Host transmission dynamics of first- and third-stage Angiostrongylus cantonensis larvae in Bullastra lessoni.

Given the importance of angiostrongyliasis as an emerging infectious disease of humans, companion animals, and wildlife, the current study focused on the transmission dynamics of first- and third-stage larvae of the parasitic nematode, Angiostrongylus cantonensis. The migration of infective larvae and their subsequent distribution within the Lymnaeidae snail, Bullastra lessoni, were investigated over time using microscopic examination of histological sections and fresh tissue. Snails were divided into four anatomical regions: (i) anterior and (ii) posterior cephalopedal masses, (iii) mantle skirt and (iv) visceral mass. The viability of free-swimming third-stage larvae, after their release from snail tissues, was evaluated in vitro by propidium iodide staining and infectivity by in vivo infection of Wistar rats. Snails were sequentially dissected over time to assess the number and anatomical distribution of larvae within each snail and hence infer their migration pathway. Herein, ongoing larval migratory activity was detected over 28 days post-infection. A comparison of infection rates and the larval distribution within the four designated snail regions demonstrated a significant relationship between anatomical region and density of infective larvae, with larvae mostly distributed in the anterior cephalopedal mass (43.6 ± 10.8%) and the mantle skirt (33.0 ± 8.8%). Propidium iodide staining showed that free-swimming third-stage larvae retained viability for between 4 and 8 weeks when stored under laboratory conditions. In contrast to viability, larval infectivity in rats remained for up to 2 weeks only. Knowledge gained from the current work could provide information on the development of new approaches to controlling the transmission of this parasite.

Differential Gamma Interferon- and Tumor Necrosis Factor Alpha-Driven Cytokine Response Distinguishes Acute Infection of a Metatherian Host with Toxoplasma gondii and Neospora caninum.

Toxoplasma gondii and Neospora caninum (both Apicomplexa) are closely related cyst-forming coccidian parasites that differ significantly in their host ranges and ability to cause disease. Unlike eutherian mammals, Australian marsupials (metatherian mammals) have long been thought to be highly susceptible to toxoplasmosis and neosporosis because of their historical isolation from the parasites. In this study, the carnivorous fat-tailed dunnart (Sminthopsis crassicaudata) was used as a disease model to investigate the immune response and susceptibility to infection of an Australian marsupial to T. gondii and N. caninum The disease outcome was more severe in N. caninum-infected dunnarts than in T. gondii-infected dunnarts, as shown by the severity of clinical and histopathological features of disease and higher tissue parasite burdens in the tissues evaluated. Transcriptome sequencing (RNA-seq) of spleens from infected dunnarts and mitogen-stimulated dunnart splenocytes was used to define the cytokine repertoires. Changes in mRNA expression during the time course of infection were measured using quantitative reverse transcription-PCR (qRT-PCR) for key Th1 (gamma interferon [IFN-γ] and tumor necrosis factor alpha [TNF-α]), Th2 (interleukin 4 [IL-4] and IL-6), and Th17 (IL-17A) cytokines. The results show qualitative differences in cytokine responses by the fat-tailed dunnart to infection with N. caninum and T. gondii Dunnarts infected with T. gondii were capable of mounting a more effective Th1 immune response than those infected with N. caninum, indicating the role of the immune response in the outcome scenarios of parasite infection in this marsupial mammal.

Toxoplasmosis in a Pet Peach-Faced Lovebird (Agapornis roseicollis).

Toxoplasma gondii atypical type II genotype was diagnosed in a pet peach-faced lovebird (Agapornis roseicollis) based on histopathology, immunohistochemistry, and multilocus DNA typing. The bird presented with severe neurological signs, and hematology was suggestive of chronic granulomatous disease. Gross post-mortem examination revealed cerebral hemorrhage, splenomegaly, hepatitis, and thickening of the right ventricular free wall. Histologic sections of the most significant lesions in the brain revealed intralesional protozoan organisms associated with malacia, spongiform changes, and a mild histiocytic response, indicative of diffuse, non-suppurative encephalitis. Immunohistochemistry confirmed the causative organisms to be T. gondii. DNA isolated from the brain was used to confirm the presence of T. gondii DNA. Multilocus genotyping based on SAG1, altSAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico markers demonstrated the presence of ToxoDB PCR-RFLP genotype #3 and B1 gene as atypical T. gondii type II. The atypical type II strain has been previously documented in Australian wildlife, indicating an environmental transmission route.

