In 1943, the antibiotic era began when penicillin, a member of the [beta]-lacam family of drugs, was developed. Since then, tens of thousands of derivatives of penicillin have been developed, but only seventeen antibiotics of this family are currently marketed in the United States. Penicillin and its derivatives work by preventing certain bacteria from building strong cell walls that keep their shape and integrity. Without well-integrated cell walls, "bacterial trying to grow in the presence of penicillin puff up and die."1
Almost all bacterial diseases have evolved some level of resistance. The "increased use of antimicrobial drugs encourages the spread of resistance and increases the prevalence of drug-resistant strains."2 In fact, most virulent strains, like many sexually transmitted diseases, require at least double the dosage that was used a decade ago. Vancomycin, commonly referred to as the "last resort drug," is being used by hospitals in ever-increasing amounts.
Bacterial resistance is the result of evolutionary responses. One cause of resistance is through mutation. In some instances, proteins used to build the cell are altered to bind penicillin poorly or not at all. A second type of resistance occurs when the bacteria preemptively breaks down penicillin into harmless by-products before they have the chance to bind with the cell wall. A greater cause for concern is the fact that "bacteria may reproduce with different bacterial species passing on resistance" to bacteria that did not previously possess the ability to resist any drugs.3
Humans are the predominant cause for drug resistance. The following are some examples of how human intervention has resulted in microbial resistance.
1. The overuse of antibiotics. Individuals within the medical profession typically perpetrate this. In third world countries, many people inappropriately use antibiotics for viral infections, likes influenza. Antibiotics can only treat bacterial infections. In nations like the United States, doctors in the past have over-prescribed medication, using antibiotics when alternatives where available. This occurs less frequently now, than it did in the past. However, doctors continue to prescribe stronger types of antibiotics then are actually required to fight the illness. Using strong types of antibiotics creates more evolutionary pressure on bacteria to create resistance. Greater resistance to stronger types of drugs reduces their effectiveness and the doctor's ability to combat disease.
2. Patients are also responsible for encouraging drug resistance when they discontinue treatment before completing their required regimen. Patients often do this because they start to feel better, they want to avoid additional costs, they find it inconvenient to take the medication, or they do not like the side effects. These side effects include allergic reactions, vomiting, or diarrhea for up to 10 days. Generally, the stronger the antibiotic, the stronger the reaction the patient will experience. When patients discontinue their treatment prematurely, they may have eliminated the majority of the bacteria, but some may remain. The bacteria that survives the initial doses are more resistant and may be transmitted to another individual, and thus propagate the resistant disease.
3. Agricultural animal farms are also a leading cause for the development of microbial resistance. Farmers usually add antibiotics to animal feed in order to enhance their growth and ensure their health. This widespread and liberal use of antibiotics in animal feed may create drug-resistant bacteria like, Enterococcus faecium in the animal. Studies have shown that "ingestion of resistance E. Faecium in the amount likely to be encountered in food [consumption], results in at least transient multiplication and carriage of the strain in the human intestine."4 Although some have argued that "few livestock live long enough to develop full antibiotic resistance."5
Other debates concerning drug-resistance arise from the commercial use of antibacterial products such as soaps and body washes. The Center for Disease Control (CDC) has announced that washing with regular soap and warm water is sufficient for eliminating bacteria from your body. Conversely, the Soap and Detergent Administration (SDA) argues that using antibacterial soaps are not harmful and that if antibacterial soaps did produce resistance, experts would have already noticed such an association. However, most people who use antibacterial soaps do not use them properly. To be effective, individuals must wash for three minutes, before rinsing, something most people do not do. Furthermore, some bacteria are good for the human body, and these soaps potentially eliminate them.
Dates of Drug Discovery and Resistance 6
The following are diseases that have shown resistance and are of most concern to health officials. Tuberculosis, and old disease that the medical community had disregard, reemerged during the mid 80s as a result of mutation. Incidents of malaria, gonorrhea, and E. coli are on the rise. A number of resistant strains of salmonella have been linked to agricultural antibiotic use. Streptococcus is the cause for both meningitis and pneumonia. Finally, staphylococcus is a major concern for hospitals as it generally affects post-operative patients.
Human may take several steps to slow the creation of drug-resistant diseases. Understanding bacterial countermeasures allow researchers to tailor antibiotics to defeat specific strains. Hospitals may use "sensible infection control measures, such as hand washing and wearing and changing rubber gloves" between patients.7 Doctors may use multiple antibiotic treatments in combination so that bacteria will not be able to develop resistance to any particular one. It has been proposed that the government remove some antibiotics from commerce altogether to permit reemergence of vulnerable strains. Finally, it is suggested that alternatives to antibiotics be developed. One particular Russian doctor believes that it is possible to use the bodies naturally produced antibodies to fight bacterial infection.8 The creation of stronger all-purpose antibiotics is only a somewhat viable solution. Aside from the stronger side effects, resistance to these drugs would eventually occur. Furthermore, development of stronger antibiotics has not progressed at great speed. Since resistance to vancomycin, currently the medical personnel's greatest weapon against bacteria, was registered fifteen years ago, only two stronger antibiotics have been proposed, neither of which has been approved.
It can be argued that allowing bacteria to remain resistant to drugs may be used as an effective form of population control. It is true that fewer cases of life-threatening infectious diseases have lead to an increase of chronic illnesses. These so-called lifestyle diseases include heart disease, cancer, and stroke. However, I believe most would prefer to take their chances with lifestyle diseases then deal with bacterial infections. Furthermore, using infectious diseases for population control would result in huge numbers of orphaned children who would become an additional burden on society.
At this time, it is impossible to prevent bacteria from creating
resistance to drugs. Resistance is a natural evolutionary response that humans
cannot stop. However, it is possible to limit the opportunity for diseases
to form these resistances. This requires a collective effort on not only individuals
within the medical profession, but from all members of the community as well.
1. Palumbi, Stephen R. The Evolution Explosion: How Humans
Cause Rapid Evolutionary Change. New York: Norton, 2001. Pg. 70.
2. Levine, Arthur A. "Death Rate Increase Linked to Antibiotic Misuse" in HealthFacts. Feb. 1996. vol. 21 n. 201 Pg. 2.
3. Palumbi. Pg. 81.
4. "Meanwhile, Back at the Farm" in Infectious Disease Alert. Nov. 1, 2001. vol. 21 i. 3 Pg. 17.
5. Palumbi. Pg. 89.
6. Palumbi. Reproduced from Table 4.1 on Pg. 75.
7. Skolnic, Andrew. "New Insight Into How Bacteria Develop Antibiotic Resistance" in The Journal of the American Medical Association. Jan. 2, 1991. vol. 265 n. 1. Pg. 14.
8. For further reading consult: Skurkovich, Simon. "Facing the Coming Plague" in World and I. June 1998. vol. 13 n. 6. Pg. 150.
FURTHER READING & USEFUL LINKS
1. This presentation was intended to be associated with the following article:
Eckert, Eric. "Diseased Soieties" in World and I. Oct. 1998. vol. 13 n. 10. Pg. 166.
2. Lappe, Marc. Breakout: The Evolving Threat of Drug-Resistant Disease. San Francisco: Sierra Club Books, 1995.
3. "How Bacteria Build Resistance to Antibiotics" presented by USA Today
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