Faecal virome of the Australian grey-headed flying fox from urban/suburban environments contains novel coronaviruses, retroviruses and sapoviruses.

Bats are important reservoirs for viruses of public health and veterinary concern. Virus studies in Australian bats usually target the families Paramyxoviridae, Coronaviridae and Rhabdoviridae, with little known about their overall virome composition. We used metatranscriptomic sequencing to characterise the faecal virome of grey-headed flying foxes from three colonies in urban/suburban locations from two Australian states. We identified viruses from three mammalian-infecting (Coronaviridae, Caliciviridae, Retroviridae) and one possible mammalian-infecting (Birnaviridae) family. Of particular interest were a novel bat betacoronavirus (subgenus Nobecovirus) and a novel bat sapovirus (Caliciviridae), the first identified in Australian bats, as well as a potentially exogenous retrovirus. The novel betacoronavirus was detected in two sampling locations 1375 km apart and falls in a viral lineage likely with a long association with bats. This study highlights the utility of unbiased sequencing of faecal samples for identifying novel viruses and revealing broad-scale patterns of virus ecology and evolution.

Gross, microscopic, radiologic, echocardiographic and haematological findings in rats experimentally infected with Angiostrongylus cantonensis.

Although the gross and microscopic pathology in rats infected with Angiostrongylus cantonensis has been well described, corresponding changes detected using diagnostic imaging modalities have not been reported. This work describes the cardiopulmonary changes in mature Wistar rats chronically infected with moderate burdens of A. cantonensis using radiology, computed tomography (CT), CT angiography, echocardiography, necropsy and histological examinations. Haematology and coagulation studies were also performed. Thoracic radiography, CT and CT angiography showed moderately severe alveolar pulmonary patterns mainly affecting caudal portions of the caudal lung lobes and associated dilatation of the caudal lobar pulmonary arteries. Presumptive worm profiles could be detected using echocardiography, with worms seen in the right ventricular outflow tract or straddling either the pulmonary and/or the tricuspid valves. Extensive, multifocal, coalescing dark areas and multiple pale foci affecting the caudal lung lobes were observed at necropsy. Histologically, these were composed of numerous large, confluent granulomas and fibrotic nodules. Adult worms were found predominantly in the mid- to distal pulmonary arteries. An inflammatory leukogram, hyperproteinaemia and hyperfibrinogenaemia were found in most rats. These findings provide a comparative model for A. cantonensis in its accidental hosts, such as humans and dogs. In addition, the pathological and imaging changes are comparable to those seen in dogs infected with Angiostrongylus vasorum, suggesting rats infected with A. cantonensis could be a model for dogs with A. vasorum infection.

Unusual presentation and urinary tract obstruction due to disseminated intra-abdominal eumycetomas caused by Curvularia species in a dog.

Intra-abdominal eumycetomas are rare in dogs and usually attributed to contamination of surgical wounds post-operatively. This is the first report of extensively disseminated intra-abdominal eumycetomas due to Curvularia resulting in urinary tract obstruction and associated chronic recurrent urinary tract infections in a Labrador retriever. Identification of the fungal genus was performed on samples obtained from culture of eumycetomic fungal grains that had been collected sterilely at necropsy.

Angiostrongylus cantonensis: a review of its distribution, molecular biology and clinical significance as a human pathogen.