Severe amoebic placentitis in a horse caused by an Acanthamoeba hatchetti isolate identified using next-generation sequencing.

A case of amoebic placentitis in a mare from eastern Australia was diagnosed postpartum by histopathological examination of the placenta. The identity of the etiological agent was confirmed as Acanthamoeba hatchetti by use of diversity profiling based on a next-generation sequencing approach.

Pentalogy of Cantrell in Two Neonate Littermate Puppies: A Spontaneous Animal Model Suggesting Familial Inheritance.

Developmental anomalies are an important cause of stillbirth and early perinatal death in companion animals. Many of these disorders remain poorly understood and provide an opportunity as a spontaneous animal model for human disease. Pentalogy of Cantrell is a rare congenital syndrome described in human neonates. It is a ventral midline closure defect with a proposed familial inheritance in humans. This syndrome involves five defects, including the thoracoabdominal wall, sternal, diaphragmatic, pericardial and cardiac malformations. Diverse expressions of these defects have been described in humans and sporadically in domestic animals. This severe syndrome commonly harbors a poor prognosis, posing an ethical and surgical dilemma. To better understand this syndrome and its presentation in dogs, we describe two rare cases of Pentalogy of Cantrell in a litter of papillon dogs. The affected puppies had anomalies compatible with the Pentalogy of Cantrell, including thoracoabdominal schisis, ectopia cordis, sternal cleft, pericardial agenesis, and diaphragmatic defects. The diagnosis was confirmed by advanced imaging (computed tomography) and postmortem examinations. The family history of this litter was explored and other cases in domestic animals were reviewed. This is the first report of the complete Pentalogy of Cantrell with ectopia cordis in the dog and the only report on papillons. Similar to human cases, possible familial inheritance and suspected male gender bias were observed. Further research on this novel animal model, its pathogenesis and its hereditary basis, may be helpful in better understanding this rare developmental disorder.

Immunohistochemical analysis of expression of VEGFR2, KIT, PDGFR-ß, and CDK4 in canine urothelial carcinoma.

Urothelial carcinomas (UCs), also known as transitional cell carcinomas, are the most common canine urinary tract neoplasms. Tyrosine kinases (TKs) are enzymes that tightly regulate cell growth and differentiation through phosphorylation. Receptor TK (RTK) inhibitors are currently used to treat UCs. Toceranib phosphate (Palladia; Pfizer) is an RTK inhibitor that blocks the activity of vascular endothelial growth factor receptor 2 (VEGFR2), platelet-derived growth factor receptor-alpha and -beta (PDGFR-α, -ß), FMS-like tyrosine kinase 3, stem cell factor receptor (KIT, kinase inhibitor targeting), and colony stimulating factor receptor. To better understand UCs and validate treatment targets, we performed immunohistochemical staining for RTKs, as well as a novel target, cyclin-dependent kinase 4 (CDK4, a central regulator of the mammalian cell cycle), on formalin-fixed, paraffin-embedded tissues from bladder biopsies from 17 dogs with UCs, 17 dogs with cystitis (diseased controls), and 8 normal dogs (negative controls). Although immunohistochemical scores could not be extrapolated to prognostic value, response to treatment, and outcome of patients with UC, we demonstrated expression of PDGFR-ß and VEGFR2 in UCs; all UC samples staining positively for VEGFR2. Minimal positive staining for KIT was noted in the tumor samples. CDK4 staining intensity was significantly weaker in UCs compared with normal and cystitis bladder samples. The intense staining of VEGFR2 in UC cells suggested that VEGFR2 may be of prognostic and/or therapeutic value in dogs with UC. Overexpression of VEGFR2 in UC cells validates this receptor as a treatment target in UC.

Oropharyngeal Shedding of Gammaherpesvirus DNA by Cats, and Natural Infection of Salivary Epithelium.

