Metastatic Uterine Adenocarcinoma in a Sable Antelope (Hippotragus niger).

A nine-year-old intact female sable antelope (Hippotragus niger) with a six-week history of gradual loss of body condition was found dead by the owner and presented for autopsy. Macroscopic examination revealed an enlarged spleen and liver with the hepatic and splenic parenchyma showing extensive infiltration with firm, white to cream-coloured nodules. The uterus showed a few small, firm, well-demarcated, white-to-cream-coloured nodules in the uterine body. Similar nodules were present in the mediastinum, parietal pleura, heart, and marrow cavity of the femur. Histological analysis of the uterus revealed densely cellular neoplastic proliferations, forming nests, tubules, and acini within an abundant fibrovascular stroma. The samples from the other tissues revealed neoplastic cells with a similar appearance to those seen in the uterus, also forming nests and acini in a fibrovascular stroma. Importantly, multiple neoplastic cells were also seen in the peribronchiolar lymphatic vessels. The neoplastic cells in the uterine sections showed positive immunohistochemical labelling for cytokeratin, as did the neoplastic cells in the sections of liver and parietal pleura, confirming they were of epithelial origin. In addition, transmission electron microscopy of the uterus and liver showed neoplastic cells arranged in groups surrounded by basement membranes and interspersed with collagen fibres. Junctions were present between the cells, and junctional complexes could be seen at some cell surfaces. This confirmed that the neoplastic cells seen in the liver sample were the same as those seen in the uterine sample and were of epithelial origin. Thus, a diagnosis was made of uterine adenocarcinoma with widespread metastasis. This is the first report of uterine adenocarcinoma in a sable antelope.

Outbreak of cryptosporidiosis in African penguins Spheniscus demersus.

Cryptosporidium spp. are parasitic intracellular protozoa that infect the digestive, respiratory, and urinary tracts of vertebrates. The disease affects many different avian species across all continents, and >25 species and genotypes of Cryptosporidium have been documented infecting birds. We report on an outbreak of cryptosporidiosis in African penguin Spheniscus demersus chicks admitted to a rehabilitation center in South Africa from February 2012 to October 2013. Eighteen cases were confirmed through histopathology. The most frequent clinical signs were regurgitation (78%), dyspnea (72%), decreased weight gain or weight loss (72%), and lethargy (50%). Clinical signs began 8-46 d after hatching or admission (median: 13 d), and death followed 1-41 d after the onset of clinical signs (median: 13.5 d). The most frequent necropsy findings were stomach distended with undigested food or gas (78%), mildly reddened lungs (56%), spleen petechial hemorrhage (44%), and kidney congestion (39%). The most frequent histopathological findings were necrotic bursitis (89%), necrotic enteritis (83%), and bursal atrophy (67%). Small round or oval basophilic bodies (3-5 µm diameter) consistent with Cryptosporidium sp. were closely associated with the surface of the epithelial cells or in the lumen of the bursa (89%), large intestine (61%), small intestine (44%), trachea (22%), and ventriculus (6%). Transmission electron microscopy of 1 case confirmed that these organisms were Cryptosporidium sp. To our knowledge, this is the first report of cryptosporidiosis in penguins, raising concern of the potential implications for the conservation of these species.

Survival of emerging pathogen Acinetobacter baumannii in water environment exposed to different oxygen conditions.

Bacterium Acinetobacter baumannii is a leading cause of hospital infections. Over the last decade, its occurrence in natural environments outside hospital settings has been reported. The aim was to examine the survival of A. baumannii in water media exposed to different ranges of oxygen supply in order to predict its behaviour in the environment. The abundance of five A. baumannii isolates was monitored in nutrient-depleted and nutrient-rich water media in aerated, intermediate and anaerobic conditions (oxygen saturation 96, 56 and 0%, respectively). A. baumannii survived in both media in all tested oxygen concentrations for 50 days. In nutrient-rich water survival of A. baumannii was lowest in anaerobic conditions, while in nutrient-depleted water there was no difference in survival regardless of oxygen availability. A. baumannii formed translucent small colony variants as the fast response (after 1 day) and dormant cells as the prolonged response (after 14 days) to anaerobic conditions. Transmission electron microscopy (TEM) images showed the outer membrane of coccobacillus dormant cells was up to four times thicker than in regular cells. Once in the environment, A. baumannii is able to survive regardless of the availability of dissolved oxygen, which represents a serious public health concern.

