Incidence and Persistence of Zoonotic Bacterial and Protozoan Pathogens in a Beef Cattle Feedlot Runoff Control–Vegetative Treatment System

Abstract

Determining the survival of zoonotic pathogens in livestock manure and runoff is critical for understanding the environmental and public health risks associated with these wastes. The occurrence and persistence of the bacterial pathogens Escherichia coli O157:H7 and Campylobacter spp. in a passive beef cattle feedlot runoff control-vegetative treatment system were examined over a 26-mo period. Incidence of the protozoans Cryptosporidium spp. and Giardia spp. was also assessed. The control system utilizes a shallow basin to collect liquid runoff and accumulate eroded solids from the pen surfaces; when an adequate liquid volume is attained, the liquid is discharged from the basin onto a 4.5-ha vegetative treatment area (VTA) of bromegrass which is harvested as hay. Basin discharge transported E. coli O157, Campylobacter spp., and generic E. coli into the VTA soil, but without additional discharge from the basin, the pathogen prevalences decreased over time. Similarly, the VTA soil concentrations of generic E. coli initially decreased rapidly, but lower residual populations persisted. Isolation of Cryptosporidium oocysts and Giardia cysts from VTA samples was infrequent, indicating differences in sedimentation and/or transport in comparison to bacteria. Isolation of generic E. coli from freshly cut hay from VTA regions that received basin discharge (12 of 30 vs. 1 of 30 control samples) provided evidence for the risk of contamination; however, neither E. coli O157 or Campylobacter spp. were recovered from the hay following baling. This work indicates that the runoff control system is effective for reducing environmental risk by containing and removing pathogens from feedlot runoff.

Lack of Direct Effects of Agrochemicals on Zoonotic Pathogens and Fecal Indicator Bacteria

“…any endemic and emerging zoonotic pathogens, such as Escherichia coli strains, Salmonella enterica, Cryptosporidium spp., Giardia spp., and zoonotic influenza viruses (15,26,30,31), can be of agricultural origin and shed in the feces of livestock (1,2,9). Many of these pathogens are waterborne and are, therefore, capable of entering water bodies via storm water and agricultural runoff as well as via subsurface transport.…”

Test of Direct and Indirect Effects of Agrochemicals on the Survival of Fecal Indicator Bacteria

“…For instance, many endemic and emerging human pathogens are derived from or associated with livestock, including pathogenic E. coli strains, Salmonella enterica, Campylobacter jejuni, Cryptosporidium spp., and zoonotic influenza viruses (53,58,59). Many of these agriculturally derived pathogens are waterborne and can enter water bodies via the introduction of runoff containing waste from livestock, such as cattle, swine, and poultry (6,10,23).…”

Sustainable manure management.

“…2000;Jenkins et al .. 2006;Ramos et al .. 2006). Methods to mitigate the offsite transport of microorganisms in runoff from manureamended soils and livestock feedlots include use of vegetative filter strips (Coyne et al .. 199 5;Fajardo et al .. 200 1) or vegetative treatment systems with a settling basin fo r solids collection and a vegetated area (Koelsch et al .. 2006;Berry et al .. 2007). Alternatively.…”