Confirmation of Elsey virus infection in a Queensland horse with mild neurologic signs

In 2011, a 2-year-old horse in northern Queensland, Australia, was reported to have developed mild neurologic signs, and a blood sample was submitted for laboratory investigation. Virus isolation was performed using the blood sample, and an orbivirus was isolated. This was confirmed to be a strain of Elsey virus (ELSV) after transmission electron microscopy and nucleotide sequencing. The nucleotide sequence was compared with those in GenBank, and had 100% identity with ELSV previously reported from the Northern Territory, Australia. ELSV is taxonomically closely related to Peruvian horse sickness virus

Pigeon adenovirus and pigeon torque teno virus associated with acute multifocal hepatic necrosis in pigeons in Queensland, Australia

In 2018, an outbreak resulting in deaths of 28 breeding pigeons was reported north of Brisbane, Australia. The affected birds had runny nasal discharge and poor body condition. Two birds were submitted to Biosecurity Sciences Laboratory, Brisbane, for investigation. A range of diagnostic tests excluded a number of known pathogens, and no virus was isolated in cell culture. Histopathological examination revealed severe acute multifocal necrosis in the liver with eosinophilic intranuclear inclusions in hepatocytes and Kupffer cells. High-throughput sequencing (HTS) revealed full-length sequences for pigeon adenovirus 1 (PiAd-A) and pigeon torque teno virus (PTTV). This report indicates concomitant PiAd-1and PTTV infections in Australian pigeons

Pyogranuloma caused by Mycobacterium asiaticum infection in a steer

In 2003, a steer carcass was condemned at a Central Queensland abattoir because of metastatic tumors. In addition, a granulomatous lesion was found in the mediastinal lymph node. Histological examination showed this to be a pyogranuloma, typically associated with Rhodococcus or the Nocardia/Streptomyces group. However, in this case, the only etiological agent was an acid-fast bacillus, which would normally be associated with a more fibrous lesion. A number of nucleic acid–based techniques were used, and the isolate was identified as Mycobacterium asiaticum. This organism is a rarely encountered opportunistic pathogen of humans, associated with subtropical climates. This is the first report of this organism causing infection in cattle. The similarities between this case and cases of human disease are discussed

Eradication of two incursions of the Red Imported Fire Ant in Queensland, Australia

Of the five known incursions of the highly invasive Red Imported Fire Ant in Australia, two are regarded to have been eradicated. As treatment efforts continue, and the programme evolves and new tools become available, eradication is still considered to be feasible for the remaining Red Imported Fire Ant populations with long-term commitment and support

Dingoes, domestic dogs, or hybrids? Genetics of peri-urban wild dogs in north-eastern Australia

Wild dogs are common residents in peri-urban areas of northeastern Australia. Improved knowledge of the ancestry of wild dogs can assist in determining management priorities, such as targeting source populations, in such areas. We studied the genetics of wild dogs from peri-urban and more regional areas in NE Australia to determine the degree of hybridisation of dog populations. Tissue or hair samples from free-ranging dogs captured through control and research programs were collected and DNA extracted. Seventeen microsatellite loci were examined. Each sample was classified as domestic dog, pure dingo, probable dingo, or hybrid through comparison of allelic data to known dingo/domestic dog reference samples (using the Average 3Q score). Total (pooled) results from all regions show that hybrid wild dogs dominate and less than 36% were of dingo/ probable dingo ancestry. Very few (~1%) were domestic dogs. Spatial and regional differences in dingo hybridisation also suggest trends of increased hybridisation with increased urbanisation. This paper presents the initial findings of the study into peri-urban wild dog genetics, and discusses how such information can assist in developing best practice management strategies and guidelines for implementing control in peri-urban areas

Isolation, small population size, and management influence inbreeding and reduced genetic variation in K’gari dingoes

Small island populations are vulnerable to genetic decline via demographic and environmental stochasticity. In the absence of immigration, founder effects, inbreeding and genetic drift are likely to contribute to local extinction risk. Management actions may also have a greater impact on small, closed populations. The demographic and social characteristics of a species can, however, delay the impact of threats. K’gari, a ~ 1 660 km2 island off the Australian east coast and UNESCO World Heritage Site (Fraser Island 1842–2023), supports an isolated population of approximately 70–200 dingoes that represent an ideal opportunity to explore the small island paradigm. To examine temporal and spatial patterns of genetic diversity in this population we analysed single nucleotide polymorphism (SNP) genotype data (72 454 SNPS) for 112 K’gari dingoes collected over a 25-year period (1996 to 2020). Genetic diversity was lower in K’gari dingoes than mainland dingoes at the earliest time point in our study and declined significantly following a management cull in 2001. We did not find any spatial genetic patterns on the island, suggesting high levels of genetic connectivity between socially discrete packs. This connectivity, combined with the social structure and behaviour of dingoes, may act in concert to buffer the population from the impacts of genetic drift in the short term. Nevertheless, a general decline in genetic variation via inbreeding and drift has occurred over the past 20 years which we suggest should be considered in any future management planning for the population. Monitoring patterns of genetic variation, together with a clearer understanding of the social ecology of K’gari dingoes, will aid in the development of measurable genetic targets set over ecologically meaningful timelines, and help ensure continued survival of this culturally important population