Survival of ESKAPE pathogen Acinetobacter baumannii in water of different temperatures and pH.

Bacterium Acinetobacter baumannii is an emergent pathogen associated with nosocomial infections, which can be also found in natural waters. The impact of ecological factors on A. baumannii is insufficiently investigated. The aim was to examine the influence of temperatures (-20 to 80 °C) and pH values (2 to 12) on the survival of environmental and clinical isolates of A. baumannii in nutrient-deprived spring water (SW) and nutrient-rich diluted nutrient broth during 5 months. A. baumannii successfully survived at -20 to 44 °C and neutral pH for 5 months, which is consistent with the persistence of this pathogen in the hospital environment. At temperatures 50 to 80 °C the survival of A. baumannii ranged from 5 days to 5 min. The pH 2 was the most lethal with survival time up to 3 hours, suggesting that acidic conditions are promising for disinfection of water contaminated with A. baumannii. Although the type of media was not statistically significant for long-time survival, the extensively resistant or pandrug-resistant isolates survived better in SW than susceptible or multidrug-resistant isolates. Two distinct colony phenotypes were recorded at extreme temperatures and pH values. The results of this study provide insight into the behaviour of this emerging pathogen in the environment.

Paraquat intoxication and associated pathological findings in three dogs in South Africa.

Paraquat is a bipyridylium non-selective contact herbicide commonly used worldwide. When ingestion occurs by humans and animals either accidentally, intentionally or maliciously, paraquat selectively accumulates in the lungs resulting in the production of oxygen-free radicals, causing membrane damage and cell death. Intoxicated subjects typically show progressive and fatal pulmonary haemorrhage, collapse and oedema. In individuals surviving the acute phase, pulmonary fibrosis develops. Gastrointestinal-, renal- and central nervous system clinical signs may also occur. Owing to the lack of effective treatment and absence of an antidote, the prognosis is poor. The clinical presentation, clinicopathological findings and treatment are briefly described of three dogs from one South African household, intoxicated with paraquat. Macroscopic and microscopic lesions in one dog that was necropsied, as well as pulmonary ultrastructure are detailed and illustrated for academic reference. All dogs presented with tachypnoea and dyspnoea 2-3 days after accidental paraquat ingestion. Treatment was aimed at reducing gastrointestinal absorption, enhancing elimination by diuresis and avoiding further oxidative damage by administration of antioxidants. All dogs, however, became progressively hypoxic despite treatment and were euthanised. Paraquat toxicity should be a differential diagnosis in dogs with unexplained progressive respiratory and gastrointestinal signs and renal failure. The local veterinary profession should be aware of accidental or intentional paraquat toxicity of animals. Existing literature, variations possible in canine clinical signs, measured parameters, lesions, as well as possible treatments, promising experimental antidotes and management options are discussed.

Sarcocystis rommeli, n. sp. (Apicomplexa: Sarcocystidae) from Cattle (Bos taurus) and its Differentiation from Sarcocystis hominis.

Cattle (Bos taurus) are intermediate hosts for three named species of Sarcocystis, S. cruzi, S. hirsuta, and S. hominis. Recently, a fourth species was identified and named S. sinensis. However, S. sinensis originally named a species of Sarcocystis in water buffalo (Bubalus bubalis) in China. Based on unverifiable evidence, it was suggested that the same parasite infects cattle. In addition, S. sinensis was recently declared as nomen nudum because its naming violated the rules of International Code of Zoological Nomenclature. Thus, the fourth species using cattle as an intermediate host does not have a valid name. Here, we propose a new name, Sarcocystis rommeli for the S. sinensis-like parasite from cattle in Argentina, and differentiate it ultrastructurally from S. hominis sarcocysts from experimentally infected cattle. Sarcocystis rommeli sarcocysts were microscopic with a 5-µm-thick wall with slender villar protrusions (Vp); the Vp were up to 5 µm long, up to 0.5 µm wide, and of uneven thickness, often bent at an angle. The ground substance layer (Gs) was up to 0.8 µm thick and smooth. Vesicular structures were seen at the base of the Vp. The bradyzoites were 10-12 µm long. Sarcocystis hominis sarcocysts had Vp that were often upright, up to 7.5 µm long, and up to 1.8 µm wide; the Gs was up to 2 µm thick and without vesicles. Its sarcocyst wall was up to 5.6 µm thick, the vp were bent at an angle, up to 5.8 µm long, the Gs was up to 2 µm thick, but without vesicles seen in S. rommeli. Beef containing sarcocysts of S. rommeli was not orally infectious for two human volunteers and a red fox (Vulpes vulpes). The Sarcocystis described here is molecularly different from S. cruzi, S. hirsuta, and S. hominis based on 18S rRNA and cox1 gene sequences.

