| Title | High-quality treated wastewater causes remarkable changes in natural microbial communities and intI1 gene abundance |
| Abstract | We carry out a mesocosms experiment to assess the impact of high-quality treated wastewater intended for agricultural reuse (HQWR) on freshwater bacteria seldom exposed to anthropogenic pollution. Effects were assessed by comparing the abundance and composition of bacterial communities as well as their resistance profile under control (source water from an unpolluted lake) and treatment conditions (source water mixed 1:1 with HQWR, with and without 5 ?g L of cefotaxime). We investigated the effect of the different conditions on the abundance of genes encoding resistance to ?-lactams and carbapenems (bla, bla, bla and bla), fluoroquinolones (qnrS), tetracyclines (tetA), sulfonamides (sul2), macrolides (ermB), arsenic and cadmium (arsB and czcA, respectively), and on the gene encoding the Class 1 integron integrase (intI1). Bacterial communities exposed to HQWR showed a significant higher abundance of tetA, arsB, czcA, and intI1 genes, whereas those exposed to Cefotaxime-amended HQWR did not. Genes conferring resistance to carbapenems, ?-lactams, fluoroquinolones, and macrolides were below detection limit in all treatments. Besides, the higher availability of nutrients under treatment conditions favored bacterial growth in comparison to those exposed to control conditions. Particularly, Acinetobacter spp. and Pseudomonas spp. were significantly enriched after 22 days of treatment exposure. The presence of cefotaxime (a third generation cephalosporine) in the feeding medium caused an enrichment of bacterial communities in sequences affiliated to Acinetobacter thus suggesting that these resistant forms may possess resistance genes other than those studied here (bla, bla and bla). Although derived from a mesocosm experiment in continuous cultures, our results call attention to the need of refined regulations regarding the use of reclaimed water in agriculture since even high-quality treated wastewater may lead to undesired effects on receiving bacterial communities in terms of composition and dissemination of antibiotic resistance genes. |
| Source | Water research (Oxf.) 167 |
| Keywords | Antibiotic resistanceAquatic bacteriaBiofilmCefotaximeHeavy metal resistanceTreated wastewater |
| Journal | Water research (Oxf.) |
| Editor | Pergamon Press., New York, Regno Unito |
| Year | 2019 |
| Type | Articolo in rivista |
| DOI | 10.1016/j.watres.2019.114895 |
| Authors | Subirats, Jèssica; Di Cesare, Andrea; Varela della Giustina, Saulo; Fiorentino, Antonino; Eckert, Ester M.; Rodriguez-Mozaz, Sara; Borrego, Carles M.; Corno, Gianluca |
| Text | 407739 2019 10.1016/j.watres.2019.114895 Scopus 2 s2.0 85072334270 Antibiotic resistance Aquatic bacteria Biofilm Cefotaxime Heavy metal resistance Treated wastewater High quality treated wastewater causes remarkable changes in natural microbial communities and intI1 gene abundance Subirats, Jessica; Di Cesare, Andrea; Varela della Giustina, Saulo; Fiorentino, Antonino; Eckert, Ester M.; Rodriguez Mozaz, Sara; Borrego, Carles M.; Corno, Gianluca Catalan Institute for Water Research; Universitat de Girona; National Research Council CNR IRSA We carry out a mesocosms experiment to assess the impact of high quality treated wastewater intended for agricultural reuse HQWR on freshwater bacteria seldom exposed to anthropogenic pollution. Effects were assessed by comparing the abundance and composition of bacterial communities as well as their resistance profile under control source water from an unpolluted lake and treatment conditions source water mixed 1 1 with HQWR, with and without 5 g L of cefotaxime . We investigated the effect of the different conditions on the abundance of genes encoding resistance to lactams and carbapenems bla, bla, bla and bla , fluoroquinolones qnrS , tetracyclines tetA , sulfonamides sul2 , macrolides ermB , arsenic and cadmium arsB and czcA, respectively , and on the gene encoding the Class 1 integron integrase intI1 . Bacterial communities exposed to HQWR showed a significant higher abundance of tetA, arsB, czcA, and intI1 genes, whereas those exposed to Cefotaxime amended HQWR did not. Genes conferring resistance to carbapenems, lactams, fluoroquinolones, and macrolides were below detection limit in all treatments. Besides, the higher availability of nutrients under treatment conditions favored bacterial growth in comparison to those exposed to control conditions. Particularly, Acinetobacter spp. and Pseudomonas spp. were significantly enriched after 22 days of treatment exposure. The presence of cefotaxime a third generation cephalosporine in the feeding medium caused an enrichment of bacterial communities in sequences affiliated to Acinetobacter thus suggesting that these resistant forms may possess resistance genes other than those studied here bla, bla and bla . Although derived from a mesocosm experiment in continuous cultures, our results call attention to the need of refined regulations regarding the use of reclaimed water in agriculture since even high quality treated wastewater may lead to undesired effects on receiving bacterial communities in terms of composition and dissemination of antibiotic resistance genes. 167 Published version http //www.scopus.com/record/display.url eid=2 s2.0 85072334270 origin=inward High quality treated wastewater causes remarkable changes in natural microbial communities and intI1 gene abundance Art. Nr. 1 Subirats et al. Wat Res 2019.pdf Articolo in rivista Pergamon Press. 0043 1354 Water research Oxf. Water research Oxf. Water res. Oxf. Water research. Oxf. gianluca.corno CORNO GIANLUCA andrea.dicesare DI CESARE ANDREA estermaria.eckert ECKERT ESTER MARIA |
