title: Denaturing gradient gel electrophoresis analyses of the vertical distribution and diversity of Vibrio spp. populations in the Cariaco Basin.
abstract: The Cariaco system is the second largest permanently anoxic marine water body in the world. Its water column is characterized by a pronounced vertical layering of microbial communities. The goal of our study was to investigate the vertical distribution and diversity of Vibrio spp. present in the Cariaco Basin waters using denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rDNA fragments. Representatives of the Vibrio genus were detected by nested and direct PCR in seawater at 10 depths. Sequence analyses of 55 DGGE bands revealed that only 11 different operational taxonomic units (OTU) are identified as Vibrio species. Between one and five OTUs were detected at each depth and the most common OTUs were OTU 1 and OTU 2, which phylogenetically clustered with Vibrio chagasii and Vibrio fortis, respectively. OTUs 3 and 4 were only found in the anoxic zone and were identified as Vibrio orientalis and Vibrio neptunius, respectively. Several Vibrio species detected are potentially pathogenic to human, prawns and corals such as Vibrio parahaemolyticus, Vibrio fischeri and Vibrio shilonii. In the Cariaco Basin, different Vibrio species were found to be specific to specific depths strata, suggesting that this genus is a natural component of the microbial communities in this marine redox environment.
authors.affiliation: Laboratorio de Fisiología Gastrointestinal, Centro de Biofísica y Bioquímica, Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela. magarcia@ivic.gob.ve
authors.forename: Maria Alexandra
authors.initials: MA
authors.lastname: García-Amado
authors.forename: Lorelei
authors.initials: L
authors.lastname: Bozo-Hurtado
authors.forename: Yrene
authors.initials: Y
authors.lastname: Astor
authors.forename: Paula
authors.initials: P
authors.lastname: Suárez
authors.forename: Andrei
authors.initials: A
authors.lastname: Chistoserdov
mesh_terms: D017691:Caribbean Region; D004269:DNA, Bacterial / Q000235:genetics; D058645:Denaturing Gradient Gel Electrophoresis; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012623:Seawater / Q000737:chemistry / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D014687:Venezuela; D014733:Vibrio / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D014871:Water Microbiology
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S