Elizabeth Macarthur Agriculture Institute

Menangle, Australia

Elizabeth Macarthur Agriculture Institute

Menangle, Australia

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Hansbro P.M.,University of Newcastle | Warner S.,Australian Department of Primary Industries and Fisheries | Tracey J.P.,Orange Agricultural Institute | Arzey K.E.,Elizabeth Macarthur Agriculture Institute | And 9 more authors.
Emerging Infectious Diseases | Year: 2010

We investigated carriage of avian influenza viruses by wild birds in Australia, 2005-2008, to assess the risks to poultry industries and human health. We collected 21,858 (7,357 cloacal, 14,501 fecal) samples and detected 300 viruses, representing a detection rate of ≈1.4%. Rates were highest in autumn (March-May) and differed substantially between bird types, areas, and years. We typed 107 avian influenza viruses and identified 19 H5, 8 H7, and 16 H9 (40% of typed viruses). All were of low pathogenicity. These viruses formed clearly different phylogenetic clades to lineages from Eurasia or North America, suggesting the potential existence of Australian lineages. H7 viruses were similar to highly pathogenic H7 strains that caused outbreaks in poultry in Australia. Several periods of increased detection rates (numbers or subtypes of viruses) were identified. This study demonstrates the need for ongoing surveillance to detect emerging pathogenic strains and facilitate prevention of outbreaks.


Kirkland P.D.,Elizabeth Macarthur Agriculture Institute | Gabor M.,Elizabeth Macarthur Agriculture Institute | Poe I.,North Coast Local Lands Services | Neale K.,Macksville Veterinary Clinic | And 8 more authors.
Emerging Infectious Diseases | Year: 2015

Hendra virus occasionally causes severe disease in horses and humans. In Australia in 2013, infection was detected in a dog that had been in contact with an infected horse. Abnormalities and viral RNA were found in the dog’s kidney, brain, lymph nodes, spleen, and liver. Dogs should be kept away from infected horses. © 2015, Centers for Disease Control and Prevention (CDC). All rights reserved.


PubMed | National Animal Disease Center, Elizabeth Macarthur Agriculture Institute and Institute of Diagnostic Virology
Type: Journal Article | Journal: Veterinary microbiology | Year: 2015

Bungowannah virus, a possible new species within the genus Pestivirus, has been associated with a disease syndrome in pigs characterized by myocarditis with a high incidence of stillbirths. The current analysis of the whole-genome and antigenic properties of this virus confirms its unique identity, and further suggests that this virus is both genetically and antigenically remote from previously recognized pestiviruses. There was no evidence of reactivity with monoclonal antibodies (mAbs) that are generally considered to be pan-reactive with other viruses in the genus, and there was little cross reactivity with polyclonal sera. Subsequently, a set of novel mAbs has been generated which allow detection of Bungowannah virus. The combined data provide convincing evidence that Bungowannah virus is a member of the genus Pestivirus and should be officially recognized as a novel virus species.


Kirkland R.D.,Elizabeth Macarthur Agriculture Institute
OIE Revue Scientifique et Technique | Year: 2015

Akabane virus is a Culicoides-bome orthobunyavirus that is teratogenic to the fetus of cattle and small ruminant species. Depending upon the stage of gestation at which infection occurs, and the length of gestation of the mammalian host, a range of congenital defects may be observed. The developing central nervous system is usually the most severely affected, with hydranencephaly and arthrogryposis most frequently observed. Less commonly, some strains of Akabane virus can cause encephalitis in the neonate or, rarely, adult cattle. Akabane viruses are known to be widespread in temperate and tropical regions of Australia, Southeast Asia, the Middle Eastand some African countries. Disease is infrequently observed in regions where this virus is endemic and the presence of the virus remains unrecognised in the absence of serological surveillance. In some Asian countries, vaccines are used to minimise the occurrence of disease.


