Bactericidal substances

Wl. Welsh, I. R. H., and Spitznagel, J. K., Distribution of lysosomal enzymes cationic proteins and bactericidal substances in subcellular fractions of human polymorphonuclear leukocytes. Infect. Immun. 4, 97-102 (1971). 

Partitioning. A substance may have limited solubility in two mutually immiscible solvents, for instance water and oil. This often happens in foods, for example with many flavoring and bactericidal substances. It then is important to know the concentration (or rather activity) in each phase. For low concentration, the partitioning or distribution law of Nernst usually holds ... 

Creation of novel biocide polymers represents important direction in present-day chemistry of high-molecular compounds. This problem became especially relevant recently when wide spreading of stable to various bactericidal substances strains and possibility of their epidemic spreading was the serious problem for the formation of effective anti-bacterial therapy. 

The bait concentration of warfarin is 0.005% for Norway rats and 0.025-0.05% for black rats or mice. Coumarin preparations are often combined with sulfaquinoxaline (28). This bactericidal substance reduces the bacterial flora producing vitamin K in the intestine. The addition of oil to the bait serves a similar purpose. In this case vitamin K is extracted from the intestine. 

Penicillins and cephalosporins specifically inhibit late stages of the enzymatic construction of the bacterial peptidoglycan cell wall component, a network of peptides and polysaccharides. Since mammalian cells do not possess such a cell wall, the jS-lactam antibiotics are very specific and virtually non-toxic. This ideal property is not shared by other bactericidal substances, which impair or prevent growth of microorganisms by other, less specific, reaction mechanisms. This is true, e.g. for compounds affecting ion transport in lipid membranes. 

Tew and Amt [92-94] have prepared amphiphilic meta-PPEs 58 and investigated their behavior at the air-water interface where they prefer an extended conformation. These PPEs are active in the lysis of phospholipid vesicles and might find application as bactericidal substances. While the derivative 58 with R = H forms clear solutions in water, the alkoxy-substituted congeners aggregate and precipitate out upon addition of water to their solution in DMSO. The structure of 58 in the solid state is assumed to be helical rather than extended. If acrylic ester substituents are placed on 59, it is possible to capture the helical intermediates by a photochemical 2-1-2 cycloaddition (Figure 6.2) [95,96]. The presence of a fixated helical structure was evident, because addition of chloroform to the cross-linked form did not... 

The OM of gram-negative bacteria protects the cell against bactericidal substances. Passage of nutrients and waste is assured by porins, the jS-barrel transmembrane channels in OMs. 

Waksman, S. A., and H. B. Woodruff Bacteriostatic and bactericidal substances produced by a soil actinomyces. Proc. Soc. Exptl. Biol. Med. 45, 609 (1940). 

Service, M. and Wardlaw, A.C. (1984) Ediinochrome-A as a bactericidal substance in the coelotnic fluid of Echinus esculentus (L.). Comp. Biochem. Physiol., 79B, 161-165. 

JORQUERA M A, RiQUELME c E, LOYOLA L A and MUNOZ L F (1999), Production of bactericidal substances by a marine Vibrio isolated from cultures of the scallop Argopecten purpuratus. Aquaculture International, 7,433-448. 

Prior to the 1990s phenyhnercuric acetate was the primary bactericide and fungicide in latex and waterborne paints. Because of the increasing concerns of mercury toxicity and the potential for high consumer and occupational exposures to mercury when present in paints, the U.S. Environmental Protection Agency (EPA) induced U.S. manufacturers of PMA and other mercury compounds to withdraw their registrations for use of these substances as biocides in paints (see AIercury). Mercury compounds are used only for very limited, specific purposes, such as the use of phenyhnercuric mXx.2LX.e[55-68-5] as a bactericide in cosmetic eye preparations (see Cosmetics). 

Bactericides are substances that destroy bacteria, and they can be used in various ways. They may be incorporated into the soluble-oil concentrate, either at concentrations suitable to protect the oil in storage, or at levels sufficient to provide a persistent bactericidal effect on the emulsion in service. The cost of providing sufficient bactericide to cover the use of the soluble oil at a high dilution might prove prohibitive. Continued use of the same bactericide may produce resistant strains of bacteria. 

Research on natural fungicides and bactericides has become of major worldwide importance. The U. S. antibiotics industry, based entirely on this field of research, now produces over 1000 tons of these substances annually, valued at more than 250,000,000. The names are becoming common words—streptomycin, penicillin, bacitracin, Terramycin. 

