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ABSTRACTS OF PAPERS
SCAD III
T152 Pathogenicity and transmission of North American H5 clade
2.3.4.4 Highly Pathogenic Avian Influenza viruses in different
gallinaceous poultry Kateri Bertran*, Charles Balzli, Mar Costa-Hurtado,
Dong-Hun Lee, Eric Dejesus, Darrell Kapczynski, Mary Pantin-Jackwood,
Erica Spackman, David Suarez, David Swayne ARS-SEPRL
Beginning in late 2014, the U.S. experienced an unpreceded outbreak of
Eurasian clade 2.3.4.4 H5 highly pathogenic avian influenza (HPAI) virus
in poultry and wild birds. Infectivity, transmissibility, and pathogenesis
of index U.S. H5N2 and H5N8 HPAI viruses were investigated in chickens, turkeys, Japanese quail, Bobwhite quail, Chukar partridges, pheasants, and guinea fowl. The mean death time (MDT) in all species was
late (3-7 days post-challenge (dpc)) compared to Eurasian H5N1 HPAI
viruses (2-3 dpc), with Japanese quail having the shortest MDT, chickens
as intermediate, and turkeys and Bobwhite quail the longest. Both H5N2
and H5N8 viruses appeared to be well adapted to Bobwhite quail, since
even the lowest dose (2 log10 EID50) caused infection, dead and permitted
transmission to contact quail. Species adaptation, measured by dose of
virus to produce infection, was slightly reduced for guinea fowl (3 log10
EID50), followed by Japanese quail, pheasants, and partridges (3-3.7 log10
EID50), and finally chickens and turkeys (5-5.7 log10 EID50). Transmission
to exposed contacts was also reduced according to species adaptation,
requiring medium (4 log10 EID50) or high (6 log10 EID50) doses to infect
contacts in most of the species except for chickens, where no transmission
occurred. In general, disease was not apparent until close to death, when
birds showed nonspecific clinical signs, with a few birds having neurological signs. Gross lesions consistent of HPAI virus infection were not
always observed in birds that died, but some showed pancreatic necrosis,
splenomegaly, renomegaly and petechial hemorrhages on myocardium.
Virus was shed in high titers both orally and cloacally, although virus titers slightly varied according to species adaptation. These results suggest
that index viruses H5N2 and H5N8 have reduced virulence and transmissibility for gallinaceous host compared to historical H5N1 HPAI viruses.
However, the high viral shedding, the absence of overt clinical signs and
gross lesions, and the late MDT, could represent a substantial threat for
these viruses to amplify, spread among poultry farms, and further adapt
to the chicken host.
Key Words: highly pathogenic avian influenza virus, poultry,
pathogenesis, H5 HPAI U.S. outbreak
T153 Pathogenicity of 2015 North American H5N2 highly pathogenic
avian influenza poultry isolates in chickens and mallards Mary PantinJackwood*, Erica Spackman, Darrell Kapczynski, David Suarez, Mar
Costa-Hurtado, Eric Dejesus, Kateri Bertran, Dong-Hun Lee, David
Swayne Southeast Poultry Research Laboratory, U.S. National Poultry
Research Center, U.S. Dept. of Agriculture, Agricultural Research Service
In late 2014 a reassortant H5N8 clade 2.3.4.4 highly pathogenic avian influenza (HPAI) virus spread by migratory birds into Europe and North
America and further reassorted with North American low pathogenicity
avian influenza viruses to produce a H5N2 HPAI virus. This virus subsequently spread through the U.S. causing severe outbreaks in poultry in
2015. Infectivity, transmissibility, and pathogenicity of four H5N2 HPAI
viruses isolated from the Midwest poultry outbreaks in 2015 was studied
in chickens and mallards and results compared to the results obtained with
the index H5N2 virus (A/Northern pintail/ Washington/2014). The mean
death time in chickens infected with the poultry H5N2 isolates was earlier
(2-3 days post inoculation) than the observed with the index H5N2 virus
(3-7 days). Three of the poultry H5N2 isolates (A/Tk/MN/12582/2015, A/
Tk/SD/12511/2015, and A/Ck/IA/13388/2015) required a lower dose of
the virus to infect the birds than the index H5N2 virus. The fourth isolate
(A/Tk/AR/7791/2015) had a similar mean bird infectious dose (BID50)
than the index virus, indicating that it was most likely a wild bird introduction. The viruses transmitted poorly to contact exposed chickens. MalPoult. Sci. 95(E-Suppl. 1)
lard ducks inoculated with A/Ck/IA/13388/2015 showed no clinical signs,
with a BID50 similar to the observed with the index H5N2 virus (BID50 ≤
2), but birds shed lower amounts of virus and for a shorter period of time.
