In 1928 Alexander Fleming observed that a contaminant mold was growing on a culture dish that he had prepared earlier (Winn, 946). He was not expecting the contaminant but because the culture was carelessly exposed to the air the contamination was made possible. Upon closer examination the said contaminant mold inhibited the growth of bacteria in the said culture. Fleming made a significant discovery that the mold, specifically Penicillium notatum “…was producing a diffusible bacteriolytic substance capable of killing bacteria” and as a result antibiotics were invented. Decades later the first case of antibiotic resistance was reported and since then the medical community has been trying to curb this problem. It is imperative that the impact of antibiotic resistance must be reduced because if this will continue there will come a time when mankind will no longer have a defense against virulent strains that are incurable.
Antibiotics
While it was Fleming who discovered the underlying scientific principle for antimicrobial medication it was not until 1939 when researchers Florey and Chain developed a technique that enabled them to extract the antimicrobial properties of Penicillium in sufficient purity and quantity (Winn, p. 946). Antibiotics became available afterwards and after World War II not only was additional antibiotics discovered, the same became readily available (Winn, p. 946). This is the beginning of a revolution wherein mankind was able to defeat major sickness and diseases. Medical problems that were considered life threatening in the past became a challenge that can be easily remedied.
Antibiotics are made from fungus and mold. It is important to remember that these living organisms can be readily found in the soil and this fact will play a major role in later discussions concerning resistance. Researchers are saying that these fungus and molds already interacted with deadly microorganisms and even prior to the discovery of antibiotics virulent bacteria already evolved based on these interactions and would explain why these microorganisms already developed some form of defense mechanisms in accordance to a long time association with the environment.
In the United States pneumococcal disease is estimated to cause 3000 cases of meningitis and 60,000 cases of bacteremia among adults annually (Bessler, Morita, & Fridkin, p. 428). This is caused by Streptococcus pneumoniae and in the past penicillin is the effective cure but this is no longer true because since the 1960s resistance to penicillin and other microbial agents has been reported (Bessler, Morita, & Fridkin, p. 429). By simply focusing on pneumonia one can already have a basic understanding of the significance of bacterial resistance. Simply put without effective medication tens of thousands of sick Americans are in danger of losing their lives because a routine medical problem that has become incurable.
Bacterial Resistance
While harmful microorganisms develop resistance through evolution the major cause for developing bacterial resistance is in the use of antibiotics. This may look like a paradox but in medicine and in biology this is easy to understand. There is a concept called “selection” where the drugs can eliminate those that have no resistance to the antibiotic and leave behind those that have developed resistance to the bacteriolytic effect of the drug. If this process continues, then the population of bacteria that are resistant to treatment will increase and this trait can be passed on to the next generation of virulent strains.
This conclusion was made when a pair of researchers tested “preserved bacteria” circa 1917-1954 (U.S. Congres, Office of Technology Assessment, p. 41). This period is known as the “pre-antibiotic era” and when tested these preserved bacteria demonstrated little if any antibiotic resistance (U.S. Congres, Office of Technology Assessment, p. 41). The same thing could not be said of several virulent strains of microorganisms in the present time.
Resistance among Bacteria
Resistance develops because of the prevalent use of antibiotics. In layman’s terms those that can survive an attack will come out of the ordeal much stronger. In the world of microbiology, virulent strains that are left behind after the initial wave of antibiotic use may develop resistance to the drugs or the drug may simply reduced the number of bacteria to tolerable levels and those that are left standing are the ones that have a defense mechanism against a particular antibiotic. The only thing needed is time for this new generation of strain to replicate and then the host will again feel the symptoms of the disease. This is the reason why bacterial resistance can be observed while a patient is currently undergoing treatment. On the other hand bacterial resistance can also be observed within a particular community such as in hospitals where microorganisms can interact with other resistant strains.
There are basically three major ways to achieve resistance and this is through mutation and selection. Mutation occurs rarely and yet it can alter the genetic make-up of the bacteria making it resistant to medication. Mutation also occur spontaneously and enabling the microorganism to modify or eliminate the effect of the antibiotic’s action (U.S. Congres, Office of Technology Assessment, p. 41). For instance, Linezolid, the first clinically available member of oxazolidinone class, acts by inhibiting protein synthesis through its binding to the initiation complex but a single point mutation in the rRNA gene can give resistance (Rice & Bonomo, p. 444).
