INTENDED USE
- BacterChrom™ UTI Agar is a chromogenic medium for the presumptive identification and differentiation of all the main micro-organisms that cause urinary tract infections (UTIs).
- The packaging with semi-permeable Cellophane film helps balance the humidity of the environment during storage.
PRINCIPLES
- BacterChrom™ UTI Agar contains two specific chromogenic substrates which are cleaved by enzymes produced by Enterococcus spp., Escherichia coli and coliforms. In addition, it contains phenylalanine and tryptophan, which provide an indication of tryptophan deaminase activity, indicating the presence of Proteus spp., Morganella spp. and Providencia spp. It is based on electrolyte deficient CLED Medium which provides a valuable non-inhibitory diagnostic agar for plate culture of other urinary organisms, whilst preventing the swarming of Proteus spp.
- One chromogen, X-Gluc, is targeted towards β-glucosidase, and allows the specific detection of enterococci through the formation of blue colonies. The other chromogen, Red-Gal, is cleaved by the enzyme β-galactosidase which is produced by Escherichia coli, resulting in pink colonies. Any uncertainty in identification may be resolved by removing suspect Escherichia coli colonies from the plate and performing an indole test using DMACA reagent. Cleavage of both chromogens occurs in the presence of coliforms, resulting in purple colonies.
- The medium also contains tryptophan which acts as an indicator of tryptophan deaminase activity, resulting in colonies of Proteus, Morganella and Providencia spp. appearing brown.