Antimicrobial Agent

Antimicrobial Agent a chemical that kills or prevents the growth of microorganisms, including bacteria, fungus, and algae, is an antimicrobial agent. Three main antimicrobial agents are (1) Disinfectants (eg, bleach or alcohol), which can eliminate a variety of microorganisms on non-living surfaces to stop the spread of disease or contamination, (2) Antiseptics, which are administered to live tissue to help prevent infection in surgery (eg, chlorhexidine, povidone-iodine, hydrogen peroxide), and (3) Antibiotics, which destroy microorganisms using different mechanism and commonly used to treat pathogen infection. Antibiotics are the most important class of antimicrobial agents. They work well against parasitic, bacterial, and fungal infections but not against viral infections. Two commonly available antibiotics are- Bactericidal antibiotics (kill the bacteria, eg, Penicillin) and Bacteriostatic antibiotics (inhibit bacterial growth, eg, Erythromycin). They can have a broad range of action, killing or inhibiting bacteria (both Gram-negative and Gram-positive), or a narrow spectrum, effective only against particular bacterial subgroups. Some common action mechanisms of antibiotics are inhibition of nucleic acid synthesis, protein synthesis, cell wall synthesis, and antimetabolite activity (bacterial metabolism inhibitors). Further, there are antimicrobial drugs that prevent the pathogenicity of microorganisms. For example, (i) Antibacterial drug: Inhibit bacterial pathogenicity, eg, Zithromax; (ii) Antifungal drug: Prevent the fungal activity in the host, eg, Miconazole; (iii) Antiviral agent: Stop pathogenic virus action, eg, Tamiflu and (iv) Antiparasitic drug: Prevent the pathogenic parasite's growth, eg, Anthelmintics. [Mohammad Riazul Islam]