Research Articles (Laboratory for Microscopy and Microanalysis)

Permanent URI for this collectionhttp://hdl.handle.net/2263/5931

A collection containing some of the full text peer-reviewed/ refereed articles published by researchers from the Laboratory for Microscopy and Microanalysis

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Now showing 1 - 9 of 9

Nemaline myopathy in a six-month-old pomeranian dog
(Medpharm Publications, 2022) Bester, Elizabeth G.; Kitshoff, Adriaan Mynhardt; Botha, W.J.; Van Wilpe, Erna; Du Plessis, Lizette; Williams, J.H. (June Heather)
Nemaline myopathy - a clinically and genetically complex heterogenous group of disorders - is described uncommonly in humans and rarely in animals, and is characterised by progressive muscle weakness. The diagnosis is confirmed by histological and/or ultrastructural identification of subsarcolemmal, thread-like, rod-shaped structures called nemaline rod bodies within more than 40% of skeletal muscle fibres. These rods contain the Z-line protein, α-actinin, that can be effectively stained in skeletal muscles using Gomori or Masson trichrome and negatively stained with periodic acid-Schiff. Similar rod-like bodies have been found in smaller numbers in dogs with endocrine disorders and occasionally in other conditions in humans. This report is of a six-month-old Pomeranian dog which had progressive exercise intolerance over a two-month period associated with severe disuse muscle atrophy of the thoracic limbs, as well as gradual pelvic limb weakness and regurgitation of food. Baseline diagnostics ruled out endocrinopathies and after histological and ultrastructural evaluation of thoracic limb muscles and nerve biopsies confirmed nemaline myopathy. The clinical course, diagnostic test results, ultrastructure of skeletal muscle and peripheral nerve, gross necropsy findings and histopathology using various stains are described and illustrated.
Metastatic uterine adenocarcinoma in a sable antelope (Hippotragus niger)
(MDPI, 2022-07-04) Van der Weyden, Louise; Bezuidenhout, Anien; Van Wilpe, Erna; O’Dell, Nicolize; nicolize.odell@up.ac.za
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.
Ultrastructure of Sarcocystis bertrami sarcocysts from a naturally infected donkey (Equus asinus) from Egypt
(Cambridge University Press, 2016-01) Dubey, Jitender P.; Van Wilpe, Erna; Verma, Shiv Kumar; Hilali, M.
There is considerable confusion concerning Sarcocystis species in equids. Little is known of Sarcocystis infections in donkeys (Equus asinus). Here we describe the structure of Sarcocystis bertrami-like from the donkey by light microscopy (LM) and transmission electron microscopy (TEM). Nineteen sarcocysts from the tongue of a donkey from Egypt were studied both by LM and TEM. By LM, all sarcocysts had variably shaped and sized projections on the sarcocyst walls, giving it a thin-walled to thick-walled appearance, depending on individual sarcocyst and plane of section. By TEM, sarcocysts walls had villar protrusions (vp) of type 11. The sarcocyst wall had conical to slender vp, up to 6 µm long and 1 µm wide; the vp were folded over the sarcocyst wall. The total thickness of the sarcocyst wall with ground substance layer (gs) was 1-3 µm. The vp had microtubules (mt) that originated deeper in the gs and continued up to the tip. The apical part of the vp had electron dense granules. The mt were configured into 3 types: a tuft of electron dense mt1 extending the entire length of the vp with a tuft of medium electron dense mt2 appearing in parallel, and fine mt3 present only in the villar tips. The gs was mainly smooth with few indistinct granules. All sarcocysts were mature and contained metrocytes and bradyzoites. Bradyzoites were approximately 11-15 × 2-3 µm in size with typical organelles.
Sindbis and Middelburg old world alphaviruses associated with disease in horses, South Africa
(Centers for Disease Control & Prevention, 2015-12) Van Niekerk, Stephanie; Human, Stacey; Williams, June Heather; Van Wilpe, Erna; Pretorius, Marthi Andréa; Swanepoel, Robert; Venter, Marietjie
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.
Sarcocystis mehlhorni n. sp. (Apicomplexa : Sarcocystidae) from the black-tailed deer (Odocoileus hemionus columbianus)
(Springer, 2015-12) Calero-Bernal, Rafael; Verma, Shiv Kumar; Cerqueira-Cezar, Camila K.; Schafer, Laurence M.; Van Wilpe, Erna; Dubey, Jitender P.
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 oreamni, n. sp. (Apicomplexa : Sarcocystidae) from the mountain goat (Oreamnos americanus)
(Springer, 2015-11) Calero-Bernal, Rafael; Van Wilpe, Erna; White, Kevin; Verma, Shiv Kumar; Cerqueira-Cezar, Camila K.; Dubey, Jitender P.
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 protusions (vp), type 29. The vp had 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 Canidae family as their definitive host.
Sarcocystis heydorni, n. sp. (Apicomplexa : Sarcocystidae) with cattle (Bos taurus) and human (Homo sapiens) cycle
(Springer, 2015-11) Dubey, Jitender P.; Van Wilpe, Erna; Calero-Bernal, Rafael; Verma, Shiv Kumar; Fayer, Ronald
Cattle (Bos taurus) are intermediate hosts for four species of Sarcocystis, S. cruzi, S. hirsuta, S. hominis, and S. rommeli. Of these four species, mature sarcocysts of S. cruzi are thin-walled (< 1μm) 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 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 Sarcocystis hominis, both calves were coinfected with a Sarcocystis species that had a thinwalled sarcocysts, distinct from Sarcocystis 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 2 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, 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.
Shuni virus as cause of neurologic disease in horses
(Coordinating Center for Infectious Diseases, Centers for Disease Control and Prevention, 2012-02) Van Eeden, Charmaine; Williams, June Heather; Gerdes, Truuske G.H.; Van Wilpe, Erna; Viljoen, Adrienne; Swanepoel, Robert; Venter, Marietjie
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.
Use of Ir192 interstitial brachytherapy for an equine malignant dermal schwannoma
(South African Veterinary Association, 2009-12) Saulez, Montague Newton; Voigt, A.; Steyl, Johan Christian Abraham; Van Wilpe, Erna; Kotzen, J.; Daniels, F.; montague.saulez@up.ac.za
A 10-year-old Hanoverian mare was evaluated for a right buccal swelling that recurred 3 months following surgical resection. Ultrasonographic examination showed a broadly pedunculated subcutaneous mass at the level of 106-109 and 406-409 cheek teeth associated with an erosive mucosal lesion on the inside of the cheek. Histological examination of a biopsy specimen revealed a well-demarcated, malignant, dermal schwannoma. Following subcutaneous placement of platinum coated Ir192 wires under general anaesthesia, low-dose radiation of 5 gray per day was delivered for 14 days. Short-term complications included loss of patency of the right nasolacrimal duct, erythema, dermatitis, leukotrichia and left-sided deviation of the muzzle. Ten months later, there has been no tumour recurrence. Findings suggest that the use of interstitial brachytherapy should be considered for a malignant, dermal schwannoma that has recurred or is not amenable to surgery.

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