Angiostrongylus cantonensis is a metastrongyloid nematode found widely in the Asia-Pacific region, and the aetiological agent of angiostrongyliasis; a disease characterized by eosinophilic meningitis. Rattus rats are definitive hosts of A. cantonensis, while intermediate hosts include terrestrial and aquatic molluscs. Humans are dead-end hosts that usually become infected upon ingestion of infected molluscs. A presumptive diagnosis is often made based on clinical features, a history of mollusc consumption, eosinophilic pleocytosis in cerebral spinal fluid, and advanced imaging such as computed tomography. Serological tests are available for angiostrongyliasis, though many tests are still under development. While there is no treatment consensus, therapy often includes a combination of anthelmintics and corticosteroids. Angiostrongyliasis is relatively rare, but is often associated with morbidity and sometimes mortality. Recent reports suggest the parasites' range is increasing, leading to fatalities in regions previously considered Angiostrongylus-free, and sometimes, delayed diagnosis in newly invaded regions. Increased awareness of angiostrongyliasis would facilitate rapid diagnosis and improved clinical outcomes. This paper summarizes knowledge on the parasites' life cycle, clinical aspects and epidemiology. The molecular biology of Angiostrongylus spp. is also discussed. Attention is paid to the significance of angiostrongyliasis in Australia, given the recent severe cases reported from the Sydney region.

Metaphyseal osteopathy in a British Shorthair cat.

Metaphyseal osteopathy, otherwise known as hypertrophic osteodystrophy, is a disease that causes pyrexia and lethargy accompanied by pain in the thoracic and pelvic limbs of rapidly growing large-breed dogs. While metaphyseal osteopathy has been descibed in association with slipped capital femoral epiphysis in cats, it has not previously been reported as a cause of limb pain and pyrexia in this species. A 7-month-old British Shorthair cat presented with a 1 month history of pyrexia, lethargy and pain in all limbs. Investigation included radiographs of the limbs and chest, abdominal ultrasound, serum biochemical analysis, haematology, bone biopsy, joint fluid aspiration and cytology. Findings were consistent with a diagnosis of metaphyseal osteopathy. The cat's clinical signs resolved following the administration of prednisolone. Symptoms recurred 1 month after the cessation of prednisolone therapy, but resolved when administration was resumed.

Deletion of the antiphospholipid syndrome autoantigen ß2 -glycoprotein I potentiates the lupus autoimmune phenotype in a Toll-like receptor 7-mediated murine model.

OBJECTIVE: The BXSB.Yaa mouse strain is a model of systemic lupus erythematosus that is dependent on duplication of the Toll-like receptor 7 gene. The objective of this study was to systematically describe the amplified autoimmune phenotype observed when the soluble plasma protein ß2 -glycoprotein I (ß2 GPI) gene was deleted in male BXSB.Yaa mice. METHODS: We generated BXSB.Yaa and NZW mouse strains in which the ß2 GPI gene had been knocked out by backcrossing the wild-type strains with C57BL/6 ß2 GPI(-/-) mice for 10 generations. Sex- and age-matched mice of the various strains were housed under identical conditions and were killed at fixed time intervals. Serum and tissue specimens were collected at various time points. Lupus-associated autoantibodies, inflammatory cytokines, and the type I interferon (IFN) gene signature were measured. Flow cytometric analyses of lymphocyte populations were performed. The severity of glomerulonephritis was graded by 2 independent renal histopathologists. RESULTS: Male BXSB.Yaa ß2 GPI(-/-) mice developed significant lymphadenopathy and splenomegaly compared with age-matched controls. Male BXSB.Yaa ß2 GPI(-/-) mice also had significantly higher levels of autoantibodies, increased levels of inflammatory cytokines including tumor necrosis factor α, interleukin-6, and BAFF, and more severe glomerulonephritis. The type I IFN gene signature in male BXSB.Yaa ß2 GPI(-/-) mice was significantly higher than that in control mice. Male BXSB.Yaa ß2 GPI(-/-) mice also had marked dysregulation of various B cell and T cell populations in the spleens and lymph nodes and a disturbance in apoptotic cell clearance. CONCLUSION: Deletion of ß2 GPI accelerates and potentiates the autoimmune phenotype in male BXSB.Yaa mice.

Targeted inactivation of dipeptidyl peptidase 9 enzymatic activity causes mouse neonate lethality.

