Background: Working of Antibiotics
What are Antibiotics?
- Antibiotics are drugs that fight infections caused by bacteria.
- In order to be effective, it has to be selectively toxic to only target bacteria which are harmful.
- Antibiotics work in the following 2 ways
- Killing the bacteria
- Inhibiting the ability of bacteria to grow and multiply
- In order to understand the different targets a brief on bacterial cell is given below.
Bacterial cell
- A bacteria is a prokaryotic organism (no well-defined nucleus)
- The bacterial cell consists of :
- A plasma membrane which encloses the cell components.
- The cytoplasm is the jelly-like fluid that fills the inside of the cell.
- The DNA of bacteria is present in bacterial chromosome in the cytoplasm (see figure)
- Ribosomes are little granular bodies where proteins are made taking cue from the the DNA.
- Further, they reproduce through a process of binary fission through which the genetic information is carried forward.
Mechanism of Antibiotics
- Antibiotics work through many mechanisms that disrupt the structure and/or function of the bacteria.
- The structure or the function which the antibiotics target are called drug-delivery target.
- There are a number of drug-delivery targets in the bacterial cell namely
- Cell Wall
- Ribosome where protein synthesis occur
- Inhibit the DNA synthesis in order to stop it from transferring the resistant gene to other bacteria
- Inhibition of metabolism by introducing other non-harmful microbes to compete for nutrition
Antibiotic resistance: The hurdle
- The problem with antibiotics is that the bacteria have developed resistance to certain antibiotics, and thus can no longer be used to control or kill the bacteria.
- Different mechanisms bacteria have adopted to resist antibiotics include
- Some bacteria pump an antibiotic out of their cells as fast as it enters.
- Some have proteins that bind to the antibiotic molecule and block its lethal effect.
- Some have enzymes that break down the antibiotic molecules.
- Penicillin hits the machinery that creates the cell wall.
In focus: Discovery of enzyme
- The new enzyme discovered helps in breaking cell walls of bacteria and hence, offers a potential for a new drug delivery target.
- This enzyme has been found to regulate the growth of the cell wall.
- Since the cell wall is fundamental for bacterial growth and division, it can be targeted in order to arrest the growth and multiplication of bacteria.
- As a result, it paves the way for new wave antibiotics.
Section : Science & Tech
