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PIC Update: Fighting a $1-billion Disease

Fighting a $1-billion disease


February 13, 2008
By Tim Nelson Executive Director and Kimberly Sheppard Research

Topics

Two different approaches to tackling the very costly problem of necrotic enteritis

Two different approaches to tackling the very costly problem of necrotic enteritis

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Understanding Necrotic Enteritis
Dr. John Prescott led a series of studies that has shed some light on
the basis of immunity to necrotic enteritis.  These results are steps
towards a vaccine and reducing antibiotic use in the future.

Consumers are driving the poultry industry away from the use of antibiotics as a disease treatment, so alternative means of control – such as immunization – need to be developed.

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Prof. John Prescott, chair of the Department of Pathobiology, University of Guelph, is working towards a vaccine for necrotic enteritis. It’s been described as a $1-billion disease by the industry, and requires antibiotics for treatment and control. 

“The threat of antibiotic-resistant genes demands that the scientific community find ways to preserve the use of antibiotics for the long term,” says Prescott.  “This means reducing the use of antibiotics in humans and animals, and I think this research is a small step towards that goal.”

Necrotic enteritis is caused by the bacterium Clostridium perfringens which produces toxins that damage the intestinal lining, leading to diarrhea. But often no signs are seen other than a sudden increase in dead chickens in the flock.
Surprisingly little is known about immunity to this disease in broiler chickens, despite its prevalence, and no vaccine is currently available.

But now, a series of three recent studies led by Prescott has shed some light on the basis of immunity to necrotic enteritis. 

“Previous understanding of the immunity to necrotic enteritis and how the bacteria caused disease was wrong,” says Prescott.  “It has been rewarding to see these scientific misconceptions overturned and take a step towards developing a vaccine.”  

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The first study concluded it is in fact possible to immunize chickens against this disease. In the second study, six secreted proteins unique to virulent C. perfringens were identified. Some of these proteins, in the third study, were found to be produce good immunity to necrotic enteritis when broiler chickens were immunized with them.

Prescott and his team of researchers are now working to engineer a live Salmonella vaccine with some of these proteins.   If this vaccine approach works, it may be further developed into an economical multivalent vaccine that provides immunity against necrotic enteritis and other important diseases affecting broiler chickens, such as Salmonella and Campylobacter.

“It’s about trying to support the industry to cope with days when
antibiotics are ineffective due to antimicrobial resistance or unavailable due to consumer preferences,” says Prescott.

Prescott’s research team includes PhD student Ravi Kulkarni and research associate Valeria Parreira. Sponsors include the Ontario Ministry of Agriculture, Food and Rural Affairs; the Poultry Industry Council of Canada; the Saskatchewan Chicken Industry Development Fund; the Canadian Poultry Research Council in a partnership with Agriculture and Agri-Food Canada; and the Natural Sciences and Engineering Research Council.

Contributed by Man-Sum Yau, a  writer with the SPARK (Students Promoting Awareness of Research Knowledge) program at the University of Guelph.

PIC featured researcher

John F. Prescott, MA VetMB PhD, Professor, Department of Pathobiology, Ontario Veterinary College, University of Guelph, Ontario, Canada. 

John F. Prescott graduated VetMB from the University of Cambridge, England, in 1973 and PhD from the same University in 1977. He has worked at the Ontario Veterinary College as a bacteriologist since 1976, initially as an Assistant Professor and clinical bacteriologist and since 1979 as a teacher and research worker. He was promoted to Professor in 1988. He is currently Chair of the Department of Pathobiology.

He has had diverse interests in bacterial infections in animals, but is best known for work in the area of Rhodococcus equi pneumonia in foals. He has an increasing interest is in poultry microbiology, specifically Clostridium perfringens as the agent of necrotic enteritis in broilers.

He was until recently Co-Editor-in-Chief of Veterinary Microbiology (Elsevier Science). He has acted as ad hoc reviewer for many other journals, as well as for grants and programs. He was a member of the Council, Canadian Veterinary Medical Association, where he served on both the National Issues Committee and the Prudent Use of Antimicrobial Drugs Committee. He was Co-Chair of the 2005 national conference on Agriculture’s Role in Managing Antimicrobial Resistance: The Road to Prudent Use, and is currently a Director of the Canadian Committee on Antibiotic Resistance.

PIC's picks

Identifying
causes for increased incidence of necrotic enteritis in broiler
chickens fed wheat- and barley-based diets compared to corn-based diets

Dr. Colleen Annett,
University of Saskatchewan

Necrotic enteritis (NE) is a common disease affecting poultry
worldwide.  Its economic impact on the industry is significant. When 
bacteria Clostridium perfringens type A (CPA) reaches high numbers in
the small intestine, necrotic enteritis results.  When this disease
strikes, the mucosa of the intestine becomes necrotic (dies), due to a
poison called alpha toxin which is produced by the CPA bacteria. 
Symptoms include severe depression, decreased appetite, dark coloured
diarrhea, closed eyes or ruffled feathers and/or rapid death. 

