Antibiotics

Antibiotics are the chemical substances produced by the microrganism such as bacteria and fungi that are capable of destroying the growth of microorganisms. The first antibiotic is penicillin antibiotic which was discovered by British Bacteriologist Alexander Fleming in 1928.

 Most commonly used antibiotics.

1) cephalosporin

2) Chloramphenicol

3) Erythromycin

4) Meomycin B

5) Gentamycin

6) Penicillin G

7) Streptomycin 

8) Tetra cyline

9) canamycine

Types of antibiotics

A. On the basis of action, antibiotics are of two types

1.  Bacteriostatic agents (antibiotics):  Those antibiotics that inhibit the growth and multiplication of microorganisms are called bacteriostatic- antibiotics. They don’t kill microorganisms but restrict their reproduction. Eg erythromycin, tetracycline.
2.  Bacteriocidal agents (antibiotics): Those antibiotics that completely kill or destroy the microorganisms are called bacteriocidal antibiotics Eg:- Streptomycin, penicillin G
3. On the basis of the effect, antibiotics are of two types:- 

• Broad-spectrum antibiotics: Those antibiotics that destroy several pathogenic species of microorganisms are called broad-spectrum antibiotics. E.g.: Chloramphenicol.
• Narrow spectrum antibiotics: Those antibiotics that target specific reactions in specific microorganisms are called narrow-spectrum antibiotics. Eg: Isoniazoid.

Application of antibiotics

1) Medicine

Antibiotics are able to control a no. of infectious diseases in human beings as well as animals.

2) As food preservation

They have been used in the preservation of food especially fresh meat, fish etc. 

3) As a supplement in animal feed

Some antibiotics have been used as animal feed to enhance the growth of animals.