Sindbis and Middelburg Old World Alphaviruses Associated with Neurologic Disease in Horses, South Africa.

Old World alphaviruses were identified in 52 of 623 horses with febrile or neurologic disease in South Africa. Five of 8 Sindbis virus infections were mild; 2 of 3 fatal cases involved co-infections. Of 44 Middelburg virus infections, 28 caused neurologic disease; 12 were fatal. Middelburg virus likely has zoonotic potential.

Herpesvirus-like respiratory infection in African penguins Spheniscus demersus admitted to a rehabilitation centre.

Rehabilitation is an important strategy for the conservation of the Endangered African penguin Spheniscus demersus, and disease has been raised as a concern in the management of the species, both in the wild and in rehabilitation centres. We report 8 cases of herpesvirus-like respiratory infection in African penguin chicks undergoing rehabilitation between 2010 and 2013 at a facility in Cape Town, South Africa. Infection was confirmed through the identification of viral inclusions in the tracheal epithelium and demonstration of particles consistent with herpesvirus by electron microscopy, whereas virus isolation in eggs, serology and PCR testing failed to detect the virus. Only penguin chicks were affected; they were in poor body condition, and in 2 cases infection occurred prior to admission to the rehabilitation centre. The role played by the herpesvirus-like infection in the overall respiratory disease syndrome is uncertain, due to identification of lesions in only a small proportion of the chicks as well as to the occurrence of other concurrent pathological processes. Further studies are advised to characterise the specific virus involved through the development of sensitive diagnostic methods and to clarify the epidemiology and significance of these infections in wild African penguins.

Sarcocystis mehlhorni, n. sp. (Apicomplexa: Sarcocystidae) from the black-tailed deer (Odocoileus hemionus columbianus).

Infection with Sarcocystis is common in many species of wild cervids but none is reported from the black-tailed deer (Odocoileus hemionus columbianus). Here, we report Sarcocystis infection in two black-tailed deer from northwest USA for the first time. Sarcocysts were microscopic, up to 556 µm long and mature. The sarcocyst wall was up to 1.39 µm thick and had rectangular 1.17-µm-long villar protrusions, type 17, with thin (230 nm) electron dense ground substance layer. Molecular characterization and phylogenetic analysis indicated that Sarcocystis in the black-tailed deer is related to structurally distinct Sarcocystis species in cervids. A new name, Sarcocystis mehlhorni, is proposed for the Sarcocystis species in black-tailed deer.

Sarcocystis heydorni, n. sp. (Apicomplexa: Sarcocystidae) with cattle (Bos taurus) and human (Homo sapiens) cycle.

Cattle (Bos taurus) are intermediate hosts for four species of Sarcocystis, namely Sarcocystis cruzi, Sarcocystis hirsuta, Sarcocystis hominis, and Sarcocystis rommeli. Of these four species, mature sarcocysts of S. cruzi are thin-walled (<1 µm), whereas S. hirsuta, S. hominis, and S. rommeli have thick walls (4 µm or more). Here, we describe a new species of Sarcocystis with thin-walled sarcocysts in cattle. Two newborn calves were fed with sporocysts from the feces of a human volunteer who had ingested raw beef. The calves were killed 111 and 222 days later. In addition to thick-walled sarcocysts of S. hominis, both calves were coinfected with a Sarcocystis species that had a thin-walled sarcocysts, distinct from S. cruzi. The sarcocysts were mature, microscopic, up to 80 µm wide, and up to 1060 µm long. By light microscopy, the sarcocyst wall was thin (<1 µm thick) and had minute protrusions. By transmission electron microscopy, the sarcocyst wall had short, conical villar protrusions (vp) that were up to 0.5 µm long and up to 0.5 µm wide, similar to type 29. The vp on the sarcocyst wall lacked microtubules but had six or more disc-shaped plaques. The ground substance layer was smooth, approximately 0.5 µm thick, and without microtubules. The bradyzoites were 8-11 µm long. The structure of the sarcocyst wall was distinct from any species of Sarcocystis reported from livestock. This unique species is named in honor of Dr. Alfred Otto Heydorn who provided the sporocysts.

