Introduction
Antimicrobial agents are an essential scientific and practical achievement that prolongs the life of people across the globe. Due to the discovery of various antimicrobial treatment options, it became possible to eliminate a variety of infecting organisms. Infections may affect various body sites including the heart, brain, respiratory, urinary tract, skin, etc. Ongoing development and research in the sphere of antimicrobial agents lead to better protection of humans against infectious diseases. Identifying and differentiating various antimicrobial agents and causes of infection helps to prescribe adequate drug treatment and, therefore, should be explored in detail.
Categories of Antimicrobial Agents
There are four main categories of antimicrobial agents such as antibacterials, antifungals, antivirals, and antiparasitics. Antibacterials are usually used to suppress bacterial pathogens. Antifungal agents are used to suppressing the activity of fungi in a patient. Antiviral and antiparasitic agents are used to do the same with viruses and parasites. Antibiotics are one of the most common drugs to use against all of these categories of infections except for viruses. There are two types of antibiotics depending on the type of action such as bactericidal and bacteriostatic ones. The former is used to eliminate all bacteria including Gram-positive and negative ones. An example of such an agent is chloramphenicol. Despite its multiple adverse effects and toxicity, in certain situations, it could be effective. For instance, if a patient has resistance or allergy to penicillin.
Bacteriostatic, on the other hand, only inhibit the action of bacteria. Bacteriostatic antibiotics can be exemplified by erythromycin. Erythromycin binds 50S ribosomal subunit and thereby inhibits the synthesis of protein in bacteria (Arcangelo, Peterson, Wilbur, & Reinhold, 2017). They are used in a variety of cases connected with respiratory tract, skin, sexually transmitted, and other infections. By the breadth of action, antibiotics are subdivided into broad and narrow spectrum ones. The first type is used against various groups of bacteria, killing even those that constitute gastrointestinal flora. Narrow spectrum, such as Penicillin G or VK target specific groups of bacteria such as Gram-positive organisms. Another group of antimicrobial agents is antiseptics and disinfectants that represent chemical solutions used to eliminate microbes from the surface of damaged tissue. Some examples of disinfectants are iodine, boric acid, or Dettol.
Antiviral agents are used against a variety of viruses including, HIV, hepatitis, influenza, and other types. The emergence and development of genetics and microbiology allowed mankind to study the inner structure of viruses and identify, which chemical agents are needed to inhibit their reproduction. Acyclovir, for instance, is a prominent antiviral agent developed to inhibit the development of herpes.
Differences between Viral and Bacterial Infections
Bacterial and viral infections exhibit certain commonalities such as transmission through air channels, contact with infected items, people, or animals (Viertel, Ritter, & Horz, 2014). Despite the common features, differences are numerous. Bacteria usually exist in a form of a single cell that is particularly resistant to adverse environmental conditions. As opposed to viruses, there are rather few bacteria able to cause infections. Most of them exist within the human body and facilitate important processes such as digestion. The number of such bacteria often does not exceed one percent.
Viruses, on the other hand, are not autonomous organisms and require the host’s cells to survive and reproduce (Viertel, Ritter, & Horz, 2014). During the cycle of their life, they alter the cells, transforming them into malignant ones. In juxtaposition to bacteria, viruses attach only to specific cells in the respiratory tract, liver, or blood. Viral infections, as opposed to bacterial ones, use host cells to continue the replication, which creates complications when it comes to treatment. Viruses can modify normal cells into cancerous ones.
Identification of Infections and Selection of Antimicrobial Agent
Many infections such as pneumonia or diarrhea can be caused by either viruses or bacteria which complicate the diagnosis (Bonkoungou et al., 2013). Both viruses and bacteria are highly adaptable to treatment and the use of antibacterial therapy should be based on solid evidence as per the cause of the infection in order not to increase their resistance. It is documented that the unwarranted use of antibiotics has led to the emergence of new strains and complete resistance to traditional treatment in others. The use of broad-spectrum antibiotics can produce an adverse effect on the body lowering its resistance and exposing it to further infections. Therefore, the identification of the pathogen that caused the infection is critical, as targeted therapy is usually less destructive and more effective. One of the best ways to determine the cause of infection is to grow the sample organism in the laboratory and use various agents in order to determine the most effective one.
There are different classes of drugs that are used to treat certain infections and clinical trials and evidence have been developed in order to foster the informed use of these classes and certain medicines. For instance, staphylococci and streptococci are vulnerable to almost all classes of antibiotics. In that case, the best solution would be to use a drug that produces fewer enzymes and does not increase bacterial resistance. For instance, glycopeptides or oxazolidinones such as vancomycin, telavancin, or tigecycline do not produce bacterial enzymes or cause decreased membrane permeability (Kumar & Chopra, 2013; Arcangelo et al., 2017).
Other cases may include methicillin-resistant staphylococcus aureus which developed resistance against many widely used antimicrobial agents including, penicillins, beta-Lactam/beta-lactamase Inhibitors, four generations of cephalosporins, carbapenems, and many others (Dasgupta, 2012). According to Arcangelo et al. (2017), resistance in good-to-excellent activity medications is not developed only in rifampin, vancomycin, telavancin, linezolid, and ceftaroline. The recent studies on the latter showed a rather low development of resistance in methicillin-resistant staphylococcus aureus as opposed to previous generations. It is also reported to be safe and effective (Duplessis, & Crum-Cianflone, 2011). It can be used as a second or third-line treatment in severe cases of skin and soft tissue infections, pneumonia. Dosage in adults should not exceed 1200 mg a day. The drug is administered through 60-minute infusions twice a day, 7-14 days.
Conclusion
All things considered, there are various antimicrobial agents that can serve as effective treatment options in certain conditions and against certain pathogens. However, informed use is paramount as bacteria and viruses easily develop resistance against antibiotics. In addition, sufficient damage to the body’s natural resistance can be done if broad-spectrum antibiotics are used in a careless fashion. All classes of antimicrobial agents are more or less effective against certain types of bacteria, yet increased attention should be paid to the identification of the causative pathogen in order to select the most effective and less resistance-building agent. If prescribed carelessly, many bacteria will develop a resistance to antibiotics and many lives can be lost before the new antibiotics emerge.
References
Arcangelo, V. P., Peterson, A. M., Wilbur, V., & Reinhold, J. A. (Eds.). (2017). Pharmacotherapeutics for advanced practice: A practical approach (4th ed.). Ambler, PA: Lippincott Williams & Wilkins
Bonkoungou, I. J. O., Haukka, K., Österblad, M., Hakanen, A. J., Traoré, A. S., Barro, N., & Siitonen, A. (2013). Bacterial and viral etiology of childhood diarrhea in Ouagadougou, Burkina Faso. BMC pediatrics, 13(1), 36-42.
Dasgupta, A. (2012). Advances in antibiotic measurement. Advances in Clinical Chemistry, 56, 75-104.
Duplessis, C., & Crum-Cianflone, N. F. (2011). Ceftaroline: A new cephalosporin with activity against methicillin-resistant staphylococcus aureus (MRSA). Clinical Medicine Reviews in Therapeutics, 3(1), 1-17. Web.
Kumar, K., & Chopra, S. (2013). New drugs for methicillin-resistant Staphylococcus aureus: An update. Journal of Antimicrobial Chemotherapy, 68(7), 1465-1470.
Viertel, T. M., Ritter, K., & Horz, H. P. (2014). Viruses versus bacteria–Novel approaches to phage therapy as a tool against multidrug-resistant pathogens. Journal of Antimicrobial Chemotherapy, 69(9), 2326-2336.