Characterization of fecal indicator bacteria in sediments cores from the largest freshwater lake of Western Europe (Lake Geneva, Switzerland)

Abstract

a b s t r a c tThis study characterized the fecal indicator bacteria (FIB), including Escherichia coli (E. coli) and Enteroccocus (ENT), disseminated over time in the Bay of Vidy, which is the most contaminated area of Lake Geneva. Sediments were collected from a site located at $ 500 m from the present waste water treatment plant (WWTP) outlet pipe, in front of the former WWTP outlet pipe, which was located at only 300 m from the coastal recreational area (before 2001). E. coli and ENT were enumerated in sediment suspension using the membrane filter method. The FIB characterization was performed for human Enterococcus faecalis (E. faecalis) and Enterococcus faecium (E. faecium) and human specific bacteroides by PCR using specific primers and a matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Bacterial cultures revealed that maximum values of 35.2 Â 10 8 and 6.6 Â 10 6 CFU g À 1 dry sediment for E. coli and ENT, respectively, were found in the sediments deposited following eutrophication of Lake Geneva in the 1970s, whereas the WWTP started operating in 1964. The same tendency was observed for the presence of human fecal pollution: the percentage of PCR amplification with primers ESP-1/ESP-2 for E. faecalis and E. faecium indicated that more than 90% of these bacteria were from human origin. Interestingly, the PCR assays for specifichuman bacteroides HF183/HF134 were positive for DNA extracted from all isolated strains of sediment surrounding WWPT outlet pipe discharge. The MALDI-TOF MS confirmed the presence of general E. coli and predominance E. faecium in isolated strains. Our results demonstrated that human fecal bacteria highly increased in the sediments contaminated with WWTP effluent following the eutrophication of Lake Geneva. Additionally, other FIB cultivable strains from animals or adapted environmental strains were detected in the sediment of the bay. The approaches used in this research are valuable to assess the temporal distribution and the source of the human fecal pollution in aquatic environments.

Changes in Enterococcal Populations and Related Antibiotic Resistance along a Medical Center-Wastewater Treatment Plant-River Continuum

“…In a municipal WWTP from Poland, E. faecium was also predominant (60.8% of enterococci) (27). Finally, in a recent study, E. faecium represented the vast majority of enterococci that were detected in the sediments of the lake of Geneva (Switzerland), which is subjected to extensive microbial contamination by WWTP outlet discharges and rivers (28).…”

Accumulation of Clinically Relevant Antibiotic-Resistance Genes, Bacterial Load, and Metals in Freshwater Lake Sediments in Central Europe

“…5,9,20 Studying the sediments allows us to address the persistence of ARGs and the potential impact of the emergence of resistant bacterial strains from WWTP to freshwater sediment microbes. Thus, the sediments offer a unique opportunity for reconstructing the pollution history and evaluating the impacts using quantitative data.…”

Evaluation of Water Quality from Suburban Shallow Wells Under Tropical Conditions According to the Seasonal Variation, Bumbu, Kinshasa, Democratic Republic of the Congo

“…The PCR amplification was performed directly on the colonies picked from selective-media plates (resuspended in 20 lL of sterile water) using human-specific Bacteroides primers HF183F-(5 0 -ATCATGAGTTCACATGTCCG-3 0 ) and Bac708R-(5 0 -CAATCGGAGTTCTTCGTG-3 0 ) (Bernhard and Field 2000; Ahmed et al 2007), with the PCR conditions as described by Thevenon et al (2012). PCR reactions of 25 lL total volume consisted of 0.025 U/lL Takara Ex Taq HS DNA polymerase (Takara Bio Europe, Saint-Germain-en-Laye, France), 19 PCR buffer (Takara, containing 2 mM of Mg 2? ), 800 lM of dNTP, 0.2 lM of each forward and reverse primers (Invitrogen), 50 ng/lL of BSA.…”

“…In some of these regions, according to the economic situation and lack of effective infrastructure, a large proportion of the population uses highly contaminated surface water, shallow wells, boreholes, springs and streams for irrigation, domestic and drinking purposes (Amanial 2015;Mwanamoki et al 2015;Rochelle-Newall et al 2015). Although most infections occur in developing countries, waterborne diseases are a worldwide problem that also concerns industrialized societies where highly populated centres draw their supply of drinking water WHO 2011;Thevenon et al 2012). In Democratic Republic of the Congo (DRC, with estimated population of 65.7 million inhabitants), despite the potential of its rich fresh water network, more than 75 % of the population have no access to safe water (UNEP 2011).…”