scholarly journals Longitudinal Emergence and Distribution of Escherichia coli O157 Genotypes in a Beef Feedlot

2006 ◽  
Vol 72 (12) ◽  
pp. 7614-7619 ◽  
Author(s):  
Michael W. Sanderson ◽  
Jan M. Sargeant ◽  
Xiarong Shi ◽  
T. G. Nagaraja ◽  
Ludek Zurek ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Feedlot Cattle ◽  
Longitudinal Distribution ◽  
Single Strain ◽  
Fecal Samples ◽  
E Coli ◽  
Before And After ◽  
Water Tanks ◽  
Feed Samples ◽  
Bird Feces

ABSTRACT The purpose of this study was to describe the prevalence and longitudinal distribution of Escherichia coli O157 in feedlot cattle and the feedlot environment. Pen floors, water tanks, other cattle in the feedlot, feed, and bird feces were sampled for 2 weeks prior to entry of the study cattle. Twelve pens of study cattle were sampled twice weekly. At each sample time cattle feces, water from tanks in each pen, bunk feed, feed components, bird feces, and houseflies were collected. Bunk feed samples were collected before and after cattle had access to the feed. Overall, 28% of cattle fecal samples, 3.9% of bird fecal samples, 25% of water samples, 3.4% of housefly samples, 1.25% of bunk feed before calf access, and 3.25% of bunk feed samples after cattle had access to the feed were positive for E. coli O157. Genetic analysis of E. coli O157 isolates was done using pulsed-field gel electrophoresis (PFGE). PFGE types identified in sampling of the feedlot prior to calf entry were different than the majority of types identified following calf entry. A single strain type predominated in the samples collected after entry of the cattle. It was first identified 5 days after entry of the first pen of cattle and was subsequently identified in all pens. Data support that the incoming cattle introduced a new strain that became the predominant strain in the feedlot.

Monitoring Escherichia coli O157:H7 in Inoculated and Naturally Colonized Feedlot Cattle and Their Environment

2005 ◽  
Vol 68 (1) ◽  
pp. 26-33 ◽  
Author(s):  
K. STANFORD ◽  
S. J. BACH ◽  
T. H. MARX ◽  
S. JONES ◽  
J. R. HANSEN ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Feedlot Cattle ◽  
Mitigation Strategies ◽  
Escherichia Coli O157 ◽  
Feeding Period ◽  
Sample Collection ◽  
E Coli ◽  
Challenge Study ◽  
On Farm ◽  
Feed Samples

On-farm methods of monitoring Escherichia coli O157:H7 were assessed in 30 experimentally inoculated steers housed in four pens over a 12-week period and in 202,878 naturally colonized feedlot cattle housed in 1,160 pens on four commercial Alberta feedlots over a 1-year period. In the challenge study, yearling steers were experimentally inoculated with 1010 CFU of a four-strain mixture of nalidixic acid–resistant E. coli O157:H7. After inoculation, shedding of E. coli O157:H7 was monitored weekly by collecting rectal fecal samples (FEC), oral swabs (ORL), pooled fecal pats (PAT), manila ropes (ROP) orally accessed for 4 h, feed samples, water, and water bowl interface. Collection of FEC from all animals per pen provided superior isolation (P < 0.01) of E. coli O157:H7 compared with other methods, although labor and animal restraint requirements for fecal sample collection were high. When one sample was collected per pen of animals, E. coli O157:H7 was more likely to be detected from the ROP than from the FEC, PAT, or ORL (P < 0.001). In the commercial feedlot study, samples were limited to ROP and PAT, and E. coli O157:H7 was isolated in 18.8% of PAT and 6.8% of ROP samples. However, for animals that had been resident in the feedlot pen for at least 1 month, isolation of E. coli O157:H7 from ROP was not different from that from PAT (P = 0.35). Pens of animals on feed for <30 days were six times more likely to shed E. coli O157:H7 than were animals on feed for >30 days. However, change in diet did not affect shedding of the organism (P > 0.23) provided that animals had acclimated to the feedlot for 1 month or longer. Findings from this study indicate the importance of introduction of mitigation strategies early in the feeding period to reduce transference and the degree to which E. coli O157:H7 is shed into the environment.

