Meeting of Australian Veterinary Poultry
Association (AVPA) and Commercial Poultry
Veterinarians , Melbourne, 3rd&4th November
2011
50th Anniversary Meeting
Opened by Nobel Laureate Dr. Peter Doherty
Tom Grimes
Dr. Peter Doherty
• Only veterinarian to receive the Nobel Prize
• Worked at Qld. DPI Animal Research Institute Yeerongpilly
from 1963-67 after graduating from Uni. Qld. in 1962
• Obtained a MVSc on Leptospirosis of Cattle
• Published on Infectious Bronchitis (IB)
– Doherty, P. C. (1967). Occurrence of Avian Infectious Bronchitis Virus in
the Tissues of Experimentally Infected Chickens. Qld. J. Agric. and
Anim. Sci. 24:75-80
• His wife Penny Stephens also worked at ARI and also
published on IB
– Stephens, P. and Simmons, G. C. (1968). Neutralising Antibodies for
Avian Infectious Bronchitis Virus in Queensland Poultry Flocks. Aust.
Vet. J. 44:29-30
Summary of Topics
• History of Poultry Diseases in Australia (B. Bains), Newcastle
Disease (P. Selleck), Avian Influenza (A. Turner), Marek’s
Disease (C. Jackson), Infectious Laryngotracheitis (T.
Bagust), Mycoplasmosis (K. Whithear), Pasteurellosis and
Coryza (P. Blackall), Infectious Bronchitis (J. Ignjatovic), and
Australian poultry industry unique points (C. Morrow)
• Review papers on AI in Asia (C. Wilks), Campylobacter
Control in NZ (D. Marks), food safety (J. Cox and D. Craig),
Coles food policy (A. Currie), registration requirements (R.
Pottie), minor food-producing species (A. Etherington) and
Pigeon Paramyxovirus outbreak (S. Mccullough)
• Research papers on ILT, IB and MG (Uni. Melb.), Pasteurella
multocida typing (Monash Uni.), Necrotic Enteritis (CSIRO),
enteric viruses (USDA Athens), S. Sofia (RMIT), E. coli (Uni.
Melb., Pfizer and R. Jenner) and composting of poultry (DPI
Vic.)
Infectious Laryngotracheitis (ILT) – Causes a Severe Respiratory Disease
Photos courtesy of Rod Reece, NSW DPI
ILT Research Results – Uni. Melb.
• Additional experimental data on a new candidate ILT vaccine,
based on a glycoprotein G deficient strain, to be marketed by
Bioproperties Aust.
• Confirmation that eyedrop vaccination with Intervet (now
MSD Animal Health) Serva strain results in a more rapid
vaccinal viral replication than drinking water vaccination and
that vaccine virus can be transmitted to in-contact susceptible
chicks with Serva strain transmitting earlier than Pfizer SA2
strain following vaccination
• Testing to show that Type 2 (Vic. 1999) and Type 4 (NSW 1970
CSW-1) ILT viruses were more similar to MSD Animal Health
Serva strain vaccine (Type 7) than to Pfizer ILT vaccines (Type
1) which contain Australian ILT viruses. MSD Animal Health
Serva vaccine was first used in Australia in late 2008.
Mycoplasma gallisepticum (MG)
Causes Sinusitis, Air Sacculitis and Egg Production Drops
Research Results on Bioproperties ts-11 Mycoplasma
gallisepticum (MG) Vaccine – Phil Markham, Uni. Melb.
• Recent research (Microbiology 2011. 157:1740-1749) has shown
that this cloned vaccine contains two types of bacterial cells, those
with GapA expression and those without GapA expression (the
majority)
• GapA is the primary cytadherence molecule in MG and is thought
to be necessary for prolonged colonization and survival of MG in
the host
• At a dose level 100 times less than the marketed ts-11 vaccine,
GapA+ ts-11 experimental vaccine produced a higher percentage of
RSAT serological positives than the marketed ts-11 vaccine,
persisted longer in the trachea and protected similar to or better
than the marketed ts-11 vaccine
• Results may explain the variability in serological response following
vaccination observed over the years
• Results also may lead to a GapA+ ts-11 MG vaccine that is freezedried and can be administered by spray; the current ts-11 MG
vaccine is frozen and must be administered by eyedrop
Infectious Bronchitis (IB)
Causes Respiratory and Kidney Disease, Egg Production Drops
and Egg Quality Abnormalities
Quasi-Species in Pfizer IB Vic S Vaccine – Kylie
Hewson, Uni. Melb.
