Disinfectants antibacterial activity

The antibacterial activity of disinfectants and antiseptics is summarized in Table 10.2. 

Table 10.2 Antibacterial activity of commonly used disinfectants and antiseptics... 

A number of tests have been deseribed which imitate, at least in part, the principle of the phenol eoeffieient test for liquid disinfectants. A culture of the test organism is mixed intimately with the semi-sohd preparation, and the mixture subcultuied by means of a loop into a suitable broth designed to disperse the base and neutrahze the antibacterial activity of the medicament. 

Triclosan cannot only be applied as an emulsion, but it also has demonstrated antibacterial and antiinflammatory efficacy in eczema therapy when used as an antiseptic wash.28,30 Likewise, 10% povidone-iodine solution as a disinfectant showed excellent antibacterial activity together with improvement of clinical severity.79 As a 1% solution, chlorhexidine digluconate has shown superior effectiveness to triclosan in vitro, but may be only suitable for therapeutic use in intertriginous areas or as part of wet wrap dressings in the treatment of AD when used as an alcoholic solution.26,80... 

Antiviral activity was established for bicyclo[n.l.O]alkylamines (691) Bifunctional ammonium salts of type 692 were claimed to be useful as disinfectants application of the bicyclo[n.l.O]alkyl ammonium group as counterion in penicillin salts has been tested, e.g. Ref. 341. A iV-cyclopropyl moiety is also part of the antibacterial agent ciprofloxacin (BAY 09867) (693) . 693 shows strong antibacterial activity especially against Enterobacteriaceae it was considerably more active than other agents tested . 

Chlorhexidine has broad-spectrum antibacterial activity hut is not active against acid-fast bacteria, spores, or viruses. It has been used for such topical uses as preoperative. skin disinfection, wound irrigation, mouthwashes, and general sanitiration. Chlorhexidine is not absorbed through skin or mucous membranes and docs not cause systemic toxicity. 

Alkyl-dimethyl-benzylammonium chlorides are constituents of many disinfectants because of their antibacterial activity. 

In 1935, almost 20 years after the introduction of these relatively simple aliphatic QACs, Dormagk reported that the substitution of a benzyl group on the quaternary nitrogen increased antibacterial activity [3]. This second type of QAC, namely alkyldimethylbenzylammonium chlorides (ADBACs), were the first class of QAC to find acceptance and utilization as disinfectants in medical applications. 

Polymers exhibiting quaternary nitrogen functionalities have commonly been used as biocidal agents [13-21], A number of polymeric disinfectants containing quaternary pyridinium groups, either in the backbone or as pendent groups, have been prepared and exhibit good antibacterial activity. 

Pinosylvin (3,5-stilbenediol) ( )-form needles, insoluble in water, soluble in acetone. )- and (Z)-isomers occur together with the corresponding mono- and dimethyl ethers in pines, firs, and conifers. Pinosylvin has antifungal and antibacterial activities and protects the wood against rot, as a disinfectant it is 30-times stronger than phenol and is highly toxic for fish. As a result of condensation with lignin, pinosylvin prevents sulfite dissolution of wood. Pinosylvin monomethyl ether acts as an antifeedant for certain rabbit species. ... 

The activity of formaldehyde vapour is dependent on RH. Various RH levels for optimum antibacterial activity have been proposed. An optimum RH of 80-90% but with no great increase in disinfection above 58% has been reported [78, 82]. Another study found an increase in the rate of kill... 

Testing Disinfectants (Phenol Coefficient Tests). The tests employed for determining the efficacy of all of the coal tar disinfectants include the Rideal-Walker test, the Chick-Martin test, the United States Food and Drug Administration (F.D.A.) method and the United States Association of Official Agricultural Chemists (A.O.A.C.) method, in which the antibacterial activity of the disinfectant is expressed in terms of its action relative to that of phenol. Each of these tests has much in common, and their main features are set out in the table below. It is necessary to follow precisely the directions as laid down in the approved method in order to get reproducible results. Each test wdll give a different coefficient... 

Inorganic Acids. Strong inorganic acids have little antimicrobial activity in themselves but inhibit microorganism growth by lowering the pH. Disinfectant toilet bowl cleaners that contain 9.5% HCl or more are antimicrobial. Carbonic acid [463-79-6] in soft drinks provides some antibacterial preservation. Sulfurous acid [7782-99-2] is an effective preservative used to preserve wines (see Wine), fmit juices (qv), and dried fmits. 

The unique property of quats is the abHity to produce bacteriostasis in very high dilution (Table 6). Because of this abHity, and the carryover of the disinfectant in early test procedures, it was originally thought that these compounds were highly bactericidal. However, for bactericidal action, 10 to 20 times the concentration is required. The quats have a narrower antibacterial spectmm than the phenols, and are much more active against gram-positive... 

Silver and mercury salts have a long history of use as antibacterial agents.241-243 The use of mercurochrome ((40), Figure 18) as a topical disinfectant is now discouraged. Silver sulfadiazene (38) finds use for treatment of severe burns the polymeric material slowly releases the antibacterial Ag+ ion. Silver nitrate is still used in many countries to prevent ophthalmic disease in newborn children.244 The mechanism of action of Ag and Hg is through slow release of the active metal ion—inhibition of thiol function in bacterial cell walls gives a rationale for the specificity of bacteriocidal action. 

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