Multiplex Quantitative PCR Assays for the Detection and Quantification of the Six Major Non-O157 Escherichia coli Serogroups in Cattle Feces†

2016 ◽  
Vol 79 (1) ◽  
pp. 66-74 ◽  
Author(s):  
P. B. SHRIDHAR ◽  
L. W. NOLL ◽  
X. SHI ◽  
B. AN ◽  
N. CERNICCHIARO ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Quantitative Pcr ◽  
Foodborne Pathogens ◽  
Virulence Genes ◽  
Target Genes ◽  
Culture Methods ◽  
Fecal Samples ◽  
E Coli ◽  
Cattle Feces ◽  
Before And After

ABSTRACT Shiga toxin–producing Escherichia coli (STEC) serogroups O26, O45, O103, O111, O121, and O145, called non-O157 STEC, are important foodborne pathogens. Cattle, a major reservoir, harbor the organisms in the hindgut and shed them in the feces. Although limited data exist on fecal shedding, concentrations of non-O157 STEC in feces have not been reported. The objectives of our study were (i) to develop and validate two multiplex quantitative PCR (mqPCR) assays, targeting O-antigen genes of O26, O103, and O111 (mqPCR-1) and O45, O121, and O145 (mqPCR-2); (ii) to utilize the two assays, together with a previously developed four-plex qPCR assay (mqPCR-3) targeting the O157 antigen and three virulence genes (stx1, stx2, and eae), to quantify seven serogroups and three virulence genes in cattle feces; and (iii) to compare the three mqPCR assays to a 10-plex conventional PCR (cPCR) targeting seven serogroups and three virulence genes and culture methods to detect seven E. coli serogroups in cattle feces. The two mqPCR assays (1 and 2) were shown to be specific to the target genes, and the detection limits were 4 and 2 log CFU/g of pure culture–spiked fecal samples, before and after enrichment, respectively. A total of 576 fecal samples collected from a feedlot were enriched in E. coli broth and were subjected to quantification (before enrichment) and detection (after enrichment). Of the 576 fecal samples subjected, before enrichment, to three mqPCR assays for quantification, 175 (30.4%) were quantifiable (≥4 log CFU/g) for at least one of the seven serogroups, with O157 being the most common serogroup. The three mqPCR assays detected higher proportions of postenriched fecal samples (P < 0.01) as positive for one or more serogroups compared with cPCR and culture methods. This is the first study to assess the applicability of qPCR assays to detect and quantify six non-O157 serogroups in cattle feces and to generate data on fecal concentration of the six serogroups.

Impact of Transportation of Feedlot Cattle to the Harvest Facility on the Prevalence of Escherichia coli O157:H7, Salmonella, and Total Aerobic Microorganisms on Hides

2007 ◽  
Vol 70 (1) ◽  
pp. 17-21 ◽  
Author(s):  
A. L. REICKS ◽  
M. M. BRASHEARS ◽  
K. D. ADAMS ◽  
J. C. BROOKS ◽  
J. R. BLANTON ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Feedlot Cattle ◽  
Lower Percentage ◽  
Escherichia Coli O157 ◽  
Sample Collection ◽  
Treatment Groups ◽  
E Coli ◽  
Sampling Locations ◽  
Before And After

Prevalences of Escherichia coli O157:H7, Salmonella, and total aerobic microorganisms were determined on the hides of beef feedlot cattle before and after transport from the feedyard to the harvest facility in clean and dirty trailers. Swab samples were taken from the midline and withers of 40 animals on each of 8 days before and after shipping. After samples were collected, animals were loaded in groups of 10 on upper and lower levels of clean and dirty trailers. Animals were unloaded at the harvest facility and kept in treatment groups for sample collection after exsanguination. Salmonella was found more often on hide swabs collected from the midline than on than samples collected from the withers from animals transported in both clean and dirty trailers. Salmonella was found on significantly more hide swabs collected at harvest from both sampling locations than on those collected at the feedyard, with no differences attributed to the type of trailer. At the feedyard, clean trucks had a lower percentage of Salmonella-positive samples than did dirty trucks before animals were loaded. However, after transport, both clean and dirty trucks had a similar prevalence of Salmonella. There were no differences in Salmonella prevalence on hides collected from animals transported on the top and bottom levels of clean and dirty trucks. E. coli O157:H7 was detected on less than 2% of the samples; therefore, no practical conclusions about prevalence could be drawn. Hides sampled at harvest had higher concentrations of aerobic microorganisms than did hides sampled at the feedyard, and concentrations were higher on the midline than on the withers. Although the prevalences of Salmonella and total aerobic microorganisms increased on hides after transport from the feedyard to the plant, this increase was not related to the cleanliness of the trailers or the location of the cattle in the trailers.

