Background: Working of Antibiotics

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