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

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.

2005 ◽  
Vol 68 (1) ◽  
pp. 6-10 ◽  
Author(s):  
SPRING M. YOUNTS-DAHL ◽  
GARY D. OSBORN ◽  
MICHAEL L. GALYEAN ◽  
J. DANIEL RIVERA ◽  
GUY H. LONERAGAN ◽  
...  

Our objective was to evaluate the effects of three doses of Lactobacillus acidophilus strain NP51 and a combination treatment of strains NP51 and NP45 on prevalence of Escherichia coli O157 in cattle. Three hundred steers were assigned randomly to 60 pens (five steers per pen) and received one of five treatments: (i) control, no added direct-fed microbial; (ii) HNP51, high dose of NP51 at 109 CFU per steer daily; (iii) MNP51, NP51 at 108 CFU per steer daily; (iv) LNP51, low dose of NP51 at 107 CFU per steer daily; and (v) NP51+45, NP51 at 109 CFU per steer daily and NP45 at 106 CFU per steer daily. All direct-fed microbial treatments included Propionibacterium freudenreichii at 109 CFU per steer. Individual rectal fecal samples were collected on arrival and every 28 days throughout the feeding period. Fecal and hide samples were collected on the day of harvest. Samples were analyzed for presence of E. coli O157 using immunomagnetic separation methods. Cattle receiving HNP51, MNP51, and LNP51 had a lower prevalence (P < 0.01) of E. coli O157 throughout the feeding period compared with the controls, and the dose response for NP51 was a linear decrease in prevalence with increasing dose (P < 0.01). No decrease in prevalence for cattle receiving the combination NP51+45 was detected compared with controls (P = 0.15). E. coli O157 prevalences averaged across collection times were 23.9, 10.5, 9.9, 6.8, and 17.3% for cattle in the control, LNP51, MNP51, HNP51, and NP51+45 groups, respectively. Least squares mean estimates of fecal prevalence at harvest of E. coli O157 were 31.7, 12.5, 17.4, 8.2, and 41.6% among cattle in the control, LNP51, MNP51, HNP51, and NP51+45 groups, respectively. Least squares mean estimates of the percentage of positive hide samples at harvest were 8.7, 5.9, 4.8, 3.4, and 8.6% among cattle in the control, LNP51, MNP51, HNP51, and NP51+45 groups, respectively. The greatest decrease in E. coli O157 carriage was achieved using NP51 at 109 CFU per steer.


2007 ◽  
Vol 70 (5) ◽  
pp. 1252-1255 ◽  
Author(s):  
T. P. STEPHENS ◽  
G. H. LONERAGAN ◽  
L. M. CHICHESTER ◽  
M. M. BRASHEARS

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.


2007 ◽  
Vol 70 (10) ◽  
pp. 2386-2391 ◽  
Author(s):  
T. P. STEPHENS ◽  
G. H. LONERAGAN ◽  
E. KARUNASENA ◽  
M. M. BRASHEARS

In this study, the effectiveness of direct-fed microbials at reducing Escherichia coli O157 and Salmonella in beef cattle was evaluated. Steers (n = 240) received one of the following four treatment concentrations: control = lactose carrier only; low = 1 × 107 CFU per steer daily Lactobacillus acidophilus NP51; medium = 5 × 108 CFU per steer daily L. acidophilus NP51; and high = 1 × 109 CFU per steer daily L. acidophilus NP51. Low, medium, and high diets also included 1 × 109 CFU per steer Propionibacterium freudenreichii NP24. Feces were collected from each animal at allocation of treatment and found to have no variation (P = 0.54) between cohorts concerning E. coli O157 recovery. Feces and hide swabs were collected at harvest and analyzed for the presence of E. coli O157 by immunomagnetic separation and Salmonella by PCR. No significant dosing effects were detected for E. coli O157 recovery from feces at the medium dose or from hides at the medium and high doses. E. coli O157 was 74% (P < 0.01) and 69% (P < 0.01) less likely to be recovered in feces from animals receiving the high and low diets, respectively, compared with controls. Compared with controls, E. coli O157 was 74% (P = 0.05) less likely to be isolated on hides of cattle receiving the low dose. No significant dosing effects were detected for Salmonella recovery from feces at the medium and low doses or from hides at any doses. Compared with controls, Salmonella was 48% (P = 0.09) less likely to be shed in feces of cattle receiving the high dose. No obvious dose-response of L. acidophilus NP51 on recovery of E. coli O157 or Salmonella was detected in our study.