Epidemiology of Escherichia coli O157 in Feedlot Cattle

1997 ◽  
Vol 60 (5) ◽  
pp. 462-465 ◽  
Author(s):  
DALE D. HANCOCK ◽  
DANIEL H. RICE ◽  
LEE ANN THOMAS ◽  
DAVID A. DARGATZ ◽  
THOMAS E. BESSER
Keyword(s):  
United States ◽  
Escherichia Coli ◽  
The United States ◽  
Feedlot Cattle ◽  
Escherichia Coli O157 ◽  
Fecal Samples ◽  
E Coli ◽  
Geographical Regions ◽  
Flagellar Antigen ◽  
Low Prevalence

Fecal samples from cattle in 100 feedlots in 13 states were bacteriologically cultured for Escherichia coli O157 that did not ferment sorbitol, lacked beta-glucuronidase, and possessed genes coding for Shiga-like toxin. In each feedlot 30 fresh fecal-pat samples were collected from each of four pens: with the cattle shortest on feed, with cattle longest on feed, and with cattle in two randomly selected pens. E. coli O157 was isolated from 210 (1.8%) of 11,881 fecal samples. One or more samples were positive for E. coli O157 in 63 of the 100 feedlots tested. E. coli O157 was found at roughly equal prevalence in all the geographical regions sampled. The prevalence of E. coli O157 in the pens with cattle shortest on feed was approximately threefold higher than for randomly selected and longest on feed pens. Of the E. coli O157 isolates found in this study, 89.52% expressed the H7 flagellar antigen. E. coli O157 was found to be widely distributed among feedlot cattle, but at a low prevalence, in the United States.

scholarly journals Understanding the transmission dynamics of Escherichia coli O157:H7 super-shedding infections in feedlot cattle

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12524
Author(s):  
Elizabeth M. Antaki-Zukoski ◽  
Xunde Li ◽  
Bruce Hoar ◽  
John M. Adaska ◽  
Barbara A. Byrne ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Feedlot Cattle ◽  
Daily Maximum ◽  
High Dose ◽  
Post Inoculation ◽  
Fecal Samples ◽  
E Coli ◽  
High Concentrations ◽  
One Year ◽  
Definition Of

Background The presence of Escherichia coli O157:H7 (E. coli O157:H7) super-shedding cattle in feedlots has the potential to increase the overall number (bio-burden) of E. coli O157:H7 in the environment. It is important to identify factors to reduce the bio-burden of E. coli O157 in feedlots by clarifying practices associated with the occurrence of super-shedders in feedlot cattle. Methods The objective of this study is to (1) identify host, pathogen, and management risk factors associated with naturally infected feedlot cattle excreting high concentrations of E. coli O157:H7 in their feces and (2) to determine whether the ingested dose or the specific strain of E. coli O157:H7 influences a super-shedder infection within experimentally inoculated feedlot cattle. To address this, (1) pen floor fecal samples and herd parameters were collected from four feedlots over a 9-month period, then (2) 6 strains of E. coli O157:H7, 3 strains isolated from normal shedder steers and 3 strains isolated from super-shedder steers, were inoculated into 30 one-year-old feedlot steers. Five steers were assigned to each E. coli O157:H7 strain group and inoculated with targeted numbers of 102, 104, 106, 108, and 1010 CFU of bacteria respectively. Results In the feedlots, prevalence of infection with E. coli O157:H7 for the 890 fecal samples collected was 22.4%, with individual pen prevalence ranging from 0% to 90% and individual feedlot prevalence ranging from 8.4% to 30.2%. Three samples had E. coli O157:H7 levels greater than 104 MPN/g feces, thereby meeting the definition of super-shedder. Lower body weight at entry to the feedlot and higher daily maximum ambient temperature were associated with increased odds of a sample testing positive for E. coli O157:H7. In the experimental inoculation trial, the duration and total environmental shedding load of E. coli O157:H7 suggests that the time post-inoculation and the dose of inoculated E. coli O157:H7 are important while the E. coli O157:H7 strain and shedding characteristic (normal or super-shedder) are not. Discussion Under the conditions of this experiment, super-shedding appears to be the result of cattle ingesting a high dose of any strain of E. coli O157:H7. Therefore strategies that minimize exposure to large numbers of E. coli O157:H7 should be beneficial against the super-shedding of E. coli O157:H7 in feedlots.

