antibiotics have become completely ineffective, according to a WHO article.

How Humans Contribute

Antibiotics resistance is accelerated by humans in a number of ways. These include:

• Taking antibiotics for viral infections:
  • There is a common belief that antibiotics can be used to treat viral infections such as the flu or a common cold. However, antibiotics are completely ineffective against viruses. Nonetheless, people will take leftover antibiotics for viral infections, thereby deploying the drug for no reason. This allows an present microbiota to developed resistance, which they could potentially pass on to pathogenic bacteria via conjugation.
• Taking the wrong antibiotic for the disease-causing bacterium
  • This is very similar to the first reason. Many people will take leftover antibiotics when they feel ill. Even if they are feeling ill due to a bacterial infection, the antibiotic they are taking my not be effective against that particular pathogen. Some antibiotics only work on Gram-positive bacteria and some only work on Gram-negative bacteria. In addition, some antibiotics only work on particular families or even species of bacteria. Again, the medicine mismatch leads to normal microbiota developing resistance while not even helping cure the disease. These resistance bacteria again have the potential of spreading resistance via conjugation.
• Not adhering to antibiotic prescription schedules
  • Many patients will stop taking their prescribed antibiotics when they begin to feel better. Unfortunately, many antibiotic regimens are lengthy and have undesirable side effects. Thus, when the patient feels better, they may stop taking their medicine even though the infection is not cleared. This allows bacteria that were somewhat resistant to the antibiotic to replicate, thereby increasing the chance that one will undergo another beneficial mutation that makes it completely unaffected by the antibiotics at all concentrations.
• Feeding livestock antibiotics in the absence of disease
  • Long-term use of antibiotics can have the effect of increased weight gain in livestock. Thus, farmers often feed their livestock antibiotics in the absence of infection in order to increase profits. Again, this unnecessary use of antibiotics allows bacteria to “learn” how to develop resistance to a drug. At the store, you can buy meat that is labeled as “antibiotic-free”. However, this generally does not mean that the animal was not fed antibiotics, it merely indicates that there was no antibiotic left in the blood of the animal at the time of slaughter. In other words, antibiotics were used but discontinued a couple of weeks before slaughter.

These are all preventable causes of antibiotic resistance. I believe it is a fault in our education system for not teaching students about antibiotic resistance, which is a central issue the interest of our general health. For example, I graduated high school knowing how to identify metaphors in poems, yet not knowing how to do taxes, how to effectively prevent STIs besides strict abstinence, and how I shouldn’t just take any old antibiotic when I have a sore throat. What’s more, I believe our healthcare system is at fault. Antibiotics and doctor’s visits are expensive; it is understandable that someone would take stop taking antibiotics early to “save some for next time” and then take that leftover antibiotic for the wrong disease in the future. Not only does this practice increase antibiotic resistance, it also allows the infection persist longer, thus potentially spreading the pathogen to many others. Thus, I think it is essential that we have some better form of universal healthcare in the United States. Lastly, we need to stop feeding antibiotics to our livestock in the absence of infection, not only in the U.S., but around the globe.