Different type of organisms (fungi, bacteria, and virus) causes different kinds of infections and diseases in humans and animals. The drug used to prevent this pathogenicity of microorganism is called an antimicrobial agent. Examples: Antibiotics, antiseptics and disinfectants. Some of the antimicrobial agents and their types with examples are discussed as follows:
Antimicrobial agents are used to prevent the infections and disease caused due to pathogens.
Different types of antimicrobial drugs are commonly available. These are as follows:
- Antibacterial drug: It is used to inhibit the pathogenic activity of bacteria. Example: Zithromax.
- Antifungal drug: A drug which is used to prevent the fungal activity in the host is called an antifungal drug. Example: Miconazole
- Antiviral agent: It is used to stop the pathogenic action of a virus. Example: Tamiflu.
- Antiparasitic drug: It is used to prevent the growth of pathogenic parasites. Example: Anthelmintics
Antibiotics are derived from microorganisms and are effective against bacterial, fungal and parasitic infections. But, antibiotics are not helpful against viral infections. The synthetic components at low concentrations can be used to kill pathogenic bacteria. Examples: Ampicillin and amoxicillin.
In 1908, Paul Ehrlich, a German bacteriologist had developed a synthetic component for the treatment of syphilis, which is called as arsphenamine or salvarsan.
Then, in 1929, Alexander Fleming discovered Penicillin from the fungus Penicilliumnotatum. It can be used to treat different type of bacterial infections.
Two types of antibiotics are commonly available. These are as follows:
- Bactericidal antibiotics –These are having killing effects on bacteria. Example: Penicillin, Aminoglycosides, Ofloxacin.
- Bacteriostatic antibiotics: These have an inhibitory effect on bacteria. Example: Erythromycin, Tetracycline, Chloramphenicol.
Antibiotics are further classified into three types. These are as follows:
- Broad spectrum antibiotics: These are widely used to kill or inhibit the Gram positive and Gram negative bacteria. Example: Chloramphenicol
- Narrow spectrum antibiotics: These are mainly effective against specific groups of bacteria. Example: Penicillin G
- Limited spectrum antibiotics: These are effective against a single organism or a single disease. Example: Dysidazirine.
Antiseptics and disinfectants
These are the chemical components which are used as antimicrobial agents.
Antiseptics are applied to the cuts, injured tissues and infected skin surfaces. Antiseptics are not prescribed to be taken orally. A few examples are given below:
- Mixture of chloroxylenol and terpineol is commonly called Dettol and is used to apply in the wounds.
- Iodine tincture and iodoform – with good antiseptic properties.
- Boric acid – It has been in usesince long time as an antiseptic agent for eyes.
To destroy the pathogenic microorganisms in the non-living objects Disinfectants are used. For ex: on floors
Example: Chlorine and sulphur dioxide at low concentration