Development and Validation of a Most-Probable-Number–Immunomagnetic Separation Methodology of Enumerating Escherichia coli O157 in Cattle Feces

2007 ◽  
Vol 70 (5) ◽  
pp. 1072-1075 ◽  
Author(s):  
T. P. STEPHENS ◽  
G. H. LONERAGAN ◽  
W. E. CHANEY ◽  
L. A. BRANHAM ◽  
M. M. BRASHEARS
Keyword(s):  
Escherichia Coli ◽  
Immunomagnetic Separation ◽  
Feedlot Cattle ◽  
Most Probable Number ◽  
Escherichia Coli O157 ◽  
Probable Number ◽  
Direct Plating ◽  
Fecal Samples ◽  
E Coli ◽  
The Difference

A method to validate enumeration of Escherichia coli O157 in fecal samples from feedlot cattle was developed in these studies. Due to background flora, bovine fecal sample enumeration cannot be performed by simple direct plating techniques. Known quantities of E. coli O157:H7 were inoculated into feces, and populations were determined by direct plating of the cocktail (studies 1, 2, and 3) and manure and cocktail (studies 4 and 5) mixtures and compared with a most-probable-number (MPN)–immunomagnetic separation (IMS) method. The three-tube MPN combined preenrichment in gram-negative broth with confirmation using IMS. Five separate enumeration studies (study 1, sterile feces inoculated with 102 E. coli O157:H7 per g; study 2, nonsterile feces inoculated with 103 E. coli O157:H7 per g; study 3, nonsterile feces inoculated with 101 E. coli O157:H7 per g; study 4, sterile feces inoculated with 104 streptomycin-resistant E. coli O157:H7 per g; and study 5, sterile feces inoculated with 102 streptomycin-resistant E. coli O157:H7 per g) were conducted. These studies were performed to determine the precision, accuracy, and specificity at low and high levels of pathogen contamination in feces, using direct plating compared with the MPN-IMS methodology tested. There was an overall difference (P < 0.01) between direct plating and MPN-IMS methodologies, but this difference was biologically negligible due to the difference in least-squares means (0.29 ± 0.10) being so low. The direct plating and MPN-IMS methods were correlated (r = 0.93). These results suggest that using the MPN-IMS procedures is an effective method of estimating E. coli O157 populations in naturally infected bovine fecal samples.

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

1997 ◽  
Vol 60 (5) ◽  
pp. 466-470 ◽  
Author(s):  
DAVID A. DARGATZ ◽  
SCOTT J. WELLS ◽  
LEE ANN THOMAS ◽  
DALE D. HANCOCK ◽  
LINDSEY P. GARBER
Keyword(s):  
Escherichia Coli ◽  
Feedlot Cattle ◽  
Escherichia Coli O157 ◽  
Sample Collection ◽  
Fecal Samples ◽  
E Coli ◽  
Factors Associated ◽  
Health History ◽  
Collection Data ◽  
Cattle Health

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).

scholarly journals Comparison of Rectoanal Mucosal Swab Cultures and Fecal Cultures for Determining Prevalence of Escherichia coli O157:H7 in Feedlot Cattle

2005 ◽  
Vol 71 (10) ◽  
pp. 6431-6433 ◽  
Author(s):  
M. A. Greenquist ◽  
J. S. Drouillard ◽  
J. M. Sargeant ◽  
B. E. Depenbusch ◽  
Xiaorong Shi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Gel Electrophoresis ◽  
Feedlot Cattle ◽  
Pulsed Field Gel Electrophoresis ◽  
Escherichia Coli O157 ◽  
Fecal Culture ◽  
Fecal Samples ◽  
Pulsed Field ◽  
E Coli ◽  
Fecal Sampling

ABSTRACT We compared fecal samples with samples collected with rectoanal mucosa swabs (RAMS) to determine the prevalence of Escherichia coli O157 in feedlot cattle (n = 747). Escherichia coli O157 was detected in 9.5% of samples collected with RAMS and 4.7% of samples tested by fecal culture. Pulsed-field gel electrophoresis analysis of isolates suggested that the strains colonizing the rectoanal junction were the same as those from the feces. Mucosal swab sampling was more sensitive than fecal sampling for determining the prevalence of E. coli O157 in feedlot cattle.

scholarly journals Inclusion of Dried or Wet Distillers' Grains at Different Levels in Diets of Feedlot Cattle Affects Fecal Shedding of Escherichia coli O157:H7

