Search Results

BD BBL™ CHROMagar™ 0157 is a selective medium for the isolation, differentiation and presumptive identification of Escherichia coli 0157:H7 from clinical human stool specimens.

BBL™ CHROMagar™ O157 formulation incorporates chromogenic substrates, which allow colonies of E. coli O157:H7 to produce a mauve color for presumptive identification from the primary isolation plate and differentiation from other organisms. Specially selected Difco™ peptones are incorporated to supply nutrients. The addition of potassium tellurite, cefixime and cefsulodin reduces the number of bacteria other than E. coli O157:H7 that grow on this medium. The chromogen mix consists of artificial substrates (chromogens), which release an insoluble colored compound when hydrolyzed by a specific enzyme. E. coli O157:H7 utilizes one of the chromoqenic substrates producing mauve colonies. The growth of mauve colonies is considered presumptive for E. coli 0157:H7 on BBL™ CHROMagar™ 0157. Non-E. coli O157:H7 bacteria may utilize other chromogenic substrates resulting in blue-green colored colonies or, if none of the chromogenic substrates are utilized, colonies may appear as their natural color. These visually distinct colored colonies facilitate the detection and differentiation of E. coli 0157:H7 from other organisms.

The Novamed, Ltd. DipStreak Urine Culture Device is used for the isolation and enumeration of bacteria in urine. A set of plastic prongs on the end of the device are dipped into the urine sample. The drops of urine which adhere to the prongs are then streaked across two different agar surfaces (CLED agar on one side, MacConkey agar on the other). A dilution effect takes place which allows the isolation of single colonies.

DipStreak comprises a plastic paddle with two types of agar attached back-to-back, housed in a closed transparent plastic tube. A ring with elongated prongs is attached to the end of the paddle so that there are prongs on each side of the slide. The ends of the prongs are dipped into the urine sample. Upon re-insertion into the plastic tube, the prongs are prevented from moving and the agar surfaces are inoculated with bacteria from the urine sample as the agar-coated paddle passes over the prongs. The result is a series of streaks of decreasing bacterial concentration which permits isolation of single colonies even when the original bacterial population of the sample was as high as 10' organisms per milliliter.