The Cryptosporidium species/genotypes commonly
identified in water can yield insights into the nature of anthropogenic inputs (i.e., human or
animal waste) and thus help inform source water protection strategies. Detection of
Cryptosporidium forms harbored by the dominant livestock species within a watershed
should be evidence for agricultural contamination. To challenge this hypothesis, parasite
occurrence and molecular profiling were used to track fecal contamination in watersheds
heavily dominated by swine production (the Bras d'Henri/Fourchette watershed, Quebec), beef or
dairy cattle (Oldman watershed, Alberta; South Nation watershed, Ontario), and intensive poultry
farming (the Sumas watershed, British Columbia). Parasites were monitored on a bi-weekly basis from the
spring to the fall of 2006 using US Environmental Protection Agency (USEPA) Method 1623. Levels of Cryptosporidium
contamination ranged widely through the sampling period with average watershed values
peaking at 0.77 oocysts/liter for the Bras d'Henri/Fourchette watershed; 0.86 oocysts/liter for
the South Nation watershed; 0.36 oocysts/liter for the Oldman watershed; and, 0.21
oocysts/liter for the Sumas watershed. Molecular forensic profiling of Cryptosporidium
positive microscope slides at high occurrence levels from these watersheds resulted in 4
species/genotypes from the Bras d'Henri/Fourchette watersheds (C. andersoni, muskrat II
genotype, W7 genotype and W15 genotype); 6 from the Oldman (C. andersoni, C. baileyi,
cervine genotype, muskrat II genotype, skunk genotype and W15 genotype); 6 from the
South Nation (C. andersoni, C. parvum, muskrat II genotype, muskrat I genotype, W7
genotype and W12 genotype) and 4 species/genotypes from Sumas watershed (C. muris,
opossum I genotype, muskrat I genotype, W15 genotype). Wildlife species of
Cryptosporidium were commonly found in all four watersheds. Surprisingly, only in the
cattle-dominated watersheds (Oldman and South Nation) did Cryptosporidium species
occurrence correlate with the dominant livestock species farmed (i.e., a predominance of C.
andersoni). In poultry and swine dominated watersheds (Sumas and Bras d'Henri/Fourchette
watersheds, respectively) the diversity of Cryptosporidium observed in the water did not
appear to correlate with host-adapted forms associated with the dominant animal agriculture
activity (i.e., C. meleagridis, C. baileyi, C. suis or pig genotype II). These preliminary
findings did not support the stated hypothesis indicating that genotyping tools are necessary
for determining the animal hosts responsible for contributing parasites into the watershed. Includes 28 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 330 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 12 |
| Published : | 11/01/2007 |