2010 ◽  
Vol 76 (21) ◽  
pp. 7238-7242 ◽  
Author(s):  
M. E. Jacob ◽  
Z. D. Paddock ◽  
D. G. Renter ◽  
K. F. Lechtenberg ◽  
T. G. Nagaraja
Keyword(s):  
Escherichia Coli ◽  
Control Diet ◽  
Phase 1 ◽  
Feedlot Cattle ◽  
Distillers Grains ◽  
Phase 2 ◽  
Fecal Samples ◽  
Fecal Shedding ◽  
E Coli ◽  
Dried Distillers Grains

ABSTRACT Our objectives were to evaluate the prevalence of Escherichia coli O157:H7 in cattle fed diets supplemented with 20 or 40% dried distillers' grains (DG) (DDG) or wet DG (WDG) and assess whether removing DG from diets before slaughter affected fecal shedding of E. coli O157:H7. Eight hundred forty steers were allocated to 70 pens (12 steers/pen). Treatments were no DG (control), 20% DDG or WDG, and 40% DDG or WDG, and each was replicated in 14 pens. In phase 1, eight floor fecal samples were collected from each pen every 2 weeks for 12 weeks for isolation of E. coli O157:H7 and detection of high shedders. In phase 2, half of the pens with DG were transitioned to the no-DG control diet, and pen floor fecal samples were collected weekly from all pens for 4 weeks. During phase 1, prevalence of E. coli O157:H7 was 20.8% and 3.2% for high shedders. The form of DG had no significant effect on fecal E. coli O157:H7 shedding. The prevalence levels of E. coli O157:H7 and the numbers of high shedders were not different between diets with 0 or 20% DG; however, cattle fed 40% DG had a higher prevalence and more high shedders than cattle fed 0 or 20% DG (P ≤ 0.05). During phase 2, overall and high-shedder prevalence estimates were 3.3% and <0.1%, respectively, and there were no differences between those for different DG forms and inclusion levels or when DG was removed from diets. The form of DG had no impact on E. coli O157:H7; however, fecal shedding was associated with the DG inclusion level.

Determining the Prevalence of Escherichia coli O157 in Cattle and Beef from the Feedlot to the Cooler

2006 ◽  
Vol 69 (12) ◽  
pp. 2824-2827 ◽  
Author(s):  
D. R. WOERNER ◽  
J. R. RANSOM ◽  
J. N. SOFOS ◽  
G. A. DEWELL ◽  
G. C. SMITH ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Risk Assessment ◽  
Fecal Sample ◽  
Mitigation Strategies ◽  
Escherichia Coli O157 ◽  
Fecal Samples ◽  
E Coli ◽  
Beef Carcasses ◽  
Before And After ◽  
Pathogen Prevalence

Prevalence of Escherichia coli O157 on cattle entering the slaughter floor may range from 10 to &gt;70%. This study was conducted to determine the effect of E. coli O157 prevalence in fecal pats collected from feedlot pen floors on subsequent E. coli O157 prevalence on carcasses at various points in the slaughter process. Fecal pats from the feedlot pen floor were collected within 3 days before slaughter. During cattle processing at the slaughter facility, additional samples were collected from the hide, from the colon, and from the carcasses before and after evisceration and after final decontamination. Of 15 lots (a group of cattle from the same pen from a feedlot) sampled, 87% had at least one positive fecal pat from the feedlot floor, 47% had a positive hide sample, 73% had a positive colon/fecal sample, and 47% had a positive carcass sample preevisceration; however, only 8% of lots had a positive carcass sample postevisceration or after final intervention. Of the total samples tested (n = 1,328), 24.7, 14.7, 27.6, 10.1, 1.4, and 0.3% of fecal pats from the feedlot floor, hide, colon, preevisceration, post-evisceration, and final intervention samples, respectively, were positive for E. coli O157. Pens with greater than 20% positive fecal pats from the feedlot floor had 25.5% hide, 51.4% colon, and 14.3, 2.9, and 0.7% carcass samples positive at preevisceration, at postevisceration, and after final intervention, respectively. However, fecal pats from feedlot floor samples that contained less than 20% positive fecal samples showed lower pathogen prevalence, with 5.0% hide, 7.5% colon, and 6.3, 0, and 0% carcass positive samples at preevisceration, postevisceration, and post–final intervention, respectively. Data from this study can be used as part of risk assessment processes in order to identify mitigation strategies to minimize prevalence of E. coli O157 on fresh beef carcasses.

Sign in / Sign up

Export Citation Format

Share Document