Bacteriostatic and bactericidal properties

ANTIBACTERIAL PROPERTIES in vitro Bacteriostatic and Bactericidal Properties 

Nitrofurazone was one of the first furan derivatives to be useful as a chemotherapeutic agent. The semicarbazones of 4-nitrobenzaldehyde, 5-nitro-thiophenaldehyde, and of 5-nitropyrrolaldehyde were less effective and not suitable for clinical use . Antibacterial activity is conferred on non-nitrated furans if a nitro group is introduced in the 5-position of the furan ring. Later this was recognized to be an indispensable prerequisite. Microbiologists of the Norwich Pharmacal Co. have summarized the activity against representative species of bacteria (Table 6.22). The six tested nitrofurans, however. 

Compound E, coli Staph. aureus Sal. typosa Pr. vulgaris Ps. aeruginosa Strept. pyogenes Aero. aerogenes 

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In topical cosmetic and toiletry applications, xylitol is used primarily for its humectant and emollient properties, although it has also been reported to enhance product stability through a combination of potentiation of preservatives and its own bacteriostatic and bactericidal properties. 

Soaps and other detergents have valuable antiseptic properties. The cationic surfactants are especially valuable for their bacteriostatic and bactericidal properties. An example is cetylpyridinium chloride, which contains the hexadecylpyridinium cation ... 

ANTIBACTERIAL PROPERTIES in vitW Bacteriostatic and Bactericidal Properties... 

Molnar et al. [69] studied antibacterial effect and plasmid curing property of several phenothaizines and tried to correlate these functions with respect to their chemical structure. They observed that diethazine, amitriptyline, and impipramine showed bacteriostatic and bactericidal effect on different bacteria. Chlorpromazine sulfoxide and fluorescein were ineffective even at 1000 Ag/ml. The antibacterial compounds deleted at 40-70% frequency the F lac-t- plasmid of Escherichia coli K12 Le-140. Similar plasmid elimination potentiality by phenothiazines was reported by the same group of authors in 1982 [72],... 

Some ingredients of eye medications may increase the permeability of the cornea. Surface-active agents are knovm to interact with membranes to increase the permeability benzalkonium chloride has surfactant properties and may well have some effect on comeal permeability, although its primary purpose is as a bacteriostat and bactericide. Chlorhexidine acetate and cetrimide, both of which are surface-active, are also used. 

Among the study suspensions, there are solutions which have bactericidal, bacteriostatic, and fungistatic properties. They may be used in areas where listed properties are desired and expected, particularly in medicine and cosmetology, where they may be a very effective alternative to previously used antibiotics, chemotherapeutics, and preservatives. Demonstrated properties predispose them to be used in the areas of household chemicals as well. 

Stevia Stevia rebaudiana) Uses Natural sweetener, hypoglycemic and hypotensive properties Actions Multiple chemical components sweetness d/t glycoside, stevioside hypotensive effect may be d/t diuretic action or vasodilation action Available forms Liq extract, powder, caps Notes/SE HA, dizziness, bloating Interactions T Hypotensive effects W/ antihypertensives esp CCB, diuretics EMS Monitor BP does not encourage dental caries may -1-glucose St. John s Wort (Hypericum perforatum) Uses Mild-mod depression, anxiety, anti-inflammatory, immune stimulant/anti-HIV/antiviral, gastritis, insomnia, vitiligo Action MAOI in vitro, not in vivo bacteriostatic bactericidal, T capillary blood flow, uterotonic activity in animals Efficacy Variable benefit w/ mild-mod depression in several trials, but not always seen in clinical practice Available forms Teas, tabs, caps, tine, oil ext for topical use Dose 2-4 g of herb or 0.2-1 mg of total hypericin (standardized extract) daily Notes/SE Photosensitivity (use sunscreen) rash, dizziness, dry mouth, GI distress Interactions Enhance MAOI activity, EtOH, narcotics, sympathomimetics EMS T Risk of photosensitivity Rxns t effects of opioids and sympathomimetics... 

