Chapters
In this article, we will discuss how penicillin acts on bacteria and why antibiotics do not affect viruses. Moreover, we will also discuss the consequences of antibiotic resistance and the steps that can be taken to reduce its impact. So, let us get started.
What are Antibiotics?
Antibiotics refer to the drugs that stop or halt the growth of the bacteria but do not adversely impact the cells of the infected organism.
Few antibiotics are derived from living organisms. For instance, penicillin is created by some fungi in the genus Penicillium. On the other hand, other antibiotics are synthetically produced in the laboratory.
Why do Antibiotics work on bacteria but not on viruses?
Antibiotics affect the target bacterium by interfering with its growth or metabolism. The antibiotics target different processes of the target bacterium such as:
- Protein activity in the bacterial cell surface membranes
- Synthesis of bacterial cell walls
- DNA synthesis of the bacteria
- Bacterial enzyme action
- Synthesis of bacterial cell walls
Antibiotics including penicillin do not affect viruses because they do not have cells or cell walls. Hence, antibiotics cannot target viruses in any of the ways as they target bacterial cells. As the virus replicates, it employs the host cell’s mechanisms for transcription and translation purposes. Hence, these processes cannot be targeted through antibiotics because antibiotics are unable to bind to the proteins that host cells employ in these processes.
How Does Penicillin Affect Bacteria?
Penicillin affects the bacteria in this way:
- The cell walls of bacteria are made up of peptidoglycans. The peptidoglycans refer to the long molecules of peptides and sugars
- The cross-links that form between these peptidoglycans hold them together
- As the new bacterial cell grows, an enzyme known as autolysins is secreted that forms tiny holes in the cell wall of the bacteria
- These holes enable the stretching of the bacterial cell wall with the new peptidoglycan molecules. Then they join up through the cross-links as described above
- Penicillin stops the formation of these cross-links by inhibiting the enzymes that speed up their formation
- However, the enzyme autolysins keep forming the holes in the cell wall of the bacteria, making it weaker and weaker
- Remember that the bacteria live in watery environments and they intake water through osmosis. Their weakened cell walls burst eventually because they cannot bear the pressure exerted on them within the cell
- This implies that the penicillin only affects the bacteria that are still in the growth phase (the enzyme autolysins do not form holes and cross-links between peptidoglycan molecules are not created once the bacterial growth is complete. This is because when the bacterial growth is complete, its cell wall does not require further expansion)
- Penicillin does not target all the bacteria such as tuberculosis because the bacteria may have the following features:
- Enzymes that break down penicillin
- Thick cell walls minimize permeability
In the next section of the article, we will discuss the consequences of antibiotic resistance and the steps that can be taken to reduce its impact.
Consequences of Antibiotic Resistance
The antibiotics that are generally prescribed have become less effective because of the following reasons:
- Unnecessarily prescribing antibiotics
- Use of antibiotics in farming on large scale to avoid diseases when livestock are kept in close quarters, even when animals are healthy
- Not completing the full course of antibiotics as prescribed by the doctors
The factors discussed above have resulted in the increased incidence of antibiotic resistance.
Superbugs (Bacteria Resistant to Antibiotics)
- The strains of bacteria that are resistant to antibiotics are referred to as superbugs.
- A well-known example of a superbug includes a strain of Staphylococcus aureus that is now resistant to the powerful antibiotic methicillin and is now called MRSA(Methicillin-resistant Staphylococcus aureus). It is also resistant to other antibiotics such as penicillin
- Bacteria present in the places where the use of various antibiotics is widespread may have plasmids that contain resistance genes of many different antibiotics. It gives them multiple resistance, thus posing a huge threat to the population
- Moreover, a non-pathogenic bacterium may be the first bacterium that became resistant to antibiotics. Then this bacterium may have passed the resistance on to the pathogenic species of the bacterium through horizontal translation
- Scientists are incessantly struggling to produce new antibiotics because resistant strains are evolving continuously
Minimizing Antibiotic Resistance and its Impact
We can minimize the antibiotic resistance and its impact in the ways described below:
- Taking strict measures in countries where the antibiotics are sold without being prescribed by the doctor
- Directing the doctors to not prescribe the antibiotics unnecessarily. When the patient absolutely needs the antibiotics only then the doctor should prescribe them. The doctors should also test the bacteria before prescribing the antibiotic. This is to ensure that the right antibiotic is prescribed for the particular ailment.
- Avoid using antibiotics in mild infections that our immune system will clear up on its own. Telling the patients to not keep the unuse antibiotics for self-medication.
- Asking the patients to finish the entire course when the antibiotics are prescribed (even if they get well in a few days). Finishing the entire course will ensure that all the bacteria are killed and none is left to mutate and become a resistant strain.
- Not prescribing antibiotics for viral infections. Antibiotics do not affect viruses in any way. Prescribing antibiotics for viral infections will just provide a needless opportunity for bacteria to become a resistant strain.
- Minimizing the use of “wide spectrum” antibiotics. Instead use the antibiotics that are highly specific to the infection, i.e. narrow-spectrum antibiotics.
- Changing the type of antibiotics being prescribed from time to time so that the same antibiotic is not prescribed for the same infections and diseases. This will minimize the chance of developing a resistant strain.
- Minimizing and strictly controlling the use of antibiotics in the agricultural industry. Today, measures are taken to minimize their use in farming, where the use of antibiotics is widespread just to prevent the diseases.
Minimizing the Spread of Already Resistant Strains
The spread of already resistant strains can be reduced by:
- Focusing on good hygiene practices like handwashing and the use of hand sanitizers. These measures have already minimized the rates of resistant strains of bacteria like MRSA in hospitals
- Preventing the spread of resistant strains from hospitals by isolating the infected patients. This is especially necessary for surgical wards where MRSA can infect surgical wounds.
Did you like this article? Rate it!
Loading...
Keep on teaching us,you are excellent teachers
This is great
Thanks a lot for this book,it really helped me a lot
It’s useful to me
Thanks a lot for your Better book!
It’s a perfect article, go ahead