Detergents, antibacterial action

The possession of surface activity per se may be an important faetor in the antibacterial action of a group of drugs, for example the eationie detergents. The addition of low concentrations of surface-active compounds may potentiate the biological effect of an antibacterial agent. Thus, phenols are often more aetive in the presence of soaps. 

The extreme dilutions of synthetic detergents used in the study of their antibacterial action are not incompatible ivith interactions of the detergent ions with protein and other components of the bacterial cell surface vide supra). Hotchkiss (59) suggests that a succession of events... 

Correlation of lytic activity to surface activity, analogous to that observed for bactericidal efficacy has been suggested (57), but it appears that the mechanism of hemolysis may be similar to that already proposed for antibacterial action. Indeed, Ponder (111) has found that both the lipide and protein components of plasma inhibit hemolyms by detergents and from this has inferred that the alkyl sulfates can combine with lecithin and cholesterol, as well as with proteins, and that hemolysis by detergents may be initiated by combination with the lipide, lipoprotein, and protein components of the red cell ultrastructure. 

Cationic surface active agents such as benzalkonium chloride and cetyltrimethylammonium bromide (Figure 1) have use as antibacterial agents, i.e., disinfectants and antiseptics, and have the advantage that the antimicrobial action is combined with a cleaning action associated with their detergent activity. 

There are other attributes from the laundering process that consumers desire beyond basic cleaning. In many cases, these attributes are mutually exclusive with maximum cleaning, and so there is an optimization of the detergent system to balance cleaning with other attributes. Some of these attributes include color protection, fabric softening, fiber restoration/protection, and antibacterial and antiallergenic action. 

The action of detergents on proteins depends on the conditions of study and may result in denaturation, precipitation, complex formation, or even catalyzed hydrolysis at acid pH. It is frequently difficult to differentiate some of these phenomena even in systems containing purified proteins. The action of detergents on biological systems is accordingly more complex, and explanation of phenomena such as the antibacterial potency of detergents must await elucidation of their interaction with components of the bacterial cell and surface, notably the proteins. 

In 1935 Domagk (40) discovered the powerful germicidal action of the quaternary ammonium salts, thus introducing the first important application of synthetic detergents to biological systems. In the last ten years reports too numerous to mention have revealed the antibacterial effects of both the cationic and anionic detergents (for reviews, see Dubos, 41, 42 Daniels, 36 and Valko, 147). 

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