A one-year longitudinal study of enterohemorrhagic Escherichia coli O157 fecal shedding in a beef cattle herd

Two hundred steers and heifers from a large feedyard (65,000-head capacity) were used to determine the prevalence levels of enterohemorrhagic Escherichia coli O157 (EHEC O157) and Salmonella spp. prior to and after shipping to a commercial packing facility. Two samples, a ventral midline hide swab and a fecal sample, were aseptically collected from each animal 2 weeks prior to the date of transportation and at the packing plant immediately after exsanguination. Samples were collected from all trailers (n = 46) before animals were loaded for transport to the packing facility. The average prevalence levels of EHEC O157 on hides (18%) and in feces (9.5%) at the feedyard decreased (P > 0.05) at the packing plant to 4.5 and 5.5%, respectively. The average prevalence levels of Salmonella spp. on hides (6%) and in feces (18%) at the feedyard increased to 89 and 46%, respectively, upon arrival at the packing plant. Average prevalence levels for EHEC O157 and Salmonella spp. on the trailers were 5.43 and 59%, respectively. The results of this study demonstrate that transportation may be a potential stressor for cattle, as evidenced by the increased shedding of Salmonella spp.

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Longitudinal Study of Escherichia coli O157:H7 in a Beef Cattle Feedlot and Role of High-Level Shedders in Hide Contamination

Applied and Environmental Microbiology ◽

10.1128/aem.00081-09 ◽

2009 ◽

Vol 75 (20) ◽

pp. 6515-6523 ◽

Cited By ~ 93

Author(s):

Terrance M. Arthur ◽

James E. Keen ◽

Joseph M. Bosilevac ◽

Dayna M. Brichta-Harhay ◽

Norasak Kalchayanand ◽

...

Keyword(s):

Escherichia Coli ◽

Longitudinal Study ◽

Beef Cattle ◽

Intervention Studies ◽

High Density ◽

Escherichia Coli O157 ◽

E Coli ◽

High Level ◽

Cattle Feedlot

ABSTRACT The objectives of the study described here were (i) to investigate the dynamics of Escherichia coli O157:H7 fecal and hide prevalence over a 9-month period in a feedlot setting and (ii) to determine how animals shedding E. coli O157:H7 at high levels affect the prevalence and levels of E. coli O157:H7 on the hides of other animals in the same pen. Cattle (n = 319) were distributed in 10 adjacent pens, and fecal and hide levels of E. coli O157:H7 were monitored. When the fecal pen prevalence exceeded 20%, the hide pen prevalence was usually (25 of 27 pens) greater than 80%. Sixteen of 19 (84.2%) supershedder (>104 CFU/g) pens had a fecal prevalence greater than 20%. Significant associations with hide and high-level hide (≥40 CFU/100 cm2) contamination were identified for (i) a fecal prevalence greater than 20%, (ii) the presence of one or more high-density shedders (≥200 CFU/g) in a pen, and (iii) the presence of one or more supershedders in a pen. The results presented here suggest that the E. coli O157:H7 fecal prevalence should be reduced below 20% and the levels of shedding should be kept below 200 CFU/g to minimize the contamination of cattle hides. Also, large and unpredictable fluctuations within and between pens in both fecal and hide prevalence of E. coli O157:H7 were detected and should be used as a guide when preharvest studies, particularly preharvest intervention studies, are designed.

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Rectal Carriage of Enterohemorrhagic Escherichia coli O157 in Slaughtered Cattle

Applied and Environmental Microbiology ◽

10.1128/aem.71.1.93-97.2005 ◽

2005 ◽

Vol 71 (1) ◽

pp. 93-97 ◽

Cited By ~ 134

Author(s):

J. Christopher Low ◽

Iain J. McKendrick ◽

Caroline McKechnie ◽

David Fenlon ◽

Stuart W. Naylor ◽

...