Presence of interfering substances 4.2 Tests for bactericidal activity... 

Disinfectant. This term implies a substance with bactericidal action. Clearly, if an environment is to be made free fiom the ability to reinfect, its bacterial population must be destroyed. A detailed description of the meaning of the terms disinfectant and disinfection is provided in Chapter 10. 

The reason for this varied behaviour is not difficult to find. A population of bacteria does not possess the uniformity of properties inherent in pure chemical substances. This fact, together with the varied manner in which bactericides exert their effect and the complex nature of the bacterial cell, should provide adequate and satisfying reasons why the precise theories of reaction kinetics should have failed to explain the disinfeclion process. 

It does have a number of draw backs. It has poor thermal stability (a property common to most formaldehyde release biocides) and, in some instances, may cause blackening of metalworking fluid concentrates if heated above 50°C for a period of time. Recently, this active ingredient was placed on Annex 1 of the Dangerous Substances Directive having been identified as a potential skin sensitiser. This means that formulations containing efficacious levels of this class of triazine in them would have to be labelled with R43 - may cause sensitisation by skin contact. This is unacceptable to many UK customers. As this material is only bactericidal, it needs to be co-formulated with a fungicide to provide complete protection for a product. 

However, many other active substances produce an equal effect at much lower concentrations. The effect of kojic acid at inhibitory levels is bacteriostatic, not bactericidal. 

The effectiveness of bacteriocins is often a function of environmental factors such as pH, temperature, food composition, structure, and food microflora (De Vuyst and Leroy 2007). A novel bacteriocin-like substance produced by Bacillus licheniformis P40 inhibits the activity of the soft rot bacterium Envinia carotovora. This compound caused a bactericidal effect on the pathogen cells at a 30 p.g/mL concentration (Cladera-Olivera and others 2006). 

The formation of antibodies is only one mechanism by which an animal may protect itself from substances or microorganisms that are potentially harmful. A mechanical protection against infection is provided by the presence of an intact skin surface and membranes together with the secretion of mucus from many internal membrane surfaces. The acids secreted by the stomach and skin have a bactericidal effect as does the presence in many body fluids of certain enzymes, particularly lysozyme. 

Significant parameters to be considered in designing a treatment and disposal facility for pharmaceutical wastewater are given in Table 12. Biochemical oxygen demand measurements of the waste have been reported to increase greatly with dilution, indicating the presence of toxic or inhibitory substances in some pharmaceutical effluents. The toxicity impact upon various biological treatments by various antibiotics, bactericidal-type compounds, and other pharmaceuticals has been described in the literature [21-24]. 

An extensive database has demonstrated that many chemicals that are positive in this test also exhibit mutagenic activity in other tests. There are, however, examples of mutagenic substances, which are not detected by this test reasons for these shortcomings can be ascribed to the specific nature of the endpoint detected, differences in metabolic activation, or differences in bioavailability. On the other hand, factors which enhance the sensitivity of the bacterial reverse mutation test can lead to an overestimation of mutagenic activity. The bacterial reverse mutation test may not be appropriate for the evaluation of certain classes of chemicals for example, highly bactericidal compounds (e.g., certain antibiotics) and those which are thought (or known) to interfere specifically with the mammalian cell replication system (e.g., some topoisomerase inhibitors and some nucleoside analogues). In such cases, mammalian mutation tests may be more appropriate. 

Regardless of the pathways of induced resistance, the end result is identical - a plant with stimulated resistance to plant pathogens. Effective use of induced resistance promoters in I PM systems will likely dramatically reduce the use of conventional chemical fungicides and bactericides in commercial agriculture. It is likely that there are many nontoxic natural substances and microbial species awaiting discovery as induced resistance promoters. 

Studies have shown that many phenolic substances of grapes and wine may possess some antibacterial properties (146, 147, 148). For an extensive review and discussion pertaining to the bactericidal effect of grape and wine phenolics, see Ref. 122. 

Ultraviolet light - A form of energy occupying a position in the spectrum of sunlight beyond the violet, and having wavelengths of less than four micrometers which is the limit of visible light. UV (ultraviolet) rays are very active chemically, exhibit bactericidal action, and cause many substances to fluoresce. UV rays accelerate deterioration of rubber parts exposed to them and can initiate polymerization. 

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