{"title":"Clostridium perfringens as an alternative fecal indicator bacteria in surface water quality: a national investigation in Chinese rivers","authors":"Wen Li, Qingbin Yuan, Xin Li, Miaomiao Teng, Zixuan Zhang, Yi Luo, Fengchang Wu","doi":"10.1016/j.watres.2025.124223","DOIUrl":null,"url":null,"abstract":"Fecal indicator bacteria (FIB) are widely used to assess microbial contamination in surface water. However, traditional FIB such as fecal coliforms and enterococcus often fail to reflect pathogen-related health risks due to differences in environmental persistence and behavior. This study evaluated <em>Clostridium perfringens</em> (<em>C. perfringens</em>) as an alternative FIB through a national-scale survey of 116 sites across seven major Chinese river basins impacted by anthropogenic contamination<em>. C. perfringens</em> was detected at all sites, with a median concentration of 700 CFU/100 mL, substantially higher than fecal coliforms (26 CFU/100 mL) and enterococcus (4 CFU/100 mL). It showed stronger correlations with priority bacterial pathogens (<em>Shigella, Salmonella, Vibrio cholerae</em>) and with microbial source tracking markers of human and livestock origin. A significant wastewater treatment plant downstream decay trend (<em>k</em> = -0.21, <em>p</em> < 0.05), aligned with key bacterial pathogens, further supports its diagnostic potential. Using reverse quantitative microbial risk assessment, generalized additive models, and species sensitivity distribution analysis, we derived a health-based guideline of 174 CFU/100 mL for <em>C. perfringens</em>, corresponding to the WHO benchmark of bacterial pathogens (10<sup>-6</sup> DALYs per person per year for drinking, swimming, and vegetable ingestion exposure). Based on this threshold, 55-100% of sites in Chinese rivers exceeded acceptable risk levels, far surpassing exceedance rates under current fecal coliform criteria. This represents the first large-scale application of <em>C. perfringens</em> as a risk-based indicator and highlights its potential to strengthen microbial water quality monitoring and public health protection.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"96 1","pages":""},"PeriodicalIF":11.4000,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Water Research","FirstCategoryId":"93","ListUrlMain":"https://doi.org/10.1016/j.watres.2025.124223","RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, ENVIRONMENTAL","Score":null,"Total":0}
引用次数: 0
Abstract
Fecal indicator bacteria (FIB) are widely used to assess microbial contamination in surface water. However, traditional FIB such as fecal coliforms and enterococcus often fail to reflect pathogen-related health risks due to differences in environmental persistence and behavior. This study evaluated Clostridium perfringens (C. perfringens) as an alternative FIB through a national-scale survey of 116 sites across seven major Chinese river basins impacted by anthropogenic contamination. C. perfringens was detected at all sites, with a median concentration of 700 CFU/100 mL, substantially higher than fecal coliforms (26 CFU/100 mL) and enterococcus (4 CFU/100 mL). It showed stronger correlations with priority bacterial pathogens (Shigella, Salmonella, Vibrio cholerae) and with microbial source tracking markers of human and livestock origin. A significant wastewater treatment plant downstream decay trend (k = -0.21, p < 0.05), aligned with key bacterial pathogens, further supports its diagnostic potential. Using reverse quantitative microbial risk assessment, generalized additive models, and species sensitivity distribution analysis, we derived a health-based guideline of 174 CFU/100 mL for C. perfringens, corresponding to the WHO benchmark of bacterial pathogens (10-6 DALYs per person per year for drinking, swimming, and vegetable ingestion exposure). Based on this threshold, 55-100% of sites in Chinese rivers exceeded acceptable risk levels, far surpassing exceedance rates under current fecal coliform criteria. This represents the first large-scale application of C. perfringens as a risk-based indicator and highlights its potential to strengthen microbial water quality monitoring and public health protection.
期刊介绍:
Water Research, along with its open access companion journal Water Research X, serves as a platform for publishing original research papers covering various aspects of the science and technology related to the anthropogenic water cycle, water quality, and its management worldwide. The audience targeted by the journal comprises biologists, chemical engineers, chemists, civil engineers, environmental engineers, limnologists, and microbiologists. The scope of the journal include:
•Treatment processes for water and wastewaters (municipal, agricultural, industrial, and on-site treatment), including resource recovery and residuals management;
•Urban hydrology including sewer systems, stormwater management, and green infrastructure;
•Drinking water treatment and distribution;
•Potable and non-potable water reuse;
•Sanitation, public health, and risk assessment;
•Anaerobic digestion, solid and hazardous waste management, including source characterization and the effects and control of leachates and gaseous emissions;
•Contaminants (chemical, microbial, anthropogenic particles such as nanoparticles or microplastics) and related water quality sensing, monitoring, fate, and assessment;
•Anthropogenic impacts on inland, tidal, coastal and urban waters, focusing on surface and ground waters, and point and non-point sources of pollution;
•Environmental restoration, linked to surface water, groundwater and groundwater remediation;
•Analysis of the interfaces between sediments and water, and between water and atmosphere, focusing specifically on anthropogenic impacts;
•Mathematical modelling, systems analysis, machine learning, and beneficial use of big data related to the anthropogenic water cycle;
•Socio-economic, policy, and regulations studies.