Antibiotic Resistance: A Descriptive Overview

By: Jessica Kopp

Abstract

Antibiotic resistance is a deadly phenomenon that can strike any one at any time.

The medical field has been fighting against antibiotic resistant microorganisms for several decades. However, this phenomenon has continued to plague us. An important step to combating this problem is to spread knowledge to the general public. Therefore, this paper will serve as a descriptive account of antibiotic resistance with the goal of increasing education. To achieve this goal, a full description of antibiotic resistance will be included. Additionally a short background and timeline of the occurrences will be outlined. Contributing factors will be examined to determine what leads to antibiotic resistance. Lastly, guidelines will be offered with the goal of decreasing antibiotic resistance.

Introduction

A grave problem has been facing humanity for several decades. This danger has the potential to strike an individual without their conscious knowledge. The threat comes from microorganisms that have developed antibiotic resistance. Harmful microorganisms have been responsible for countless diseases throughout human history. However, mankind found tools to combat these detrimental effects in the discovery of antibiotics. It was thought that antibiotics were miracle drugs that could cure many illnesses and antibiotics have been used throughout history time and time again to abate dangerous bacteria. Unfortunately, bacteria have discovered a way to overcome our defenses by changing their DNA becoming resistant to antibiotics that once were used to fight them. Moreover, these bacteria have not only acquired a resistance to the specific antibiotics taken to destroy them, but also to antibiotics not taken. Resistant bacteria have also developed a way to transfer their ability to resist antibiotics to other nonresistant bacteria. The capability of bacteria to overcome our defenses poses a serious dilemma to human health.

As the issue of antibiotic resistance continues to grow, it is important that we understand this problem. Therefore this paper is an introduction to antibiotic resistance which describes the problem of antibiotic resistance, provides a short background and time line of the evolution of antibiotic resistance, discusses contributing factors leading to antibiotic resistance, and offers guidelines on how to decrease the antibiotic resistance.

What is antibiotic resistance?

According to the medical dictionary, antibiotic resistance refers to microorganisms, often bacteria, which have acquired the ability to resist antibiotics that once would have killed the microorganism (MedicineNet, 2010). In other words, disease causing bacteria that were once susceptible to antibiotic treatment no longer show this vulnerability. Instead, these bacteria are able to cause illnesses in their attended victims despite treatment of antibiotics.

Background

Antibiotic resistance has become a major problem in today’s health field. In order to overcome a problem, it is important to understand its origin. Antibiotic resistance was first discovered in the 1940’s when it was identified in a microorganism called Staphylococcus aureus which was resistant to penicillin. Until the discovery of antibiotic resistance, penicillin was regarded as somewhat of a miracle drug and was used to fight a vast array of human conditions (Levy, 2002). The appearances of antibiotic resistance caused health practitioners to begin to slightly question this wonder drug notion. However, it wasn’t until years later in 1959 that transferable resistance was discovered. Transferable resistance refers to a bacterium’s ability to transfer its resistance from itself to other bacterium not only in the same organism but in other organism of a different species. This finding marked the beginning of truly understanding the incredible power of bacteria to spread their resistance. Since this time numerous disease-causing bacteria have developed resistance to multiple drugs. Antibiotic resistance has also been found in humans, plants, and animals. In order to cover this in a more concise manner, a timeline will be used.

Timeline

· 1947: _Staphylococcus aureus_ resistant to Penicillin

· 1959: _Shigella dysenteriae_ resistant to multiple antibiotics

· 1959:_Esterichia coli_ resistant to multiple antibiotics

· 1967: _Streptococcus pneumoniae_ resistant to penicillin

· 1967: _Neisseria gonorrhea_ resistant to penicillin

· 1970: _Staphylococcus aureus_ resistant to methicillin

· 1983: _Enterococcus faecium_ resistant to penicillin

· 1983: _Shigella_ resistant to multiple antibiotics

· 1983: _Escherichia coli_ resistant to many strains of fluoroquinolones

· 1984: _Mycobacterium tuberculosis_ resistant to multiple antibiotics

· 1989: _Enterococcus_ resistant to Vancomycin

· 2001: _Campylobacter_ resistant to fluroquinolones

· 2002 _Staphylococcus aureus_ resistant to Vancomycin

Note: Information for this timeline came from Levy, 2002 and P.A.C.E.

Contributing factors of antibiotic resistance

In order to combat antibiotic resistance, the contributing factors must be investigated and limited. The first step in this process is identifying how bacteria become resistant to antibiotics. Bacteria gain antibiotic resistance through three distinct processes. First, antibiotic resistance can become present in bacteria through a spontaneous DNA mutation. According to a review by Blazquiz, Oliver, and Gomez-Gomez (2002), there is a grave danger from antibiotic resistance spreading through bacteria’s hypermutability. Secondly, bacteria are capable of reproducing, and therefore exchanging their antibiotic resistant DNA through genetic transfer including conjugation, transposition, and transformation. Conjugation is a direct cell-to-cell transfer of genetic material. Hence, when two bacterial cells come into contact with one another they are able to pass antibiotic resistance through contact.

The second type of DNA transfer is transposition, transposition is conducted by transposons. Transposons consist of a wide variety of elements of bacterium. Their common factor is their ability to transfer DNA by moving a gene from one cell to another by “essentially jumping” (Bennett, 2008). Transformation is the process of bacteria taking in free DNA molecules and replicating them. Therefore, if a DNA molecule in the cell that possesses antibiotic resistance is taken into a bacterium, that bacterium is able to duplicate the free DNA’s resistance. Lastly, bacterium can transfer their ability to resist antibiotics through transferring plasmids from one bacterium to another (Levy, 2002). Bacterial plasmids are components of the bacteria that are capable of moving bacterial genes from cell to cell (Bennett, 2008). It is in this motility that a bacterium’s plasmid is able to spread antibiotic resistance to other bacterium.

