title: Occurrence of glucocorticoids discharged from a sewage treatment plant in Japan and the effects of clobetasol propionate exposure on the immune responses of common carp (Cyprinus carpio) to bacterial infection.
abstract: The present study evaluated the environmental risks to common carp (Cyprinus carpio) posed by glucocorticoids present in sewage treatment plant (STP) effluent. To gather information on the seasonal variations in glucocorticoid concentration, the authors sampled the effluent of a Japanese STP every other week for 12 mo. Six of 9 selected glucocorticoids were detected in the effluent, with clobetasol propionate and betamethasone 17-valerate detected at the highest concentrations and frequencies. The present study's results indicated that effluent glucocorticoid concentration may depend on water temperature, which is closely related to the removal efficiency of the STP or to seasonal variations in the public's use of glucocorticoids. In a separate experiment, to clarify whether glucocorticoids in environmental water increase susceptibility to bacterial infection in fish, the authors examined the responses to bacterial infection (Aeromonas veronii) of common carp exposed to clobetasol propionate. Clobetasol propionate exposure did not affect bacterial infection-associated mortality. In fish infected with A. veronii but not exposed to clobetasol propionate, head kidney weight and number of leukocytes in the head kidney were significantly increased (p < 0.05), whereas these effects were not observed in infected fish exposed to clobetasol. This suggests that clobetasol propionate alleviated bacterial infection-associated inflammation. Together, these results indicate that susceptibility to bacterial infection in common carp is not affected by exposure to glucocorticoids at environmentally relevant concentrations.
authors.affiliation: Center for Marine Environmental Studies, Ehime University, Matsuyama, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Nakayama
authors.affiliation: Center for Marine Environmental Studies, Ehime University, Matsuyama, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Sato
authors.affiliation: Department of Biology, Faculty of Science, Ehime University, Matsuyama, Japan.
authors.forename: Takazumi
authors.initials: T
authors.lastname: Shibano
authors.affiliation: Center for Marine Environmental Studies, Ehime University, Matsuyama, Japan.|Center for Environmental Health Science, National Institute for Environmental Studies, Tsukuba, Japan.
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Isobe
authors.affiliation: Center for Material Cycles and Waste Management Research, National Institute for Environmental Studies, Tsukuba, Japan.
authors.forename: Go
authors.initials: G
authors.lastname: Suzuki
authors.affiliation: Center for Marine Environmental Studies, Ehime University, Matsuyama, Japan.
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Kitamura
mesh_terms: D000333:Aeromonas / Q000502:physiology; D000818:Animals; D002347:Carps / Q000276:immunology* / Q000382:microbiology; D002452:Cell Count; D002990:Clobetasol / Q000633:toxicity*; D005938:Glucocorticoids / Q000633:toxicity*; D016905:Gram-Negative Bacterial Infections / Q000276:immunology; D007564:Japan; D007668:Kidney / Q000187:drug effects; D008214:Lymphocytes / Q000187:drug effects; D009929:Organ Size / Q000187:drug effects; D012722:Sewage / Q000737:chemistry*; D014865:Waste Disposal, Fluid; D018508:Water Purification
chemical_list: D005938:Glucocorticoids; D012722:Sewage; D002990:Clobetasol
keywords: Aquatic toxicology; Disease susceptibility; Glucocorticoid; Immunotoxicity; Pharmaceuticals; Sewage treatment plant