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.

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.

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).

Dietary Supplementation with Lactobacillus- and Propionibacterium-Based Direct-Fed Microbials and Prevalence of Escherichia coli O157 in Beef Feedlot Cattle and on Hides at Harvest

2004 ◽  
Vol 67 (5) ◽  
pp. 889-893 ◽  
Author(s):  
S. M. YOUNTS-DAHL ◽  
M. L. GALYEAN ◽  
G. H. LONERAGAN ◽  
N. A. ELAM ◽  
M. M. BRASHEARS
Keyword(s):  
Escherichia Coli ◽  
Intervention Strategy ◽  
Immunomagnetic Separation ◽  
Feedlot Cattle ◽  
High Dose ◽  
Standard Diet ◽  
Escherichia Coli O157 ◽  
Feeding Period ◽  
E Coli ◽  
Finishing Beef Cattle

The objective of this study was to describe the prevalence of Escherichia coli O157 in the feces and on the hides of finishing beef cattle fed a standard diet and those fed diets supplemented with direct-fed microbials. Two hundred forty steers received one of four treatments throughout the feeding period: (i) control: no added microbials; (ii) HNP51: high dose of Lactobacillus acidophilus strain NP 51 (109 CFU per steer daily) and Propionibacterium freudenreichii (109 CFU per steer daily); (iii) HNP51+45: high dose of NP 51 (109 CFU per steer daily), P. freudenreichii (109 CFU per steer daily), and L. acidophilus NP 45 (106 CFU per steer daily); or (iv) LNP51+ 45: low dose of NP 51 (106 CFU per steer daily), P. freudenreichii (109 CFU per steer daily), and NP 45 (106 CFU per steer daily). Samples were collected from each animal and analyzed for the presence of E. coli O157 using immunomagnetic separation methods on day 0 (feces), 7 days before harvest (feces), and at harvest (feces and hide). At the end of the feeding period, cattle receiving HNP51 were 57% less likely to shed detectable E. coli O157 in their feces than were the controls (P < 0.01). For animals receiving HNP51+ 45 and LNP51+ 45, fecal prevalence did not differ from that of the controls. The prevalence of positive hide samples was least among cattle receiving HNP51+ 45 (3.3%); these animals were 79% less likely (P < 0.06) to have a positive hide sample than were the controls (prevalence = 13.8%). There was poor agreement of the culture results between fecal and hide samples collected from the same animal (κ = 0.08; confidence interval = −0.05 to 0.2). Cattle supplemented with a high dose of NP 51 had reduced E. coli O157 prevalence in both fecal and hide samples, indicating that this treatment may be an efficacious preharvest intervention strategy.

Prevalence and Enumeration of Escherichia coli O157 in Steers Receiving Various Strains of Lactobacillus-Based Direct-Fed Microbials

2007 ◽  
Vol 70 (5) ◽  
pp. 1252-1255 ◽  
Author(s):  
T. P. STEPHENS ◽  
G. H. LONERAGAN ◽  
L. M. CHICHESTER ◽  
M. M. BRASHEARS
Keyword(s):  
Escherichia Coli ◽  
Lactobacillus Acidophilus ◽  
Immunomagnetic Separation ◽  
Feedlot Cattle ◽  
Most Probable Number ◽  
Escherichia Coli O157 ◽  
Feeding Period ◽  
Probable Number ◽  
Selective Enrichment ◽  
E Coli

The objective of this research was to evaluate the effect of daily dietary inclusion of specific strains of Lactobacillus acidophilus on prevalence and concentration of Escherichia coli O157 in harvest-ready feedlot cattle. Five hundred yearling steers were housed in pens of 10 animals each. At arrival, steers were randomly allocated to one of five cohorts. Four of the cohorts were fed various strains and dosages of Lactobacillus-based direct-fed microbials throughout the feeding period. Fecal samples were collected from the rectum of each animal immediately prior to shipment to the abattoir. E. coli O157 was detected using selective enrichment and immunomagnetic separation techniques. For positive samples, E. coli O157 concentration was estimated using a most-probable-number (MPN) technique that included immunomagnetic separation. Prevalence varied among the cohorts (P < 0.01). The prevalence in the controls (26.3%) was greater (P < 0.05) than that in cattle supplemented with L. acidophilus strains NP51, NP28, or NP51-NP35 (13.0, 11.0, and 11.0%, respectively). The greatest E. coli O157 concentration was also observed in the controls (3.2 log MPN/g of feces); this concentration was greater (P < 0.05) than that observed in positive animals receiving NP51, NP28, or NP51-NP35 (0.9, 1.1, 1.7 log MPN/g of feces, respectively). Specific strains of Lactobacillus-based direct-fed microbials effectively reduced the prevalence and concentration of E. coli O157 in harvest-ready cattle, whereas others did not. When using direct-fed microbials to reduce carriage of E. coli O157 in cattle, it is important to select appropriately validated products.

