COMPARATIVE PERFORMANCE OF COLISURE

Colisure presence absence medium was compared with standard reference methods for detecting low numbers of total coliform bacteria and E. co li in drinking water when the bacteria were subjected to chlorine stre ss. When Colisure was compared with established reference methods to d etect total coliforms in dilute, disinfected samples, Colisure yielded more positive results after 24, 28, and 48 h than lauryl tryptose bro th (LTB) confirmed in bile green lactose broth after 48 h. Colisure al so detected higher levels of chlorine-injured E. coli than LTB confirm ed in EC medium with 4-methylumbelliferyl B-D-glucuronide (EC/MUG). Th e sensitivity and specificity of Colisure were also evaluated and were determined to be between 96 and 100 percent on nonchlorinated samples when positive and negative tests were verified.