One of the more interesting discoveries relating to bacterial resistance is linked to how resistant strains are able to influence other microorganisms, even those that belong to different species. This means that the transfer of genetic traits favoring resistance is not only limited to parent and offspring or in this case from one replicate to the next but is also possible using genetic material coming from the environment as well as microorganisms that are nearby (Winn, p. 947). For instance, researchers discovered that there are microorganisms that can use DNA material from dead bacteria (Winn, p. 947). These microbes have the ability to gather the said genetic material from the environment and then incorporate it into their own while replicating. Therefore the new generation of virulent strains contains an improved or altered microbe that can prove resistant to treatment.
This is very important to consider because this means that microorganisms may be simple-celled living things but they have mechanisms to protect themselves from harm. Mutation and selection processes that may result in the emergence of resistant strain is difficult to control in microorganisms because while humans, “…whose evolution is relatively slow, bacteria multiply and evolve rapidly … a 24-hour period allows 1 million or more opportunities for the development of mutations for many bacteria” (Rice & Bonomo, p. 441). It also means that they have the capacity to adapt well to the environment and as seen in the preceding discussion, they even have the capacity to use existing materials from the environment to develop a defense system. This is an added challenge to bacteriologists and all those who labor in the medical community.
The implications of highly-evolved defense mechanisms are compounding the problem because of two factors: 1) there is a considerable increase in the use of antibiotics all over the world; and 2) mankind is no longer stationary but mobile in a planet that is shrinking due to efficient transportation and communication. At first globalization was seen to impact only the economic aspect of the community but this time it is very much evident that its influence goes far beyond business and social networks. Globalization can also add into the current problem of bacterial resistance. Those who developed resistance to a particular drug can travel to different parts of the world and by doing so can spread microorganisms that have the genetic capability to develop defense mechanisms against antibiotics. This means that there are more opportunities to develop highly resistant strains as well as the fact that it is creating an international health problem.
Since resistance to antibiotics is due mainly to the abuse of antibiotics the thought that resistant bacteria can be transferred through migration is a major cause of concern especially when considering the movement of bacteria into Third World countries. In depressed areas of the globe there are serious deficiencies in medical care and this includes the lack of medicines and health workers. When it comes to the link between antibiotic use and the development of resistance to medication, the improper use of antibiotics can readily contribute to the problem.
Conclusion
There is a need to reduce the emergence of resistant strain. One way to do this is to develop a more scientific approach to the use of antibiotics. This is linked to the research findings that aside from the chromosomes bacteria use plasmids to transmit “antibiotic resistant traits” to the next generation of bacteria or even to those of belonging to other species that it is in contact with (Winn, p. 45). As a result this new strains carry “excess baggage” in their genetic make-up and will have difficulty of thriving (Winn, p. 45). This behavior must then be reinforced with the limited use of antibiotics and by doing so the struggling population is diminished while at the same time denying it the chance to develop a defense mechanism against the drug (Winn, p. 45).
If these issues are not dealt with, mankind could be facing an epidemic of global proportions. In the past decades there was a triumphant celebration of how humans were able to overcome the forces of deadly diseases such as tuberculosis, pneumonia, smallpox, polio etc. This time it is difficult to be as confident. Instead of eradicating these problems it seems that the medical world has succeeded in creating virulent strains that are incurable in the long run. This is a grim outlook for many especially those in poor countries that do not have access to healthcare.
Works Cited
- Bessler, Richard, Julia Morita, & Scott Fridkin. “Public Health Responses to Antimicrobial Resistance in Outpatient and Inpatient Settings.” Bacterial Resistance to Antimicrobials. Ed. Kim Lewis & Abigail Salyers. New York: Marcel Dekker, Inc., 2002. 427-435.
- Miller, Paul & Philip Rather. “Global Response Systems that Cause Resistance.” Bacterial Resistance to Antimicrobials. Ed. Kim Lewis & Abigail Salyers. New York: Marcel Dekker, Inc., 2002. 37-45.
- Rice, Louis & Robert Bonomo. “Genetic and Biochemical Mechanisms of Bacterial Resistance to Antimicrobial Agents.” Antibiotics in Laboratory Medicine. Ed. Victor Lorian. PA: Lipincott Williams & Wilkins, 2005.
- U.S. Congres, Office of Technology Assessment. Impacts of Antibiotic-Resistant Bacteria. Washington, DC: U.S. Government Printing Office, 1995.
- Winn, Jr. Washington. Koneman’s Color Atlas and Textbook of Diagnostic Microbiology. 6th ed. Baltimore, MD: Lippincott Williams & Wilkins, 2006.