The Evolution of Drug Resistance in Viruses and Bacteria - Literature review Example

The Evolution of Drug Resistance in Viruses and Bacteria Introduction The rise in the frequency of drug resistance in viruses and bacteria in the contemporary medicine world is notable in a wide range of drugs used to treat different varieties of diseases. Such resistance may also result from the evolution of new genes in viruses and bacteria where such genes have drug-resistant qualities. Drug resistance is a designed feature involving pre-existing genes that enable viruses and bacteria to compete against drug components that make entry into their environment. The drug resistance developed by viruses and bacteria leads to a reduction in the efficiency of drugs, including antimicrobial drugs in curing the health conditions involved. The resultant nature of upcoming bacteria and viruses leads to drug tolerance. In most cases, pathogens acquire newer forms and abilities of resistance through evolution. In a broad sense, the pathogens acquire a stronger resistance against drugs and thus, repel any upcoming drugs, making them ineffective. The development of drug resistance specifically stems from drugs that aim at eradicating specific viral and bacterial proteins. Since such drugs are mainly specific to given viruses and bacteria, any mutation in such pathogens interferes with its destructive nature, which results in drug resistance. As the drugs become more developed, the viruses and bacteria mutate to acquire protective qualities that are commensurate to the strength of the developed drugs. With this in mind, the innate capacity of bacteria and viruses to evolve to such an extent of outpacing upcoming drugs suggests that stakeholders in the medical field should work towards achieving long-term and viable anti-microbial therapies that will evolve with the pathogens’ ability to adapt to the situation. Evolution of Drug Resistance and Reasons for Occurrence A succinct analysis of Bryskier (2005), reveals that antibiotics are composed of natural secretions by fungi and bacteria that aim at engulfing and killing other bacteria that are pose competition over limited nutrients. The drugs used in treating diseases in the contemporary originate from such secretions. Professionals in the medical field remain alarmed by the discovery that some viruses and bacteria have developed resistance to drugs, and further evolved through mutations or DNA alterations. Based on information outlined by Fisher and Mobashery (2010), rresidential areas and health facilities act as proper breeding grounds for drug resistant qualities of bacteria and viruses. Such bacteria flourish in an environment dominated by people with ailments and whose immune systems are weak. Additionally, drugs eliminate competing bacteria that have low resistance in such environment. Viruses and bacteria resistant to the contemporary drugs may even survive in older conditions, especially, which were present before synthesis of the current drugs takes place (Tanaka & Omura, 1990). In contributing to this argument, Fisher and Mobashery (2010), argue that the ability of viruses and bacteria to become resistance to drugs continues to expand for a myriad of reasons. Such reasons include antibiotics over-prescription by health professionals, failure to complete drug doses, the application of drugs in organisms, especially as growth enhancers in the food industry, poor health facility hygiene, as well as increased cases of change in living environment (Nielsen, 2005). In the presence of the viable conditions, bacteria and viruses gain resistance against drugs through two main ways including mutation and developing a built-in structural design that ensures swapping of DNA, where the bacteria or the viruses share their resistance genes. An antibiotic constituent kills viral and bacterial cells by disrupting their critical functions (Demain & Sanchez, 2009). An antibiotic merges with a protein with the aim of preventing the protein from functioning properly. The working and normal protein is mainly involved in the process of copying and replicating the DNA, making bacterial or viral cell walls, as well as making the required profits, which is detailed better in the work by the American Academy of Microbiology (2008). Such functions are essential in ensuring the growth and development of the bacterial and viral organisms. In instances where the bacteria develop mutations in their DNA that codes the proteins, the respective antibiotic cannot bind to the changed protein, and as such, the mutant virus or bacteria survive. Contrary, presence of antibiotics, natural selection processes occur, which favor the growth and survival of mutant virus and bacteria as provided by Nielsen (2005). In this case, the mutant bacteria or virus have better ability to survive, even in the absence of the antibiotic and thus, continue to have an impact on disease harbored by the patient. Even if the mutant bacteria or viruses have the ability to survive well in