Felis catus gammaherpesvirus-1 (FcaGHV1), a novel candidate oncogenic virus, infects cats worldwide. Whether the oropharynx is a site of virus shedding and persistence, and whether oronasal carcinomas harbor FcaGHV1 nucleic acid were investigated. In a prospective molecular epidemiological study, FcaGHV1 DNA was detected by cPCR in oropharyngeal swabs from 26/155 (16.8%) of cats. Oropharyngeal shedding was less frequently detected in kittens ≤3 months of age (5/94, 5.3%) than in older animals; >3 months to ≤1 year: 8/26, 30.8%, (p = 0.001, OR 7.91, 95% CI (2.320, 26.979)); >1 year to ≤6 years: 10/20, 50%, (p < 0.001, OR 17.8 95% CI (5.065, 62.557)); >6 years: 3/15, 33% (p = 0.078). Provenance (shelter-owned/privately owned) was not associated with shedding. In situ hybridization (ISH) identified FcaGHV1-infected cells in salivary glandular epithelium but not in other oronasal tissues from two of three cats shedding viral DNA in the oropharynx. In a retrospective dataset of 11 oronasopharyngeal carcinomas, a single tumor tested positive for FcaGHV1 DNA by ISH, a papillary carcinoma, where scattered neoplastic cells showed discrete nuclear hybridization. These data support the oronasopharynx as a site of FcaGHV1 shedding, particularly after maternal antibodies are expected to decline. The salivary epithelium is identified as a potential site of FcaGHV1 persistence. No evidence supporting a role for FcaGHV1 in feline oronasal carcinomas was found in the examined tumours.

Gynaecomastia in a male neutered cat with an adrenal tumour and associated hyperprogesteronism, hypercortisolism and hyperaldosteronism.

CASE SUMMARY: A 7-year-old male neutered domestic longhair cat was presented with chronic progressive gynaecomastia, polydipsia, polyphagia, weight loss and poor fur regrowth. Sexualised behavioural changes were not reported and virilisation was not present on physical examination. Pertinent haematology, biochemistry and urinalysis findings at the time of referral included mild hypokalaemia. Left adrenomegaly and mild prostatomegaly were identified on a CT scan. Evaluation of adrenal hormones with a low-dose dexamethasone suppression test, serum progesterone, testosterone, oestradiol, plasma aldosterone, renin, plasma metanephrine and normetanephrine measurement supported a diagnosis of hyperprogesteronism, hyperaldosteronism and hypercortisolism. Adrenalectomy was performed and histopathology was consistent with an adrenocortical tumour. Clinical signs and hormone elevations resolved postoperatively. RELEVANCE AND NOVEL INFORMATION: To our knowledge, this is the second report of gynaecomastia secondary to an adrenal tumour in a male neutered cat and the first associated with hyperprogesteronism.

Disseminated invasive aspergillosis caused by Aspergillus felis in a cat.

A 2-year-old male desexed Ragdoll cat with a 1-year history of sneezing and nasal discharge presented with a large subcutaneous cervical mass, identified as the right medial retropharyngeal lymph node on computed tomography (CT). A right orbital mass, destructive sino-nasal cavity disease and multiple pulmonary nodules were also identified. Aspergillus felis was cultured from the lymph node. After treatment with posaconazole and liposomal amphotericin B the lymph node enlargement and orbital mass resolved but left frontal sinus involvement and pulmonary lesions persisted despite additional caspofungin therapy. The cat was euthanized 14 months after diagnosis with dysphagia and chronic progressive exophthalmos. A meningeal granuloma with intravascular fungal hyphae was identified at post-mortem and A felis was cultured from the left frontal sinus and a right retrobulbar fungal granuloma. This case demonstrates that disseminated disease is a possible sequel to invasive fungal rhinosinusitis caused by A felis in cats.

Implantation and long-term assessment of the stability and biocompatibility of a novel 98 channel suprachoroidal visual prosthesis in sheep.

Severe visual impairment can result from retinal degenerative diseases such as retinitis pigmentosa, which lead to photoreceptor cell death. These pathologies result in extensive neural and glial remodelling, with survival of excitable retinal neurons that can be electrically stimulated to elicit visual percepts and restore a form of useful vision. The Phoenix99 Bionic Eye is a fully implantable visual prosthesis, designed to stimulate the retina from the suprachoroidal space. In the current study, nine passive devices were implanted in an ovine model from two days to three months. The impact of the intervention and implant stability were assessed using indirect ophthalmoscopy, infrared imaging, and optical coherence tomography to establish the safety profile of the surgery and the device. The biocompatibility of the device was evaluated using histopathological analysis of the tissue surrounding the electrode array, with a focus on the health of the retinal cells required to convey signals to the brain. Appropriate stability of the electrode array was demonstrated, and histological analysis shows that the fibrotic and inflammatory response to the array was mild. Promising evidence of the safety and potential of the Phoenix99 Bionic Eye to restore a sense of vision to the severely visually impaired was obtained.