Sarcocystis oreamni, n. sp. (Apicomplexa: Sarcocystidae) from the mountain goat (Oreamnos americanus).

Numerous species of Sarcocystis have been reported from wild ruminants, but none has been named from the Rocky Mountain goat (Oreamnos americanus). Mature sarcocysts were found in frozen muscle samples of three of seven mountain goats from Alaska, USA. Two morphological types of sarcocysts were found; one had Sarcocystis cornagliai-like sarcocysts, previously named from the Alpine ibex (Capra ibex) from Europe. Two other goats were infected with a new species, Sarcocystis oreamni. Sarcocystis oreamni sarcocysts were microscopic with 2 µm-thick sarcocyst wall. By transmission electron microscopy, the sarcocyst wall had 1.7 µm-thick with unusual molar tooth-like villar protrusions (vp), type 29. The vp had an electron dense core and two disc-shaped plaques at the tip with fine microtubules. Bradyzoites were 8.6-9.1 µm long. Single nucleotide polymorphism (SNP) identified in 18S rRNA, and 28S rRNA loci of rDNA regions that suggested S. oreamni molecularly apart from related species. The phylogenetic analysis based on 18S rRNA and 28S rRNA sequences suggested S. oreamni is related with Sarcocystis species that employ members of the Canidae family as their definitive host.

Sarcocystis cafferi n. sp. (Protozoa: Apicomplexa) from the African buffalo (Syncerus caffer).

Sarcocystis infections have been reported from the African buffalo ( Syncerus caffer ), but the species have not been named. Here we propose a new name Sarcocystis cafferi from the African buffalo. Histological examination of heart (92), skeletal muscle (36), and tongue (2) sections from 94 buffalos from the Greater Kruger National Park, South Africa, and a review of the literature revealed only 1 species of Sarcocystis in the African buffalo. Macrocysts were up to 12 mm long and 6 mm wide and were located in the neck muscles and overlying connective tissue. They were pale yellow; shaped like a lychee fruit stone or cashew nut; turgid or flaccid and oval to round (not fusiform). By light microscopy (LM) the sarcocyst wall was relatively thin. By scanning electron microscopy (SEM), the sarcocyst wall had a mesh-like structure with irregularly shaped villar protrusions (vp) that were of different sizes and folded over the sarcocyst wall. The entire surfaces of vp were covered with papillomatous structures. By transmission electron microscopy (TEM), the sarcocyst wall was up to 3.6 µm thick and had highly branched villar protrusions that were up to 3 µm long. The villar projections contained filamentous tubular structures, most of which were parallel to the long axis of the projections, but some tubules criss-crossed, especially at the base. Granules were absent from these tubules. Longitudinally cut bradyzoites were 12.1 × 2.7 µm in size, had a long convoluted mitochondrion, and only 2 rhoptries. Phylogenetic analysis of 18S rRNA and cytochrome C oxidase subunit 1 (cox1) gene sequences indicated that this Sarcocystis species is very closely related to, but distinct from, Sarcocystis fusiformis and Sarcocystis hirsuta. Thus, morphological findings by LM, SEM, and TEM together with molecular phylogenetic data (from 18S rRNA and cox1) confirm that the Sarcocystis species in the African buffalo is distinct from S. fusiformis and has therefore been named Sarcocystis cafferi.

Analytical confirmation of Xanthium strumarium poisoning in cattle.