the environment of a health facility, the change carries a cost. The changed protein has less efficiency in the performance of its normal functions, which makes the bacteria inadequately fit in the absence of antibiotics within the environment (Nielsen, 2005). Non-mutant bacteria and viruses are able to compete for nutrients in a better manner and multiply at a faster rate than the mutant forms. The dynamics surrounding natural selection and mutation help bacteria and viruses in becoming more drug resistant (Bryskier, 2005). However, mutation can also result in bacteria and viruses with defective proteins whose normal functions are absent. Evolution requires possession of functional systems for viruses and bacteria to evolve completely and with all organs working. Mutations, as well as natural selection, taken as major forces in evolution, only cause a situation where functional systems are lost. As such, drug resistance by bacteria and viruses is not a form of actual evolution but rather a variation in the form of the bacteria and virus (Nielsen, 2005). Curbing Drug Resistance Solutions on whether drug resistance is avoidable or not require the consideration of such approaches as disease ecology, genetics, evolutionary biology, as well as the epidemiology of the disease. The challenging task of identifying the main determinants in the probability of resistance is approachable from different starting points. However, the main way to the center of the problem is to establish the evolution of drug resistance through natural selection (Tanaka & Omura, 1990). From the perspective of the disease-causing agent, drug-treated patients may pose a harsh environment to viruses and bacteria. Any mutation in the disease-causing agent that reduces the efficiency with which drugs curb them is beneficial to them and thus, subject to possible positive selection. Biological situations that delay the spread of beneficial mutations may lead to clues for coming up with the most favorable drug policies that could act to slow down the domination of resistant parasites. Thus, aspects of population genetics and theoretical provisions are vital in investigating the positive selection in organisms in order to solve issues of drug resistant as provided in the research study by Andersson (2006). Medical procedures could help in curbing the drug resistance feature in bacteria and viruses-related disorders. Such practices include avoiding the use of placid doses of antibiotics over long periods. In situations where infections need to be controlled using antibiotics, it is important to use high-dosage and short-term prescriptions (Bryskier, 2005). Such will help in getting rid of all disease-causing bacteria, which in turn leaves no survivors. In addition, a combination of drugs may help in the full treatment of bacterial infections. The use of a stronger drug would help in strengthening the selective pressure and achieve a super-resistant strain. Using different types of drugs leads to a new encounter towards bacteria and viruses and thus, a form of a selective pressure that could consequently result in their extinction. Conclusion Four or five decades ago, courtesy of antibiotics, health professionals thought drugs had all but exterminated infectious agents including bacteria and viruses as major health threats. On the contrary, the recent decades have experienced a startling resurgence of a wide range of infectious diseases and the emergence of new ones. In the contemporary society, malaria, tuberculosis, AIDS virus, and other infectious diseases pose great hazards to global human health. The upsurge of these diseases has been because of the growing resistance of the disease-causing agent to drugs. Bacteria and viruses are mutating by day and lead to a case where they cannot be overwhelmed by drugs. The long-term use of antibiotics leads to the development of resistance against them, which later culminates into the evolution of the disease-causing agents to organisms that are resistant to elimination making them resistant to drugs. References American Academy of Microbiology. (2008). Antibiotic resistance: an ecological perspective on an old problem. Based on a colloquium held in the Fondation Mérieux Conference Center in Annecy, France. Washington, DC: ASM Press. Andersson, D. (2006). The Biological Cost of Mutational Antibiotic Resistance: Any Practical Conclusions? Current Opinion in Microbiology, 461-465. Bryskier, A. (2005). Antimicrobial Agents: Antibacterials and Antifungals. Washington, DC: ASM Press. Demain, A., & Sanchez, S. (2009). Microbial Drug Discovery: 80 Years of Progress. Tokyo: J. Antibiot. Fisher, J., & Mobashery, S. (2010). Enzymology of Bacterial Resistance". "Comprehensive Natural Products II. Enzymes and Enzyme Mechanisms, 8, 443–201. Nielsen, R. (2005). Molecular Signatures of Natural Selection. Annual Review of Genetics, 39, 197-218. Tanaka, Y., & Omura, S. (1990). Metabolism and Products of Actinomycetes: An Introduction. Actinomycetologica , 4, 13-14. Read More