Alleles and algorithms: The role of genetic analyses and remote sensing technology in an ant eradication program

Eradication programs for invasive ants are often hampered by a lack of effective tools to detect, contain and kill the pests. Among the range of tools employed in the course of a 20-year eradication program for red imported fire ant, Solenopsis invicta, in Australia, two of the most crucial for success are genetic analysis at both individual colony and population scales, and remote sensing for the detection of S. invicta mounds over large areas. Several genetic analyses are used by the program as an everyday operational tool to guide the eradication effort; for example, genotyping of the social form determines where and how far we need to search and treat, whereas nest relatedness derived from microsatellites aids in deciding when and where to target investigations into human-assisted movement of the pest. Microsatellite genotyping can determine the origin of new invasions into the country and has been used to verify the eradication of six distinct incursions of S. invicta in Australia, as well as demonstrating the pressure being exerted on the remaining Queensland population by the current eradication activities. Remote sensing played a key role in delimiting the extent of the S. invicta infestation in southeast Queensland in 2015, and in the future will assist in both delimitation and in verifying eradication of this ant in treatment areas as part of the proof of freedom process. Unquestionably, without these tools, the battle to eradicate S. invicta from Australia would be severely constrained, if not lost. These technologies may be applicable in management or eradication programs for S. invicta worldwide, and potentially for other invasive ant species

Complete genome sequence of a white spot syndrome virus associated with a disease incursion in Australia

White spot disease is a serious viral panzootic affecting prawn aquaculture. The causative agent is white spot syndrome virus (WSSV), a large double-stranded circular DNA virus. In November 2016, WSSV was identified following the onset of disease in a prawn farm near Brisbane, Queensland, Australia (previously free of white spot disease). The prawn farming industry in Queensland is valued at approximately AU$87 million annually, and the potential impact of establishment of endemic WSD would be severe. We report the complete genome sequence of the Australian WSSV (WSSV-AU) and the analysis of previously described genomic markers that have been reported to show variation among WSSV strains. WSSV-AU genome length was 285,973 bp, shorter than most but within the previously reported size range of 281 kbp to 312 kbp. There are high levels of homology (91–97%) between the WSSV-AU and other reported genomes sequences. The WSSV-AU genome sequence has a number of substantial deletions, most significantly in regions that were previously reported as genomic markers (regions known to contain variable numbers of tandem repeats and regions with deletions of variable length). Additionally, several deletions of regions reported to encode envelope proteins were deleted. It may be that some of the envelope proteins needed for an ancestral natural host infection are redundant, and therefore expendable, with respect to infection of penaeids. Hence, that deletion of redundant regions may show homoplasy and be an unreliable epidemiological tool. In light of the undetermined epidemiological relevance of deletions, including those associated with long tandem repeats, it is concluded that the comparison of reported complete genome sequences cannot identify the source of the virus in Queensland and an alternative genotyping method is required

A hypothetical model for VHML phage conversion of Vibrio harveyi

The bacteriophage VHML (Vibrio harveyi myoviruslike) originated from a toxin producing strain of Vibrio harveyi. It has been demonstrated previously that the presence of the VHML prophage can induce virulence to V. harveyi in the laboratory. Here, a hypothetical model for phage virulence conversion of V. harveyi is presented. Through the nucleotide sequence determination of the entire VHML genome (43,193 bp), we have identified putative phage structural genes consistent with the physical characteristics of the virions as observed by TEM. We have also identified putative genes consistent with integration of the genome,\ud supporting the theory that VHML integrates the host V. harveyi genome as a prophage. In addition, we have identified a potential toxin gene on the VHML genome. This gene includes DNA sequence similar to the reported active site of the ADP-ribosylating group of toxins. These ADP-RT's indude toxins from other bacteria reported previousiy to be a result of bacteriophage conversion. This presentation will illustrate how the phage genes could cause\ud infection of VIbrio harveyi host cells, integration of the phage genome into the hosts' chromosome and subsequent production of the putative toxin, thereby conferring virulence to Vibrio harveyi