title: Identification of free-living amoebae and amoeba-associated bacteria from reservoirs and water treatment plants by molecular techniques.
abstract: The occurrence of free-living amoebae (FLA) was investigated in 83 water samples from reservoirs and water treatment plants, with culture positive in 64 of them (77.1%). Polymerase chain reaction (PCR) of partial 18S rRNA gene and ITS region was performed in order to identify amoeba isolates, and the presence of Legionella pneumophila , Mycobacterium spp., Pseudomonas spp., and Microcystis aeruginosa was investigated in 43 isolates of amoebae by multiplex PCR. Of the isolated amoebae, 31 were Acanthamoeba spp., 21 were Hartmannella vermiformis, 13 were Naegleria spp., and one was Vanella spp. T2, T4, and T5 genotypes of Acanthamoeba have been identified, and T4 isolates were grouped into five subgenotypes and graphically represented with a Weblog application. Inside amoebae, L. pneumophila was detected in 13.9% (6/43) of the isolates, and Pseudomonas spp. and Mycobacterium spp. were detected in 32.6% (14/43) and 41.9% (18/43), respectively. No statistical correlation was demonstrated between FLA isolation and seasonality, but the presence of intracellular bacteria was associated with warm water temperatures, and also the intracellular presence of Mycobacterium spp. and Pseudomonas spp. were associated. These results highlight the importance of amoebae in natural waters as reservoirs of potential pathogens and its possible role in the spread of bacterial genera with interest in public and environmental health.
authors: Area of Parasitology and §Area of Biomedicine and Public Health Biostatistics, Department of Microbiology, Preventive Medicine and Public Health, Faculty of Medicine, University of Zaragoza, 50009 Zaragoza, Spain.
authors: Alicia
authors: A
authors: Garcia
authors: Pilar
authors: P
authors: Goñi
authors: Joanna
authors: J
authors: Cieloszyk
authors: Maria Teresa
authors: MT
authors: Fernandez
authors: Laura
authors: L
authors: Calvo-Beguería
authors: Encarnacion
authors: E
authors: Rubio
authors: Maria Francisca
authors: MF
authors: Fillat
authors: Maria Luisa
authors: ML
authors: Peleato
authors: Antonio
authors: A
authors: Clavel
mesh_terms: D000656:Amoeba / Q000235:genetics / Q000302:isolation & purification* / Q000382:microbiology*; D001419:Bacteria / Q000235:genetics* / Q000302:isolation & purification*; D001483:Base Sequence; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000379:methods*; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D016415:Sequence Alignment; D014871:Water Microbiology; D018508:Water Purification
chemical_list: D012337:RNA, Ribosomal, 18S