Alfred Hitchcock,the price of gas,and the incidence of foodborne disease in the United States

Jeffrey LeJeune, Food Animal Health Research ProgramOARDC

Shiga toxin-producing E. coli (STEC)An emerging disease

1982 – Severe abdominal cramps– Bloody diarrhea– No fever– Edema in intestine– No usual pathogens isolated – History of recent hamburger

consumption• 1993

– 600 people affected

What is special about O157?

• Attachment to intestinal cells– Via intimin (eae gene)

• Production of toxin– Shiga toxin

• Also O26, O111, O145, O45, O103, O111

Disease Transmission in Humans

• Foods of bovine origin: hamburger, roast, salami, raw milk

• Other foods: apple cider, salads, deer jerky

• Drinking/recreational water• Person-to-person• Direct cow-to-person• Environment-to-person

Public’s Back to Nature Mentality

Farm-to-Table Approach to Food Safety

• E. coli O157 tracked to cattle• Bovine prevalence linked to carcass prevalence

How to control E. coli in cattle

1. Control transmission between farms

3. Control replication within individual cows

2. Control transmission between cows, within farms

A

B

A B

AB

Control Between Farms A

B

Hypothesis

European Starlings contribute to the prevalence of Escherichai coli O157 on dairy farms

Methods

• Experimental carriage by birds

• Transmission studies between starlings and cattle

• Radio telemetry of birds• Bird census vs. bovine

Prevalence (150 farms)• Molecular sub-typing of

isolates

DoylestownSterling

Orrville

Lime Lakes Roost

7:12 AM

7:25 AM7:27 AM7:30 AM

8:02 AM

7:32 AM

DoylestownStaging Area

3.5 Miles

Sterling0.5 Miles

DoylestownSterling

Orrville

6:51 PM6:30 PM5:59 PM

5:50 PM

5:45 PM

5:30 PM

Lime LakesRoost

Staging Area

4 Miles

Results

• Association between bird populations and bovine prevalence: More Birds, more O157

• Matching of E. coli O157 isolates between farms

Impact- Application: Results will predict if bird control will have impact on E. coli O157 carriage in cattle.

Between cow, within farm control• Prevalence on individual farms often remains

stable for years: frequently high, or frequently low

• Role for management to influence E. coli ?

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Date

Farm Y Farm X

A B

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10

A B C D E F G H I J

Farm Pair

% E

. co

li O

157

Sawdust Sand

Bedding and E. coli • Bedding material linked to coliform mastitis• Sawdust bedding linked to higher E. coli O157

3.1% 1.4%

E. coli O157 less prevalent on among cattle in sand-bedded herds (P=0.05)

Sand Recycling

Hypothesis: Recycled sand bedding is populated with bacterial communities suppressive to E. coli O157

Heat-labile suppression

Fresh In-use Washed Dry Fresh In-use Washed Dry

• T-RFLP analysis of bacterial communities• Regression Analysis of abundance of TRF and suppression• Cloning and sequencing of TRFs

ResultsTRFs

•Cytophaga-Flexibacter-Bacteriodetes

•Gamma proteobacteria •Firmicutes

Impact-ApplicationIsolating these organisms, and enriching for their presence in bedding may be a way to control E. coli O157 in the farm environment.

Within Cow

Overall O157 Prevalence

-2.0% -1.0% 0.0% 1.0% 2.0% 3.0% 4.0% 5.0%

Prevalence Difference

4.4%3.1%

Corn

Barley

AB

15 pen pairs

•Probiotics, Vaccination•Bacteriophage Therapy•Grain vs. Hay feeding ???

Distillers’ Grains

Within Cow Control

Hypothesis:

Different feed components provide specific nutrients to the hind gut that influence microbial populations that either promote or suppress E. coli O157 carriage by cattle.

Effect of DGs on E. coli O157

Additional Methods

• Determine available nutrients in mucin of cattle fed different diets

• Determine preferred carbohydrate sources of E. coli O157

• Determine association between : feed-mucin carbohydrates- E. coli O157-

microbial communites

Results

• Initial results indicate specific microbial communities associated with– DG vs. corn feeding– E. coli O157-positive and E. coli O157-negative

animals

Impact- ApplicationsIdentifying microbial populations inhibitory to

E. coli O157 can aid in the control of the organism in the live animal.

Take- Home Messages

1. Multiple factors interplay on the safety of the food supply

2. Holistic approach critical in weighing costs and benefits

3. Interdisciplinary teams valuable to answer complex questions

Acknowledgements and Collaborators

• Bird Study– David Pearl, U of Guelph– Jeff Homan George Linz, USDA Wildlife Services– USDA NRI Grant 2006-01227

• Bedding Study– McSpadden Gardener & Lab– Steve Abedon, Dept Microbiology, OSU Mansfield– OARDC SEEDs Interdisciplinary Grant

• Distillers’ Grain– McSpadden Gardener Plant Pathology, OSU– Steve Loerch, Animal Sciences, OSU– USDA, AFRI 2009-03960

LeJeune Lab