Use of two presence/absence systems for the detection of E. coli and coliforms from water

The Colilert system presence/absence test and LMX broth were compared for their ability to recover E. coli and coliforms from water. Both methods gave similar recoveries for both groups of organisms. The LMX system, however, gave a significant number of false positives, largely due to the presence of Aeromonas spp. It is concluded that care must be taken in the interpretation of results obtained using some presence/absence methods where no confirmation of the identity of bacteria is performed.