Keyword(s):

Escherichia Coli ◽

Enterohemorrhagic Escherichia Coli ◽

Fecal Excretion ◽

Escherichia Coli O157 ◽

Fecal Shedding ◽

E Coli ◽

Mucosal Surfaces ◽

Human Illness ◽

Experimental Findings ◽

High Level

ABSTRACT Escherichia coli O157:H7 is an important cause of diarrhea, hemorrhagic colitis, and potentially fatal human illness. Cattle are considered a primary reservoir of infection, and recent experimental evidence has indicated that the terminal rectum is the principal site of bacterial carriage. To test this finding in naturally colonized animals, intact rectum samples from 267 cattle in 24 separate lots were obtained immediately after slaughter, and fecal material and mucosal surfaces were cultured for E. coli O157 by direct and enrichment methods. Two locations, 1 and 15 cm proximal to the recto-anal junction, were tested. In total, 35 animals were positive for E. coli O157 at at least one of the sites and 232 animals were negative as determined by all tests. The frequency of isolation and the numbers of E. coli O157 cells were higher at the site closer to the recto-anal junction, confirming our previous experimental findings. We defined low- and high-level carriers as animals with E. coli O157 levels of <1 Ã¯Â¿Â½ 103 CFU g−1 or <1 Ã¯Â¿Â½ 103 CFU ml−1 and animals with E. coli O157 levels of ≥1 Ã¯Â¿Â½ 103 CFU g−1 or ≥1 Ã¯Â¿Â½ 103 CFU ml−1 in feces or tissues, respectively. High-level carriage was detected in 3.7% of the animals (95% confidence interval, 1.8 to 6.8%), and carriage on the mucosal surface of the terminal rectum was associated with high-level fecal excretion. In summary, our results support previous work demonstrating that the mucosal epithelium in the bovine terminal rectum is an important site for E. coli O157 carriage in cattle. The data also support the hypothesis that high-level fecal shedding (≥1 Ã¯Â¿Â½ 103 CFU g of feces−1) of enterohemorrhagic E. coli O157 results from colonization of this site.

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Escherichia coli O157:H7 Shedding in Vaccinated Beef Calves Born to Cows Vaccinated Prepartum with Escherichia coli O157:H7 SRP Vaccine

Journal of Food Protection ◽

10.4315/0362-028x.jfp-11-034 ◽

2011 ◽

Vol 74 (10) ◽

pp. 1599-1604 ◽

Cited By ~ 13

Author(s):

B. W. WILEMAN ◽

D. U. THOMSON ◽

K. C. OLSON ◽

J. R. JAEGER ◽

L. A. PACHECO ◽

...

Keyword(s):

Escherichia Coli ◽

Treatment Group ◽

Beef Cattle ◽

Media Coverage ◽

Escherichia Coli O157 ◽

Fecal Shedding ◽

Beef Calves ◽

Calf Health ◽

E Coli ◽

Field Efficacy

Extensive research, intervention equipment, money, and media coverage have been directed at controlling Escherichia coli O157:H7 in beef cattle. However, much of the focus has been on controlling this pathogen postcolonization. This study was conducted to examine the performance, health, and shedding characteristics of beef calves that were vaccinated with an E. coli O157:H7 SRP bacterial extract. These calves had been born to cows vaccinated prepartum with the same vaccine. Cows and calves were assigned randomly to one of four treatments: (i) neither cows nor calves vaccinated with E. coli O157:H7 SRP (CON), (ii) cows vaccinated with E. coli O157:H7 SRP prepartum but calves not vaccinated (COWVAC), (iii) calves vaccinated with E. coli O157:H7 SRP but born to cows not vaccinated (CALFVAC), (iv) cows vaccinated with E. coli O157:H7 SRP prepartum and calves also vaccinated (BOTH). Calves born to vaccinated cows had significantly higher titers of anti–E. coli O157:H7 SRP antibodies (SRPAb) in circulation at branding time (P < 0.001). Upon entry to the feedlot, overall fecal E. coli O157:H7 prevalence was 23% among calves, with 25% in the CON treatment group, 19% in the CALFVAC group, 32% in the COWVAC group, and 15% in the BOTH group (P > 0.05). Fecal shedding of E. coli O157 on arrival to the feedlot was not correlated with fecal shedding at slaughter (Spearman's rho = −20.02; P = 0.91). No significant effects of cow or calf E. coli O157:H7 SRP vaccination treatment were found on feedlot calf health or performance (P > 0.05), prevalence of lung lesions or liver abscess (P > 0.05), or morbidity, retreatment, or mortality numbers (P > 0.05). The findings of this study indicate that the timing of vaccination of calves against E. coli O157:H7 may be an important consideration for maximizing the field efficacy of this vaccine.