However, some ducks inoculated with A/Tk/MN/12582/2015 presented
neurological signs and two died, and virus was detected up to 14 days post
inoculation in oral and cloacal swabs. All direct contact ducks became infected, with the exception of two ducks from the group inoculated with the
low dose of A/Ck/IA/13388/2015, demonstrating the easy transmission
of these H5N2 viruses among ducks. These results suggest that the more
recent H5N2 HPAI viruses have increased infectivity and transmissibility
for chickens compared to the earlier H5N2 virus, indicating adaptation
after circulating in poultry. In mallards, one of these poultry isolates was
highly infective, and different from the index H5N2 virus, caused disease
in some ducks, but the second virus appeared less adapted to ducks.
Key Words: H5N2 highly pathogenic avian influenza, chickens,
mallards, pathogenicity, infectivity
T154 Asian lineage H5N1 clade 2.3.4.4 highly pathogenic avian
influenza virus evolution into subgroups with intercontinental spread
and generation of novel reassortant viruses in the United States DongHun Lee*1, Justin Bahl2, Mia Torchetti3, Mary Killian3, Hon Ip4, David
Swayne1 1Southeast Poultry Research Laboratory, ARS-USDA; 2The
University of Texas School of Public Health; 3National Veterinary Services
Laboratories, APHIS-USDA; 4National Wildlife Health Center, USGS
H5N1 highly pathogenic avian influenza (HPAI) virus emerged in 1996
in Guangdong China and has evolved into multiple genetic clades with
recent reassortment of gene segments to produce H5N8, H5N6, H5N5
and other H5 reassortant HPAI virus strains. Since November 2013, Asian
lineage H5 HPAI virus clade 2.3.4.4 spread globally with introduction into
North America in late 2014. In this study, we sequenced 32 H5 HPAI virus
clade 2.3.4.4 identified in United States and compared with clade 2.3.4.4
viruses identified in other continents using temporally informed phylogenetic reconstruction to improve our understanding of the origin and pattern
of spread to North America of this clade. Phylogenetic analysis suggests
that the hemagglutinin gene of the H5 clade 2.3.4.4 HPAI viruses have
evolved into four distinct subgroups and has spread to multiple countries. We used a Bayesian analysis to estimate the timing of introduction
to North America and subsequent H5N1 and H5N2 reassortment events.
The introduction timing of H5N8 viruses corresponded to autumn bird
migration season, and supports the hypothesis of introduction into North
America by migratory birds. Subsequently, H5N2 and H5N1 reassortant
viruses were estimated to have emerged in November and December
2014, respectively. Enhanced active surveillance is required to monitor
the spread of novel reassortant viruses.
