Microbial Source Tracking in Adjacent Karst Springs

Abstract

cModern man-made environments, including urban, agricultural, and industrial environments, have complex ecological interactions among themselves and with the natural surroundings. Microbial source tracking (MST) offers advanced tools to resolve the host source of fecal contamination beyond indicator monitoring. This study was intended to assess karst spring susceptibilities to different fecal sources using MST quantitative PCR (qPCR) assays targeting human, bovine, and swine markers. It involved a dual-time monitoring frame: (i) monthly throughout the calendar year and (ii) daily during a rainfall event. Data integration was taken from both monthly and daily MST profile monitoring and improved identification of spring susceptibility to host fecal contamination; three springs located in close geographic proximity revealed different MST profiles. The Giach spring showed moderate fluctuations of MST marker quantities amid wet and dry samplings, while the Zuf spring had the highest rise of the GenBac3 marker during the wet event, which was mirrored in other markers as well. The revelation of human fecal contamination during the dry season not connected to incidents of raining leachates suggests a continuous and direct exposure to septic systems. Pigpens were identified in the watersheds of Zuf, Shefa, and Giach springs and on the border of the Gaaton spring watershed. Their impact was correlated with partial detection of the Pig-2-Bac marker in Gaaton spring, which was lower than detection levels in all three of the other springs. Ruminant and swine markers were detected intermittently, and their contamination potential during the wet samplings was exposed. These results emphasized the importance of sampling design to utilize the MST approach to delineate subtleties of fecal contamination in the environment.

Application of a microbial source tracking based on bacterial and chemical markers in headwater and coastal catchments

“…The review of 32 studies focusing on the HF183 marker by Ahmed and co-workers in 2016 (Ahmed et al, 2016) show an overall host sensitivity and specificity of 83.1% (n=1242 targeted fecal samples analysed) and 94.6% (n=2966 non targeted fecal samples tested). In addition, Pig2Bac marker was also found highly specific in USA and Israel and Rum2Bac in USA (Raith et al, 2013;Heaney et al, 2015;Ohad et al, 2015).…”

Opening the black box of spring water microbiology from alpine karst aquifers to support proactive drinking water resource management

“…Of these approaches, many are currently being evaluated for their application predominantly at surface water resources (Boehm et al, ; Hagedorn, Blanch, & Harwood, ; Mayer et al, ; Reischer et al, ). For (karst) ground water systems, however, just a few studies have been realized since the pioneering LKAS/DKAS work (Bucci, Petrella, Celico, & Naclerio, ; Diston, Robbi, Baumgartner, & Felleisen, ; Diston, Sinreich, Zimmermann, Baumgartner, & Felleisen, ; Ohad et al, ; Zhang, Kelly, Panno, & Liu, ). However, these studies already indicate the high potential of identifying host‐associated genetic qPCR markers to support traditional fecal pollution monitoring and to guide proactive and target‐oriented management in such systems.…”

Spatial and temporal dynamics of bacterioplankton community composition in a subtropical dammed karst river of southwestern China

“…Karst rivers are commonly regulated by damming, yet the influence of these dams on changes in hydrological series of water discharge is negative or positive (Miao, Ni, Borthwick, & Yang, ). Although the diversity and dynamics of microbes in karst springs (Farnleitner et al., ; Ohad et al., ; Savio et al., ), unsaturated and saturated karst aquifers (Cooper et al., ; Gray & Engel, ; Johnson et al., ; Lin et al., ; Menning et al., ), and water pools (Shabarova et al., ) as well as in groundwater‐surface water exchange systems (Li, Song, et al., ) have been discussed in the literature, much less attention has been paid to the structure of bacterioplankton communities in dammed karst rivers. In addition, previous studies on bacterioplankton communities in the canyon‐shaped and meso‐eutrophic Rimov Reservoir (Simek et al., ), the dammed Ebro River (Ruiz‐González, Proia, Ferrera, Gasol, & Sabater, ), and the rivers controlled by the Three Gorges Dam (Huang et al., ; Li, Lu, et al., ; Yan et al., ) did not include the seasonal variation or depth dynamics in bacterioplankton.…”