Bacterial inhibition assay

The Guthrie test is a bacterial inhibition assay for the measurement of phenylalanine. 

The use of a biomarker for detecting metabolic disease began nearly 50 years ago when Robert Guthrie developed a bacterial inhibition assay to screen for... 

NBS and the use of dried blood spot (DBS) began almost 50 years ago, when, in the early 1960s, Dr. Robert Guthrie developed a bacterial inhibition assay [1] for the measurement of phenylalanine (Phe). This biological assay utilized cultured bacteria that could only grow in the presence of Phe. This analysis was sufficiently sensitive to measure elevated concentrations of Phe from the DBS of newborns in the first 2-3 days of life. Although a somewhat imprecise assay, it was sufficiently accurate to reliably detect PKU, an inherited disorder of Phe metabolism. Untreated PKU results in profound mental retardation and possible institutionalization. Early and continued treatment by dietary intervention throughout life prevents mental retardation and substantially improves the health of affected individuals. 

Besides physicochemical methods, the use of microbiological growth-inhibition assays to test meat and milk for the presence of antibiotics residues is popular over a long period of time. These tests use antibiotic-sensitive bacterial reporter strains, such as Bacillus subtilis and Bacillus stearothermophilus var. calidolactis. These bacteria are inoculated under optimal conditions with and without sample. After culturing, results are read from visible inhibition zones or from the color change of the bacterial suspension in agar gels [6]. 

Explosivity Acute inhalation toxicity Bacterial respiration inhibition assay... 

Bacterial luminescence inhibition assay on Vibrio fischeri (formerly Photobacterium phosphoreum). 

Bacterial or enzymatic toxicity tests are used to assay the activity of organic compounds including solvents. A survey of environmental bacterial or enzymatic test systems is given by Bitton and Koopman. The principles of these test systems are based on bacterial properties (growth, viability, bioluminescence, etc.) or enzymatic activities and biosynthesis. The toxicity of several solvents were tested in bacterial or enzymatic systems, e.g., pure solvents such as phenol in growth inhibition assays (Aeromonas sp.), solvents in complex compounds such as oil derivates, solvents in environmental samples such as sediments or solvents used in the test systems.The efficiency of several test systems, e.g., Microtox tests or ATP assays, vary, e.g., looking at the effects of solvents. ... 

From a purely clinical or analytical chemistry perspective, the most unique aspect of NBS is the DBS. This special purpose filter paper was originally developed by Dr. Robert Guthrie to collect blood from the heel of an infant. It was developed as part of a bacterial inhibition screening assay for PKU [15], The DBS is also known as the Guthrie card or the PKU card. It is prepared from... 

NBS is sharing with LC-MS/MS the same sample collection (filter paper collection and handling is now referred as dried blood spot (DBS)) and sometimes this creates some confusion in the terminology. For example, Guthrie card was intended to be the filter paper where blood is collected and today, with the adoption of LC-MS/MS, this definition is still used, even if LC-MS/MS has nothing to do with the Guthrie test (bacterial growth inhibition assay). 

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