Sensitivity of free-living amoeba trophozoites and cysts to water disinfectants.

Mathieu Dupuy (1) , Florence Berne (2) , Pascaline Herbelin , Marie Binet , Nelsie Berthelot (2) , Marie-Hélène Rodier (1) , Sylvie Soreau , Yann Héchard (3)

1 EBI [Poitiers] - Écologie et biologie des interactions
2 IC2MP [Poitiers] - Institut de chimie des milieux et matériaux de Poitiers [UMR 7285]
3 MDE - Microbiologie de l'Eau [Équipe du laboratoire EBI Poitiers]

: Free-living amoebae are naturally present in water. These protozoa could be pathogenic and could also shelter pathogenic bacteria. Thus, they are described as a potential hazard for health. Also, free-living amoebae have been described to be resistant to biocides, especially under their cyst resistant form. There are several studies on amoeba treatments but none of them compare sensitivity of trophozoites and cysts from different genus to various water disinfectants. In our study, we tested chlorine, monochloramine and chlorine dioxide on both cysts and trophozoites from three strains, belonging to the three main genera of free-living amoebae. The results show that, comparing cysts to trophozoites inactivation, only the Acanthamoeba cysts were highly more resistant to treatment than trophozoites. Comparison of the disinfectant efficiency led to conclude that chlorine dioxide was the most efficient treatment in our conditions and was particularly efficient against cysts. In conclusion, our results would help to adapt water treatments in order to target free-living amoebae in water networks.

Domaines: Microbiologie et Parasitologie

Mathieu Dupuy, Florence Berne, Pascaline Herbelin, Marie Binet, Nelsie Berthelot, et al.. Sensitivity of free-living amoeba trophozoites and cysts to water disinfectants.. International Journal of Hygiene and Environmental Health, 2014, 217, pp.335-339. ⟨10.1016/j.ijheh.2013.07.007⟩. ⟨hal-00934566⟩