Studies on the host range of Eimeria chinchillae De Vos & Van der Westhuizen, 1968

A case of an Eimeria sp. with a lack of host specificity is reported. Eimeria chinchillae DeVos & Van der Westhuizen, 1968, originally described from the chinchilla, was successfully transmitted to seven other rodents, viz. Praomys (Mastomys) natalensis (Smith, 1847), Rhabdomys pumilio (Sparrman, 1784), white mice, Otomys irroratus (Brants, 1827), white rats, Mystromys albicaudatus (Smith, 1834) and Arvicanthis niloticus (Desmarest, 1822). Of these, the first four species were more susceptible to infection than the last three and showed symptoms of coccidiosis and even mortality after administration of 400,000 sporulated oocysts. Susceptible chinchillas were infected with oocysts obtained from P. (M.) natalensis, R. pumilio, white mice and white rats. In the chinchilla the endogenous stages were found only in the caecum but in P. (M.) natalensis, R. pumilio and white mice small numbers were also found in the small intestine. The prepatent period of the infection in chinchillas was 8 or 9 days as compared to 7 or 8 days in the new hosts. The oocysts discharged by these animals were indistinguishable from those passed by chinchillas.The journals have been scanned in colour with a HP 5590 scanner; 600 dpi. Adobe Acrobat v.11 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.

Immunogenicity and pathogenicity of three South African strains of Babesia bovis in Bos indicus cattle

A strain of Babesia bovis, which has been routinely used in the locally produced babesiosis vaccine for two decades and maintained by needle passage, was of low virulence and therefore safe, but it induced poor protection to challenge with two field isolates. Animals infected with this attenuated strain and subsequently challenged heterologously with a field strain were solidly immune when challenged later with a second field strain. The two field strains, though more virulent, conferred a high degree of immunity to heterologous challenge.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

C9orf72 plays a central role in Rab GTPase-dependent regulation of autophagy

A GGGGCC hexanucleotide repeat expansion in the first intron of the C9orf72 gene is the most common genetic defect associated with amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) (C9ALS/FTD). Haploinsufficiency and a resulting loss of C9orf72 protein function has been suggested as a possible pathogenic mechanism in C9ALS/FTD. C9ALS/FTD patients exhibit specific ubiquitin and p62/sequestosome-1 positive but TDP-43 negative inclusions in the cerebellum and hippocampus, indicating possible autophagy deficits in these patients. In a recent study, we investigated this possibility by reducing expression of C9orf72 in cell lines and primary neurons and found that C9orf72 regulates the initiation of autophagy. C9orf72 interacts with Rab1a, preferentially in its GTP-bound state, as well as the ULK1 autophagy initiation complex. As an effector of Rab1a, C9orf72 controls the Rab1a-dependent trafficking of the ULK1 initiation complex prior to autophagosome formation. In line with this function, C9orf72 depletion in cell lines and primary neurons caused the accumulation of p62/sequestosome-1-positive inclusions. In support of a role in disease pathogenesis, C9ALS/FTD patient-derived iNeurons showed markedly reduced levels of autophagy. In this Commentary we summarise recent findings supporting the key role of C9orf72 in Rab GTPase-dependent regulation of autophagy and discuss autophagy dysregulation as a pathogenic mechanism in ALS/FTD

Chemotherapy of Theileria parva lawrencei infections in cattle with halofuginone

Halofuginone lactate, given once orally at a dosage rate of 1,2 mg/kg body mass on the 1st, 3rd or 5th days of fever, resulted in the recovery of only 1 out of 5 splenectomized cattle. Three splenectomized animals, treated on the 1st as well as the 4th day of fever, recovered and were then carriers. Six untreated controls all died. The potential value of a chemotherapeutic agent for Theileria parva lawrencei infections in South Africa is discussed.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

The effect of tick control on the epidemiology of bovine babesiosis

The effect of tick control on the infection rates of Babesia bovis and Babesia bigemina are reported for 6 geographical regions in South Africa. Under conditions of poor tick control the situation for B. bovis as one of apparent enzootic instability in the 2 regions where its presence was recorded. Under similar conditions the situation for B. bigemina was generally stable. With good tick control B. bovis infection rates were reduced to very low levels, with minimal losses being recorded. In the case of B. bigemina, good tick control reduced the infection rates in cattle but increased the risk of outbreaks. We concluded that, unless regular dipping is necessary to limit damage done by ticks per se, control of ticks is not justified economically as a means of minimizing the risks of babesiosis outbreaks in South Africa.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Studies on a bovine Babesia transmitted by Hyalomma marginatum rufipes Koch, 1844

