Performance tests antimicrobials

Let us perform the computation using the data in Example 2.1 to demonstrate this procedure. The researcher s question is how long an exposure to the test antimicrobial product is required to achieve a 2 logio reduction from the baseline ... 

Many antimicrobial efficacy evaluations of topical antimicrobial products involve measurements of microbial population reductions at a specific time point after exposure to the product. To determine this accurately, the antimicrobial action of the product must be stopped at the time specified for sample, and it is for this action that neutralizer systems are employed. The validity of the neutralizer system must be established prior to performing the antimicrobial efficacy test. This concern for neutralizer validity has long been known, and a number of methods have been proposed for validating neutralizer systems [1-5]. Each of the methods focuses on two major concerns (1) the neutralizer system must demonstrably neutralize the antimicrobial properties of the product, and (2) the neutralizer system must be proven nontoxic to the test microorganism(s). Few validation methods apply techniques of statistical analysis to the determination of their validity... 

All specific conditions of the antimicrobial efficacy test must be duplicated in the validation. All equipment, types of media, incubators, and temperatures should be identical to those applied in the antimicrobial efficacy test. Even the technician who will be performing the antimicrobial efficacy test should also perform the validation of the neutralization system. 

Evaluation of the Performance of Antimicrobial in/on Polymeric Solids Against Staining by Streptoverticillium reticulum , E-1428, American Society For Testing Materials, 1996. 

There are many ways textiles can be contaminated, due to their uses and/or through their environment. Potential threats include germs and fungi. However, there are a number of antimicrobial and antifungal medical textiles available nowadays. Antimicrobial performance testing using appropriate standard methods, test results, validation, and documentation is important. These tests are described in the foUowing section. 

Microbiological aspects will need to be discussed, but the amount of information will depend on the type of product. For nonsterile products there will need to be a description of the microbiological attributes of the product and, if appropriate, a rationale for not performing microbial limit tests. For preserved products the selection of the antimicrobial preservatives will need to be discussed and the effectiveness of the selected system demonstrated. For sterile products there will need to be appropriate process validation data and information on the integrity of the container-closure system. 

Fahr, A. M. Eigner, U. Armbrust, M. Caganic, A. Dettori, G. Chezzi, C. Bertoncini, L. Benecchi, M. Menozzi, M. G. Two-center collaborative evaluation of the performance of the BD Phoenix automated microbiology system for identification and antimicrobial susceptibility testing of Enterococcus spp. and Staphylococcus spp. J. Clin. Microbiol. 2003, 41,1135-1142. 

In this review, we use the terms, biologically active or bioactive for any substance which elicits some biological response in another organism. Early investigations on bioactive marine isonitriles focussed on compounds that might serve as chemical defense agents (cf. Sect. 5.1). As chemists began to resolve mixtures into individual components, other tests related to antiviral, antimicrobial, or antiparasitic activity, were reported. Often, bioassays were performed... 

Clinical CLSI (2007) Performance standards for antimicrobial susceptibility testing MIOO-S17. Wayne, PA, 27... 

FSIS has developed a series of overnight, inexpensive, easy to perform swab bioassay tests for screening tissues, body fluids, or feed extracts for antibiotic residues. The swab tests are used on the farm, in the slaughter plant, or in the laboratory for their designated purpose. Swab test results indicate whether antimicrobial activity is present in the sample at or above allowable levels or absent. Further testing with more sophisticated tests is required to identify and quantify the antibiotics producing the antimicrobial activity. These are usually done in a laboratory as required. 

This study should be independently repeated a sufficient number of times to establish an upper limit of cfu for the particular plating conditions. There is a lower limit at which the ability of the antimicrobial effectiveness test to recover microorganisms becomes unreasonable. If the first plating is performed with 1 ml of 10 dilution, cfu in the range of 1 to 10 per ml would not be seen. On this dilution plating, only the lower number of cfu may be reduced to three, allowing as few as 30 cfu/ml survivors to be reported. 

It is recommended that a stasis test be performed when antibiotics, inherently antimicrobial, or preserved products are tested. The stasis test can identify problems with dehydrated commercial media that were not apparent when a validation test was conducted at the beginning of the incubation period. It is necessary to demonstrate that growth-promoting qualities of media are retained and that preservative inhibitors remain stable for the full test period. 

In 1993, the incidence of antimicrobials in car tanker milk and the suitability of different tests for the detection of antimicrobials on the MRL level has been examined in Northern Germany using an integrated detection system (14). This system comprised microbial inhibitor tests for screening, immunochemical tests for preliminary confirmation, and high-performance liquid chromatography (HPLC) for final confirmation either in a parallel or a subsequent fashion in case of positive or questionable screening results. 

In Australia, the general antimicrobial screen is performed on kidney and is able to detect -lactam, aminoglycoside, tetracycline, and macrolide antimicrobials and to identify the class of antimicrobial compound present. Where the screen test identifies a class of compounds, confirmation and quantitation are done by the specific HPLC or gas chromatographic (GC) method appropriate for the class of antimicrobial. 

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