Distribution of human fecal marker genes and their association with pathogenic viruses in untreated wastewater determined using quantitative PCR

Authors

Warish Ahmed, CSIRO Land and Water, Ecosciences Precinct, 41 Boggo Road, Dutton Park, QLD 4102, Australia. Electronic address: Warish.Ahmed@csiro.au.
Aaron Bivins, School of Transportation Engineering, Southeast University, Nanjing 210096, China.
Weiguang Zhang, School of Transportation Engineering, Southeast University, Nanjing 210096, China.
Shihui Shen, Rail Transportation Engineering, Pennsylvania State University, 216E Penn Building, Altoona, PA 16601, USA.
Shenghua Wu, Department of Civil, Coastal, and Environmental Engineering, University of South Alabama, Baton Rouge, AL 36688, USA.
Louay N. Mohammad, Louisiana Transportation Research Center, Department of Civil and Environmental Engineering, Louisiana State University, Mobile, LA 70808, USA.
Xuhui She, School of Transportation Engineering, Southeast University, Nanjing 210096, China.

Document Type

Article

Publication Date

11-1-2022

Abstract

Quantitative microbial risk assessment (QMRA) of human health risks using human fecal marker genes (HFMGs) is an useful water quality management tool. To inform accurate QMRA analysis, generation of probability distribution functions for HFMGs, and reference pathogenic viruses can be improved by input of correlation and ratios based upon measurement of HFMGs and gene copies (GC) of pathogenic viruses in untreated wastewater. The concentrations of four HFMGs (Bacteroides HF183, Lachnospiraceae Lachno3, CrAssphage and pepper mild mottle virus (PMMoV)), and GC of three reference pathogenic viruses human adenovirus 40/41 (HAdV 40/41), human norovirus GI + GII HNoV GI + GII and enterovirus (EV) were measured in untreated wastewater samples collected over a period of 12 months from two wastewater treatment plants in Sydney, Australia using quantitative polymerase chain reaction (qPCR) and reverse transcription qPCR (RT-qPCR). Over the course of the study, the GC of potential pathogenic viruses were 3-5 orders of magnitude lower than HFMGs in untreated wastewater. The GC of pathogenic viruses were highly variable over the course of the study, which contrasted with the concentrations of HFMGs that were quite stable with little variation observed within and between WWTPs. Among the HFMGs, HF183, CrAssphage and PMMoV correlated well with pathogenic virus GC, whereas weak or negative correlations were observed between Lachno3 and pathogenic virus GC. While the two assessed WWTPs had dissimilar population service sizes, the ratios between log transformed pathogenic virus GC and HFMGs demonstrated similar central tendency and variability for the same combinations between WWTP A and WWTP B with no difference between the WWTPs. This suggests the widespread presence of these HFMGs in both populations serviced by these two WWTPs. The observed correlation and ratios of HFMGs and GC of reference pathogenic viruses can contribute to improved QMRA of human health risks in environmental waters subject to fresh sewer overflows.

Publication Source (Journal or Book title)

Water research

First Page

119093

Recommended Citation

Ahmed, W., Bivins, A., Zhang, W., Shen, S., Wu, S., Mohammad, L. N., & She, X. (2022). Distribution of human fecal marker genes and their association with pathogenic viruses in untreated wastewater determined using quantitative PCR. Water research, 226, 119093. https://doi.org/10.1016/j.watres.2022.119093