Additives antimicrobial agents

The only way for microbes to enter a healthy plant is via the stomata or at sites of injury, inflicted by herbivory, wind, or other accidents. At the site of wounding, plants often accumulate suberin, lignin, callose, gums, or other resinous substances which close off the respective areas (4.17). In addition, antimicrobial agents are produced such as lysozyme and chitinase, lytic enzymes stored in the vacuole which can degrade bacterial and fungal cell walls, protease inhibitors which can inhibit microbial proteases, or secondary metabolites with antimicrobial activity. 

Initial Treatment Intravenous ciprofloxacin 10 mg/kg/dose every 12 hours (maximum 400 mg/dose) or 15 mg/kg/dose every 12 hours orally (maximum 500 mg/dose) (Centers for Disease Control and Prevention, 2001), OR intravenous doxycycline 2.2 mg/kg/dose every 12 hours or orally (maximum 100 mg/dose) (Centers for Disease Control and Prevention, 2001), PLUS one or two additional antimicrobial agents (Centers for Disease Control and Prevention, 2001). 

Chemical suppHers include basic manufacturers of active ingredients, formulators, and distribution or service industries. The relative importance of each depends greatly upon the industry being suppHed. In many instances, the vendor may supply a number of performance chemicals (eg, corrosion control agents or stabilizers) in addition to the antimicrobial agent. 

Resistance to antimicrobial agents is of concern as it is well known that bacterial resistance to antibiotics can develop. Many bacteria already derive some nonspecific resistance to biocides through morphological features such as thek cell wall. Bacterial populations present as part of a biofilm have achieved additional resistance owkig to the more complex and thicker nature of the biofilm. A system contaminated with a biofilm population can requke several orders of magnitude more chlorine to achieve control than unassociated bacteria of the same species. A second type of resistance is attributed to chemical deactivation of the biocide. This deactivation resistance to the strong oxidising biocides probably will not occur (27). 

Miscellaneous, New, and Developmental Antimicrobial Agents. Table 11 shows some of the antimicrobials that do not neady fit into the principal families. Acrolein (qv) is a unique chemical used for secondary oil recovery (43). Biobor has become the antimicrobial addition of choice for aviation fuels (44). Cbloropbtbalonil (tetrachloroisophthalnitrile [1897-45-6]) is a significant agricultural fungicide, in addition to being one of the most important latex paint film preservatives (producer, ISK). 

Antimicrobial agents are used where there is a need to inhibit bacterial and fungal growth. The additives can consist of copper, germanium, zinc and zinc compounds, metal oxides or sulfides, metal zeofltes, as well as silver and copper oxide-coated inorganic core particles (154—159) (see Industrial ANTIMICROBIAL AGENTS). 

An antimicrobial agent that reduces dental plaque and can be deUvered effectively from toothpaste is a combination of Triclosan [3380-34-5] (0.2% in the toothpaste) and zinc citrate (0.5%) (7). This agent influenced plaque accumulation and reduced the incidence of gingival bleeding in clinical tests. Additional dentifrices for improved gingival health are in the offing. 

Dried organic deposits m inhibit penetration of the chemical agent. Where possible, objects to be disinfected should be thoroughly cleaned. The presence of ions in water can also affect activity of antimicrobial agents, thus water for testing biocidal activity can be made artifieially hard by addition of ions. 

Very occasionally a combination of antimicrobial agents exhibits synergy. Synergy is measured against a single microorganism and is exhibited when a combination of two compounds exerts a greater inhibitory effect than could be expected from a simple additive effect of the two compounds in the mixture. 

Bisulfite Adduct. A bisulfite addition complex of an aldehyde or dialdehyde has been proposed for use as an antimicrobial agent [1858,1859]. The complex is less toxic than free glutaraldehyde. In oil wells, its digestion by the sulfate-reducing bacteria releases the free dialdehyde that controls the bacteria. In these ways, a more economic and environmentally safer use of antimicrobial additives is likely. 

Nebulizer formulation conforms to sterile product preparation, which means that drug stability in solution in the presence of additives must be evaluated. Historically, it was sufficient to use antimicrobial agents in the formulation, notably benzalkonium chloride. Adding antimicrobials is not now considered an acceptable approach to the formulation of nebulizer solutions. The solubility of the drug is important since it may impact upon the performance of the solution in a selected nebulizer. Additives may form complexes with the drug. 

Antimicrobial additives can be used in polymeric materials to prevent or reduce the growth of bacteria and other organisms. A common antimicrobial agent is 2,4,4 -trichloro-2 -hydroxydiphenyl ether also known as triclosan. Its presence can be detected using combined GC/MS (Figures 8 and 9). 

Jensen, S.E., Paradkar, A.S., Mosher, R.H. et al. (2004) Five additional genes are involved in clavulanic acid biosynthesis in Streptomyces clavuligerus. Antimicrobial Agents and Chemotherapy, 48, 192-202. 

Although the mechanical periodontal treatment alone is adequate to ameliorate or resolve the clinical condition in most cases, adjunctive antimicrobial agents, delivered either systemically or locally, can enhance the effect of therapy. In this connection, two recent meta-analyses [60, 61] have shown that systemic antimicrobials in conjunction with SRP can offer an additional benefit over SPR alone in the treatment of periodontitis both in terms of change in the clinical attachment level and probing pocket depth. When examining the effect of individual antibiotics, it was found that there were statistically significant improvements in clinical attachment level with tetracy-... 

Antimicrobial acrylic fibers, 11 215-219 Antimicrobial agents, 12 31. See also Antimicrobial compounds in continuous-filament yarns, 19 758 as preservatives, 12 57-59 silylating agents and, 22 700 as soap bar additives, 22 746 sulfonamides as, 23 494 Antimicrobial compounds, microbiological methods for determining, 20 132 Antimicrobial nanoemulsion technology, 3 630-631... 

---