Evidence of Legionella pneumophila in some arthropods and related natural aquatic habitats

Abstract Using direct fluorescent antibody (DFA) staining technique, Legionella pneumophila SG 1, 3 and 5 was evident in water samples collected from different localities of central Italian regions, Marche and Abruzzi; L. pneumophila SG 1 and 3 was also detected in aquatic stages of arthropods living in the Legionella -positive waters. Diptera, Coleoptera, Collembola and Isopoda were found to be positive for legionellas by DFA. Diptera, the most common in the waters surveyed, were represented by Chironomidae and Culicidae families, the latter being larval and pupal stages of genus Anopheles and Culex . Mosquito adults, emerged in laboratory from pupae collected in one sample of positive water, were also positive. The findings that aquatic arthropods harbor legionellas and whether they could be involved in the maintenance and dissemination of legionellas in nature are discussed.