Increased incidences of necrotic enteritis have been associated with
anything that causes intestinal irritation (co-infection, parasites,
the ingestion of fishmeal or high fibre litter).  Research has shown
that high levels of animal source protein may predispose chickens to
necrotic enteritis.  This disease is also more prevalent in broilers
fed a wheat-based or barley-based diet than a corn based diet.  In
western Canada, the primary feed ingredient in poultry feed is wheat or
barley, due to their availability and affordability. 

To get a better handle on why broilers fed wheat and barley result in
higher incidences of necrotic enteritis than those fed corn, Dr.
Colleen Annett with the University of Saskatchewan has been
investigating whether there are compounds in wheat, barley, or corn
that could contribute to or reduce the incidence of necrotic enteritis.
Previous work by her research team has shown that CPA bacteria has
greater proliferation in wheat- and barley-based fluid compared to
corn-based.  Recently, the effects of wheat and corn on proliferation
of CPA bacteria and its alpha toxin production have been investigated
in the lab.

Her findings?  The gluten found in corn meal could be the key to
reducing incidences of necrotic enteritis in broilers fed corn-based
diets.  To read more visit: www.poultryindustrycouncil.ca  and click on “Research Results.” This study is PIC Project 142.

This year kicks off with a change in our role. Taking our lead from the October ‘07  industry research and education planning sessions followed by some intensive planning of our own (the outcomes of which will become apparent in the coming year), we’ve developed a reworked role which we believe much more accurately describes what we do and how we’ll do it. 

Our reworked role reads as follows: To manage research and education on behalf of the Poultry Industry in Ontario.

PIC will accomplish its role by:

•     Identifying the relevant issues by facilitating the development  of an industry prepared and supported R&E strategy,

•     Responding to the industries expressed needs through the pro-active management of targeted R&E initiatives, 

•    Communicating and co-ordinating research results to promote their application in the appropriate context and,

•    Evaluating the impact of R&E initiatives in order to be accountable for progress and demonstrate the value from the industries investment.

Big plans and changes in 2008

In line with the new role we’re doing things a bit differently in 2008.

Research proposals are currently being called. This year we’ve used the results of the strategic planning sessions to guide our investment and our call for proposals. There are 4 program areas: The Market, Production, Capacity Building (investing in people) and Evaluation (return on investment), underpinned by some very clear direction as to the objectives we’re looking to meet through the projects we invest in.

Our call for proposals released at the end of January, reflects the above priority areas and will be out at the end of January.

We’ll bring you the important highlights of the new R&E Strategy in the March edition of CPM and the full document is available on our website at www.poultryindustrycouncil.ca or by contacting PIC  at 519-837-0284.

The Poultry Health Conference

The Poultry Health Conference is changing its name to the Poultry Innovation Conference.

The planning for the Conference on 10th (afternoon only) and 11th November this year is already well under way. Local MPP and Minister for Innovation and Research, the Hon. John Wilkinson, will be opening proceedings on day 2.

We’re making sure we’re bringing you the very latest in up to date technology, management techniques, market innovations and poultry business management. A call for abstracts has gone out nationally and internationally to find most informed speakers to ensure the information you hear at the conference is the best there is. Check the website for details.

Good local stories

Got any good local stories to share? In response to your comments following the talks by Sandi Brock and Dr. Rae Fischer, as well as your suggestions at the 2007 conference, we’re also on the lookout for local producers who have a story to tell in relation to an innovation they’ve implemented successfully or are planning. Don’t be shy in putting someone else’s name forward!!

Golf getting bigger

Due to unprecedented demand the 2008 golf tournament will be moving to the Foxwood 27-hole course. We’ve had some great tournaments at St. Marys but such is the demand from players we’ve finally outgrown it. Despite the being able to accommodate more players we still recommend booking early so why not take a corporate membership package that includes sponsoring the golf tournament?

Upcoming at PIC

April 8–9 – The London Poultry Show
Exhibitors stands were sold out pre-2008, which can only mean that this year’s show will be jam packed with plenty of new ideas, technologies and information for the producer and processor.

For this year’s show, which runs on April 9th and 10th , Al Dam with the Ontario Ministry of Agriculture, Food and Rural Affairs, will again be pulling together a producer update series for the two days.  On top of all this excitement the show is just simply a great place to catch up with friends!

May 15 – Research Day is fast approaching and this year is being held at the Arboretum, (free parking) University of Guelph. Whilst this is a day predominantly for researchers there is plenty of interest for industry people. Mark your calendars.