The Occurrence of Shiga-Toxin Producing Escherichia Coli (Stec) and Salmonella Species in Cattle Feedlot Runoff

Abstract

Zoonotic foodborne pathogens such as shiga-toxin producing Escherichia coli (STEC) and Salmonella on farm environments can potentially contaminate organic manure or agricultural watersheds and subsequently fresh produce during fertilization or irrigation. This study investigated the occurrence of STEC and Salmonella serotypes in cattle feedlot runoff samples in two feedlots in North Dakota. Using standard laboratory culture methods this study reported a 39% prevalence of STEC O45, 33 % (O103), 31 % (O157), 27 % (O121), 16 % (O26), 10% (O111), 10% (O113), 10 % (O145) and 39.7 % Salmonella. Additionally, occurrence of some STEC serotypes was influenced by feedlot (O111 and O121), sampling location in relation to vegetative filter strips (O157), and sampling time (O45 and O121). Although this study was the first to report occurrence of STEC serotypes including non-O157 serotypes in cattle feedlot runoff, further studies are needed to quantify the pathogen load in runoff prior to disposal.