| Title | Intermediate concentrations of synthetic antibiotics drive drastic changes in aquatic bacterial communities |
| Abstract | The spread of resistances to commonly used synthetic antibiotics (AB) in natural environments is one of the major threats to human health. A large number of publications investigated the relations between different human pathogens and the spread of AB resistances, but a comparably low number of studies targeted the ecological effect of the presence of synthetic AB on nonâEURpathogenic bacteria in waters. We tested the longâEURterm impact of a cocktail of synthetic antibiotics of commercial use (Imipenem, Levofloaxcin, and Tetracycline) on artificial bacterial communities miming a very simplified natural freshwater community. The experimental setup consisted in a 24 daysâEURlong continuous culture system where the bacterial communities were expose to three different AB concentrations: no AB (control), subâEURlethal AB concentration (comparable to anthropized European lakes), and in AB concentration 10 folds higher (comparable to heavily contaminated water treatment plants). Bacterial number and morphological distribution were daily monitored (epifluorescence microscopy), while community composition (CARDâEURFISH) and antibiotic resistance were assessed biâEURweekly. Bacterial production, and thus abundance, dropped by 75% in the presence of AB, independently by their concentration, while bacterial community composition resulted highly affected by intermediate AB concentration, with reversal in the proportion of the dominant groups (A. hydrophila and Brevundimonas sp.). These results, for the first time focussing on the ecological consequences of AB on a experimental bacterial community, highlight the potential risk posed by low AB concentrations in waters. Their effect is not only limited to the spread of potentially pathogenic strains, but it extends to modification of interspecific ecological interactions, weakening the natural resistance of the aquatic communities to the success of allochtonous, and potentially dangerous, strains. |
| Source | S.It.E: XXIII Congresso della Società Italiana di Ecologia "Ecologia per la sostenibilità e crescita della Blue e Green economy", Ancona, 16-18 settembre 2013 |
| Keywords | Antibiotic resistanceAquatic bacterial communities |
| Year | 2013 |
| Type | Abstract in atti di convegno |
| Authors | Gianluca Corno; Marco Giardina; Sonia Plechuk; Manuela Coci |
| Text | 312711 2013 Antibiotic resistance Aquatic bacterial communities Intermediate concentrations of synthetic antibiotics drive drastic changes in aquatic bacterial communities Gianluca Corno; Marco Giardina; Sonia Plechuk; Manuela Coci Gianluca Corno CNR ISE, Pallanza Verbania; Marco Giardina, Sonia Plechuk, Manuela Coci Laboratory of Molecular Microbiology and Antibiotic Resistance, Department of Bio Medical Sciences, University of Catania Published version ID_PUMA cnr.ise/2013 B6 009. Acronimo titolo evento S.It.E. S.It.E XXIII Congresso della Societa Italiana di Ecologia Ecologia per la sostenibilita e crescita della Blue e Green economy Ancona 16 18 settembre 2013 Nazionale Contributo The spread of resistances to commonly used synthetic antibiotics AB in natural environments is one of the major threats to human health. A large number of publications investigated the relations between different human pathogens and the spread of AB resistances, but a comparably low number of studies targeted the ecological effect of the presence of synthetic AB on nonaEURpathogenic bacteria in waters. We tested the longaEURterm impact of a cocktail of synthetic antibiotics of commercial use Imipenem, Levofloaxcin, and Tetracycline on artificial bacterial communities miming a very simplified natural freshwater community. The experimental setup consisted in a 24 daysaEURlong continuous culture system where the bacterial communities were expose to three different AB concentrations no AB control , subaEURlethal AB concentration comparable to anthropized European lakes , and in AB concentration 10 folds higher comparable to heavily contaminated water treatment plants . Bacterial number and morphological distribution were daily monitored epifluorescence microscopy , while community composition CARDaEURFISH and antibiotic resistance were assessed biaEURweekly. Bacterial production, and thus abundance, dropped by 75% in the presence of AB, independently by their concentration, while bacterial community composition resulted highly affected by intermediate AB concentration, with reversal in the proportion of the dominant groups A. hydrophila and Brevundimonas sp. . These results, for the first time focussing on the ecological consequences of AB on a experimental bacterial community, highlight the potential risk posed by low AB concentrations in waters. Their effect is not only limited to the spread of potentially pathogenic strains, but it extends to modification of interspecific ecological interactions, weakening the natural resistance of the aquatic communities to the success of allochtonous, and potentially dangerous, strains. Intermediate concentrations of synthetic antibiotics drive drastic changes in aquatic bacterial communities 2013_B6_009.pdf Abstract in atti di convegno Edizioni Zara. 1127 5006 Atti della Societa italiana di ecologia Atti della Societa italiana di ecologia Atti Soc.ital. ecol. S.IT.E. Atti gianluca.corno CORNO GIANLUCA TA.P04.016.004 Ecologia teorica e applicata degli ecosistemi acquatici |
