Canadian Poultry Magazine

PIC Update: Exploring Gut Immunity

By PIC   

Features Profiles Researchers

Exploring Gut Immunity

Tim Nelson, Executive Director and Kimberly Sheppard, Research Co-ordinator

The use of antibiotics in poultry production has raised concerns about
the development of antimicrobial resistance in microbes.

Research investigates how antibiotics are affecting the chicken intestinal and immune systems


Results of Dr. Shayan Sharif’s studies have provided critical information about how antibiotics are affecting the chicken intestinal
and immune systems.

The use of antibiotics in poultry production has raised concerns about the development of antimicrobial resistance in microbes. Also of concern is the fact that antibiotic use often results in destabilization of the various bacteria in the gut – many of which help to develop and regulate gut function. Some bacteria are even capable of controlling food-borne pathogens such as salmonella and campylobacter. This suggests that imprudent use of antibiotics may potentially adversely affect animal health and also raises some food safety concerns.

It’s been reported that gut bacteria and changes in the microbial community could affect the chicken immune system. As the use of antibiotics in food animal production develops, having a better understanding of how antibiotics affect chicken gut microflora and the immune system could lead to the development of more effective antimicrobials.

Dr. Shayan Sharif and his research team at the University of Guelph in collaboration with Dr. Joshua Gong (Agriculture and Agri-Food Canada) have been investigating interactions between antibiotics, gut microbes and the chicken immune system. They looked at the effects of virginiamycin on the various bacteria in the chicken gut.

Their findings? They discovered that virginiamycin treatment altered the variety of bacteria, including beneficial bacteria within the Lactobacillus family (Lactobacilli are commonly used as probiotics in poultry production). Dr. Sharif and his team also showed that virginiamycin possesses immune enhancing properties and that by manipulating the gut microflora we may be able to positively impact the development of immune response in other parts of the body. These results have provided critical information about how antibiotics are affecting the chicken intestinal and immune systems. To read more, please visit .


Dr. Shayan Sharif graduated with a DVM degree from the Faculty of Veterinary Medicine, University of Tehran, Iran in 1991. The area of Dr. Sharif’s DVM thesis was genetic resistance to Marek’s disease in chickens, which sparked an interest in him to pursue a career in chicken immunology and immunogenetics. Upon graduation, Dr. Sharif worked for close to two years in the broiler industry in Iran before migrating to Canada. He pursued a PhD program in the area of immunology and immunogenetics at the Ontario Veterinary College, Guelph. Dr. Sharif was recruited in 2001 as a faculty member and also a member of the PIC-sponsored Poultry Program Team by the Department of Pathobiology, University of Guelph. He is currently supervising a team consisting of four students, three technicians and twp post-doctoral fellows. There are three active research programs in Dr. Sharif’s lab: (1) Immunology and genetics of resistance against Marek’s disease, (2) Avian influenza virus immunity, and (3) Studies of chicken gut immune system in health and disease.


Mansel Griffiths, University of Guelph

Identifying methods to rapidly detect and identify pathogens in the
food chain more efficiently has been widely researched over the last 20
years. One of the most promising detection methods for pathogens found
in poultry and poultry products (e.g., salmonella, campylobacter and
listeria) is polymerase chain reaction (PCR) technology. PCR allows for
the production of millions of copies of a particular segment of DNA
that allows scientists to use a very small sample, and from that
sample, amplify a particular DNA sequence to detectable levels.

In order to raise pathogens to detectable levels, however, an
enrichment period is usually required. This step is time consuming,
rendering it less than ideal for practical use. The other disadvantage
of PCR is that it does not allow for the detection of viable
campylobacter, or the quantification of the actual number of pathogens
in the original sample if an enrichment step is included.

There are currently several accepted (published) methods for the direct
detection of bacteria in biological samples that do not involve an
enrichment period. However, these methods usually use a very small
sample size. Because pathogens are usually present in foods in low
numbers and regulatory agencies require detection of as few as one cell
per 25 grams of sample, large volumes should be used in the analysis to
ensure that even one cell within that sample can be detected. To date,
only a very small number of studies have successfully used larger
samples for direct detection of very low amounts of pathogens in food.

To seek a solution to this conundrum Drs. Mansel Griffiths and Petra
Wolffs at the University of Guelph have been developing a practical
method for rapid quantitative assessment of salmonella, campylobacter
and listeria – not only in end products but also within the production

Their findings? Using a combination of a filtration “setup” and
real-time PCR, Griffiths and his team have developed a method capable
of detecting and quantifying salmonella and campylobacter
simultaneously within four hours to levels equivalent to one cell per
millilitre of sample. This is a big step foward in improving the
efficiency and accuracy of rapid early detection of pathogens along the
supply chain. To read more, please visit


Poultry Worker Award
Each year at the Annual Poultry Conference in November the industry recognizes an individual who has made a significant contribution to our industry. Anyone can nominate someone for this award. The nominations are then screened and references checked by an independent panel, who then make the final assessment and decision.

So many brilliant people work in our industry and it’s always very hard to select just one. The process takes time, so it’s really important that if you feel there is an individual who is deserving of this prestigious honour that you nominate them before Sept. 16, when nominations close.  

Golf Tournament Sept. 10, at Foxwood Golf and Country Club, filling fast. If you haven’t registered please do so today. Although we have increased capacity this year, we’re almost sold out.

Funded Research
This year 44 projects were received and of those the PIC has approved 26 for funding. The standard of applications was high. Those projects that have been granted funds are on the PIC website and details will be published in next month’s Canadian Poultry magazine. PIC is currently seeking supplementary funds to ensure that the 26 approved projects receive the maximum amount of funding possible to undertake the important work that has been proposed.

The Inaugural Poultry Innovation Conference
The first Poultry Innovation Conference will be held at Bingeman’s in Kitchener, Ont., on Nov. 10 and 11, and will offer two days of learning and networking for the whole industry. Day 1 comprises an afternoon of research reports in a similar format enjoyed by so many of you at this year’s Research Day. Day 2 will offer plenty for everyone with very practical sessions designed by producers for producers and industry service professionals. The day will culminate in a gala dinner to celebrate our industry. Spend some social time with friends and have the pleasure and privilege of hearing our guest speaker and one of our industry’s legends, Donald McQueen Shaver, O.C. D.Sc.

Dr. Shaver will share his thoughts on today’s poultry industry, agriculture at large, the challenges that lay ahead and based on his vast experience and knowledge some suggestions on how to deal with them. This is an opportunity to hear someone who has “lived” the industry and played an integral role in shaping what we see today.

The opinions of this elder statesman of poultry are important, inspirational and informative – don’t miss this. For more information, call PIC.   

Board Membership
Nominations for PIC Board membership for 2008/09 close on Aug. 31, 2008. Individuals interested in making a difference in our industry through research and education are invited to apply.
Please contact PIC for details or Bob Guy at OBHECC who is the chairman of the PIC Nominating Committee.

Annual Meeting
This year’s Annual Meeting (all members are encouraged to attend) will be held at the Victoria East Golf club at 11-30 a.m. on Oct. 7. The meeting will be followed by lunch at the club at 12 noon provided by PIC.

Prior to the meeting we will be running a “report and review” session looking at the current research and the new proposals, and updating the Ontario Poultry Industry R&E Strategy – more details on this event will be published in next month’s Canadian Poultry magazine.

For more details on any of the items in the PIC Update please contact PIC at 519-837-0284 or e-mail us at .

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