The antimicrobial properties of silver and its salts have been discussed in various books [14, 16-18] and particular reference must be made to Grier s review in 1983 [15]. Ag usually used in the form of silver nitrate, is bacteriostatic or bactericidal [19-29], antifungal [30-32], protozoicidal [33] and lethal to herpes simplex virus [34]. However, bacterial spores [19], cysts of Entamoeba histolytica [19] and mycobacteria [35] are not killed by Ag. Brown and Anderson [20] observed a non-linear order of death in Pseudomonas aeruginosa exposed to Ag, whereas Ricketts et al. [22] reported a rapid bactericidal action of Ag in water, but not in broth, at concentrations of silver nitrate of 0.5 and 1 pg/ml (2.9 x 10 and 5.8 x 10 M, respectively) with inactivation at concentrations above 1 p.g/ml being too fast for measurement. 

Antimicrobial activity benzyl alcohol is bacteriostatic and is used as an antimicrobial preservative against Gram-positive bacteria, molds, fungi, and yeasts, although it possesses only modest bactericidal properties. Optimum activity occurs at pH below 5 little activity is shown above pH 8. Antimicrobial activity is reduced in the presence of nonionic surfactants, such as polysorbate 80. However, the reduction in activity is less than is the case with either hydroxybenzo-ate esters or quaternary ammonium compounds. The activity of benzyl alcohol may also be reduced by incompatibilities with some packaging materials, particularly polyethylene see Section 12. 

Abbreviations of prominent use properties of the various classes of commercial surfactants are shown in Table 1. Antimicrobial activity includes germicidal, bactericidal, and bacteriostatic effects emolliency describes lubrication or a soft feel imparted to skin by surfactants a hair conditioner is a substantive surfactant appHed from aqueous solution to impart a lubricating or antistatic effect and opacifters are used to thicken hand-dishwashing products and cosmetic preparations to convey an appearance of high concentration and to retard solvent drainage from foam. 

Certain strains of bacteria are resistant to the lytic properties of penicillins but remain. su.sccptible to their growth-inhibiting effects. Thus, the action of the antibiotic has been converted from bactericidal to bacteriostatic. This mechanism of resistance is termed tolerance and apparently results from impaired autolysin activity in the bacterium. 

The synthesis and preparation of macromolecules with bactericidal or bacteriostatic properties are reviewed. The synthesis of polymers with antibacterial groups and the irmnobilisation of antibacterial reagents, such as iodine, qrratemary ammonitrm salts or antibiotics, are presented. Particular attention is paid to bacterium-adsorbing polymers, which can remove bacterial cells from aqueous media. Filter membranes coated with bacteria-adsorbing macromolectrles are also discussed. 103 refs. 

Due to their excellent bactericidal and bacteriostatic properties and their general lack of serious side-effects (ref. 16) the B-lactam antibiotics still belong to the most favoured antibacterial drugs that are avaible. The research activities in the field of 6-lactam antibiotics including the chemical synthesis of 6-lactam antibiotics and related compounds, have increased up to now (ref. 16). 

A composition of a selected chitosan form and its derivative, such as microcrystalline chitosan or a gel from chitosan salt with poly-Af-vinylopyrolidone, was used to manufacture new dressings for veterinary use to protect injured animal skin successfully (Wisniewska-Wrona et al. 2002). Strong bacteriostatic/bactericidal activity and improved mechanical properties were reported for these dressings. 

Even though conventional osteopathy of the early 1900s did not incorporate the use of some other interventions, such as pharmacological ones, today maity contemporary osteopathic physicians do use pharmacological interventions. This can be seen not in contrast or in abandonment of the principles, but rather in further analysis, as a further pUca-tion of these principles. For example, medications such as antibiotics have bactericidal and bacteriostatic properties. In acting in this fashion, they may maintain or reduce the absolute load of bacteria to the point at which the individual s immimological mechanisms can recover and produce adequate defense... 

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