| Title | Persistence of the antibiotic sulphametoxazole in river water microcosms |
| Abstract | Many recent studies have reported the ubiquitous occurrence of antibiotics in
aquatic ecosystems. Antibiotics can both kill natural microbial populations and act
as a pressure for the selection of resistant bacteria. Following administration,
antibiotics are only partially metabolized and, therefore, a large amount is excreted
unaltered or as active metabolites via urine and faeces; consequently, human
antibiotics reach wastewater treatment plants. The latter are not specifically
designed for antibiotic removal, and consequently these molecules are released
directly into the receiving environments. The fate and effects on health ecosystem
of these compounds is not still well known. Sulfamethoxazole (SMX) is one of the
most widely synthesized sulfonamides, prescribed to treat urinary infections; it is
also used in veterinary practice, aquaculture and livestock breeding. Its mechanism
of action is based on the inhibition of folic acid synthesis in bacteria. SMX has been
detected in groundwater, in effluents of WWTPs and in surface water, including
drinkable water. SMX has been reported to be not readily biodegradable, resistant
to hydrolysis and the photo-degradation as a possible degradation process in surface
waters. Data on biodegradation in natural water ecosystem are quite scarce. In this
context, the aim of the present work was to investigate the persistence of the
antibiotic sulphametoxazole in river water, focusing on both the biodegradation and
photodegradation processes. For this purpose, two different microcosm
experiments were set up using river water treated with 500 µg/L of SMX in the
presence or absence (river water sterilized) of the natural microbial community. In
order to evaluate SMX biodegradation, the first experiment was performed in the
dark. In the second one, river water microcosms were incubated under UV-light, in
order to evaluate the possible photodegradation of SMX. At fixed times, water
sample were collected from microcosms for measuring SMX residual
concentrations over time by-using HLPC-UV. The disappearance time of 50% of
the initial SMX concentration (DT50) was evaluated in both experiments. Moreover,
the effects of the antibiotic on the natural microbial community were assessed in
terms of cell vitality, abundance and phylogenetic diversity comparing the treated
river water microcosms with those no treated one. |
| Source | SETAC Europe 27th Annual Meeting, Bruxelles, 7-11/05/2017 |
| Keywords | Antibioticsnatural microbial communitiesriver water |
| Year | 2017 |
| Type | Abstract in atti di convegno |
| Authors | Rauseo J, Ademollo N, Grenni P, Barra Caracciolo A, Cardoni M, Patrolecco L |
| Text | 373459 2017 Antibiotics natural microbial communities river water Persistence of the antibiotic sulphametoxazole in river water microcosms Rauseo J, Ademollo N, Grenni P, Barra Caracciolo A, Cardoni M, Patrolecco L IRSA CNR Environmental Quality Through Transdisciplinary Collaboration SETAC Europe, Brussels Published version https //brussels.setac.org/wp content/uploads/2016/06/1702712_abstractbook.pdf PRINT ISSN 2309 8031 ONLINE ISSN 2310 3043 SETAC Europe 27th Annual Meeting Bruxelles 7 11/05/2017 Internazionale Contributo Many recent studies have reported the ubiquitous occurrence of antibiotics in aquatic ecosystems. Antibiotics can both kill natural microbial populations and act as a pressure for the selection of resistant bacteria. Following administration, antibiotics are only partially metabolized and, therefore, a large amount is excreted unaltered or as active metabolites via urine and faeces; consequently, human antibiotics reach wastewater treatment plants. The latter are not specifically designed for antibiotic removal, and consequently these molecules are released directly into the receiving environments. The fate and effects on health ecosystem of these compounds is not still well known. Sulfamethoxazole SMX is one of the most widely synthesized sulfonamides, prescribed to treat urinary infections; it is also used in veterinary practice, aquaculture and livestock breeding. Its mechanism of action is based on the inhibition of folic acid synthesis in bacteria. SMX has been detected in groundwater, in effluents of WWTPs and in surface water, including drinkable water. SMX has been reported to be not readily biodegradable, resistant to hydrolysis and the photo degradation as a possible degradation process in surface waters. Data on biodegradation in natural water ecosystem are quite scarce. In this context, the aim of the present work was to investigate the persistence of the antibiotic sulphametoxazole in river water, focusing on both the biodegradation and photodegradation processes. For this purpose, two different microcosm experiments were set up using river water treated with 500 µg/L of SMX in the presence or absence river water sterilized of the natural microbial community. In order to evaluate SMX biodegradation, the first experiment was performed in the dark. In the second one, river water microcosms were incubated under UV light, in order to evaluate the possible photodegradation of SMX. At fixed times, water sample were collected from microcosms for measuring SMX residual concentrations over time by using HLPC UV. The disappearance time of 50% of the initial SMX concentration DT50 was evaluated in both experiments. Moreover, the effects of the antibiotic on the natural microbial community were assessed in terms of cell vitality, abundance and phylogenetic diversity comparing the treated river water microcosms with those no treated one. Abstract Book 1702712_abstractbook.pdf Abstract in atti di convegno jasmin.rauseo RAUSEO JASMIN CARDONI MARTINA luisa.patrolecco PATROLECCO LUISA anna.barracaracciolo BARRA CARACCIOLO ANNA paola.grenni GRENNI PAOLA nicoletta.ademollo ADEMOLLO NICOLETTA TA.P04.005.011 Vulnerabilita degli ecosistemi delle acque sotterranee e attenuazione naturale degli inquinanti nel suolo e nel sottosuolo |
