Microbial contamination evaluation

Irregular and flat surfaces Firefly luciferin/luciferase HRP/H202/luminol AP/dioxetanes Firefly luciferin/luciferase Bacterial luciferin/luciferase Detection of ATP as an indicator of microbial contamination Evaluation of the spatial distribution of immobilized biomolecules... 

In addition to the chemicals evaluated in this volume, some synthetic and soluble fluids may contain chlorinated paraffins, formaldehyde (see lARC, 1995a)-releasing biocides, microbial contaminants and metal and metal alloy contaminants (National Institute for Occupational Safety and Health, 1998). 

Evaluating the integrity of the container can be done in several ways. Two of the most common tests are dye penetration and microbial ingress. Container closure systems stored in a dye solution and exposed to pressure and vacuum cycles are examined for dye leakage into the container. The microbial ingress is similar in fashion but determines the microbial contamination of the contents when soaked in a media contaminated with bacteria. Other quantitative tests that can be run are vacuum/pressure decay, helium mass spectrometry, and gas detection. 

The first set of requirements that closures for lyophilized product containers must meet are those described for stoppers used in containers for parenteral drugs. They must serve as a barrier to microbial contamination, be compatible with the formulated drug product, and not leach out toxic materials. They must be tested in the prescribed manner for seal integrity and product capability. The reader is referred to sections in the United States, European, and Japanese pharmacopoeias for appropriate test methods for evaluating extractables. 

Recall that observational data are obtained by nonexperimental methods. There are times a researcher may collect data (x and y) within the environment to perform a regression evaluation. For example, a quality assurance person may suspect that a relationship exists between warm weather (winter to spring to summer) and microbial contamination levels in a laboratory. The microbial counts (y) are then compared with the months, x(l -6), to determine whether this theory holds (Figure 2.6). 

M Ritter, M Erench, H Eitzen. Evaluation of microbial contamination of surgical gloves during actual use. Clin Orthop Res 117 303-306, 1976. 

To evaluate the effectiveness of handwashing compared to gloving, a two-phase study was designed. The first phase evaluated the ability of hand-contaminant bacteria to penetrate compromised vinyl glove barriers. The second phase evaluated the microbial contamination level picked up on the hands from handling contaminated hamburger. 

Therefore, it is necessary to develop strategies to distinguish and quantify fungal infection, and possibly toxins production, at early stages. One of the most promising techniques is the analysis of volatile compounds which are released by the coffee in the headspace gas surrounding the samples. For this reason, the ability of the EOS to early detect microbial contamination of Arabica green coffee was evaluated [36]. 

The performance of immobilized reactors in continuous operation can be negatively influenced by several incidents such as enzyme/cell leakage, thermal denaturation of the enzyme, disintegration of the support, or microbial contamination. These parameters can be evaluated experimentally, and approaches can thus be designed in order to counter their negative effect on bioreactor performance. 

The presence or absence of mycelium or pseudomycelium is demonstrated by growing the fungi as a slide culture (Section 12.6). However, microscopic evaluation requires removal of the slide culture from the Petri plate, thereby increasing the potential for microbial contamination. To minimize contamination, the number of examinations should be limited such that results can be obtained after only one to two observations. 

We have become dependent on the use of petroleum fuels to provide heat, power equipment and provide transportation. This has led to a concern that there could be an interruption in a secure, adequate supply of crude oil needed to manufacture these fuels. Continued reports of microbial contamination in petroleum fuels have also caused concern. Scientists have been evaluating the use of alternate sources to petroleum to prepare fuel (synthetic fuels) such as oil shale, tar sands and coal. Studies of the microbial susceptibility of Jet JP-5 and diesel fuels prepared from these alternate sources demonstrated that the synthetic fuels would not support more microbial contamination than their petroleum-derived fuel counterparts and that fuel derived from pyrolyzed coal may even have fewer problems (May and Neihof, 1982). Coal JP-5 jet fuel inhibited growth of Hormoconis resinae and Candida spp. (caused by constituents in the coal-derived fuel that have not been identified) (Neihof and May, 1984). 

A set volume of fuel is filtered through an appropriate sterile filtration unit. The filter can be evaluated for microbial contamination by directly placing it on agar media or suspending it in sterile liquid media to extract microorganisms and then plating the liquid media onto agar media (Institute of Petroleum, 1996). 

This is a rapid (detection within four hours) and sensitive method to identify microbial contaminants. However, you must have the appropriate equipment and trained personnel to run the test and interpret the test results. Immunofluorescence was evaluated by Gaylarde et al. (1998) as a method for identifying Hormoconis resinae in aviation kerosene fuel. There was little cross-reaction with other fuel fungi. The hyphae and spores of Hormoconis resinae were detected in a biofilm. 

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