title: Do drying and rewetting cycles modulate effects of sulfadiazine spiked manure in soil?
abstract: Naturally occurring drying-rewetting events in soil have been shown to affect the dissipation of veterinary antibiotics entering soil by manure fertilization. However, knowledge of effects on the soil microbial community structure and resistome is scarce. Here, consequences of drying-rewetting cycles on effects of sulfadiazine (SDZ) in soil planted with Dactylis glomerata L. were investigated in microcosms. Manure containing SDZ or not was applied to the pregrown grass and incubated for 56 days in a climate chamber. Water was either added daily or reduced during two drying events of 7 days, each followed by a recovery phase. Total community DNA was analyzed to reveal the effects on the bacterial community structure and on the abundance of sul1, sul2, intI1 ,intI2, qacE+qacEΔ1, traN and korB genes relative to 16S rRNA genes. 16S rRNA gene-based DGGE fingerprints indicated that drying-rewetting cycles modulated the effects of SDZ on the bacterial community structure in the soil. Furthermore, the SDZ treatment increased the relative abundance of sulfonamide resistance and integrase genes compared to the control. However, this increase was not different between moisture regimes, indicating that drying-rewetting had only a negligible effect on the selection of the resistome by SDZ in the manured soil.
authors.affiliation: Julius Kühn-Institut - Federal Research Centre for Cultivated Plants (JKI), Institute for Epidemiology and Pathogen Diagnostics, Messeweg 11-12, 38104 Braunschweig, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Jechalke
authors.affiliation: Helmholtz Zentrum München, German Research Center for Environmental Health, Research Unit for Environmental Genomics, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany.
authors.forename: Viviane
authors.initials: V
authors.lastname: Radl
authors.affiliation: Helmholtz Zentrum München, German Research Center for Environmental Health, Research Unit for Environmental Genomics, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Schloter
authors.affiliation: Julius Kühn-Institut - Federal Research Centre for Cultivated Plants (JKI), Institute for Epidemiology and Pathogen Diagnostics, Messeweg 11-12, 38104 Braunschweig, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Heuer
authors.affiliation: Julius Kühn-Institut - Federal Research Centre for Cultivated Plants (JKI), Institute for Epidemiology and Pathogen Diagnostics, Messeweg 11-12, 38104 Braunschweig, Germany kornelia.smalla@julius-kuehn.de.
authors.forename: Kornelia
authors.initials: K
authors.lastname: Smalla
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D000900:Anti-Bacterial Agents / Q000378:metabolism*; D001419:Bacteria / Q000145:classification* / Q000378:metabolism; D003890:Desiccation; D024881:Drug Resistance, Bacterial; D008372:Manure / Q000032:analysis*; D006109:Poaceae / Q000382:microbiology*; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D013411:Sulfadiazine / Q000378:metabolism*; D014867:Water
chemical_list: D000900:Anti-Bacterial Agents; D008372:Manure; D012987:Soil; D014867:Water; D013411:Sulfadiazine
keywords: drying; mobilome; resistome; rewetting; rhizosphere; sulfadiazine