Frost M.J.,Elizabeth Macarthur Agriculture Institute | Zhang J.,Elizabeth Macarthur Agriculture Institute | Edmonds J.H.,University of Queensland | Prow N.A.,University of Queensland | And 15 more authors.
Emerging Infectious Diseases | Year: 2012

To determine the cause of an unprecedented outbreak of encephalitis among horses in New South Wales, Australia, in 2011, we performed genomic sequencing of viruses isolated from affected horses and mosquitoes. Results showed that most of the cases were caused by a variant West Nile virus (WNV) strain, WNVNSW2011, that is most closely related to WNV Kunjin (WNVKUN), the indigenous WNV strain in Australia. Studies in mouse models for WNV pathogenesis showed that WNVNSW2011 is substantially more neuroinvasive than the prototype WNVKUN strain. In WNVNSW2011, this apparent increase in virulence over that of the prototype strain correlated with at least 2 known markers of WNV virulence that are not found in WNVKUN. Additional studies are needed to determine the relationship of the WNVNSW2011 strain to currently and previously circulating WNVKUN strains and to confirm the cause of the increased virulence of this emerging WNV strain.


Watson J.,Australian Animal Health Laboratory | Daniels P.,Australian Animal Health Laboratory | Kirkland P.,Elizabeth Macarthur Agriculture Institute | Carroll A.,Khan Research Laboratories | Jeggo M.,Australian Animal Health Laboratory
OIE Revue Scientifique et Technique | Year: 2011

In August 2007 Australia experienced its first outbreak of equine influenza. The disease occurred first in a quarantine station for imported horses near Sydney and subsequently escaped into the general horse population. After an extensive campaign the disease was eradicated and Australia is again recognised as free of this disease. Equine influenza was then, and is now, recognised to be the major disease risk associated with live horse imports into Australia and measures designed to mitigate this risk formed the basis of the quarantine protocols then in place. Subsequent investigations into the cause of the outbreak identified failures in compliance with these quarantine requirements as a contributing factor. It is also likely that the immunity of horses vaccinated as part of the import protocol was less than optimal, and that this had a significant role to play in the escape of the disease from quarantine.


Kirkland P.D.,Elizabeth Macarthur Agriculture Institute | Read A.J.,Elizabeth Macarthur Agriculture Institute | Frost M.J.,Elizabeth Macarthur Agriculture Institute | Finlaison D.S.,Elizabeth Macarthur Agriculture Institute
Animal Health Research Reviews | Year: 2015

Bungowannah virus was discovered following an outbreak of stillbirths and sudden death in young pigs. Affected animals consistently showed a myocardopathy with signs of cardiac failure. After virus isolation and PCR investigations were unsuccessful, direct fetal inoculation was undertaken. Nucleic acid purified from serum from infected fetuses was subjected to sequence-independent single-primer amplification and nucleic acid sequencing. Sequences consistent with a pestivirus were obtained. The entire genome was identified but was genetically remote from the recognized pestivirus species. This virus was not recognized by pan-pestivirus reactive monoclonal antibodies but was subsequently detected in cell cultures by immunoperoxidase staining using convalescent sow serum. Experimental infections of sows at different stages of gestation reproduced the myocarditis syndrome. Pre-weaning losses of 70 and 29% were observed following infection at days 35 and 90, respectively. Piglets infected at day 35 were shown to be persistently infected, while chronic infections were observed after fetal infection at day 55. Chronically infected piglets showed growth retardation and were viremic for up to 7 months. Myocarditis was associated with infection in late gestation (day 90). Non-pregnant sheep and cattle have been experimentally infected but with no evidence of disease. Infection of pregnant cattle in early gestation resulted in both maternal and fetal infection, but all infected fetuses mounted an antibody response to the virus. Analysis of the nucleic acid sequence confirmed that Bungowannah has a number of changes not observed in other pestiviruses. Genes encoding some of the structural proteins remain fully functional when inserted into a bovine viral diarrhea virus (BVDV) backbone. Cell culture-based studies have shown that Bungowannah virus will grow in cells extending from humans to bats as well as farm animals. Copyright © Cambridge University Press 2015.


