title: Occurrence of Legionella in groundwater: an ecological study.
abstract: The natural habitat of Legionella is the water environment. Little is known about their presence in groundwater in spite of the fact that many millions around the globe regularly rely on groundwaters. This pilot study was aimed at evaluating the occurrence of Legionella in groundwater samples (water and biofilms) collected from various sites. Water and biofilm samples from selected groundwater sources were examined for Legionella using culture media (selective and non-selective) and a semi-nested PCR assay. Innovative approaches such as immunomagnetic separation (IMS) in combination with cultivation and flow cytometry were also evaluated. The findings available thus far show that (a) Legionella could be readily recovered from groundwater samples by cultivation even though their numbers showed considerable variations, (b) surprisingly, the PCR methodology was not yet as sensitive as cultivation and (c) flow cytometry was not directly applicable on natural samples because of debris and the high number of heterotrophic associated microflora from which some members were likely to cross-react with the monoclonal antibody used for separation procedures (IMS).
authors.affiliation: Centre for Research on Environmental Microbiology (CREM), Faculty of Medicine, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, Canada K1H 8M5. sriffard@uottawa.ca
authors.forename: S
authors.initials: S
authors.lastname: Riffard
authors.forename: S
authors.initials: S
authors.lastname: Douglass
authors.forename: T
authors.initials: T
authors.lastname: Brooks
authors.forename: S
authors.initials: S
authors.lastname: Springthorpe
authors.forename: L G
authors.initials: LG
authors.lastname: Filion
authors.forename: S A
authors.initials: SA
authors.lastname: Sattar
mesh_terms: D018441:Biofilms; D004269:DNA, Bacterial / Q000032:analysis; D004784:Environmental Monitoring; D005434:Flow Cytometry; D006801:Humans; D007875:Legionella; D016133:Polymerase Chain Reaction; D011157:Population Dynamics; D011634:Public Health; D012680:Sensitivity and Specificity; D012988:Soil Microbiology; D014881:Water Supply
chemical_list: D004269:DNA, Bacterial