Dipeptidyl Peptidase (DPP) 4 and related dipeptidyl peptidases are emerging as current and potential therapeutic targets. DPP9 is an intracellular protease that is regulated by redox status and by SUMO1. DPP9 can influence antigen processing, epidermal growth factor (EGF)-mediated signaling and tumor biology. We made the first gene knock-in (gki) mouse with a serine to alanine point mutation at the DPP9 active site (S729A). Weaned heterozygote DPP9 (wt/S729A) pups from 110 intercrosses were indistinguishable from wild-type littermates. No homozygote DPP9 (S729A/S729A) weaned mice were detected. DPP9 (S729A/S729A) homozygote embryos, which were morphologically indistinguishable from their wild-type littermate embryos at embryonic day (ED) 12.5 to ED 17.5, were born live but these neonates died within 8 to 24 hours of birth. All neonates suckled and contained milk spots and were of similar body weight. No gender differences were seen. No histological or DPP9 immunostaining pattern differences were seen between genotypes in embryos and neonates. Mouse embryonic fibroblasts (MEFs) from DPP9 (S729A/S729A) ED13.5 embryos and neonate DPP9 (S729A/S729A) mouse livers collected within 6 hours after birth had levels of DPP9 protein and DPP9-related proteases that were similar to wild-type but had less DPP9/DPP8-derived activity. These data confirmed the absence of DPP9 enzymatic activity due to the presence of the serine to alanine mutation and no compensation from related proteases. These novel findings suggest that DPP9 enzymatic activity is essential for early neonatal survival in mice.

Tawny frogmouths and brushtail possums as sentinels for Angiostrongylus cantonensis, the rat lungworm.

The objective of this study was to determine the prevalence of angiostrongylosis in tawny frogmouths (Podargus strigoides) and brushtail possums (Trichosurus vulpecula) with signs of neurological disease, and to describe the clinicopathological features of angiostrongylosis in both species. Tawny frogmouths and brushtail possums with signs of neurological disease were sampled from the Sydney metropolitan area between October 1998 and June 2010. Samples from 100 tawny frogmouths and 31 brushtail possums from the Australian Registry of Wildlife Health (ARWH), the Wildlife Assistance and Information Foundation (WAIF) and Wildlife Health and Conservation Centre (WHCC), University of Sydney were examined. Histological examinations of the brain, spinal cord and other available tissues were used to characterize the disease responsible for each animal's clinical signs. Of the 100 tawny frogmouths with neurological disease examined, angiostrongylosis was considered responsible in 80 (80%), traumatic injury in 17 (17%), protozoal infection in 3 (3%) and other diseases in 2 (2%) and the cause of clinical signs was unknown in 10 (10%). Eleven tawny frogmouths presenting with neurological signs associated with head trauma had concurrent angiostrongylosis. Of the 31 brushtail possums, Wobbly Possum Syndrome (WPS) was diagnosed in 21 (68%), angiostrongylosis in 4 (13%) and other diseases in the remaining 6 (19%). Angiostrongylosis was overrepresented in hand reared juvenile possums. Cases of angiostrongylosis in tawny frogmouths followed a strong seasonal pattern peaking through late summer and autumn. The results confirm that Angiostrongylus cantonensis is endemic in Sydney, Australia and that tawny frogmouths could be important sentinels for this zoonotic parasite.

Twenty two cases of canine neural angiostrongylosis in eastern Australia (2002-2005) and a review of the literature

