Quantification of enterococci and bifidobacteria in Georgia estuaries using conventional and molecular methods
Document Type
Article
Publication Date
2008
Publication Title
Water Research
Abstract
Fecal pollution is a serious threat to the estuarine environment along the Georgia coast. Culture-dependant and molecular methodologies were utilized to compare and evaluate the abundance of fecal indicator bacteria in four Georgia estuaries (Darien River, Frederica River, Gulley Hole Creek, and St. Marys River). The functionality of enterococci and bifidobacteria as indicator organisms in marine environments was assessed, as well as Bifidobacterium adolescentis densities. At each study site, enterococci were enumerated as colony forming units (CFU) on mEI agar. For quantitative polymerase chain reaction (qPCR), genus- and species-specific primer sets were used to quantify bifidobacteria and B. adolescentis as 16S rRNA gene copies and enterococci as tuf gene copies. A high correlation (r = 0.925) was observed between CFU and qPCR enumeration of enterococci. Enterococci densities in the estuarine rivers ranged from 3-449 CFU/100 ml on mEI plates and 4.58-5.39 Log10 gene copies/100 ml by qPCR. Bifidobacteria densities ranged from 3.62-4.14 Log10 gene copies/100 ml and suggested the Frederica River as least affected by fecal bacteria and the Darien River as most affected by fecal pollution. A correlation of 0.46 was observed among qPCR densities of enterococci and bifidobacteria at all sample sites. Quantitative polymerase chain reaction detection of B. adolescentis was a rapid (i.e., less than 2 h) indicator of presumptive human fecal pollution and suggested that Gulley Hole Creek, the Darien River, and the St. Marys River were affected by fecal bacteria derived from a human source. Gulley Hole Creek and the Darien River had the highest levels of fecal pollution detected in the studied estuaries. Molecular quantification of bifidobacteria may be a more accurate method of determining immediate health risks associated with fecal pollution in estuarine water than traditional and contemporary assessments of enterococci.
Department
Biological and Environmental Sciences
Volume Number
42
Issue Number
14
First Page
4001
Last Page
4009
DOI
10.1016/j.watres.2008.07.021
Recommended Citation
Morrison, C.R., Bachoon, D.S., & Gates, K.W. (2008). Quantification of enterococci and bifidobacteria in Georgia estuaries using conventional and molecular methods. Water Research, 42(14), 4001-4009.
Comments
© 2008 Elsevier Ltd. All rights reserved.