Intracellular Microbial Urease

Abstract

THE urease reaction has been used as a diagnostic method for a number of groups of bacteria. It is particularly useful in differentiating Proteus species from enteric pathogens^1,2 and has also been used to differentiate Brucella suis from B. abortus and B. melitensis³. It also has been suggested that urease activity may serve as an indicator of pathogenic potential and of drug resistance among some groups of bacteria^4–6. The urease activity of bacteria can readily be determined by inoculating the organisms on to a number of bacteriological media^1,2. Seneca et al.^6,7 reported that urease activity was observed in cell-free extracts obtained by sonic oscillation, even in groups characterized as lacking this enzyme by sensitive culture methods. The crude extracts such as were used in those investigations may contain large amounts of compounds which readily yield alkaline products; for example, extracts from enteric bacteria have been shown to produce amines from amino-acids⁸. Therefore, in order to eliminate spurious results, the more specific method involving reaction of acetylbenzoyl with urea has been used to determine urease activity of cell-free preparations⁹.