For isolation and differentiation of UTI pathogens
CHROMOGENIC CLED AGAR BASE is used for isolation and presumptive identification of pathogens associated with urinary tract infection. The medium consists of peptone, special, as a source for nitrogen, carbon and vitamins required for organism growth. L-cystine is added as a growth supplement for cystine-dependent coliforms. Agar acts as a solidifying agent. The chromogenic substrates are cleaved by enzymes produced by Enterococcus sp., E. coli and coliforms (1-7). Lack of electrolytes prevents the swarming of Proteus species (8). Enterococci cleave one chromogen by β-glucosidase activity and give blue colonies. The enzyme β-galactosidase, produced by E. coli, cleaves other chromogen, resulting in development of pink colonies. Cleavage of both the chromogens by coliforms, produce purple colour colonies.