• Kylie Hewson of the Uni. Melbourne discovered that this
vaccine contains two sub-species (VicS-v and VicS-del)
which differed molecularly
• Pathogenicity testing revealed that the combination of
the two viruses was more virulent than VicS-v alone
• The VicS-v virus was of similar virulence to the other two
Serotype B IB virus vaccines, namely Inghams Strain
registered by Pfizer and Bioproperties and Steggles strain
registered by MSD Animal Health
• These results probably explain why VicS vaccine is not
the favoured vaccine for day-old chicks because of
sporadic vaccine reactions but is often used as a
“booster” vaccine in egg layers and breeders
Colibacillosis
Causes Mortality due to Fibrino-purulent Inflammation
of Various Internal Organs
Escherichia coli Vaccines
• Phil Lehrbach detailed a Pfizer live aroA gene deleted mutant
strain 078 E. coli vaccine that is registered overseas
• Marc Marenda of the Uni. Melbourne reported on initial
research findings on a candidate live mutant E. coli vaccine
lacking tonB and Fur genes
• Kelly Tivendale of the Uni. Melbourne concluded from her
research that human and Avian Pathogenic E. coli (APEC) that
cause extra-intestinal E. coli infections are very similar; she
recommended that protective gear such as masks and gowns
should be worn when servicing poultry
• Rod Jenner questioned the need to use E. coli vaccines in
poultry, as E. coli is normally considered to be a secondary
pathogen of which the harmful effects can be controlled by
identifying and correcting the primary cause
Fowl Cholera (Pasteurella multocida Infection)
Pasteurella multocida Serotyping – John Boyce, Monash Uni.
• Currently P. multocida is differentiated into 16 serovars by the
Heddleston gel immunodiffusion test which is thought to
recognise lipopolysaccaride (LPS) antigens which are specific to
each type and are thought to be related to protection
• Fowl Cholera vaccines are designed to protect against Heddleston
serovars
• However there is growing un-ease with the reliability and
repeatability of the Heddleston scheme so Monash Uni.
researchers are developing a Rapid Multiplex PCR assay to
replace serotyping
• However they have found that this PCR technology recognises 8
LPS genotypes in the 16 Heddleston serovars; additional chemical
tests are being undertaken in Canada to try to clarify this finding
• In addition, the Monash Uni. group are undertaking challenge
studies to further investigate the correlation between serovar and
immunovar
Salmonella enterica Serovar Sofia – Emily Gan, RMIT
Melbourne
• S. Sofia (a Group B salmonella) is the most common
salmonella isolated from chicken meat in Australia but
causes no known disease in poultry and there are very few
reports of food poisoning in humans due to this serovar
• Emily studied in vitro and molecular characteristics of S.
Sofia and S. Typhimurium, another Group B salmonella
which is a pathogen of both poultry and humans
• Emily concluded that avirulence of S. Sofia was due to
changes in a large number of virulence-associated genes
• Hence it is unlikely that S. Sofia can become virulent,
which is good news for the Australian chicken meat
industry
Avian Paramyxovirus Type 1 Outbreak in Pigeons in
Victoria – Sam Mccullough, CSIRO AAHL Geelong
• Sam detailed some laboratory findings of the PPMV-1 virus that has
been isolated from this outbreak in the Melbourne and Shepparton
areas of Victoria which has killed 50-100% of infected pigeons
• The origin of the virus has not been determined but molecularly it is
similar to European PPMV-1 viruses
• While the existing AAHL tests developed with the support of industry
funding in past years were able to diagnose and classify the virus,
additional tests have now been developed at AAHL to differentiate the
virus from other ND viruses including Australian NDV
• First passage virus did not result in clinical signs in chickens but a
further four passages will be undertaken to determine if this PPMV-1
can adapt and cause disease in chickens
• The finding of PPMV-1 in feral pigeons in seven cases in the Melbourne
area is of concern to industry, but the current ND vaccination programs
should protect broilers, egg layers and chicken breeders against this
virus if it becomes virulent to chickens
Enteric Viruses – Michael Day, USDA Athens
Georgia
• Michael presented two talks on various viruses and
bacteria that have been identified in cases of Poult
Enteritis Complex (PEC), Poult Enteritis Mortality
Syndrome (PEMS) and Runting-Stunting Syndrome
(RSS) of chickens.
• Metagenomic analysis using the Roche/454 Life
Sciences technology has been used to identify and
quantify various micro-organisms which includes some
previously unknown viruses
• The significance of most of these micro-organisms is
unknown at this stage
Coles Egg and Chicken Meat Initiatives
• Andrea Currie, a Food Technologist with Coles, presented a
talk on “What Customers tell us – Eggs and Chicken Meat”
• She stressed that the keyword is “trust” which is facilitated
by auditable, creditable and transparent standards
• Types of “product complaints” and who influences Coles
policies were listed
• “Value”, shorter shelf-life, cage-free eggs in home brand by
2013, stocking density of free-range egg layers,
introduction of free-range turkey and higher welfare broiler
products such as Bendigo Valley Chicken and Lilydale Free
Range chicken and “free to roam” advertising for broilers
received particular mention
Summary
• As the 2-day meeting was recognising the 50th anniversary of the
AVPA, there were a number of historical presentations on diseases
by acknowledged experts in these diseases, which both the older
and younger attendees seemed to value
• The research papers in general reported very good research, mostly
with definable outcomes. Presentation technique was deficient in
some cases, partly due to the configuration of the meeting room
• The Australian Poultry CRC, which has been in operation for about
10 years, has greatly expanded the poultry research output in
Australia which previously depended mainly on funding from the
Chicken Meat Committee of the Rural Industries and Research
Corporation and the Australian Egg Corporation Limited, both of
which continue to fund poultry research in Australia in addition to
the Poultry CRC.
• I have supplied an electronic copy of the proceedings to the
secretary. Individual speakers may be willing to provide their
presentations if requested personally