Antisepsis and its requirements
Antisepsis is a complex of preventive measures, which allows suppressing microbial growth and dissemination upon intact or injured skin, mucosal tissues, wounds, and within the body’s compartments.
- The main group of antiseptics (or antiseptic drugs) is of chemical origin. Biological (e.g., bacteriophages), physical and mechanical factors (surgical treatment, lavage, drainage, absorption) augment the favorable effects of antiseptics.
- Together with other chemical antimicrobial compounds (disinfectants and antibiotics) antiseptics are referred to as biocides including alcohols, phenols, iodine, and chlorine.
- Biocides are a chemical agent that helps in inactivating microorganisms.
- The most common resident organisms of the skin are the coagulase-negative staphylococci, with Staphylococcus epidermidis.
The main requirements to antiseptics include:
- high antimicrobial activity with tolerance for skin and mucosal tissues;
- the absence of irritative, toxic, allergic, mutagenic, carcinogenic, or teratogenic effects;
- antiseptics should be readily dissolved in lipids and poorly or moderately – in water to block drug absorption by internal host tissues, albeit promoting their accumulation inside the skin;
- they must confine infectious agent within the wound, thereby preventing its penetration into lymph and blood;
- antiseptics should block the microbial adhesion, suppress bacterial virulence factors, and synergize with the action of antibiotics and physical antimicrobial factors.
All antiseptics are divided into following classes due to their chemical structure:
- detergents (anionic and cationic, e.g. quaternary ammonium compounds like benzalkonium chloride, miramistin);
- halogen-releasing agents (chlorine-, bromine-, iodine-containing antimicrobials, e.g. sodium hypochlorite, iodine);
- biguanides (chlorhexidine);
- oxidizing agents (Н2О2, peracetic acid, КМnО4);
- aldehydes (formaldehyde, glutaraldehyde);
- metal-containing compounds (silver nitrate and other salts, alloys or organic complexes of Ag and Cu);
- phenols (triclosan, oxyquinoline);
- alcohols (ethanol);
- acids (benzoic, salicylic, boric and others);
- alkali (sodium hydrocarbonate);
- sulfonamides (sulfacyl-sodium or sulfacetamide);
- dyes (brilliant green, methylene blue, etc.);
- phytoncides (e.g., chlorophyllipt);
- antibiotics (tetracyclines, aminoglycosides, neomycin, etc.)
Also, antiseptics are discernible by their specified mode of action.
The destructive antiseptics cause denaturation and destruction of biopolymers (proteins, lipids, or DNA) within microbial cells. This activity is essential for aldehydes, halogens, metal salts, alcohols, phenols, acids and alkali, etc.
Oxidizing antiseptics (Н2О2 and peracetic acid, halogen-releasing agents – sodium hypochlorite) break down microbial structures by the generation of highly active free radicals.
Membrane attacking antimicrobials affect the permeability of microbial membranes (e.g., detergents, chlorhexidine).
Anti-metabolites and enzyme-inhibiting antiseptics block bacterial enzymatic systems (e.g., sulfonamides, silver nitrate).
Among the most efficient antiseptics are halogen-releasing agents and oxidizers (sodium hypochlorite, peracetic acid), quaternary ammonium compounds, and chlorhexidine, which are broadly used now in clinical practice.
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