Safety and biocompatibility of a bionic eye: Imaging, intraocular pressure, and histology data.

The data presented here are related and supplementary data to the research article "Implantation and long-term assessment of the stability and biocompatibility of a novel 98 channel suprachoroidal visual prosthesis in sheep" [1]. In Eggenberger et al., nine sheep of the Suffolk (N=2) and Dorper (N=7) breeds were implanted in the left eye with an electrically inactive, suprachoroidal retinal stimulator (Bionic Eye) for durations of up to 100 days. The surgical safety, implant stability and device biocompatibility were assessed. Intraocular pressure measurements, indirect and infrared ophthalmoscopy and optical coherence tomography were performed at fixed time points to evaluate the clinical effects of the surgery and device implantation. Post-mortem eye tissue collection and histology was performed to measure the effects of the intervention at the cellular level. The data, including a comprehensive collection of fundus, infrared, optical coherence tomography and histology images can be used as a reference for comparison with other research, for example, active retinal stimulators. Furthermore, these data can be used to evaluate the suitability of the sheep model, in particular Dorper sheep, for future research.

Fulminant Tritrichomonas foetus 'feline genotype' infection in a 3-month old kitten associated with viral co-infection.

Tritrichomonas foetus is a flagellate protist which commonly causes a waxing and waning large bowel diarrhoea in young cats. We report severe T. foetus infection of the colon, cecum and ileum with concurrent feline enteric coronavirus (FCoV) and feline panleukopenia virus (FPV) in a 3-month-old Bengal kitten with an 8-day history of vomiting, diarrhoea, failure to thrive and coughing. Protozoa filling the lumen and crypts and occasional invading into lamina propria were identified within the affected colon and confirmed by PCR as T. foetus 'feline genotype'. Assessment of faeces by PCR revealed concurrent infection with FCoV and FPV. It is possible that immunosuppression by FPV played a role in the unprecedented T. foetus infection intensity observed histologically. Studies during and after resolution of FPV infection, will be critical to determine if T. foetus co-infection affects long-term prognosis of FPV survivors.

Transcriptome Analysis and In Situ Hybridization for FcaGHV1 in Feline Lymphoma.

Lymphoma is one of the most common malignancies in domestic cats. The lymphomagenic potential of Felis catus gammaherpesvirus 1 (FcaGHV1), a common infection in domestic cats, is unknown. In other species, including humans, cellular transformation by gammaherpesviruses is typically mediated by viral genes expressed during latency. We analysed tumour RNA, from diffuse large B-cell lymphomas (DLBCL) appearing in cats coinfected with FcaGHV1 and feline immunodeficiency virus (FIV) (n = 10), by high throughput transcriptome sequencing and reverse transcription PCR. A limited repertoire of FcaGHV transcripts was identified in five tumors, including homologs of oncogenic latency-associated transcripts, latency-associated nuclear antigen (LANA, ORF73) and vFLIP (F7), lytic genes (ORF50, ORF6, ORF59, F10), and an ORF unique to FcaGHV1, F20. In situ hybridization of FIV-associated DLBCLs (n = 9), post-transplant lymphomas (n = 6) and high-grade B and T-cell intestinal lymphomas (n = 8) identified a single case in which FcaGHV1 nucleic acid was detectable. These results demonstrate that FcaGHV1 transcripts can be detected in some FIV-associated lymphomas, but at low copy number, precluding assessment of a potential role for FcaGHV1 in lymphomagenesis. Future investigation of the FcaGHV1 transcriptome in clinical samples might employ viral enrichment and greater sequencing depth to enhance the retrieval of viral reads. Our results suggest prioritization of a subset of intestinal T-cell tumors, large granular lymphocyte lymphoma, for study.

A fungal granuloma of the frontal sinus in a llama.

A 12-year-old, castrated male llama (Lama glama) presented with a 12-cm diameter cranial mass. Computed tomography and postmortem examination revealed that the mass invaded the calvarium and compressed the rostral part of the brain. Light microscopic examination confirmed a fungal granuloma.

The utility of diversity profiling using Illumina 18S rRNA gene amplicon deep sequencing to detect and discriminate Toxoplasma gondii among the cyst-forming coccidia.

