title: Decay of enteric microorganisms in biosolids-amended soil under wheat (Triticum aestivum) cultivation.
abstract: There is a growing need for better assessment of health risks associated with land-applied biosolids. This study investigated in-situ decay of seeded human adenovirus (HAdV), Salmonella enterica, Escherichia coli, and bacteriophage (MS2) in biosolids-amended soil under wheat cultivation. The biosolids seeded with microorganisms were placed in decay chambers which were then placed in the topsoil (10 cm depth) at three different sites. Sites were selected in arid wheat-growing regions of Australia with loamy-sand soil type (Western Australia) and sandy soil (South Australia). Seeded E. coli and S. enterica had a relatively short decay time (T90 = 4-56 days) in biosolids-amended soil compared to un-amended soil (T90 = 8-83 days). The decreasing soil moisture over the wheat-growing season significantly (P < 0.05) influenced survival time of both bacteria and MS2 at Western Australia (Moora) and South Australia (Mt Compass) sites, particularly in the un-amended soils. Increasing soil temperature also significantly (P < 0.05) influenced the decay of MS2 at these sites. In this study, no notable decline in HAdV numbers (PCR detectable units) was observed in both biosolids-amended and the un-amended soils at all three sites. The HAdV decay time (T90 ≥ 180 days) in biosolids-amended and un-amended soils was significantly higher than MS2 (T90 = 22-108 days). The results of this study suggest that adenovirus could survive for a longer period of time (>180 days) during the winter in biosolids-amended soil. The stability of adenovirus suggests that consideration towards biosolids amendment frequency, time, rates and appropriate withholding periods are necessary for risk mitigation.
authors.affiliation: Department of Environment and Agriculture, Curtin University, GPO Box U1987, Perth, Western Australia 6845, Australia.
authors.forename: K R
authors.initials: KR
authors.lastname: Schwarz
authors.affiliation: CSIRO Land and Water, EcoSciences Precinct, 41 Boggo Road, Dutton Park, Queensland 4102, Australia. Electronic address: Jatinder.Sidhu@csiro.au.
authors.forename: J P S
authors.initials: JP
authors.lastname: Sidhu
authors.affiliation: Department of Environment and Agriculture, Curtin University, GPO Box U1987, Perth, Western Australia 6845, Australia.
authors.forename: D L
authors.initials: DL
authors.lastname: Pritchard
authors.affiliation: CSIRO Animal, Food and Health Sciences, Queensland Biosciences Precinct, 306 Carmody Road, St Lucia, QLD 4067, Australia.
authors.forename: Y
authors.initials: Y
authors.lastname: Li
authors.affiliation: CSIRO Land and Water, EcoSciences Precinct, 41 Boggo Road, Dutton Park, Queensland 4102, Australia; School of Population Health, University of Queensland, Herston Road, Herston, Brisbane, QLD 4006, Australia.
authors.forename: S
authors.initials: S
authors.lastname: Toze
mesh_terms: D000260:Adenoviruses, Human / Q000502:physiology*; D004926:Escherichia coli / Q000502:physiology*; D005308:Fertilizers; D017909:Levivirus / Q000502:physiology*; D050296:Microbial Viability; D019779:Salmonella enterica / Q000502:physiology*; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology; D013997:Time Factors; D014908:Triticum / Q000502:physiology*; D014887:Weather
chemical_list: D005308:Fertilizers; D012987:Soil
keywords: Biosolids-amended soil; Human adenovirus; MS2; Pathogen decay; Salmonella enterica