Culture and sensitivity study

Preexisting antimicrobial resistance is an increasing cause of treatment failure and is estimated to account for up to 70% of all treatment failures. Geography is the most important factor in HP resistance. Metronidazole-resistant strains are more prevalent in Asia (85%) than North America (30%).15 Primary resistance to amoxicillin and tetracycline remains low in both the United States and Europe. Clarithromycin resistance rates are estimated to be approximately 10% in the United States. Another confounding factor when evaluating potential antibiotic resistance is that culture and sensitivity studies are not routinely performed with HP infection. 

The selection of a particular antibiotic depends upon the diagnosis and, when appropriate, in vitro culture and sensitivity studies of clinical samples. The pathogens isolated from most infected dermatoses are group A B-hemolytic streptococci, Staphylococcus aureus, or both. The pathogens present in surgical wounds will be those resident in the environment. 

Because of the antibiotic resistance of many subspecies of Staphylococcus, it is recommended that culture and sensitivity studies of any purulent material be undertaken to maximize the chance for successful treatment of canaliculitis. Antibiosis should be directed at the specific causative organism isolated. Systemic penicillin is usually recommended in treating actinomyces, in addition to topical penicillin. 

Identifying the pathogen using a culture and sensitivity study before prescribing an antimicrobial. 

Resistance to the antibiotic is another problem that can occur. Culture and sensitivity studies should be performed on all infections in order to determine which antibiotics will work for the microorganism that is causing the infection. The test can be performed on blood or wound drainage to identify the bacteria and help identify which antibiotic will be effective. 

Deep tissue specimens obtained during surgical irrigation and debridement should be sent for Gram stain, culture, and sensitivity.3 Imaging Studies... 

Urine appearance and color Urine culture and sensitivity Urine flow studies Urine odor Urine pH... 

The purpose of this chapter is to review relevant work in the area, including an evaluation of methods employed for shear sensitivity studies, comparison of bases for data analysis and an outline of current knowledge of the interface between the hydrodynamic environment and the plant cells themselves. Coverage is limited to cell suspension cultures and does not extend to other tissue or organ systems. 

Portal infusion of NAPQl into rats and mice produces necrosis in the periportal region (unpublished results quoted by Nelson, 1990). Studies of cultured hepatocytes sensitized to paracetamol by the induction of cytochrome P450 by 3-methylcholanthrene have shown that paracetamol-induced cytotoxicity was dependent on ROM generation (Gerson et al., 1985). 

This study showed that hydroquinone was glycosated by the barley to form arbutln and was therefore effectively detoxified. If the equilibrium of the detoxification mechanism of a plant is sensitive to an oversupply of the toxic and detoxified compound, an oversupply of a detoxified compound could produce equilibrium amounts of the toxic compound. Cell culture bloassay (Table II) showed that hydroquinone is not significantly detoxified in vivo in leafy spurge, indicating the succeptiblllty of the plant to low levels of hydroquinone which could originate from an oversupply of arbutln. The observed toxicity of -benzoquinone in the cell cultures and seed bloassays also indicates that oxidation processes affecting hydroquinone will not detoxify the compound vivo. 

Lee and Webber studied the toxicity of CR in HeLa cells In culture. In vivo experiments had disclosed only negligible effects on tissue cells, except for the sensory elements of the nervous sys-tern. Lee and Webber,believed that suitable cell cultures might react to compounds of moderate toxicity, thus constituting sensitive tests that would indicate which cellular elements were attacked by compounds like CR. 

Selenium, at 5 X10 M, stimulated the growth of primary cell cultures of normal mammary cells and C4 preneoplastic cells and the established cell line YN-4 but not the growth of D2 preneoplastic cells and tumors in primary cell cultures and of established cell lines CL-S1 and Waz-2t. The differential response of cells from preneoplastic outgrowth lines C4 and D2 and of D2 primary tumors in vitro correlated with the sensitivity of these same cell populations to selenium mediated inhibition of growth and tumorigenesis in vivo. Selenium had little effect on 3 or 4 preneoplastic mammary outgrowth lines. Recent studies by Poirier et al., (70) have shown that... 

The monolayer culture technique is frequently employed in cytotoxicity tests with cancer lines and in studies of chemical sensitivity of different tumor types. This method offers high flexibility with respect to drug exposure and recuperation conditions, as well as to the quantification of any effect. Among all methods, cell culture in a monolayer requires a lower cell number and allows the evaluation of multiple drugs in large concentration ranges. 

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