Presence of Legionella Species in Residential Water Reservoirs of Resistencia Chaco, Argentina

Abstract

INTRODUCTION: Legionella genus includes species that are found in a variety of aquatic environments, but must be incorporated into aerosols and inhaled to produce disease. Although most cases of pneumonia are caused by L. pneumophila, of the 58 species that constitute this genus, 24 were related to human disease. The aim of this study was to evaluate the presence of Legionella species in residential reservoirs of drinking water of Resistencia, Chaco. METHODS: Forty six water samples taken from different points in the city were studied. Legionella detection in the samples was performed by culture as set out in the ISO standard 11731:1998. Real-time polymerase chain reaction (qPCR) assays were applied to isolates obtained by culture and identified as Legionellaspp. according to the ISO standard. The target sequences used corresponded to 23S rRNA gene, for the confirmation of the genus, and mip gene specific for the species L. pneumophila. RESULTS: In 16 (34.8%) of the 46 samples studied Legionella spp. was recovered. Molecular technique confirmed the presence of Legionella pneumophila in 15 samples. In addition, 3 of these samples (6.5%) were also positive for anotherspecies of the genus Legionella. CONCLUSIONS: This study demonstrated the presence of L. pneumophila and other species in residential drinking water reservoirs in Resistencia.