Factors Associated with the Presence of Escherichia coli O157 in Feces of Feedlot Cattle

Abstract

Fecal samples were collected from pens of cattle in a total of 100 feedlots in 13 states. Fecal samples were cultured for Escherichia coli O157. E. coli O157 isolates were probed for the genetic coding for verotoxin production. At the time of sample collection, data were collected on the type of cattle present in the pen, as well as the length of time these cattle were in the feedlot, ingredients for the current ration, and cattle health history since arriving in the feedlot. Factors associated with increased likelihood of a pen being positive (one or more samples probe-positive for E. coli O157) included feeding of barley (odds ratio [OR] = 2.75) and cattle being on feed less than 20 days (OR = 3.39). Factors associated with a reduced likelihood of a pen being positive included feeding soy meal (OR = 0.50), a cattle entry weight of at least 700 lb (ca. 317.5 kg) (OR = 0.54), and at least 85% of the cattle in the pen being beef-type heifers (OR = .33).

Longitudinal Study of Fecal Shedding of Escherichia coli O157:H7 in Feedlot Cattle: Predominance and Persistence of Specific Clonal Types despite Massive Cattle Population Turnover

“…The observed higher prevalence of bovine fecal E. coli O157:H7 early in the feeding period was consistent with previous reports for both E. coli O157:H7 specifically and other Shiga toxin-producing E. coli (10,18,33). The reported E. coli O157:H7 prevalence of beef calves at the time of weaning is 7.4% Ϯ 6.2% (mean Ϯ standard deviation) (27), comparable to the prevalence observed during the first sampling period in this study.…”

“…Likewise, the prevalence of E. coli O157:H7 in calves is also typically higher than the prevalence in adult cattle (46). Feedlot animals under 317 kg are more likely to test positive for E. coli O157:H7 than cattle of greater weights (10). Finally, higher fecal prevalence of E. coli O157:H7 has been observed during summer months, and it is possible that at least some of the apparent temporal variation in fecal prevalence in this study represented seasonal variation (8,9,19,35).…”

Evaluation by Conductance Assay of Shiga Toxin-Producing Escherichia coli (STEC) O157 and O26 and teir Sensitivity to Selected Disinfectants

“…Among the main sources of these alimentary infections are insufficiently heat procesed foods of bovine origin Morgan et al 1993;Bell et al 1994), contaminated water (Swerdlow et al 1992;D e v et al 1991;Danon-Schaffer 2001)and direct contact with animals in farms (Trevena et al 1996;Bielaszewska et al 2000). Quite a number of results of the studies pointed out the frequent occurrence of STEC O157 in faeces of healthy feedlot and dairy cattle, seasonal dynamics of excretion with culmination in summer months and different incidence of germ-carrier in herds depending on the age of animals, kind of feedstuff and intensity of farming (Dargatz et al 1997;Hancock et al 1997;âíÏek et al 1999). Germ-carrying and excretion of STEC in faeces of healthy animals is irregular and is dangerous especially with regard to the possibility of direct milk contamination during milking and meat contamination in slaughter process of animals.…”

Isolation and characterization Shiga toxin-producing Escherichia coli from sheep and goats inJordanwith evidence of multiresistant serotype O157:H7

“…The frequency of the bacteria shedding in cattle is influenced by various factors (Dargatz et al, 1997;Hancock et al, 1997a,b;Cray et al, 1998). STEC shedding has also been demonstrated in small ruminants (Beutin et al, 1993(Beutin et al, , 1996aKudva et al, 1996;Zschock et al, 2000), and that may represent an equally serious risk for people as cattle infections as evidenced by a recent finding of STEC O157 in sheep milk in Supported by the Grant Agency of the Czech Republic (Grant No.…”