Evidence for free-living Bacteroides in Cladophora along the shores of the Great Lakes

Aquatic Microbial Ecology
By: , and 

Links

Abstract

Bacteroides is assumed to be restricted to the alimentary canal of animals and humans and is considered to be non-viable in ambient environments. We hypothesized that Bacteroides could persist and replicate within beach-stranded Cladophora glomerata mats in southern Lake Michigan, USA. Mean Bacteroides concentration (per GenBac3 Taqman quantitative PCR assay) during summer 2012 at Jeorse Park Beach was 5.2 log calibrator cell equivalents (CCE) g-1 dry weight (dw), ranging from 3.7 to 6.7. We monitored a single beach-stranded mat for 3 wk; bacterial concentrations increased by 1.6 log CCE g-1 dw and correlated significantly with ambient temperature (p = 0.003). Clonal growth was evident, as observed by >99% nucleotide sequence similarity among clones. In in vitro studies, Bacteroides concentrations increased by 5.5 log CCE g-1 after 7 d (27°C) in fresh Cladophora collected from rocks. Partial sequencing of the 16S rRNA gene of 36 clones from the incubation experiment showed highly similar genotypes (≥97% sequence overlap). The closest enteric Bacteroides spp. from the National Center for Biotechnology Information database were only 87 to 91% similar. Genomic similarity, clonality, growth, and persistence collectively suggest that putative, free-living Bacteroides inhabit Cladophora mats of southern Lake Michigan. These findings may have important biological, medical, regulatory, microbial source tracking, and public health implications.

Study Area

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Evidence for free-living Bacteroides in Cladophora along the shores of the Great Lakes
Series title Aquatic Microbial Ecology
DOI 10.3354/ame01688
Volume 72
Issue 2
Year Published 2014
Language English
Publisher Inter-Research
Publisher location Oldendorf/Luhe, Germany
Contributing office(s) Great Lakes Science Center
Description 10 p.
First page 117
Last page 126
Country United States
Other Geospatial southern Lake Michigan
Online Only (Y/N) N
Additional Online Files (Y/N) N