A multicenter study of viable PCR using propidium monoazide to detect Legionella in water samples

作者：Scaturro Maria^*; Fontana Stefano; Dell'eva Italo; Helfer Fabrizia; Marchio Michele; Stefanetti Maria Vittoria; Cavallaro Mario; Miglietta Marilena; Montagna Maria Teresa; De Giglio Osvalda; Cuna Teresa; Chetti Leonarda; Sabattini Maria Antonietta Bucci; Carlotti Michela; Viggiani Mariagabriella; Stenico Alberta; Romanin Elisa; Bonanni Emma; Ottaviano Claudio; Franzin Laura; Avanzini Claudio; Demarie Valerio; Corbella Marta; Cambieri Patrizia; Marone Piero

来源：Diagnostic Microbiology and Infectious Disease, 2016, 85(3): 283-288.

DOI：10.1016/j.diagmicrobio.2016.04.009

• Legionella
• Propidium monoazide
• Quantitative PCR
• Viable PCR
• Culture

Legionella quantification in environmental samples is overestimated by qPCR. Combination with a viable dye, such as Propidium monoazide (PMA), could make qPCR (named then vPCR) very reliable. In this multicentre study 717 artificial water samples, spiked with fixed concentrations of Legionella and interfering bacterial flora, were analysed by qPCR, vPCR and culture and data were compared by statistical analysis. A heat-treatment at 55 degrees C for 10 minutes was also performed to obtain viable and not-viable bacteria. When data of vPCR were compared with those of culture and qPCR, statistical analysis showed significant differences (P < 0.001). However, although the heat-treatment caused an abatement of CFU/mL <= 1 to 1 log(10) unit, the comparison between untreated and heat-treated samples analysed by vPCR highlighted non-significant differences (P > 0.05). Overall this study provided a good experimental reproducibility of vPCR but also highlighted limits of PMA in the discriminating capability of dead and live bacteria, making vPCR not completely reliable.

• 出版日期2016-7