Cases of canine neural angiostrongylosis (NA) with cerebrospinal fluid (CSF) evaluations in the peer-reviewed literature were tabulated. All cases were from Australia. A retrospective cohort of 59 dogs was contrasted with a series of 22 new cases where NA was diagnosed by the presence of both eosinophilic pleocytosis and anti-Angiostrongylus cantonensis immunloglobulins (IgG) in CSF, determined by ELISA or Western blot. Both cohorts were drawn from south east Queensland and Sydney. The retrospective cohort comprised mostly pups presented for hind limb weakness with hyperaesthesia, a mixture of upper motor neurone (UMN) and lower motor neurone (LMN) signs in the hind limbs and urinary incontinence. Signs were attributed to larval migration through peripheral nerves, nerve roots, spinal cord and brain associated with an ascending eosinophilic meningo-encephomyelitis. The contemporary cohort consisted of a mixture of pups, young adult and mature dogs, with a wider range of signs including (i) paraparesis/proprioceptive ataxia (ii) lumbar and tail base hyperaesthesia, (iii) multi-focal central nervous system dysfunction, or (iv) focal disease with neck pain, cranial neuropathy and altered mentation. Cases were seen throughout the year, most between April and July (inclusive). There was a preponderance of large breeds. Often littermates, or multiple animals from the same kennel, were affected simultaneously or sequentially. A presumptive diagnosis was based on consistent signs, proximity to rats, ingestion/chewing of slugs or snails and eosinophilic pleocytosis. NA was diagnosed by demonstrating anti-A. cantonensis IgG in CSF. Detecting anti-A. cantonensis IgG in serum was unhelpful because many normal dogs (20/21 pound dogs; 8/22 of a hospital population) had such antibodies, often at substantial titres. Most NA cases in the contemporary series (19/22) and many pups (16/38) in the retrospective cohort were managed successfully using high doses of prednisolone and opioids. Treatment often included antibiotics administered in case protozoan encephalomyelitis or translocated bacterial meningitis was present. Supportive measures included bladder care and physiotherapy. Several dogs were left with permanent neural deficits. Dogs are an important sentinel species for NA. Human cases and numerous cases in tawny frogmouths were reported from the same regions as affected dogs over the study period.

Concurrent infection with Cryptococcus neoformans/gattii species complex and Mycobacterium avium affecting the subcutis and bone of a pelvic limb in a cat.

This paper describes a cat with severe localised infections with Cryptococcus neoformans/gattii species complex and Mycobacterium avium affecting the subcutis and underlying fascia and bone of the right pelvic limb. The simultaneous isolation of both pathogens in this patient was unexpected and posed unique issues concerning both diagnosis and clinical management. The aetiopathogenesis of this infection is discussed in relation to aspects of diagnosis and therapy.

Extensive production of Neospora caninum tissue cysts in a carnivorous marsupial succumbing to experimental neosporosis.

Experimental infections of Sminthopsis crassicaudata, the fat-tailed dunnart, a carnivorous marsupial widely distributed throughout the arid and semi-arid zones of Australia, show that this species can act as an intermediate host for Neospora caninum. In contrast to existing models that develop relatively few N. caninum tissue cysts, dunnarts offer a new animal model in which active neosporosis is dominated by tissue cyst production. The results provide evidence for a sylvatic life cycle of N. caninum in Australia between marsupials and wild dogs. It establishes the foundation for an investigation of the impact and costs of neosporosis to wildlife.

Most species are not driven to extinction before genetic factors impact them.

There is controversy concerning the role of genetic factors in species extinctions. Many authors have asserted that species are usually driven to extinction before genetic factors have time to impact them, but few studies have seriously addressed this issue. If this assertion is true, there will be little difference in genetic diversity between threatened and taxonomically related nonthreatened species. We compared average heterozygosities in 170 threatened taxa with those in taxonomically related nonthreatened taxa in a comprehensive metaanalysis. Heterozygosity was lower in threatened taxa in 77% of comparisons, a highly significant departure from the predictions of the no genetic impact hypothesis. Heterozygosity was on average 35% lower (median 40%) in threatened taxa than in related nonthreatened ones. These differences in heterozygosity indicate lowered evolutionary potential, compromised reproductive fitness, and elevated extinction risk in the wild. Independent evidence from stochastic computer projections has demonstrated that inbreeding depression elevates extinction risk for threatened species in natural habitats when all other threatening processes are included in the models. Thus, most taxa are not driven to extinction before genetic factors affect them adversely.