title: Occurrence of Clostridium difficile in two types of wastewater treatment plants.
abstract: Wastewater is a potential environmental source of Clostridium difficile, although a direct link with community-acquired C. difficile infection (CA-CDI) in humans has not yet been established. The present study was performed to determine the occurrence of C. difficile in two types of wastewater treatment plants (WWTPs) in Isfahan, Iran. A total of 95 samples were taken from a conventional activated sludge treatment plant and a waste stabilization ponds system, and analyzed for the presence of C. difficile. C. difficile was found in 13.6% (3/22) of digested sludge samples. However, no C. difficile was detected in inlet and outlet samples or in raw sludge of activated sludge. C. difficile was also detected in 5% (2/40) of the samples from waste stabilization ponds. Polymerase chain reaction (PCR) analysis showed that all strains of C. difficile detected were toxigenic (tcdB gene positive). This study shows that C. difficile was present in WWTPs, which might constitute a potential source of community-acquired C. difficile infection.
authors.affiliation: Department of Environmental Health Engineering, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran. Electronic address: nikaeen@hlth.mui.ac.
authors.forename: Mahnaz
authors.initials: M
authors.lastname: Nikaeen
authors.affiliation: Department of Environmental Health Engineering, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Hajar
authors.initials: H
authors.lastname: Aghili Dehnavi
authors.affiliation: Department of Statistics and Epidemiology, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Akbar
authors.initials: A
authors.lastname: Hssanzadeh
authors.affiliation: Department of Pathobiology, University of Guelph, Canada.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Jalali
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D001427:Bacterial Toxins / Q000235:genetics; D016360:Clostridioides difficile / Q000302:isolation & purification*; D004782:Environmental Health; D005243:Feces / Q000382:microbiology*; D006801:Humans; D007492:Iran; D016133:Polymerase Chain Reaction; D062065:Wastewater / Q000382:microbiology*
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D062065:Wastewater; C031815:toxB protein, Clostridium difficile
keywords: community-acquired C. difficile; conventional activated sludge; polymerase chain reaction; tcdB; waste stabilization ponds