Portable microfluidic-based device for in situ detection of viable Legionella.

Legionella outbreaks have great sanitary, economic and social implications. Diagnostic method use to prevent and control Legionella is bacteria culture. Available detection kits are based on DNA technology, unable to discriminate between viable and non-viable bacteria. On the contrary, RNA is widely used as a viable bacteria indicator. Although molecular based techniques, as PCR and qPCR, have become essential tools in genetic analyses due to its high sensitivity and accuracy, they show drawbacks as time-consuming and expensive. Recent development of integrated microfluidic systems has allowed time, volume and analysis cost reduction. An important application of microfluididc systems is the ability to efficiently process raw samples and perform the required analytical assays “on-chip”. There is no portable system to detect viable Legionella on-site in the market. This device will avoid sample pre-treatment therefore reducing data acquisition. Moreover, rapid result gathering will allow implementing a rapid plan of action for bacteria eradication. The project aims to develop a portable microfluidic device composed of a filtration and bacteria collection system and a disposable card (containing a microfluidic chamber for nucleic acids concentration, a microfluidic chamber for RNA amplification through NASBA, and a detection system based on a NALFIA strip). An essential part of PINVIALEG is the development of a portable device where the filtration system is integrated to a microfluidic based cartridge. Thus, the whole process of Legionella detection (from sample collection to results) can be performed on site. NASBA is an isothermal process, facilitating portable equipment production. Development of a NALFIA strip able to detect NASBA products as a reading system will make the device very simple to use by non-qualified personnel. A new innovative tool will be produced to detect viable Legionella on-site, with rapid result acquisition and easy to use.