A Babesia sp. was recently observed in Hyalomma marginatum rufipes and found to be transmissible to bovines. Further observations were carried out on this parasite and a study made of the morphology of stages in both erythrocytes and tick haemolymph. Apart from Babesia divergens intra-erythrocytic parasites were not readily distinguishable from bovine Babesia spp. Merozoites in tick haemolymph morphologically resembled those of Babesia bigemina, but they were significantly larger. This Babesia sp. proved to be highly infective for adult H. m. rufipes, with transmission taking place transovarially and next generation nymphae and adults transmitting the infection. Features of the infection were its very low pathogenicity, even in splenectomized animals, and the tendency of parasitized erythrocytes to accumulate in capillaries. Serologically, this species could be differentiated from Babesia bigemina, B. divergens, B. bovis and B. major. A serological survey of 25 farms showed a wide distribution of this species in South Africa and its high rate of transmission on most properties. It was concluded that this is a true but hitherto undescribed bovine Babesia sp. and the name Babesia occultans n. sp. is proposed.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

The isolation of Theileria? taurotragi in South Africa

In 3 out of 4 attempts strains of a Theileria sp. of low virulence were isolated in the laboratory by feeding adult Rhipicephalus appendiculatus collected from the field on susceptible cattle. One of the strains, previously identified as Theileria? taurotragi (Tzaneen), was found to be serologically cross-reactive with the other 2 strains. It was concluded that T.? taurotragi is prevalent in South Africa in those parts where the vector exists. Infection was characterized by a transient fever and small numbers of macroschizonts and piroplasms. Subinoculation of the infection with small volumes of blood proved to be difficult.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Observations on the transmission of Theileria mutans in South Africa

Four isolates of Theileria mutans obtained from geographically distant parts of South Africa by sub inoculation of infected blood were found to be readily transmitted by the bont tick Amblyomma hebraeum. All attempts to transmit these isolates with Rhipicephalus appendiculatus were unsuccessful. Possible explanations for differences between these results and those reported by earlier workers in this country are discussed.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Uterine coccidiosis of the impala caused by Eimeria neitzi spec. nov.

Four cases of uterine coccidiosis showing readily-detectable macroscopic lesions were collected over a period of two years during which 451 female impalas [Aepyceros melampus (Lichtenstein, 1812)] were examined post mortem in the Kruger National Park. This report includes descriptions and illustrations of macroscopic and microscopic lesions and various developmental stages of sexual reproduction of the parasite. Because of certain morphological features of the oocysts, the causative organism was determined by the authors to be a new Eimeria for which they propose the name Eimeria neitzi. This coccidium parasitizes mainly the distal portions of the uterine glands and the adjacent surface epithelium. Another distinctive feature of Eimeria neitzi is that sporogony occurs while the oocysts are still within host cells. On the basis of present knowledge, uterine coccidiosis is of very low incidence among impalas in the Kruger National Park and probably of little herd significance under the prevailing veld conditions. Its effect on reproduction was not determined.The journals have been scanned in colour with a HP 5590 scanner; 600 dpi. Adobe Acrobat v.11 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.

Eimeria chinchillae De Vos & Van der Westhuizen, 1968 and other Eimeria spp. from three South African rodent species

Eimeria chinchillae De Vos & Van der Westhuizen, 1968, an organism originally described from the chinchilla and subsequently shown to be transmissible to other rodents, was found to occur naturally in Rhabdomys pumilio (Sparrman, 1784) in South Africa. The morphology of the oocysts, the site of development of the endogenous stages and the prepatent period of the infection were similar to those of E. chinchillae obtained from chinchillas and transmitted experimentally to R. pumilio. The identity of the organism was confirmed by the successful infection of chinchillas. Three additional Eimeria spp. were found in R. pumilio. Oocysts of Eimeria pumilioi n. sp. measured 18 by 12 µ, those of Eimeria rhabdomyis n. sp., 13 by 12 µ and those of Eimeria pretoriensis n. sp., 24 by 19 µ. Two Eimeria spp. were also found in Praomys (Mastomys) natalensis (Smith, 1834). Oocysts of Eimeria mastomyis n. sp. measured 27 by 21 µ and those of Eimeria theileri n. sp. 20 by 17 µ. A single Eimeria sp., Eimeria otomyis n. sp., was found in Otomys irroratus (Brants, 1827). The oocysts measured 20 by 15 µ.The journals have been scanned in colour with a HP 5590 scanner; 600 dpi. Adobe Acrobat v.11 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format..mn201