Comparison of Two Sampling Methods for Escherichia coli O157:H7 Detection in Feedlot Cattle

2005 ◽  
Vol 68 (8) ◽  
pp. 1724-1728 ◽  
Author(s):  
M. L. KHAITSA ◽  
M. L. BAUER ◽  
P. S. GIBBS ◽  
G. P. LARDY ◽  
D. DOETKOTT ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Sampling Methods ◽  
Feedlot Cattle ◽  
Sampling Time ◽  
Escherichia Coli O157 ◽  
Confounding Factors ◽  
Rank Tests ◽  
E Coli ◽  
Signed Rank ◽  
Sampling Times

Two sampling methods (rectoanal swabs and rectal fecal grabs) were compared for their recovery of Escherichia coli O157:H7 from feedlot cattle. Samples were collected from 144 steers four times during the finishing period by swabbing the rectoanal mucosa with cotton swabs and immediately obtaining feces from the rectum of each individual steer. The number of steers with detectable E. coli O157:H7 increased from 2 of 144 (1.4%) cattle on arrival at the feedlot to 10 of 144 (6.9%) after 1 month, 76 of 143 (52.8%) after 7 months, and 30 of 143 (20.8%) at the last sampling time before slaughter. Wilcoxon signed-rank tests indicated that the two sampling methods gave different results for sampling times 3 and 4 (P < 0.05) but not for sampling time 2 (P = 0.16). Agreement between the two sampling methods was poor (kappa < 0.2) for three of the four sampling times and moderate (kappa = 0.6) for one sampling time, an indication that in this study rectoanal swabs usually were less sensitive than rectal fecal grabs for detection of E. coli O157:H7 in cattle. Overall, the herd of origin was not significantly associated with E. coli O157:H7 results, but the weight of the steers was. Further investigation is needed to determine the effects of potential confounding factors (e.g., size and type of swab, consistency of feces, site sampled, and swabbing technique) that might influence the sensitivity of swabs in recovering E. coli O157:H7 from the rectoanal mucosa of cattle.

Escherichia coli O157 in Cull Dairy Cows on Farm and at Slaughter

1997 ◽  
Vol 60 (11) ◽  
pp. 1386-1387 ◽  
Author(s):  
DANIEL H. RICE ◽  
ERIC D. EBEL ◽  
DALE D. HANCOCK ◽  
THOMAS E. BESSER ◽  
DONALD E. HERRIOTT ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Dairy Cattle ◽  
Dairy Cows ◽  
Dairy Herds ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Cull Cows ◽  
On Farm

Cull dairy cattle both on the farm and at slaughter from herds in the states of Idaho, Oregon, and Washington were surveyed for Escherichia coli O157 by culturing fecal swab samples. A total of 205 cull cows from 19 dairy herds were sampled on the farm of origin; 7 (3.4%) tested positive for E. coli O157. A total of 103 cull cows from 15 dairy herds were sampled at slaughter; 4 (3.9%) were positive for E. coli O157. Eighty-nine cull cows were sampled both at the farm and at slaughter; 2 (2.2%) were positive in both locations, 3 (3.3%) only on the farm, and 2 (2.2%) only at the slaughter plant. Seven (7.9%) of the 89 cull cows tracked from farm to slaughter were positive in at least one location. This suggests a higher prevalence of E. coli O157 in cull dairy cattle than previously has been reported to occur in other ages and classes of cattle.

Fecal Shedding of Escherichia coli O157:H7 in North Dakota Feedlot Cattle in the Fall and Spring

2006 ◽  
Vol 69 (5) ◽  
pp. 1154-1158 ◽  
Author(s):  
MARGARET L. KHAITSA ◽  
MARC L. BAUER ◽  
GREGORY P. LARDY ◽  
DAWN K. DOETKOTT ◽  
REDEMPTA B. KEGODE ◽  
...  
Keyword(s):  
United States ◽  
Escherichia Coli ◽  
North Dakota ◽  
The United States ◽  
Extreme Weather ◽  
Early Spring ◽  
Feedlot Cattle ◽  
Escherichia Coli O157 ◽  
Fecal Shedding ◽  
E Coli

Cattle are an important reservoir of Escherichia coli O157:H7, which can lead to contamination of food and water, and subsequent human disease. E. coli O157:H7 shedding in cattle has been reported as seasonal, with more animals shedding during summer and early fall than during winter. North Dakota has relatively cold weather, especially in winter and early spring, compared with many other regions of the United States. The objective was to assess fecal shedding of E. coli O157: H7 in North Dakota feedlot cattle over the fall, winter, and early spring. One hundred forty-four steers were assigned randomly to 24 pens on arrival at the feedlot. Samples of rectal feces were obtained from each steer four times (October and November 2003, and March and April 2004) during finishing. On arrival (October 2003), 2 (1.4%) of 144 cattle were shedding E. coli O157:H7. The shedding increased significantly to 10 (6.9%) of 144 after 28 days (November 2003), to 76 (53%) of 143 at the third sampling (March 2004), and dropped significantly to 30 (21%) of 143 at the fourth (last) sampling (March 2004) before slaughter. Unfortunately, we were unable to sample the cattle during winter because of the extreme weather conditions. Sampling time significantly (P < 0.0001) influenced variability in E. coli O157:H7 shedding, whereas herd (P = 0.08) did not. The prevalence of E. coli O157:H7 shedding in North Dakota steers in fall and early spring was comparable to what has been reported in other parts of the United States with relatively warmer weather. Further research into E. coli O157:H7 shedding patterns during extreme weather such as North Dakota winters is warranted in order to fully assess the seasonal effect on the risk level of this organism.

