Microbial Contamination Detection in Water Resources: Interest of Current Optical Methods, Trends and Needs in the Context of Climate Change

Abstract

Microbial pollution in aquatic environments is one of the crucial issues with regard to the sanitary state of water bodies used for drinking water supply, recreational activities and harvesting seafood due to a potential contamination by pathogenic bacteria, protozoa or viruses. To address this risk, microbial contamination monitoring is usually assessed by turbidity measurements performed at drinking water plants. Some recent studies have shown significant correlations of microbial contamination with the risk of endemic gastroenteresis. However the relevance of turbidimetry may be limited since the presence of colloids in water creates interferences with the nephelometric response. Thus there is a need for a more relevant, simple and fast indicator for microbial contamination detection in water, especially in the perspective of climate change with the increase of heavy rainfall events. This review focuses on the one hand on sources, fate and behavior of microorganisms in water and factors influencing pathogens’ presence, transportation and mobilization, and on the second hand, on the existing optical methods used for monitoring microbiological risks. Finally, this paper proposes new ways of research.

Estimating the microbiological risks associated with inland flood events: Bridging theory and models of pathogen transport

“…Characteristics of rainfall and runoff, such as rainfall pattern, effective rainfall volume, and overland flow velocity, have been identified as some of the most critical factors affecting transport of pathogens from the land surface (Funari, et al 2012, Bhavnani, et al 2014, Jamieson, et al 2004, Ferguson, et al 2005, Jung, et al 2014, Tsihrintzis and Hamid 1997). However, the relationship of these factors with in-stream pathogen concentrations across sites is complex.…”

Human-Driven Microbiological Contamination of Benthic and Hyporheic Sediments of an Intermittent Peri-Urban River Assessed from MST and 16S rRNA Genetic Structure Analyses

“…Nevertheless, some studies indicated that river bed sediments could be significant reservoirs of certain bacterial pathogens. These could get re-suspended when the river flow reaches a critical level (Brookes et al, 2004; Jung et al, 2014; Frey et al, 2015). These reservoirs can thus be significant in the global epidemiology of waterborne pathogens.…”

Rapid Water Quality Monitoring for Microbial Contamination

“…There are several substrates available in the literature for the detection of these enzymes, and interested readers can refer elsewhere. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]45,50,[56][57][58] We have selected a combination (similar to the one used in MWK 45 ) of Red-Gal and MUG as substrates for the enzymes β-D-galactosidase and β-Dglucuronidase, thereby enabling simultaneous detection of total coliform and E. coli. Red-Gal was used as the substrate to target β-Dgalactosidase produced by total coliform to yield 4-chloro-indoxyl, which upon dimerization produces a red colored indigo derivative.…”

“…Immunological methods [11][12][13][14][15][16][17][18] target specific antigens of bacteria using specific antibodies. The indicator bacteria releases an antigen which can be detected using antigen-antibody interaction.…”

“…Current technologies rely on collecting water samples and sending samples to microbiological laboratories, which through multiple tube fermentation, membrane filtration, and/or plate counts, provide conclusive results, typically within 24 -48 hrs. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] Such a lengthy wait period is very much disadvantageous to communities, particularly in Canada's North and First Nation communities and limited resource communities in developing economies (i.e., India, China, Brazil), where even access to a reliable water quality monitoring laboratory is rare. Hence, researchers have developed innovative field-deployable rapid test methods to evaluate the quality of water for microbial contamination.…”