Next-generation sequencing (NGS) has the capacity to screen a single DNA sample and detect pathogen DNA from thousands of host DNA sequence reads, making it a versatile and informative tool for investigation of pathogens in diseased animals. The technique is effective and labor saving in the initial identification of pathogens, and will complement conventional diagnostic tests to associate the candidate pathogen with a disease process. In this report, we investigated the utility of the diversity profiling NGS approach using Illumina small subunit ribosomal RNA (18S rRNA) gene amplicon deep sequencing to detect Toxoplasma gondii in previously confirmed cases of toxoplasmosis. We then tested the diagnostic approach with species-specific PCR genotyping, histopathology and immunohistochemistry of toxoplasmosis in a Risso's dolphin (Grampus griseus) to systematically characterise the disease and associate causality. We show that the Euk7A/Euk570R primer set targeting the V1-V3 hypervariable region of the 18S rRNA gene can be used as a species-specific assay for cyst-forming coccidia and discriminate T. gondii. Overall, the approach is cost-effective and improves diagnostic decision support by narrowing the differential diagnosis list with more certainty than was previously possible. Furthermore, it supplements the limitations of cryptic protozoan morphology and surpasses the need for species-specific PCR primer combinations.

Comparison of genotypes of Toxoplasma gondii in domestic cats from Australia with latent infection or clinical toxoplasmosis.

Whether Toxoplasma gondii genotype is associated with disease severity in naturally occurring toxoplasmosis in domestic cats is unknown. The aim of this study was to compare genotypes of T. gondii in latently infected cats with those in cats with clinical toxoplasmosis. Results of a PCR targeting the B1 gene to detect T. gondii DNA were positive in tissue samples from 11 of 17 (65%) seropositive cats tested including four with clinical toxoplasmosis and seven with latent infections, as determined by serology, histologic findings and immunohistochemistry. Three of the four cats with clinical toxoplasmosis were immunosuppressed. Complete genotyping was performed in seven cats using PCR-RFLP at 12 loci (SAG1, 5'SAG2 and 3'SAG2, altSAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico) and direct sequencing of the multi-copy B1 gene. Partial genotyping using six loci was performed in one cat with latent infection. T. gondii type II (ToxoDB genotype #3) was determined in four cats with clinical toxoplasmosis and three cats with latent toxoplasmosis Novel T. gondii B1 gene polymorphisms were detected in two strains (at nucleotide posititions 233, 366 and 595) and a B1 gene polymorphism unique to Australia was identified in another (guanine/adenine at nucleotide position 378). One cat was co-infected with two or more type-II like strains at 3'SAG2. The results of this study suggest that the infecting T. gondii genotype, based on these 12 loci, is not a determinant of clinical disease in cats naturally infected with T. gondii and type II strains are prevalent in Australia.

Clinical and pathological features of toxoplasmosis in free-ranging common wombats (Vombatus ursinus) with multilocus genotyping of Toxoplasma gondii type II-like strains.

Toxoplasma gondii is a cosmopolitan zoonotic protozoan parasite with the capacity to infect virtually any warm blooded vertebrate species. Australian native marsupials are thought to be highly susceptible to toxoplasmosis; however, most reports are in captive animals and little is known about T. gondii associated disease in free-ranging marsupials, including wombats (Vombatus ursinus). This study describes the clinical and pathological features of eight cases of toxoplasmosis in free-ranging common wombats in Tasmania and New South Wales (NSW) from 1992 to 2013, including a morbidity and mortality event investigated in the Southern Highlands NSW in the autumn of 2010. The diagnosis of T. gondii infection was confirmed using either immunohistochemistry, molecular diagnostics or both. Utilizing the combination of direct DNA sequencing of B1, SAG1, 5'- and 3'-SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico DNA markers and virtual RFLP to genetically characterize two of the T. gondii strains, we found a nonarchetypal type II-like strain (ToxoDB PCR-RFLP genotype #1) and an atypical type II-like strain (ToxoDB PCR-RFLP genotype #3) to be the causal agents of toxoplasmosis in wombats from the 2010 morbidity and mortality event. This study suggests that T. gondii may act as a significant disease threat to free-ranging common wombats. Our findings indicate neurologic signs are a very common clinical presentation in common wombats with toxoplasmosis and T. gondii infection should be considered as a likely differential diagnosis for any common wombat exhibiting signs of blindness, head tilt, circling and changes in mentation.

A review of neosporosis and pathologic findings of Neospora caninum infection in wildlife.