Once the process of how bacteria acquire antibiotic resistance is understood, the contributing factors that increase bacterial antibiotic resistance needs to be examined. The primary cause of increased antibiotic resistance appears to be overuse and misuse of antibiotics. Overuse of antibiotics may have become so prevalent due to health practitioners overprescribing antibiotics for many illnesses that do not require antibiotic therapy (Goossens, Ferech, Stichele, Elseviers, 2005). Additionally, in many underdeveloped or developing countries antibiotics can be obtained over the counter due to lack of governmental regulation (Levy, 2002).

Misuse of antibiotics also contributes extensively to antibiotic resistance. When an individual obtains an antibiotic they are usually given instructions on how to take the drug either through a pamphlet provided with the medication, by a pharmacist, or by their health practitioner. However, these instructions are not always strictly followed. Many times when individuals’ symptoms begin to subside they discontinue their antibiotic therapy. By doing this the bacteria that are causing the illness may not be completely killed. The bacteria that survive the therapy are able to use it to their advantage. They can develop a resistance to not only the antibiotic used, but also to other similar antibiotics (Levy, 2002). Additionally, not taking the recommended doses can lead to subtherapeutic levels of antibiotic in the bloodstream. This also leads to bacteria surviving the course of treatment and becoming resistant.

Antibiotics used for other purposes than disease therapy have also contributed to antibiotic resistance. One field that has used antibiotics extensively is agriculture. Antibiotics have been used both with livestock and crops to ensure the health of animals and plants. Moreover, in some markets such as the cattle market, antibiotics have been used as a growth factor to increase the size of cattle. By introducing antibiotics to these fields we have helped bacteria to acquire resistance. This can occur similarly to how antibiotic resistance occurred in humans, through overuse and misuse. Once these bacteria are resistance, they can be spread to humans due to the close contact workers have with plants and animals and also through consumption of these products (Levy, 2002 & Canton, 2008).

Guidelines

· Do not suggest to your health practitioner that you need an antibiotic for every ailment. Instead, allow the practitioner to perform a thorough investigation of your illness and determine the best course of therapy on their own.

· When prescribed an antibiotic, ask your health practitioner or pharmacist for specific information on how to use the antibiotic.

· Always finish the therapy by taking the entire course of antibiotics, even if your symptoms begin to subside

· Follow all time schedules for your antibiotics. Taking an antibiotic at the same time every day ensures that blood levels of the antibiotics remain at therapeutic doses.

· Determine if your antibiotic needs to be taken with food. Food intake affects the absorption of drugs and improper food intake can lead to subtherapeutic levels of antibiotics.

· Read and understand the drug information provided by the pharmacist.

· Only take antibiotics prescribed to you by a licensed health practitioner.

· Never take antibiotics bought illegally or that were prescribed to another individual.

· Keep your antibiotics in a safe place where others may not access them.

· For antibiotics in agriculture, never use antibiotics for purposes other than to treat illnesses or as probiotics in animals and plants.

Note: Information for this section came from Levy, 2002 and an interview conducted with a Thrifty White pharmacist, Dave Olson

Conclusion

As can be seen, antibiotic resistance is a grave problem that faces our health field today. It can affect anyone at any point in time. Therefore, it is important for the general public to understand what antibiotic resistance is, what causes it, and how can they protect themselves from it. Antibiotic resistance is the ability of bacteria to negate the healing effects of antibiotics. The primary causes of antibiotic resistance are from over using and improperly using antibiotics to treat illnesses. Additionally, the misuse of antibiotics in other fields such as agriculture also contributes to antibiotic resistance in humans. Lastly, in order to decrease antibiotic resistance, it is vital to treat antibiotic with respect and use them properly.

References

Bennett, P. M. (2008). Plasmid encoded antibiotic resistance: Acquisition and transfer of antibiotic resistance genes in bacteria. British Journal of Pharmacology, 153, S347-S357.

Blazquez, J., Oliver, A., & Gomez-Gomez, J. M., (2002). Mutation and evolution of antibiotic resistance: Antibiotics as promoters of antibiotic resistance? Current Drug Targets, 3, 345-349.

Canton, R. (2008). Antibiotic resistance genes from the environment: A perspective through newly identified antibiotic resistance mechanisms in clinical setting. European Society of Clinical Microbiology and Infectious Diseases, 15, 20-25.

Goossens, H., Ferech, M., Stichele, R.V., Elseviers, M. (2005). Outpatient antibiotic use in Europe and association with resistance: A cross-national database study. Lancet, 365, 579-587.

Levy, S. B. (2002). The antibiotic paradox: How the misuse of antibiotics destroys their curative powers. Cambridge: Perseus Publishing.

Normark, B. H., & Normark, S. (2002). Evolution and spread of antibiotic resistance. Journal of Internal Medicine, 252, 91-106.

Medicine Net. Antibiotic resistance. Retrieved October 28, 2010. http://www.ncctinc.com/documents/Antibiotic%20Resistance.pdf.

P.A.C.E. (2008). Antibiotic Resistance. Retrieved November 3, 2010. http://www.ncctinc.com/documents/Antibiotic%20Resistance.pdf

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