2005 ◽  
Vol 68 (1) ◽  
pp. 26-33 ◽  
Author(s):  
K. STANFORD ◽  
S. J. BACH ◽  
T. H. MARX ◽  
S. JONES ◽  
J. R. HANSEN ◽  
...  

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.


2010 ◽  
Vol 73 (2) ◽  
pp. 366-371 ◽  
Author(s):  
TERRANCE M. ARTHUR ◽  
JOSEPH M. BOSILEVAC ◽  
NORASAK KALCHAYANAND ◽  
JAMES E. WELLS ◽  
STEVEN D. SHACKELFORD ◽  
...  

Direct-fed microbials (DFM) have been identified as potential preharvest interventions for the reduction of foodborne bacterial pathogens such as Escherichia coli O157:H7. This study evaluated the efficacy of a DFM consisting of Bacillus subtilis strain 166 as an antimicrobial intervention strategy for the reduction of prevalence and load of E. coli O157:H7 in feces and on hides of feedlot cattle. Cattle (n = 526) were divided among 16 feedlot pens. Half of the pens received the DFM, and the other half did not. Hide and fecal samples were collected from each animal on days 28, 63, and 84 of the feeding trial. Over the course of the 84-day feeding period, there were no significant differences observed between treatments for either hide or fecal prevalence of E. coli O157:H7, or for the percentage of animals that were shedding E. coli O157:H7 at high levels (≥200 CFU/g) in their feces or harboring E. coli O157:H7 at high levels (≥40 CFU/cm2) on their hides. In addition, there was no significant difference between the average daily gains for the treated and control groups, with both groups averaging 1.3 kg/day. We concluded that the DFM tested would not be an effective preharvest intervention against E. coli O157:H7.


2007 ◽  
Vol 70 (5) ◽  
pp. 1072-1075 ◽  
Author(s):  
T. P. STEPHENS ◽  
G. H. LONERAGAN ◽  
W. E. CHANEY ◽  
L. A. BRANHAM ◽  
M. M. BRASHEARS

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.


2007 ◽  
Vol 70 (2) ◽  
pp. 287-291 ◽  
Author(s):  
R. E. PETERSON ◽  
T. J. KLOPFENSTEIN ◽  
G. E. ERICKSON ◽  
J. FOLMER ◽  
S. HINKLEY ◽  
...  

A 2-year study was conducted during the summer months (May to September) to test the effectiveness of feeding Lactobacillus acidophilus strain NP51 on the proportion of cattle shedding Escherichia coli O157:H7 in the feces and evaluate the effect of the treatment on finishing performance. Steers (n = 448) were assigned randomly to pens, and pens of cattle were assigned randomly to NP51 supplementation or no supplementation (control). NP51 products were mixed with water and applied as the feed was mixed daily in treatment-designated trucks at the rate of 109 CFU per steer. Fecal samples were collected (n = 3,360) from the rectum from each animal every 3 weeks, and E. coli O157:H7 was isolated by standard procedures, using selective enrichment, immunomagnetic separation, and PCR confirmation. The outcome variable was the recovery of E. coli O157:H7 from feces, and was modeled using logistic regression accounting for year, repeated measures of pens of cattle, and block. No significant differences were detected for gain, intakes, or feed efficiency of control or NP51-fed steers. The probability for cattle to shed E. coli O157:H7 varied significantly between 2002 and 2003 (P = 0.004). In 2002 and 2003, the probability for NP51-treated steers to shed E. coli O157:H7 over the test periods was 13 and 21%, respectively, compared with 21 and 28% among controls. Over the 2 years, NP51-treated steers were 35% less likely to shed E. coli O157: H7 than were steers in untreated pens (odds ratio = 0.58, P = 0.008). This study is consistent with previous reports that feeding NP51 is effective in reducing E. coli O157:H7 fecal shedding in feedlot cattle.


2004 ◽  
Vol 70 (1) ◽  
pp. 377-384 ◽  
Author(s):  
J. T. LeJeune ◽  
T. E. Besser ◽  
D. H. Rice ◽  
J. L. Berg ◽  
R. P. Stilborn ◽  
...  

