The Target Microorganism

Brenn et al. [ 153] compared the efficacy of antibiotics commonly used in dental and oral clinical practice in application to the bacteria most frequently isolated in odontogenic infections (S. viridans, Peptostreptococcus spp, Prevotella intermedia, Porphyromona gingivalis and Fusobacterium nucleatum) based on pharmacokinetic and pharmacodynamic (PK/PD) analyses (effect of the human body upon the drug, reflected by the plasma concentration profile-pharmacokinetics, and the effect of the drug upon the body, as defined by the minimum inhibitory concentration, or MIC-pharmacodynamics). Antibiotics commonly used in dental practice, such as erythromycin, metronidazole or azithromycin, were found to be ineffective in apphcation in over 30% of the strains (39.1%, 50.5% and 33.2%, respectively) [154]. 

Slightly divergent results have been published by Linares and Martin-Herrero [155], who considered amoxicillin-clavulanate to be the option with the fewest resistant strains. 

To summarize, and as pointed out by Morcillo [163], a polymicrobial flora has been described in odontogenic infections, with strict anaerobes, and with a relatively limited microbial spectrum (despite the enormous variety of bacteria that transit through or colonize the oral cavity). This means that of the broad range of antibacterials available, few drugs will suffice to treat odontogenic infections despite the empirical approach to management. 

the ongoing emergence of multidrug-resistant bacteria and many diseases mainly caused by free radicals are serious global problems. Thus, new antimicrobials and novel approaches to combat these problems are urgently needed. Combination therapy is a new approach that may be helpful in treating multidrug-resistant bacteria 

The following section summarizes our approach of combining conventional free radical chemistry with innovative development of functional dental restorative material in order to have bioactive and bonding properties suitable for use in dentine and enamel, as well as the beneficial preventative and therapeutic properties. 

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Both absolute quantitation and relative quantitation of species in mixtures is of interest in some circumstances. Quantitation in a 5-minute analysis can be achieved by addition of an internal standard, ideally the target microorganism grown in special media to incorporate heavy isotopes92-95 and determination of the relative peak heights of pairs of proteins from the analyte and the standard. Isotope-labeled proteins or peptides, selected to match proteins or peptides characteristic of target microorganisms, can also serve as internal standards for isotope ratio measurement. The addition of unmatched proteins or peptides is less reliable for either ESI or MALDI measurements because of unpredictable suppression in the variable mixture. 

The mechanism of action of rifaximin depends on the inhibition of DNA-dependent RNA polymerase of the target microorganisms, leading to the suppression of initiation of chain formation in RNA synthesis. 

Despite the variability in susceptibility of microorganisms to PDT, it can be concluded that, in the majority of cases, a PS can be identified that will effectively destroy the target microorganism by PDT. 

This section is required only for anti-infective products. Because these products affect microbial, rather than clinical, physiology, reports relevant to the product s in vivo and in vitro effects on the target microorganisms are critical for establishing product effectiveness. 

Selwyn and Ellis emphasize, and I strongly concur, that pertinent questions include What and where are the target microorganisms and What are the characteristics of the available chemical agents and how do we evaluate them in vivo ... 

The efficacy of disinfectants is affected by various factors, such as the target microorganisms, the environment of the microorganisms, the contaminated object, the microbicidal ingredients, and the mode of application. Three of these five factors - the microorganisms, the environment, and the object - are given by the disinfection task. The other two factors - the microbidde, the mode of application - depend on the disinfection method itself (Spicher, 1996). 

Sulfosuccinate (anionic) is used as a vehicle for metallic ions or as an adjunct for benzyl alcohol to increase its incorporation into antiseptic cosmetic formulas. The sulfosuccinate salt changes the permeability of the microbial cell wall, allowing penetration of the active into the target microorganism. This allows the active to be incorporated in greater amounts in formulas which claim disinfectant or hygienic effects. 

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