Translator Disclaimer
1 December 2012 Use of quantitative PCR of functional genes to monitor coliforms and enteric bacteria in a constructed, urban wetland
Domingo Molina IV, Kristine L. Lowe
Author Affiliations +

Constructed wetlands are an economical method to treat wastewater. Wetland plants may assist in removing chemicals and wetland microorganisms decompose organic matter in the water. Furthermore, constructed wetlands may serve as habitat for a variety of species, such as birds, reptiles, and amphibians. However, constructed wetlands many contain potentially pathogenic enteric organisms from the wastewater or from animal fecal waste. Coliforms are traditionally used as indicators of fecal and enteric pollution, and are detected by culture-based techniques. Molecular methods such as Polymerase Chain Reaction (PCR) and quantitative PCR (qPCR) are faster and detect organisms that culturing cannot. In this study, the presence and abundance of fecal coliforms, other coliforms, and enteric bacteria (e.g., Escherichia coli, Salmonella sp., Shigella sp.) were estimated in a constructed urban wetland. Water samples were taken from a wetland pond and an adjacent canal, and used to detect target bacteria using traditional culturing and qPCR of functional genes lacZ, lamB and uidA. Traditional culturing and qPCR assays both detected the three groups of organisms; however, qPCR detected a higher abundance of coliforms and enteric bacteria, especially in the pond, than would be predicted based on culturing experiments. This suggests that a significant number of coliforms and enteric bacteria are present in constructed wetlands that resist culturing. Moreover, qPCR using functional genes was better at detecting groups of enteric organisms rather than just single species. This allows for greater numbers of organisms to be detected. qPCR is therefore considered a better method for monitoring indicator organisms in constructed wetlands compared to culturing methods.

Domingo Molina IV and Kristine L. Lowe "Use of quantitative PCR of functional genes to monitor coliforms and enteric bacteria in a constructed, urban wetland," BIOS 83(4), 136-144, (1 December 2012).
Received: 23 November 2011; Accepted: 1 July 2012; Published: 1 December 2012

Get copyright permission
Back to Top