A fluorescence-based method coupled with Disruptor filtration for rapid detection of F + RNA phages

Abstract

F + RNA phages are commonly used as indicators of faecal contamination. This study evaluated a fluorescent method for the detection of F + RNA phages based on testing the phage-mediated release of β-galactosidase. Factors that may potentially interfere with phage detection were investigated, and the assay was optimized. Low numbers of F + RNA phages were detected by the fluorescent method coupled with a concentration step using a Disruptor filter. The fluorescent method, when used alone, detected 1 log PFU ml(-1) of F+RNA phages within 3 h, while 0.01 PFU ml(-1) was detected within 5 h when the method was combined with the concentration step. This is the first time to combine a fluorescent method with a filtration step by the use of Disruptor filter for rapid detection of low numbers of F + RNA phages, and this method can be adapted to detect other lytic phages infecting host cells that produce measurable enzyme activity. A fluorescent method coupled with Disruptor filtration was evaluated for the first time to rapidly detect low numbers of F + RNA phages. Rapid detection of F + RNA phages provides an effective way to monitor faecal contamination of environmental water and thus helps prevent contamination of fresh produce via irrigation.