Rapid Detection and Monitoring of Flavobacterium psychrophilum in Water by Using a Handheld, Field‐Portable Quantitative PCR System.

Advances in technology are making it easier for rapid field detection of microbes in aquaculture. Specifically, real‐time quantitative PCR (qPCR) analysis, which has traditionally been confined to laboratory‐based protocols, is now available in a handheld, field‐portable system. The feasibility of using the Biomeme handheld qPCR system for rapid (<50 min) on‐site detection and monitoring of Flavobacterium psychrophilum from filtered water samples was evaluated. Paired water samples were collected over a 23‐d period from microcosm tanks that housed fish injected with known levels of F. psychrophilum. Water samples were filtered through 0.45‐μm nitrocellulose filters and were analyzed with both the Biomeme qPCR platform and a traditional bench qPCR protocol. The two methods identified similar fluctuations in F. psychrophilum DNA throughout the study. Standard curves relating quantification cycles to the number of F. psychrophilum colony‐forming units (CFU) were constructed and analyzed; results indicated that CFU increased rapidly between days 6 and 8 of the trial and then progressively decreased during the remaining 15 d. Average calculated log10(CFU/mL) values were significantly correlated between the two platforms. Rapid, field‐based qPCR can be incorporated into daily water quality monitoring protocols to help detect and monitor microbes in aquaculture systems. [ABSTRACT FROM AUTHOR]