Xanthium strumarium, commonly referred to as "cocklebur," rarely causes poisoning in cattle. When mature, this robust, annual weed bears numerous oval, brownish, spiny burs. Only the seeds in the burs and young seedlings (cotyledonary leaves) contain the toxic principle, carboxyatractyloside. In the Frankfort district of the Free State Province of South Africa, a herd of 150 Bonsmara cows were allowed to graze on the banks of a small river, where mature cocklebur was growing. Four cows died while grazing in this relatively small area. Clinical signs ranged from recumbency, apparent blindness, and hypersensitivity to convulsive seizures. During necropsy, burs completely matted with ingesta were located in the rumen content. The most distinctive microscopic lesions were severe, bridging centrilobular to midzonal hepatocyte necrosis and hemorrhage. Ultrastructurally, periacinar hepatocytes were necrotic, and novel electron-dense cytoplasmic needle-like crystals were observed, often in close association with peroxisomes. Carboxyatractyloside concentrations were determined using liquid chromatography-high-resolution mass spectrometry (LC-HRMS). Carboxyatractyloside was present in rumen contents at 2.5 mg/kg; in burs removed from the rumen at 0.17 mg/kg; in liver at 66 ng/g, and was below the limit of quantitation in the kidney sample, estimated at approximately 0.8 ng/g. Based on the presence of the plants on the riverbank, the history of exposure, the clinical findings, the presence of burs in the rumen, and the microscopic and ultrastructural lesions, X. strumarium poisoning in the herd of cattle was confirmed and was supported by LC-HRMS.

Kupffer cell structure in the juvenile Nile crocodile, Crocodylus niloticus.

The morphology of Kupffer cells was examined in the liver of the juvenile Nile crocodile using light microscopy and transmission electron microscopy. Pleomorphic Kupffer cells were located in the sinusoids, in the space of Disse, in the hepatic parenchyma and often connected adjacent sinusoids. The cell surfaces were irregular due to the presence of filopodia and lamelliapodia with phagocytosis of white blood cells, red blood cells and thrombocytes being evident. The cells were in close contact with endothelial cells and pit cells in the sinusoidal lumen and with stellate cells in the space of Disse. The cytoplasm contained large phagosomes comprising a combination of ceroid pigment, melanosomes and siderosomes. The nuclei were often indented and eccentrically placed due to the presence of the phagosomes. Conspicuous clusters of membrane-bound tubular organelles with a filamentous or crystalline interior were observed in the cytoplasm. The clusters were sometimes separated into smaller groups around phagosomes. A clear zone existed between the limiting membrane and the interior of these tubular organelles with the electron-dense interior profiles being, respectively, circular, angular or divided. The tubular organelles have not previously been described in Kupffer cells and possibly represent lysosomes with specialized functions. Mitochondria, microtubules, Golgi profiles, granular and smooth endoplasmic reticulum, and a few cytoplasmic lipid droplets were also present. The presence of the tubular organelles and the occurrence of the Kupffer cells in different locations in the liver of the juvenile Nile crocodile are indicative of particularly active and mobile cells.

Pathology of fatal lineage 1 and 2 West Nile virus infections in horses in South Africa.

Since 2007, West Nile virus (WNV) has been reported in South African horses, causing severe neurological signs. All cases were of lineage 2, except for one case that clustered with lineage 1 viruses. In the present study, gross and microscopic lesions of six South African lineage 2-infected horses and the one lineage 1 case are described. Diagnoses were confirmed by real-time reverse-transcriptase polymerase chain reaction (RT-PCR) of central nervous system (CNS) tissue and one by RT-PCR of a brain virus isolate. The CNS of all cases was negative by RT-PCR or immunohistochemistry (IHC) for African horse sickness (AHS), equine encephalosis virus, equine herpes viruses 1 and 4, other zoonotic flaviviruses, alphaviruses, and shunivirus, and either by immunofluorescence or IHC for rabies. Gross visceral lesions were nonspecific but often mimicked those of AHS. The CNS histopathology of WNV lineage 2 cases resembled the nonsuppurative polioencephalomyelitis reported in the Northern Hemisphere lineage 1 and recent Hungarian lineage 2 cases. Occasional meningitis, focal spinal ventral horn poliomalacia, dorsal and lateral horn poliomyelitis, leucomyelitis, asymmetrical ventral motor spinal neuritis and frequent olfactory region involvement were also seen. Lineage 2 cases displayed marked variations in CNS lesion severity, type and distribution, and suggested various viral entry routes into the CNS, based on findings in experimental mice and hamsters. Lineage 1 lesions were comparable to the milder lineage 2 cases. West Nile virus IHC on CNS sections with marked lesions from all cases elicited only two antigen-positive cells in the olfactory cortex of one case. The presence in the CNS of T-lymphocytes, B-lymphocytes, plasma cells and macrophage-monocytes was confirmed by cluster of differentiation (CD) 3, CD20, multiple myeloma oncogene 1 (MUM1) and macrophage (MAC) 387 IHC.