ABSTRACT Identification of the sources and methods of transmission of Escherichia coli O157:H7 in feedlot cattle may facilitate the development of on-farm control measures for this important food-borne pathogen. The prevalence of E. coli O157:H7 in fecal samples of commercial feedlot cattle in 20 feedlot pens between April and September 2000 was determined throughout the finishing feeding period prior to slaughter. Using immunomagnetic separation, E. coli O157:H7 was isolated from 636 of 4,790 (13%) fecal samples in this study, with highest prevalence earliest in the feeding period. No differences were observed in the fecal or water trough sediment prevalence values of E. coli O157:H7 in 10 pens supplied with chlorinated drinking water supplies compared with nonchlorinated water pens. Pulsed-field gel electrophoresis of XbaI-digested bacterial DNA of the 230 isolates obtained from eight of the pens revealed 56 unique restriction endonuclease digestion patterns (REDPs), although nearly 60% of the isolates belonged to a group of four closely related genetic subtypes that were present in each of the pens and throughout the sampling period. The other REDPs were typically transiently detected, often in single pens and on single sample dates, and in many cases were also closely related to the four predominant REDPs. The persistence and predominance of a few REDPs observed over the entire feeding period on this livestock operation highlight the importance of the farm environment, and not necessarily the incoming cattle, as a potential source or reservoir of E. coli O157:H7 on farms.


2007 ◽  
Vol 70 (11) ◽  
pp. 2568-2577 ◽  
Author(s):  
R. E. PETERSON ◽  
T. J. KLOPFENSTEIN ◽  
R. A. MOXLEY ◽  
G. E. ERICKSON ◽  
S. HINKLEY ◽  
...  

Preharvest intervention strategies to reduce Escherichia coli O157:H7 in cattle have been sought as a means to reduce human foodborne illness. A blinded clinical trial was conducted to test the effect of a vaccine product on the probability that feedlot steers, under conditions of natural exposure, shed E. coli O157:H7 in feces, are colonized by this organism in the terminal rectum, or develop a humoral response to the respective antigens. Steers (n = 288) were assigned randomly to 36 pens (eight head per pen), and pens were randomized to vaccination treatment in a balanced fashion within six dietary treatments of an unrelated nutrition study. Treatments included vaccination or placebo (three doses at 3-week intervals). Fecal samples for culture (n = 1,410) were collected from the rectum of each steer on pretreatment day 0 and posttreatment days 14, 28, 42, and 56. Terminal rectum mucosal (TRM) cells were aseptically collected for culture at harvest (day 57 posttreatment) by scraping the mucosa 3.0 to 5.5 cm proximal to the rectoanal junction. E. coli O157:H7 was isolated and identified with selective enrichment, immunomagnetic separation, and PCR confirmation. Vaccinated cattle were 98.3% less likely to be colonized by E. coli O157:H7 in TRM cells (odds ratio = 0.014, P < 0.0001). Diet was also associated with the probability of cattle being colonized (P = 0.04). Vaccinated cattle demonstrated significant humoral responses to Tir and O157 lipopolysaccharide. These results provide evidence that this vaccine product reduces E. coli O157:H7 colonization of the terminal rectum of feedlot beef cattle under conditions of natural exposure, a first step in its evaluation as an effective intervention for food and environmental safety.


2007 ◽  
Vol 70 (10) ◽  
pp. 2230-2234 ◽  
Author(s):  
T. W. THOMPSON ◽  
T. P. STEPHENS ◽  
G. H. LONERAGAN ◽  
M. F. MILLER ◽  
M. M. BRASHEARS

Rapid enzyme-linked immunosorbent assays (ELISAs) are approved for detection of Escherichia coli O157 in beef products. However, these kits have also been used in the industry to detect this pathogen on hides or in feces of cattle, although this use has not been validated. The objective of this study was to compare commercially available ELISAs (E. coli Now, Reveal, and VIP) with immunomagnetic separation along with selective media to detect E. coli O157 on hides, in feces, and in medium- and low-level-inoculated ground beef and carcasses (simulated by using briskets) samples. Naturally infected hide and fecal samples were subjected to both the immunomagnetic separation method and ELISAs for the detection of E. coli O157. Additionally, E. coli O157 inoculated and noninoculated ground beef and beef briskets were used to simulate meat and carcass samples. When comparing the detection results from the ELISAs (E. coli Now, Reveal, and VIP) to the immunomagnetic separation method, poor agreement was observed for fecal samples (kappa = 0.10, 0.02, and 0.03 for E. coli Now, Reveal, and VIP, respectively), and fair-to-moderate agreement was observed for hide samples (kappa = 0.30, 0.51, and 0.29 for E. coli Now, Reveal, and VIP, respectively). However, there was near-perfect agreement between the immunomagnetic separation method and ELISAs for ground beef (kappa = 1, 1, and 0.80 for E. coli Now, Reveal, and VIP, respectively) and brisket (kappa = 1, 1, and 1 for E. coli Now, Reveal, and VIP, respectively) samples. Assuming immunomagnetic separation is the best available method, these data suggest that the ELISAs are not useful in detecting E. coli O157 from hide or fecal samples. However, when ELISAs are used on ground beef and beef brisket samples they can be used with a high degree of confidence.


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