Biomedical subjects
Publications and source records attributed to J Boomker.
The first outbreak of bothriocephalosis in common carp in South Africa is recorded. This condition was caused by Bothriocephalus acheilognathi, a pseudophyllid tapeworm not previously identified in this country. Methods to limit its spread are suggested.
This paper describes the light-microscopic appearance of both the erythrocytes and the thrombocytes and their developmental stages of catfish (Clarias gariepinus) and Mozambique bream (Sarotherodon mossambicus). Apart from some minor differences in the shape and staining affinities of the polychromatophilic erythrocytes, the erythrocytic series is similar in catfish and bream. The thrombocytes and the reactive stages of thrombocytes of both species are similar to those of birds. A possible mechanism of erythro- and thrombopoiesis is postulated.
Descriptions of the 1st, 2nd and 3rd instar larvae and the puparium of Kirkioestrus minutus are gives. First instar larvae, which have not previously been described, can be distinguished from other oestrid larvae by the ventral spinulation of segments IV-XII and the spinulation of the anal protuberance. Of 55 blue wildebeest examined in the Kruger National Park all but two 1-month-old and one 2-month-old animals were infested. First stage larvae are probably deposited in or on the nostrils and may develop within 30 days, initially in the nasal passages and then in the frontal sinuses to mature 3rd stage larvae. Development within the host appears to take longer during the cooler months of the year. Pupal periods very from approximately 32 days in early or late summer to more than 50 days in winter. Three of 6 blesbok examined at Badplaas in the eastern Transvaal were infested with 1st instar larvae only of K. minutus and it is suggested that blesbok may not be suitable hosts of this fly. Four black wildebeest in the Golden Gate National Park in the eastern Orange Free State were not infested.
Excessive mortalities were experienced in the bigger rainbow trout (Salmo gairdneri) at an efficiently managed trout farm. All tests for known toxins in the feed and water proved to be negative. A faecal Streptococcus which belongs to the Lancefield group D but which could not be identified as belonging to any of the recognized species within this group, was isolated from the spleens, livers and kidneys of affected fish. Pathogenicity studies with this organism proved it to be highly fatal to trout but not to Mozambique bream (Sarotherodon mossambicus), banded bream (Tilapia sparrmenii), carp (Cyprinus carpio) or largemouth bass (Micropterus salmoides). The isolation and biochemical characteristics of the organism are described. The symptoms, gross- and histopathology of this disease are described and discussed. The disease resembles a haemorrhagic septicaemia and appears to be associated with intensification and conditions of stress.
A new species of nematode. Cooperia connochaeti, was collected from cross-bred blue and black wildebeest at Krugersdorp (Transvaal), blue wildebeest Connochaetes taurinus (Burchell, 1823) from the Kruger National Park (Transvaal) and Lake Xhau (Botswana), as well as from impala Aepyceros melampus (Lichtenstein, 1812) at Malelane (Transvaal) and Pafuri (Kruger National Park). These nematodes are smaller than Cooperia pectinata Ransom, 1907, and their spicules, which are bifid in the distal third, are shorter (145-166 micron) than those of C. pectinata (240-280 micron). In addition, the lateral branches of the dorsal ray of C. connochaeti are directed ventrally and slightly anteriorly, while those of C. pectinata are directed posteriorly.
The haemopoietic organs of the catfish, Clarias gariepinus, and the Mozambique bream, Sarotherodon mossambicus, were studied. In both species the primary haemopoietic organs are the pronephros, the mesonephros and the spleen. The peritoneum and, particularly in catfish, the omentum are of secondary importance in haemopoiesis.
The history, clinical signs and pathological findings in a 9-year-old Labrador dog with an intracranial tumour, are described. The tumour conformed to the rare meningiothelial meningioma with focal ossification.
Brain lesions in 2 natural cases of canine encephalitozoonosis were studied by light and electron microscopy. Granulomatous reactions, associated with small vessels and capillaries, partly originated from extensive perithelial cell proliferation which ultimately produced the epithelioid cell component. Diffuse glial reactions apparently occurred in relation to the vasculitis. Lymphoid cells infiltrated the epithelioid and glial cell inflammation. Encephalitozoon in all its reproductive stages was identified as the aetiological agent, and ultrastructurally differentiated from Nosema on the basis that a single nucleus was observed. Viable organisms were present only within endothelial cells. Macrophages containing dead spores were usually seen around parasitized vessels and, less frequently, in the neuropil. Organisms, whether viable or non-viable, were never seen extracellularly at the ultrastructural level. Selected histochemical stains and electron microscopy were used to differentiate between viable and non-viable spores. Vasculitis is demonstrated as the underlying lesion of canine encephalitozoonosis affecting the brain and is suggested to be the basic factor in the pathogenesis of this disease.
Black grain mycetoma occurred in two horses, one a cross-bred pony and the other a Thoroughbred racehorse. Lesions were limited to wart-like growths in one case and a deep-seated girth gall in the other. In both cases the granules in the affected tissues were similar in pigmentation and structure to those produced by Curvularia geniculata in dogs. Since all the specimens were received in formalin, the causative fungus could not be isolated. These are the first cases of maduromycosis in animals to be recorded in South Africa.
Fascioloides magna from a Brahman heifer recently imported from the USA is recorded for the first time in South Africa. The pathological findings are briefly described. The possibility of this parasite becoming established in this country is also discussed.
A revision of the genus Impalaia Mönnig, 1924 forms the subject of this report. Besides the type species, Impalaia tuberculata Mönnig, 1924, there are 2 valid species, viz., I. nudicollis Mönnig, 1931 and I. okapiae (Van den Berghe, 1937). I. tuberculata longispiculata (Wetzel & Fortmeyer, 1960), I. somaliensis (Crovieri, 1929) and I. aegyptiaca Soliman, 1956 are synonymous with I. tuberculata. I. taurotragi (Le Roux, 1936) appears to be an aberrant form of I. nudicollis. A parasite/host checklist is included.
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