Spirocerca lupi-associated vertebral changes: a radiologic-pathologic study.

Spirocerca lupi causes a caudal esophageal mass in dogs which may be accompanied by aortic changes and caudal thoracic spondylitis. Previous literature hypothesized that the spondylitis was caused by either aberrant larval migration or was secondary to the inflammation caused by the aortic migration. The current study aimed to evaluate these hypotheses. Ten dogs of various breeds and ages with radiographic evidence of spondylitis, which were necropsied, had the affected vertebrae removed and prepared for light and transmission electron microscopy examination. Transverse and sagittal sections of the ventral vertebrae were taken from 27 spondylitis and 8 spondylosis deformans lesions as well as from 8 normal vertebrae. Early spondylitis changes were characterized by periosteal woven new bone covered by hyperplastic periosteum with some involvement of the ventral longitudinal ligament. More mature lesions were characterized by nodules of denser trabecular bone and cartilage, also covered by hyperplastic periosteum and involved the ventral longitudinal ligament. It was difficult to distinguish the spondylitis and spondylosis deformans new bone. Inflammation was seen in five spondylitis cases (edema, lymphocytes, plasma cells, eosinophils and fibrin fibers). Spirocerca eggs were seen in one histologic section. This study shows that inflammation is mild and inconsistent in spirocercosis-induced spondylitis and that aberrant migration of the larvae or adults did not appear to be a predominant cause. Inflammatory mediators or osteoproliferative growth factors, which may be related to the primary esophageal lesion or to the worm itself, could be involved. This requires further investigation.

Shuni virus as cause of neurologic disease in horses.

To determine which agents cause neurologic disease in horses, we conducted reverse transcription PCR on isolates from of a horse with encephalitis and 111 other horses with acute disease. Shuni virus was found in 7 horses, 5 of which had neurologic signs. Testing for lesser known viruses should be considered for horses with unexplained illness.

Avian poxvirus epizootic in a breeding population of Lesser Flamingos (Phoenicopterus minor) at Kamfers Dam, Kimberley, South Africa.

Avian pox has a worldwide distribution, but prior to this investigation has not been reported in free-ranging flamingo populations. During observations of the first successful breeding of Lesser Flamingos on a purpose-built island, at Kamfers Dam near Kimberley, South Africa, multiple small, raised, crusted plaques on the legs and facial area were noticed on 30% of the fledgling flamingos. A diagnosis of avipoxvirus infection was made on the basis of the macroscopic, histologic, and electron microscopic features, and was further confirmed by DNA sequence analysis. The avipoxvirus detected was very similar to that previously detected in albatross and falcons.

Cerebellar cortical degeneration in cattle caused by Solanum kwebense.

The pathology of maldronksiekte, a sporadic neurological disorder of cattle caused by the ingestion of the plant Solanum kwebense in certain parts of South Africa, was studied in three chronic field cases. There was loss of cerebellar Purkinje cells with the remaining neurons either swollen or shrunken and showing degeneration and necrosis. Ultrastructurally, neurons with a swollen perikaryon showed depletion and empty dilated cisternae of granular endoplasmic reticulum. In a few Purkinje cells, the cytoplasm contained small numbers of lamellar and membranous bodies. In the shrunken neurons, the highly condensed cytoplasm contained distended Golgi saccules, dense clusters of granular endoplasmic reticulum and swollen mitochondria. Lectin histochemistry revealed that the cytoplasmic vacuoles in some distended Purkinje cells stained strongly with Canavalia ensiformis (ConA) agglutinin and weakly with Triticum vulgaris (WGA) and succinyl-WGA (S-WGA) agglutinin. The pattern of lectin binding only partially agreed with that reported in calves poisoned with Solanum fastigiatum, causing a presumed glycolipid storage disease. Apoptosis was not detected in neurons using a commercial deoxyuridine triphosphate nick-end labelling (TUNEL) method. The pathogenesis of the cerebellar lesions is unknown but the intoxication may have resulted from the inability of neurons, in particular Purkinje cells, to metabolise a plant toxin or cellular substrate.