Occurrence of Traditional and Alternative Fecal Indicators in Tropical Urban Environments under Different Land Use Patterns

Abstract

This study evaluated the geospatial distribution of fecal indicator bacteria (FIB) (i.e., , spp.) and the alternative fecal indicator pepper mild mottle virus (PMMoV) in tropical freshwater environments under different land use patterns. Results show that the occurrence and concentration of microbial fecal indicators were higher for urban than for parkland-dominated areas, consistent with land use weightage. Significant positive correlations with traditional FIB indicate that PMMoV is a suitable indicator of fecal contamination in tropical catchments waters (0.549 ≤ rho ≤ 0.612; < 0.01). PMMoV exhibited a strong significant correlation with land use weightage (rho = 0.728; < 0.01) compared to traditional FIB (rho = 0.583; < 0.01). In addition, chemical tracers were also added to evaluate the potential relationships with microbial fecal indicators. The relationships between diverse variables (e.g., environmental parameters, land use coverage, and chemical tracers) and the occurrence of FIB and PMMoV were evaluated. By using stepwise multiple linear regression (MLR), the empirical experimental models substantiate the impact of land use patterns and anthropogenic activities on microbial water quality, and the output results of the empirical models may be able to predict the sources and transportation of human fecal pollution or sewage contamination. In addition, the high correlation between PMMoV data obtained from quantitative real-time PCR (qPCR) and viral metagenomics data supports the possibility of using viral metagenomics to relatively quantify specific microbial indicators for monitoring microbial water quality (0.588 ≤ rho ≤ 0.879; < 0.05). The results of this study may support the hypothesis of using PMMoV as an alternative indicator of human fecal contamination in tropical surface waters from the perspective of land use patterns. The predictive result of the occurrence of human fecal indicators with high accuracy may reflect the source and transportation of human fecal pollution, which are directly related to the risk to human health, and thereafter, steps can be taken to mitigate these risks.

Pepper mild mottle virus: A plant pathogen with a greater purpose in (waste)water treatment development and public health management

“…While many papers have utilized the Zhang et al . primers and probes (2006; Ahmed et al, 2018, Colson et al, 2010, Hruby et al, 2013, Hughes et al, 2017, Peng et al, 2015, Rosario et al, 2009b, Sangsanont et al, 2016, Symonds et al, 2014), most recent papers have used the PMMV-FP1-rev and PMMV-RP1 primers, with the PMMV-Taqman MGB probe or equivalent type of probe (Asami et al, 2016, Betancourt et al, 2014, Gu et al, 2018, Haramoto et al, 2013, Kato et al, 2018, Kitajima et al, 2014, Kuroda et al, 2015, Lee et al, 2018, Lee et al, 2017, Rachmadi et al, 2015, Rosiles-González et al, 2017, Saeidi et al, 2018, Sassi et al, 2018, Schmitz et al, 2016, Shirasaki et al, 2017, Shirasaki et al, 2018, Shrestha et al, 2018, Symonds et al, 2015, Symonds et al, 2016, Symonds et al, 2017, Tandukar et al, 2018, Verbyla et al, 2016).…”

“…Since PMMoV was first proposed as an indicator of fecal pollution, this virus has been incorporated into 16 published studies analyzing microbial quality of freshwater, brackish waters, and seawater with and without known sources of domestic wastewater pollution in Australia (Hughes et al, 2017), Bolivia (Verbyla et al, 2016), Costa Rica (Symonds et al, 2017), Germany (Hamza et al, 2011), Japan (Haramoto et al, 2013), Mexico (Rosiles-González et al, 2017), Nepal (Shrestha et al, 2018, Tandukar et al, 2018), Singapore (Gu et al, 2018, Saeidi et al, 2018), United States of America (Betancourt et al, 2014, McGinnis et al, 2018, Rosario et al, 2009b, Sassi et al, 2018, Symonds et al, 2016), and Vietnam (Kuroda et al, 2015). It is important to note that PMMoV has not been detected in environmental waters in the absence of human fecal pollution and that PMMoV RNA persisted in seawater for approximately one week at temperatures ranging from 31 to 33°C, and in river water for approximately 10 days at 25°C and as long as 21 days at 4°C (Hamza et al, 2011, Rosario et al, 2009b).…”

“…PMMoV did not significantly correlate with FIB in coastal waters (Hughes et al, 2017, Symonds et al, 2016, Symonds et al, 2017) or inland freshwater (Hamza et al, 2011, McGinnis et al, 2018, Symonds et al, 2016). However, one study in Singapore identified significant positive correlations between PMMoV and the FIB Enterococci and E. coli in fresh surface waters (Saeidi et al, 2018). PMMoV concentrations were also correlated with residential and green areas in Singapore (Saeidi et al, 2018).…”

“…However, one study in Singapore identified significant positive correlations between PMMoV and the FIB Enterococci and E. coli in fresh surface waters (Saeidi et al, 2018). PMMoV concentrations were also correlated with residential and green areas in Singapore (Saeidi et al, 2018).…”

“…published their study in 2006, other metagenomic studies have verified the abundance of PMMoV in human feces (Moore et al, 2015, Nakamura et al, 2009, Victoria et al, 2009), untreated domestic wastewater (Wang et al, 2018), tertiary-treated domestic wastewater (Rosario et al, 2009a), and even indoor air filters (Rosario et al, 2018). Additionally, PMMoV has been incorporated in over 29 peer-reviewed and published investigations related to microbial water and food quality as well as (waste)water treatment technologies throughout the world (Ahmed et al, 2018, Asami et al, 2016, Betancourt et al, 2014, Fout et al, 2017, Gu et al, 2018, Hamza et al, 2011, Han et al, 2014, Haramoto et al, 2013, Hruby et al, 2013, Hughes et al, 2017, Kato et al, 2018, Kitajima et al, 2014, Kuroda et al, 2015, Lee et al, 2017, Rachmadi et al, 2015, Rosiles-González et al, 2017, Saeidi et al, 2018, Sangsanont et al, 2016, Sassi et al, 2018, Schmitz et al, 2016, Shirasaki et al, 2017, Shirasaki et al, 2018, Shrestha et al, 2018, Symonds et al, 2015, Symonds et al, 2016, Symonds et al, 2014, Symonds et al, 2017, Tandukar et al, 2018, Verbyla et al, 2016, Wang et al, 2018). The main purpose of this review is to consolidate the available information from a variety of different disciplines to understand how and when PMMoV can best be used as an enteric virus surrogate and/or domestic wastewater marker (Figure 1).…”