title: 23S rRNA gene-based enterococci community signatures in Lake Pontchartrain, Louisiana, USA, following urban runoff inputs after Hurricane Katrina.
abstract: Little is known about the impacts of fecal polluted urban runoff inputs on the structure of enterococci communities in estuarine waters. This study employed a 23S rRNA gene-based polymerase chain reaction (PCR) assay with newly designed genus-specific primers, Ent127F-Ent907R, to determine the possible impacts of Hurricane Katrina floodwaters via the 17th Street Canal discharge on the community structure of enterococci in Lake Pontchartrain. A total of 94 phylotypes were identified through the restriction fragment length polymorphism (RFLP) screening of 494 clones while only 8 phylotypes occurred among 88 cultivated isolates. Sequence analyses of representative phylotypes and their temporal and spatial distribution in the lake and the canal indicated the Katrina floodwater input introduced a large portion of Enterococcus flavescens, Enterococcus casseliflavus, and Enterococcus dispar into the lake; typical fecal groups Enterococcus faecium, Enterococcus durans, Enterococcus hirae, and Enterococcus mundtii were detected primarily in the floodwater-impacted waters. This study provides a global picture of enterococci in estuarine waters impacted by Hurricane Katrina-derived urban runoff. It also demonstrates the culture-independent PCR approach using 23S rRNA gene as a molecular marker could be a good alternative in ecological studies of enterococci in natural environments to overcome the limitation of conventional cultivation methods.
authors.affiliation: Department of Environmental Sciences, School of Coast and Environment, Louisiana State University, Baton Rouge, LA 70803, USA.
authors.forename: Hee-Sung
authors.initials: HS
authors.lastname: Bae
authors.forename: Aixin
authors.initials: A
authors.lastname: Hou
mesh_terms: D055867:Cyclonic Storms; D004269:DNA, Bacterial / Q000235:genetics; D004190:Disasters; D016983:Enterococcus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D004784:Environmental Monitoring; D005243:Feces / Q000382:microbiology; D055868:Floods; D015723:Gene Library; D060106:Lakes / Q000382:microbiology*; D008145:Louisiana; D010802:Phylogeny; D012150:Polymorphism, Restriction Fragment Length; D012338:RNA, Ribosomal, 23S / Q000235:genetics; D014872:Water Movements; D014876:Water Pollution / Q000032:analysis*; D060753:Water Quality
chemical_list: D004269:DNA, Bacterial; D012338:RNA, Ribosomal, 23S