Neospora caninum is an apicomplexan parasite that is the etiologic agent of neosporosis, a devastating infectious disease regarded as a major cause of reproductive loss in cattle and neuromuscular disease in dogs worldwide. This protozoan pathogen is maintained in the environment by a heteroxenous life cycle that involves a definitive canid host and a wide range of intermediate hosts. In recent years, a number of wildlife species have been investigated for their possible involvement in the N. caninum life cycle and many have been implicated as intermediate hosts. However, in many instances these studies have utilized serological and molecular techniques to detect infection in clinically normal animals, and investigation of possible associated morbidity, mortality, and pathology has been neglected. As such, the occurrence and importance of Neospora-associated disease in wildlife species are unknown. In order to improve our understanding of the significance of N. caninum infection in nondomestic species, the present review provides an up-to-date summary of clinical neosporosis and N. caninum-associated pathologic lesions in naturally and experimentally infected wildlife species. We provide a list of all free-ranging and captive wildlife species identified with N. caninum infection to date using currently available diagnostic tools. The advantages and disadvantages of diagnostic methods in wildlife are addressed in order to recommend optimal diagnosis of confirming N. caninum infection and neosporosis in nondomestic species. Although current data would suggest that N. caninum infection does not adversely impact wildlife populations, there is a need for greater international uniformity in the diagnosis of N. caninum infection and neosporosis in nondomestic species in order to assess the true consequences of parasite infection.

A retrospective study of Babesia macropus associated with morbidity and mortality in eastern grey kangaroos (Macropus giganteus) and agile wallabies (Macropus agilis).

This is a retrospective study of 38 cases of infection by Babesia macropus, associated with a syndrome of anaemia and debility in hand-reared or free-ranging juvenile eastern grey kangaroos (Macropus giganteus) from coastal New South Wales and south-eastern Queensland between 1995 and 2013. Infection with B. macropus is recorded for the first time in agile wallabies (Macropus agilis) from far north Queensland. Animals in which B. macropus infection was considered to be the primary cause of morbidity had marked anaemia, lethargy and neurological signs, and often died. In these cases, parasitised erythrocytes were few or undetectable in peripheral blood samples but were sequestered in large numbers within small vessels of visceral organs, particularly in the kidney and brain, associated with distinctive clusters of extraerythrocytic organisms. Initial identification of this piroplasm in peripheral blood smears and in tissue impression smears and histological sections was confirmed using transmission electron microscopy and molecular analysis. Samples of kidney, brain or blood were tested using PCR and DNA sequencing of the 18S ribosomal RNA and heat shock protein 70 gene using primers specific for piroplasms. The piroplasm detected in these samples had 100% sequence identity in the 18S rRNA region with the recently described Babesia macropus in two eastern grey kangaroos from New South Wales and Queensland, and a high degree of similarity to an unnamed Babesia sp. recently detected in three woylies (Bettongia penicillata ogilbyi) in Western Australia.

Multisystemic toxoplasmosis associated with a type II-like Toxoplasma gondii strain in a New Zealand fur seal (Arctocephalus forsteri) from New South Wales, Australia.

We report the first confirmed case of toxoplasmosis in an Australian pinniped. Presence of Toxoplasma gondii DNA was detected in the brain of a free-ranging subadult New Zealand fur seal (Arctocephalus forsteri) with nonsuppurative meningoencephalitis, hypophysitis, posterior uveitis, retrobulbar cellulitis, and myocarditis associated with protozoan cysts and tachyzoites. The emaciated seal stranded moribund on a beach in northern Sydney in New South Wales. Histopathology coupled with specific immunohistochemistry and PCR assays confirmed the presence of T. gondii. The T. gondii sample (NZfs8825) identified in this study has an identical genotype as the type II (ToxoDB PCR-RFLP genotype #1) based on the direct sequencing and virtual RFLP of multilocus DNA markers including SAG1, 5'- and 3'-SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico. Direct sequencing of T. gondii B1 DNA marker from the T. gondii sample (NZfs8825) identified a type II-like strain, based on presence of non-archetypal B1 gene polymorphisms previously reported as unique to Australia. This study suggests that T. gondii oocysts originating from mainland Australia, which has a large population of feral cats, may act as a disease threat to native marine fauna. Therefore, emerging toxoplasmosis in the Arctic has a relevant parallel in the Southern Ocean within Australian waters with yet unknown relevance to Antarctica.