TY - JOUR
T1 - Transport of Cryptosporidium parvum oocysts in soil columns following applications of raw and separated liquid slurries
AU - Petersen, Heidi Huus
AU - Enemark, Heidi L.
AU - Olsen, Annette
AU - Amin, Mostofa
AU - Dalsgaard, Anders
PY - 2012/9
Y1 - 2012/9
N2 - The potential for the transport of viable Cryptosporidium parvum oocysts through soil to land drains and groundwater was studied using simulated rainfall and intact soil columns which were applied raw slurry or separated liquid slurry. Following irrigation and weekly samplings over a 4-week period, C. parvum oocysts were detected from all soil columns regardless of slurry type and application method, although recovery rates were low (<1%). Soil columns with injected liquid slurry leached 73 and 90% more oocysts compared to columns with injected and surface-applied raw slurries, respectively. Among leachate samples containing oocysts, 44/72 samples yielded viable oocysts as determined by a dye permeability assay (DAPI [4',6'-diamidino-2- phenylindole]/propidium iodide) with the majority (41%) of viable oocysts found in leachate from soil columns with added liquid slurry. The number of viable oocysts was positively correlated (r=0.63) with the total number of oocysts found. Destructively sampling of the soil columns showed that type of slurry and irrigation played a role in the vertical distribution of oocysts, with more oocysts recovered from soil columns added liquid slurry irrespective of the irrigation status. Further studies are needed to determine the effectiveness of different slurry separation technologies to remove oocysts and other pathogens, as well as whether the application of separated liquid slurry to agricultural land may represent higher risks for groundwater contamination compared to application of raw slurry.
AB - The potential for the transport of viable Cryptosporidium parvum oocysts through soil to land drains and groundwater was studied using simulated rainfall and intact soil columns which were applied raw slurry or separated liquid slurry. Following irrigation and weekly samplings over a 4-week period, C. parvum oocysts were detected from all soil columns regardless of slurry type and application method, although recovery rates were low (<1%). Soil columns with injected liquid slurry leached 73 and 90% more oocysts compared to columns with injected and surface-applied raw slurries, respectively. Among leachate samples containing oocysts, 44/72 samples yielded viable oocysts as determined by a dye permeability assay (DAPI [4',6'-diamidino-2- phenylindole]/propidium iodide) with the majority (41%) of viable oocysts found in leachate from soil columns with added liquid slurry. The number of viable oocysts was positively correlated (r=0.63) with the total number of oocysts found. Destructively sampling of the soil columns showed that type of slurry and irrigation played a role in the vertical distribution of oocysts, with more oocysts recovered from soil columns added liquid slurry irrespective of the irrigation status. Further studies are needed to determine the effectiveness of different slurry separation technologies to remove oocysts and other pathogens, as well as whether the application of separated liquid slurry to agricultural land may represent higher risks for groundwater contamination compared to application of raw slurry.
U2 - 10.1128/AEM.07829-11
DO - 10.1128/AEM.07829-11
M3 - Journal article
SN - 0099-2240
VL - 78
SP - 5994
EP - 6000
JO - Applied and Environmental Microbiology
JF - Applied and Environmental Microbiology
IS - 17
ER -