Ecological Relationships between the Prevalence of Cattle Shedding Escherichia coli O157:H7 and Characteristics of the Cattle or Conditions of the Feedlot Pen†

2001 ◽  
Vol 64 (12) ◽  
pp. 1899-1903 ◽  
Author(s):  
DAVID SMITH ◽  
MARK BLACKFORD ◽  
SPRING YOUNTS ◽  
RODNEY MOXLEY ◽  
JEFF GRAY ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Feedlot Cattle ◽  
Escherichia Coli O157 ◽  
Water Tank ◽  
Weight Class ◽  
E Coli ◽  
Ecological Relationships ◽  
Average Body ◽  
Tank Water ◽  
Average Body Weight

This study was designed to describe the percentage of cattle shedding Escherichia coli O157:H7 in Midwestern U.S. feedlots and to discover relationships between the point prevalence of cattle shedding the organism and the characteristics of those cattle or the conditions of their pens. Cattle from 29 pens of five Midwestern feedlots were each sampled once between June and September 1999. Feces were collected from the rectum of each animal in each pen. Concurrently, samples of water were collected from the water tank, and partially consumed feed was collected from the feedbunk of each pen. Characteristics of the cattle and conditions of each pen that might have affected the prevalence of cattle shedding E. coli O157:H7 were recorded. These factors included the number of cattle; the number of days on feed; and the average body weight, class, and sex of the cattle. In addition, the temperature and pH of the tank water were determined, and the cleanliness of the tank water and the condition of the pen floor were subjectively assessed. The samples of feces, feed, and water were tested for the presence of E. coli O157:H7. E. coli O157:H7 was isolated from the feces of 719 of 3,162 cattle tested (23%), including at least one animal from each of the 29 pens. The percentage of cattle in a pen shedding E. coli O157:H7 did not differ between feedyards, but it did vary widely within feedyards. A higher prevalence of cattle shed E. coli O157:H7 from muddy pen conditions than cattle from pens in normal condition. The results of this study suggest that E. coli O157:H7 should be considered common to groups of feedlot cattle housed together in pens and that the condition of the pen floor may influence the prevalence of cattle shedding the organism.

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 Escherichia coli O157:H7 in Environments of Culture-Positive Cattle

2005 ◽  
Vol 71 (11) ◽  
pp. 6816-6822 ◽  
Author(s):  
Margaret A. Davis ◽  
Karen A. Cloud-Hansen ◽  
John Carpenter ◽  
Carolyn J. Hovde
Keyword(s):  
Escherichia Coli ◽  
Room Temperature ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Different Temperatures ◽  
Farm Structures ◽  
On Farm ◽  
Culture Positive ◽  
Culture Negative ◽  
Over Time

ABSTRACT Outbreaks of Escherichia coli O157:H7 disease associated with animal exhibits have been reported with increasing frequency. Transmission can occur through contact with contaminated haircoats, bedding, farm structures, or water. We investigated the distribution and survival of E. coli O157:H7 in the immediate environments of individually housed, experimentally inoculated cattle by systematically culturing feed, bedding, water, haircoat, and feed bunk walls for E. coli O157:H7 for 3 months. Cedar chip bedding was the most frequently culture-positive environmental sample tested (27/96 or 28.15%). Among these, 12 (44.0%) of positive bedding samples were collected when the penned animal was fecal culture negative. Survival of E. coli O157:H7 in experimentally inoculated cedar chip bedding and in grass hay feed was determined at different temperatures. Survival was longest in feed at room temperature (60 days), but bacterial counts decreased over time. The possibility that urine plays a role in the environmental survival of E. coli O157:H7 was investigated. Cedar chip bedding moistened with sterile water or bovine urine was inoculated with E. coli O157:H7. Bedding moistened with urine supported growth of E. coli O157:H7, whereas inoculated bedding moistened with only water yielded decreasing numbers of bacteria over time. The findings that environmental samples were frequently positive for E. coli O157:H7 at times when animals were culture negative and that urine provided a substrate for E. coli O157:H7 growth have implications for understanding the on-farm ecology of this pathogen and for the safety of ruminant animal exhibits, particularly petting zoos and farms where children may enter animal pens.

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