title: Global survey of diversity among environmental saltwater Bacteriovoracaceae.
abstract: Halophilic Bacteriovorax (Bx), formerly known as the marine Bdellovibrio, are Gram-negative, predatory bacteria found in saltwater systems. To assess their genetic diversity and geographical occurrence, the small subunit rRNA (ssu-rRNA) gene sequences were analysed from 111 marine, salt lake and estuarine isolates recovered from 27 locations around the world. Phylogenetic analysis of these isolates using Geobacter as the outgroup revealed eight distinct ribotype clusters each with at least two isolates. Each cluster was composed of isolates with >or= 96.5% similarity in ssu-rRNA sequences. Three single isolate outliers were observed. Many of the Bx ribotypes were widely dispersed among different types of ecosystems (e.g. cluster III was recovered from the Great Salt Lake, the Atlantic Ocean, Pacific Ocean, Chesapeake Bay and gills of aquarium fish). However, cluster V was only recovered from a single ecosystem, estuaries. Cluster V was originally detected in the Chesapeake Bay and subsequently in the Pamlico Sound/Neuse River system. Principal coordinate analysis revealed that the sequences of the isolates from different environments were distinct from each other. The results of this study reveal the saltwater Bx to be phylogenetically and environmentally more diverse than was previously known.
authors.affiliation: Department of Medical and Research Technology, School of Medicine, University of Maryland, Baltimore, MD 21201, USA. spineiro@som.umaryland.edu
authors.forename: Silvia A
authors.initials: SA
authors.lastname: Pineiro
authors.forename: O Colin
authors.initials: OC
authors.lastname: Stine
authors.forename: Ashvini
authors.initials: A
authors.lastname: Chauhan
authors.forename: Susan R
authors.initials: SR
authors.lastname: Steyert
authors.forename: Richard
authors.initials: R
authors.lastname: Smith
authors.forename: Henry N
authors.initials: HN
authors.lastname: Williams
mesh_terms: D000818:Animals; D001483:Base Sequence; D020564:Deltaproteobacteria / Q000235:genetics* / Q000302:isolation & purification; D017753:Ecosystem; D014644:Genetic Variation; D008969:Molecular Sequence Data; D010125:Ostreidae; D010802:Phylogeny; D012335:RNA, Ribosomal / Q000235:genetics; D021521:Ribotyping / Q000379:methods; D054712:Salinity; D012623:Seawater / Q000382:microbiology*; D014871:Water Microbiology