title: Detection of free-living amoebae by using multiplex quantitative PCR.
abstract: Free-living amoebae (FLA) are protozoa found worldwide in soil and aquatic environments, which are able to colonize man-made water networks. Some FLA have the potential to be pathogenic and others might harbour pathogenic bacteria. Indeed, FLA feed on bacteria, but some bacteria could resist phagocytosis and either survive in FLA or even multiply within FLA. These bacteria are collectively named amoeba resistant bacteria (ARB). The best characterized example is Legionella pneumophila, for which FLA is the main reservoir in the environment. Not only could FLA be a reservoir that protects ARB, some bacteria might become more resistant to treatment and be more virulent. Thus, it is of medical significance to quantify FLA populations in soil, water or the environment. The main limitation for the quantification of FLA is that classical culture is not efficient and reliable for many genera and 'strains'. Thus, several PCR-based quantification methods have been published for various FLA. However, thus far, no method has been published to simultaneously quantify the main FLA genera in the same PCR reaction. In this study, we developed a multiplex qPCR method to detect both Amoebozoan (i.e. Acanthamoeba, Hartmannella and Echinamoeba) and Vahlkampfiidae (i.e. Vahlkampfia and Naegleria) using 18S ribosomal RNA as the target gene. This method was shown to be specific, reliable and sensitive, could be used for the quantification of FLA and is likely to be useful to anticipate risks due to FLA or pathogenic bacteria, such as L. pneumophila.
authors.affiliation: Equipe de Microbiologie, Laboratoire de Chimie de l'Eau et de l'Environnement, UMR CNRS 6008, Université de Poitiers, 40 avenue du recteur Pineau, 86022 Poitiers, France. thomas.lecalvez@gmail.com
authors.forename: Thomas
authors.initials: T
authors.lastname: Le Calvez
authors.forename: Marie-Cécile
authors.initials: MC
authors.lastname: Trouilhé
authors.forename: Philippe
authors.initials: P
authors.lastname: Humeau
authors.forename: Marina
authors.initials: M
authors.lastname: Moletta-Denat
authors.forename: Jacques
authors.initials: J
authors.lastname: Frère
authors.forename: Yann
authors.initials: Y
authors.lastname: Héchard
mesh_terms: D056894:Amoebozoa / Q000235:genetics* / Q000302:isolation & purification; D004269:DNA, Bacterial / Q000737:chemistry; D016133:Polymerase Chain Reaction / Q000379:methods*; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D012988:Soil Microbiology
chemical_list: D004269:DNA, Bacterial; D012337:RNA, Ribosomal, 18S