Key Words: avian influenza
T155 Virus-like particle vaccines expressing H5 hemagglutinin gene
protects chicken from multiple clades of highly pathogenic avian
influenza Klaudia Chrzastek*1, Peter Pushko2, Terry Tumpey3, Darrell
Kapczynski1 1USDA SEPRL; 2Medigen, Inc.; 3Influenza Division, Centers
for Disease Control and Prevention
The rapid and unpredictable nature of avian influenza virus (AIV) evolution requires new vaccines to be produced to match circulating virus
strains. Virus-like particles (VLPs) are multiprotein structures that mimic
the organization and conformation of authentic native viruses but lack the
complete viral genome, which makes them non-replicating and therefore
safe and cost-effective vaccine candidates. In this study, VLPs containing de novo synthesized recombinant H5 genes from A/chicken/Germany/2014 (clade 2.3.4.4), A/chicken/West Java/Subang/29/2007 (clade
2.1.3) and A/chicken/Egypt/121/2012 (clade 2.2.1), along with influenza
neuraminidase (NA) were expressed in Sf9 cells and used as a vaccine
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ABSTRACTS OF PAPERS
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against H5 highly pathogenic avian influenza (HPAI) virus challenge.
Immunogenicity and protective efficacy was confirmed in SPF chickens
challenged with three homologous clades of AIV. Vaccination with VLPs
elicited high anti-influenza virus antibody titers and completly protected
chickens from lethal influenza virus challenge, highlighting the potential
clinical use of VLPs against HPAI H5 viruses
alone, virus oral shedding significantly increased and infected birds readily transmitted virus to naïve contact controls. Taken together, this data
demonstrates that the hemagglutinin is the principal determinant of H7
Chinese LPAIV replication and transmission in poultry.
Key Words: virus like particles, vaccine, HPAIV, chicken
T157 A Novel DNA-Immunostimulant for exploring Innate Immunity
in Avian Health Roy Jacob*, Barry Kelly Bayer
T156 H7 Chinese influenza virus transmission in poultry is directly
related to the hemagglutinin gene Marisela Rodriguez*, David Suarez
USDA, ARS, United States National Poultry Research Center
H7N9 and H7N7 Chinese low pathogenic avian influenza (LPAIV) viruses pose a zoonotic threat and have been circulating in poultry, particularly
in live bird markets, over the last few years. Poultry exposure in these
bird markets are suspected of being the primary source of human H7N9
infections in China. These H7 viruses contain a poultry adapted H9N2 internal gene cassette that is endemic in China. However, poultry transmission studies revealed that the Chinese H7 viruses transmit poorly by direct
contact to naïve chickens and quail suggesting that these H7 viruses are
not poultry adapted as previously thought. We sought to determine which
genes are responsible for poultry adaptation of this H7 lineage utilizing
reverse genetics (RG) systems established for the H7N9 A/Anhui/1/2013
(Anhui) and H7N7 A/Ck/Wenzhou/678/2013 (Wenzhou) virus. A complimentary panel of reassortant influenza viruses was created with the Anhui
and Wenzhou background genes using various HA and NA genes from
HPAIV/LPAIV viruses circulating in China. Chickens and, in some cases
quail, were inoculated with various RG viruses and monitored for oral
virus shedding and their ability to transmit virus to naïve controls. Chickens inoculated with RG-generated Anhui and Wenzhou variant viruses
displayed low to moderate levels of oral viral shedding in most birds and
virus transmission to contact controls was poor. Substitution of several
Anhui internal genes gave similar replication and transmission patterns
as the parental RG H7 viruses. However, when the HA and NA genes of
the H7 RG viruses were substituted with H9 and N2 genes or the H9 gene
Key Words: Influenza, tranmission, reverse genetics
Innate Immunity is a science that dates back more than 100 years and yet
remains as a potential area to be explored in infectious disease management in livestock. While the options for triggering the innate immune system are many, the CpG Oligodeoxynucleotides (CpG ODNs) have been
creating tremendous interest in both human as well as animal health. The
critical factors that determine the utility and success of CpG ODNs have
been the dose, stability, timing, specificity and cost effectiveness in modern
day production systems to show tangible benefits. However, the intracellular location of CpG recognizing receptors has been a major drawback in
their therapeutic use. Previous studies have demonstrated that the uptake
and immunostimulatory effects of CpG ODNs could be improved by lipid
based drug delivery systems. This presentation is intended to highlight a
commercial novel immunostimulant that contains CpG motif DNA derived
from E. coli plasmid, that is the first licensed product by USDA for use inovo against Avian Pathogenic E. coli (APEC) to reduce mortality. Through
a unique DNA liposome complex, this product rapidly triggers the animal’s
innate immune system by mimicking a pathogen, preparing it to better fight
infection when challenged by E. coli bacteria. Studies demonstrated as
much as 50% reduced mortality under heavy E. coli challenge. The product was proven in an APEC challenge model and the results have been
validated in commercial settings, thus providing an alternate approach to
effectively combat APEC that reduces hatchability and first week mortality.
