title: Effects of manure-application practices on curli production by Escherichia coli transported through soil.
abstract: The release of Escherichia coli into the environment from untreated manure can pose a threat to human health. Environmental survival of E. coli has been linked to extracellular fibers called curli. We investigated the effect of manure management (surface application followed by incorporation versus immediate incorporation) on the relative abundance of curli-producing E. coli in subsurface drainage effluent. Samples were collected from three dairy farms. The proportion of curli-producing E. coli in the manure storage facilities was uniform across the farms. However, the abundance of curli-producing E. coli was much greater (P < 0.05) in the tile drains of farms performing surface application of manure than in the tile drain of the farm that incorporated manure. This field observation was tested with controlled soil column experiments; the abundance of curli-producing E. coli in soil column effluents was greater (P < 0.05) when manure was surface-applied than when it was incorporated. Our findings suggest selection pressures resulting from the different manure application methods affected curli production by E. coli isolates transported through soil. Given the importance of curli production in pathogenesis, this work highlights the effect that manure management strategies may have on pathogenesis-associated phenotypes of bacteria in agricultural subsurface runoff.
authors.affiliation: Department of Biological and Environmental Engineering, Cornell University , Ithaca, New York 14853, United States.
authors.forename: Allison M
authors.initials: AM
authors.lastname: Truhlar
authors.forename: Anthony E
authors.initials: AE
authors.lastname: Salvucci
authors.forename: M Todd
authors.initials: MT
authors.lastname: Walter
authors.forename: Lorin D
authors.initials: LD
authors.lastname: Warnick
authors.forename: Anthony G
authors.initials: AG
authors.lastname: Hay
authors.forename: Tammo S
authors.initials: TS
authors.lastname: Steenhuis
mesh_terms: D018830:Adhesins, Escherichia coli / Q000378:metabolism*; D000383:Agriculture; D001422:Bacterial Adhesion / Q000502:physiology; D001426:Bacterial Proteins / Q000378:metabolism*; D004784:Environmental Monitoring; D004926:Escherichia coli / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D008372:Manure / Q000382:microbiology*; D012988:Soil Microbiology
chemical_list: D018830:Adhesins, Escherichia coli; D001426:Bacterial Proteins; D008372:Manure; C077481:Crl protein, Bacteria