Coliphages as viral indicators in municipal wastewater: A comparison between the ISO and the USEPA methods based on a systematic literature review

Gisele A R Kelmer; Elloís R Ramos; Edgard H O Dias

doi:10.1016/j.watres.2023.119579

Coliphages as viral indicators in municipal wastewater: A comparison between the ISO and the USEPA methods based on a systematic literature review

Water Res. 2023 Feb 15:230:119579. doi: 10.1016/j.watres.2023.119579. Epub 2023 Jan 5.

Authors

Gisele A R Kelmer¹, Elloís R Ramos², Edgard H O Dias³

Affiliations

¹ Postgraduate Programme in Civil Engineering (PEC), Faculty of Engineering, Federal University of Juiz de Fora (UFJF). Rua José Lourenço Kelmer, s/n, Campus UFJF. São Pedro, Juiz de Fora - MG, CEP 36036-900, Brazil.
² Environmental and Sanitary Engineering Course, Faculty of Engineering, Federal University of Juiz de Fora (UFJF). Rua José Lourenço Kelmer, s/n, Campus UFJF. São Pedro, Juiz de Fora - MG, CEP 36036-900, Brazil.
³ Postgraduate Programme in Civil Engineering (PEC), Faculty of Engineering, Federal University of Juiz de Fora (UFJF). Rua José Lourenço Kelmer, s/n, Campus UFJF. São Pedro, Juiz de Fora - MG, CEP 36036-900, Brazil; Department of Sanitary and Environmental Engineering (ESA), Faculty of Engineering, Federal University of Juiz de Fora (UFJF). Rua José Lourenço Kelmer, s/n, Campus UFJF. São Pedro, Juiz de Fora - MG, CEP 36036-900, Brazil. Electronic address: edgard.dias@ufjf.br.

PMID: 36640612
DOI: 10.1016/j.watres.2023.119579

Abstract

The use of traditional faecal indicator bacteria as surrogate organisms for pathogenic viruses in domestic wastewater has been noted as a problematic as concentrations and removal rates of bacteria and viruses do not seem to correlate. In this sense, bacteriophages (phages) emerge as potential viral indicators, as they are commonly found in wastewater in high levels, and can be quantified using simple, fast, low-cost methods. Somatic and F-specific coliphages comprise groups of phages commonly used as indicators of water quality. There are two internationally recognised methods to detect and enumerate coliphages in water samples, the International Standardization Organization (ISO) and the US Environmental Protection Agency (USEPA) methods. Both methods are based on the lysis of specific bacterial host strains infected by phages. Within this context, this systematic literature review aimed at gathering concentrations in raw and treated domestic wastewater (secondary, biological treatment systems and post-treatment systems), and removal efficiencies of somatic and F-specific coliphages obtained by ISO and USEPA methods, and then compare both methods. A total of 33 research papers were considered in this study. Results showed that the ISO method is more commonly applied than the USEPA method. Some discrepancies in terms of concentrations and removal efficiencies were observed between both methods. Higher removal rates were observed for both somatic and F-specific coliphages in activated sludge systems when using the USEPA method compared to the ISO method; in other secondary (biological) treatment systems, this was observed only for F-specific coliphages. The use of different standardised methods available might lead to difficulties in obtaining and comparing phage data in different conditions and locations. Future research comparing both ISO and USEPA methods as well as viral and bacterial pathogens and indicators in WWTP is recommended.

Keywords: Bacteriophages; Enteric viruses; Surrogate organisms; Wastewater treatment.

Publication types

Systematic Review
Review

MeSH terms

Bacteria
Bacteriophages*
Coliphages
Reference Standards
Sewage / microbiology
United States
United States Environmental Protection Agency
Wastewater*
Water Microbiology

Substances

Wastewater
Sewage