PubMed | Elizabeth Macarthur Agriculture Institute
Type: Journal Article | Journal: Animal health research reviews | Year: 2015

Bungowannah virus was discovered following an outbreak of stillbirths and sudden death in young pigs. Affected animals consistently showed a myocardopathy with signs of cardiac failure. After virus isolation and PCR investigations were unsuccessful, direct fetal inoculation was undertaken. Nucleic acid purified from serum from infected fetuses was subjected to sequence-independent single-primer amplification and nucleic acid sequencing. Sequences consistent with a pestivirus were obtained. The entire genome was identified but was genetically remote from the recognized pestivirus species. This virus was not recognized by pan-pestivirus reactive monoclonal antibodies but was subsequently detected in cell cultures by immunoperoxidase staining using convalescent sow serum. Experimental infections of sows at different stages of gestation reproduced the myocarditis syndrome. Pre-weaning losses of 70 and 29% were observed following infection at days 35 and 90, respectively. Piglets infected at day 35 were shown to be persistently infected, while chronic infections were observed after fetal infection at day 55. Chronically infected piglets showed growth retardation and were viremic for up to 7 months. Myocarditis was associated with infection in late gestation (day 90). Non-pregnant sheep and cattle have been experimentally infected but with no evidence of disease. Infection of pregnant cattle in early gestation resulted in both maternal and fetal infection, but all infected fetuses mounted an antibody response to the virus. Analysis of the nucleic acid sequence confirmed that Bungowannah has a number of changes not observed in other pestiviruses. Genes encoding some of the structural proteins remain fully functional when inserted into a bovine viral diarrhea virus (BVDV) backbone. Cell culture-based studies have shown that Bungowannah virus will grow in cells extending from humans to bats as well as farm animals.


PubMed | Oklahoma State University and Elizabeth Macarthur Agriculture Institute
Type: Journal Article | Journal: Archives of virology | Year: 2016

Bovine herpesvirus subtype 1.2b (BoHV-1.2b) is associated primarily with bovine infectious pustular vulvovaginitis. We report here the complete genomic sequence of four BoHV-1.2b isolates. The DNA sequence identity of the four genomes is 98.9%. Differences were primarily in regions containing direct repeats, specifically gene UL36 and the terminal repeat regions immediately flanking gene BICP22. BoHV-1.2b and BoHV-1.1 genomes are similar in size (~135kb), completely orthologous with respect to regional structure and gene location, and have a 97.5% DNA sequence homology. The most notable difference is the structure of the DNA replication origin of the two viruses.


PubMed | Elizabeth Macarthur Agriculture Institute
Type: Comparative Study | Journal: Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc | Year: 2014

Infection with Bluetongue virus (BTV) is a significant impediment to the global movement of bovine semen. Repeat testing of blood from donor animals is specified in the World Organization for Animal Health (OIE) Manual for the export of semen from regions where BTV may be present. Screening of blood or semen samples has usually been carried out by virus isolation (VI) either by inoculation of chicken embryos followed by passage onto insect and mammalian cell cultures or in vivo inoculation of sheep followed by serology to detect seroconversion. Direct testing of semen for BTV would enable earlier release of semen samples and avoid repeat testing of the donor, as well as provide an option for releasing batches of semen that were collected without certification of the donor. Quantitative (real-time) reverse transcription polymerase chain reaction (qRT-PCR) assays overcome most of the limitations of other methods and have the potential to provide higher sensitivity. The present study compared 5 qRT-PCR assays, including 2 commercially available kits, for the detection of BTV in semen serially collected from 8 bulls over a period of 90 days after experimental infection. The results of the study show that at least one of the qRT-PCR assays is extremely reproducible and has both very high sensitivity and specificity to reliably detect all available serotypes. The preferred qRT-PCR gave consistently superior results to VI, sheep inoculation, and conventional RT-PCR. Therefore, the assay can be recommended for the screening of bovine semen for freedom from BTV.

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