This non-antibiotic technology also supports antibiotic-free hatcheries and
does not contain any antibiotics or preservatives.
Key Words: Immunostimulant, E. coli, CpG ODN, mortality
Metabolism & Nutrition VI
T158 Effect of L-Dopa on performance and growth hormone secretion
in broiler chickens Richard Omidiwura*, Adebisi Agboola, Eustace Iyayi
University of Ibadan
Pure form of L-Dopa is used to enhance muscular development, fat breakdown and suppress Parkinson disease in humans. However, the L-Dopa
in mucuna seed, when present with other antinutritional factors, causes
nutritional disorders in monogastric animals. Information on its effect
on growth hormone secretion and utilization in monogastric animals is
scanty. Therefore, effect of L-Dopa on growth performance and carcass
characteristics in broiler chickens was investigated. Two hundred oneday-old chicks were allotted to five standard energy (SE) diets: SE+0.0%,
SE+0.1%, SE+0.2%, SE+0.3% and SE+0.4% L-Dopa. All treatments had
4 replicates in a completely randomized design. Body weight gain, final
weight, feed intake, dressed weight and carcass characteristics were determined. Blood (5ml) was sampled from the birds to determine growth
hormone, serum and hematological parameters using standard procedures. The feed intake and body weight gain of birds fed SE+0.1% diet
(1032.8±17.1g and 741.6±22.7g, respectively) were observed to be higher
than those fed other treatments at the starter phase. The growth hormone
concentration and hematological parameters were not remarkably influenced by the dietary treatments. However, the albumin (1.88g/dL) of
broilers fed Control diet (SE+0.0% L-Dopa) was similar to birds fed 0.1%
L-Dopa (1.80g/dL) but significantly higher than those fed other diets. The
lowest albumin value was observed in birds fed 0.4% L-Dopa (1.50g/dL)
supplemented diet. L-Dopa extract, at levels tested, had no detrimental effect on broilers, rather better bird performance was observed especially at
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0.1% L-Dopa inclusion rates. Therefore, 0.1% inclusion is recommended
in diets of broiler chickens for improved performance.
Key Words: L-Dopa, Broilers, Performance, Growth hormone, Blood
profile
T159 Chemistry curtailing bacterial enteritis in broilers and turkeys
Jeroen Baeyens*1, Tina Rogge1, Jan Anné1, Wael Gad1, Francisco Dias2,
Jeroen De Gussem3 1Proviron; 2Vetworks; 3Poulpharm
Gut health challenges are significant and costly in global poultry production. Although antibiotics (AB) are used to treat systemic, respiratory,
leg as well as gut infections, at least 50% of the treatments are directly
related to gut problems, especially dysbacteriosis and bacterial enteritis
(BE), triggered by Clostridium perfringens. BE in poultry causes loss of
performance, higher feed conversion rate (FCR), wet litter problems and
macroscopic and histologic alterations of the intestines. Therefore, there is
a great interest in effective and nontoxic alternatives to AB.
In vitro trials showed activity of ProvifeedTM Optigut, a specific combination of esterified fatty acids, against industrial relevant pathogenic strains
such as Clostridium perfringens. These in vitro data were further confirmed in several in vivo trials with a BE model in commercial broilers
(Ross 308). BE was provoked by supplying a high dose of coccidiosis
vaccine to the broilers. Both performance parameters (Average end weight
(AEW) and FCR) as health parameters (histopathological lesions) were
determined.
Poult. Sci. 95(E-Suppl. 1)