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Reduction of fecal shedding of enterohemorrhagic Escherichia coli O157:H7 in lambs by feeding microbial feed supplement

Small Ruminant Research ◽

10.1016/s0921-4488(00)00168-1 ◽

2001 ◽

Vol 39 (1) ◽

pp. 31-39 ◽

Cited By ~ 74

Author(s):

M Lema ◽

L Williams ◽

D.R Rao

Keyword(s):

Escherichia Coli ◽

Enterohemorrhagic Escherichia Coli ◽

Escherichia Coli O157 ◽

Feed Supplement ◽

Fecal Shedding

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Inhibition of Fecal Shedding of Enterohemorrhagic Escherichia coli O157: H7 in Cattle Fed Hay

Kansenshogaku zasshi ◽

10.11150/kansenshogakuzasshi1970.77.635 ◽

2003 ◽

Vol 77 (8) ◽

pp. 635-636

Author(s):

Muneo NAKAZAWA ◽

Toshiya SAMESHIMA

Keyword(s):

Escherichia Coli ◽

Enterohemorrhagic Escherichia Coli ◽

Escherichia Coli O157 ◽

Fecal Shedding

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Bacteriophages reduce Escherichia coli O157:H7 levels in experimentally inoculated sheep

Canadian Journal of Animal Science ◽

10.4141/cjas08083 ◽

2009 ◽

Vol 89 (2) ◽

pp. 285-293 ◽

Cited By ~ 15

Author(s):

S J Bach ◽

R P Johnson ◽

K. Stanford ◽

T A McAllister

Keyword(s):

Escherichia Coli ◽

Oral Administration ◽

Coliform Bacteria ◽

Escherichia Coli O157 ◽

Fecal Shedding ◽

Total Coliforms ◽

E Coli ◽

Oral Inoculation ◽

Experimental Treatments ◽

And Control

Bacteriophage biocontrol has potential as a means of mitigating the prevalence of Escherichia coli O157:H7 in ruminants. The efficacy of oral administration of bacteriophages for reducing fecal shedding of E. coli O157:H7 by sheep was evaluated using 20 Canadian Arcott rams (50.0 ± 3.0) housed in four rooms (n = 5) in a contained facility. The rams had ad libitum access to drinking water and a pelleted barley-based total mixed ration, delivered once daily. Experimental treatments consisted of administration of E. coli O157:H7 (O157), E. coli O157:H7+bacteriophages (O157+phage), bacteriophages (phage), and control (CON). Oral inoculation of the rams with 109 CFU of a mixture of four nalidixic acid-resistant strains of E. coli O157:H7 was performed on day 0. A mixture of 1010 PFU of bacteriophages P5, P8 and P11 was administered on days -2, -1, 0, 6 and 7. Fecal samples collected on 14 occasions over 21 d were analyzed for E. coli O157:H7, total E. coli, total coliforms and bacteriophages. Sheep in treatment O157+phage shed fewer (P < 0.05) E. coli O157:H7 than did sheep in treatment O157. Populations of total coliforms and total E. coli were similar (P < 0.05) among treatments, implying that bacteriophage lysis of non-target E. coli and coliform bacteria in the gastrointestinal tract did not occur. Bacteriophage numbers declined rapidly over 21 d, which likely reduced the chance of collision between bacteria and bacteriophage. Oral administration of bacteriophages reduced shedding of E. coli O157:H7 by sheep, but a delivery system that would protect bacteriophages during passage through the intestine may increase the effectiveness of this strategy as well as allow phage to be administered in the feed.Key words: Escherichia coli O157:H7, bacteriophage, sheep, environment, coliforms

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