Estimating Potential Environmental Loadings ofCryptosporidiumspp. andCampylobacterspp. from Livestock in the Grand River Watershed, Ontario, Canada

Abstract

Exposure to waterborne pathogens in recreational or drinking water is a serious public health concern. Thus, it is important to determine the sources of pathogens in a watershed and to quantify their environmental loadings. The natural variability of potentially pathogenic microorganisms in the environment from anthropogenic, natural, and livestock sources is large and has been difficult to quantify. A first step in characterizing the risk of nonpoint source contamination from pathogens of livestock origin is to determine the potential environmental loading based on animal prevalence and fecal shedding intensity. This study developed a probabilistic model for estimating the production of Cryptosporidium spp. and Campylobacter spp. from livestock sources within a watershed. Probability density functions representing daily pathogen production rates from livestock were simulated for the Grand River Watershed in southwestern Ontario. The prevalence of pathogenic microorganisms in animals was modeled as a mixture of beta-distributions with parameters drawn from published studies. Similarly, gamma-distributions were generated to describe animal pathogen shedding intensity. Results demonstrate that although cattle are responsible for the largest amount of manure produced, other domesticated farm animals contribute large numbers of the two pathogenic microorganisms studied. Daily pathogen production rates are highly sensitive to the parameters of the gamma-distributions, illustrating the need for reliable data on animal shedding intensity. The methodology may be used for identifying source terms for pathogen fate and transport modeling and for defining and targeting regions that are most vulnerable to water contamination from pathogenic sources.

The detection of Yersinia enterocolitica in surface water by quantitative PCR amplification of the ail and yadA genes

“…Both gene targets were detected most frequently at the Canagagigue Creek sampling location. The Canagagigue Creek subwatershed is located in a region with the highest livestock density in the watershed (Dorner et al 2007) and where estimates for daily manure production were also highest (Dorner et al 2004). for Yersinia in water also noted a higher rate of isolation during colder months of the year (Meadows & Snudden 1982;Fukushima et al 1984).…”

“…It provides part of the drinking water supply for approximately 500,000 people, and is also used for recreational activities (Dorner et al 2004). This system is one of the most heavily impacted watersheds in Canada, receiving inputs from both agricultural and urban activities (Dorner et al 2004), and a number of enteric pathogens typically found in surface waters have been previously detected (Dorner et al 2007). This research provides information for an emerging waterborne pathogen that is not well characterized in water sources.…”

Interaction Forces Drive the Environmental Transmission of Pathogenic Protozoa

“…Microbial pathogen modeling basically incorporates specific information about microbial dynamics in conjunction with soil composition, hydrological dynamics, climatic conditions, vegetation, and land management (35). It has been clearly demonstrated that mathematical models for bacteria are not suitable for predicting the fate and transport of parasitic protozoa (17,28,35). In particular, fecal indicators fail to reflect water contamination by Cryptosporidium and Giardia parasites because of the ability of oocysts and cysts to interact and aggregate reversibly with other particles, in contrast to other microorganisms (35,49).…”

“…In particular, fecal indicators fail to reflect water contamination by Cryptosporidium and Giardia parasites because of the ability of oocysts and cysts to interact and aggregate reversibly with other particles, in contrast to other microorganisms (35,49). Several specific models have been successfully used for estimating protozoan loads in watersheds in some particular contexts (17,28,35). To our knowledge, no such models exist for Toxoplasma oocysts on a large scale, mainly because there is too little information on their transport properties, survival, and prevalence in the environment (31,60,100).…”

Epilithon isotope composition as an environmental archive in rivers receiving wastewater

“…The Grand River (south western Ontario, Canada) has been thoroughly characterized, with studies ranging from nutrient uptake (BARLOW-BUSCH et al, 2006), species composition along seasonal and nutrient gradients (METCALFE-SMITH et al, 2000;ROTT et al, 1998;SREENIVASA and DUTHIE, 1973), nitrogen cycling (ROSAMOND et al, 2011), fish ecology (COOKE and BUNT, 1999) to health risks from livestock rearing (DORNER et al, 2004) and human activities (LISSEMORE et al, 2006). The Grand River receives agricultural and urban inputs from both point (sewage plants, tile drainage) and non-point sources (agriculture, chiefly from manure spreading).…”