A highly prevalent and specific cryptic plasmid pBI143 for human fecal pollution tracking in a subtropical urban river

Yawen Liu; Wendy J M Smith; Metasebia Gebrewold; Rory Verhagen; Stephen Cook; Stuart L Simpson; Bethany Oceguera Johnson; Kyle Bibby; Warish Ahmed

doi:10.1016/j.watres.2024.122992

A highly prevalent and specific cryptic plasmid pBI143 for human fecal pollution tracking in a subtropical urban river

Water Res. 2024 Dec 16:273:122992. doi: 10.1016/j.watres.2024.122992. Online ahead of print.

Authors

Yawen Liu¹, Wendy J M Smith², Metasebia Gebrewold², Rory Verhagen³, Stephen Cook⁴, Stuart L Simpson², Bethany Oceguera Johnson⁵, Kyle Bibby⁵, Warish Ahmed⁶

Affiliations

¹ State Key Laboratory of Marine Environmental Science, College of the Environment & Ecology, Xiamen University, Xiamen 361102, China; CSIRO Environment, Ecosciences Precinct, 41 Boggo Road, Dutton Park, QLD 4102, Australia.
² CSIRO Environment, Ecosciences Precinct, 41 Boggo Road, Dutton Park, QLD 4102, Australia.
³ Queensland Alliance for Environmental Health Sciences (QAEHS), The University of Queensland, 20 Cornwall Street, Woolloongabba, QLD 4103, Australia.
⁴ Commonwealth Scientific and Industrial Research Organization, Darwin, NT 0828, Australia.
⁵ Department of Civil and Environmental Engineering and Earth Science, University of Notre Dame, Notre Dame, IN 46656, United States.
⁶ CSIRO Environment, Ecosciences Precinct, 41 Boggo Road, Dutton Park, QLD 4102, Australia. Electronic address: Warish.Ahmed@csiro.au.

PMID: 39729959
DOI: 10.1016/j.watres.2024.122992

Abstract

Microbial source tracking (MST) is a critical tool for identifying sources of human and animal fecal pollution in aquatic environments. To enhance human fecal pollution tracking, this study evaluated the performance characteristics of pBI143, a cryptic plasmid recently identified for potential MST applications. Nucleic acid samples from ten animal species were screened for pBI143, revealing its presence in a small number of pigs, cows, dogs, cats, and flying fox fecal samples. Despite minor cross-detection with non-human fecal samples, pBI143 exhibited a high specificity value (up to 0.93). In untreated urban wastewater, pBI143 was consistently detected in all samples, exhibiting higher concentrations than the well-established human Bacteroides HF183 marker gene. Following a wastewater discharge event, pBI143 concentrations were monitored in an urban river and correlated well with both HF183 and enterococci 23S rRNA marker genes. Using conditional probability analysis, the likelihood of human fecal pollution was estimated to be 89.3 % when pBI143 was detected in 50 % of the river water samples. This study demonstrates that pBI143 is a highly abundant and specific human fecal marker for tracking human fecal pollution in environmental waters. Monitoring of pBI143 could significantly improve the accuracy of human fecal source identification in environmental waters, offering valuable insights for public health risk management and pollution mitigation strategies.

Keywords: Enterococci; HF183; Marker genes; Microbial source tracking; Public health risk; Untreated wastewater; qPCR.