Tick- Borne Diseases: 1-Incidence of Babesiosis Amongst Livestock During 2013-2018 At Alkadaru Teaching Veterinary Hospital, Bahri, Khartoum North

During 2013-2018 A total of 3457 different animals were admitted to the Teaching Veterinary Hospital (TVH), College of veterinary Medicine, University of Bahri . Blood samples were taken from the ear vein and smears were prepared, stained and examined in the laboratory for babesia parasite. A total of 687 (19.87%) samples were positive out of which 433(63.02%) were cattle,55(8.01%)sheep,177(25.76%)goat, 13 (1.89%) camel , 5(0.72%) horses, one(0.15%) donkey, one(0.15%)deer , and 2(0.30%) dogs . Compared to other years, the positive cases of babesosis were higher, 337 (49.05%) during 2017. In cattle, during the study period there was fluctuation amongst different seasons comparing between different years. However, comparing between seasons, generally the prevalence of babesia was significantly higher during summer (p˂0.05) and autumn (p˂0.01).In sheep, comparing between different years there was fluctuation amongst different seasons. However, comparing between seasons, generally the prevalence of babesia was significantly higher during autumn (p˂0.05). In goats, between years there were fluctuations for babesia prevalence in different seasons, while comparing between seasons, winter had significantly (p˂0.05) higher values. It is concluded that, babesiosis is one of the serious health problems in North Bahri that may negatively affect animals’ production mainly cattle and goats. This study also revealed that, babesia showed seasonal fluctuations in its occurrence. Restrict tick control strategies should be implemented by the veterinary authorities . A seroprevalence study should be performed for genetic characterization of babesia in the area. Moreover, studies to investigate drug resistance and epidemiological studies should be conducted amongst animal labors and owners.

Tick vitellogenin receptor reveals critical role in oocyte development and transovarial transmission of Babesia parasite

A cDNA encoding the vitellogenin receptor of the ixodid tick, Haemaphysalis longicornis Neumann (HlVgR) was cloned and characterized. The full-length cDNA is 5631 bp, including an intact ORF encoding an expected protein with 1782 amino acids. The deduced amino acid sequence of the HlVgR cDNA revealed two ligand-binding domains with four class A cysteine-rich repeats in the first domain and eight in the second domain similar to those of insect VgRs. The immunoblot analysis detected ~197 kDa protein in both tick ovary and egg. The developmental expression profile demonstrated that HlVgR mRNA exists throughout the ovarian development, and the transcriptional level is especially high in the previtellogenic period. Immuno electron microscopy analysis demonstrated that the localization of HlVgR is detected on the external surface of oocyte plasma membrane. RNAi showed that eggs of HlVgR dsRNA-injected adult ticks had not developed into fully mature oocytes and laid abnormal eggs. The Babesia parasite DNA was not detected in the eggs of HlVgR dsRNA-injected tick that fed on Babesia gibsoni infected dog, whereas it was detected in the eggs of PBS-injected ticks and noninjected ticks. Expression of HlVgR was increased by the vitellogenic hormone 20-hydroxyecdysone. These results indicate that HlVgR, which is produced by the developing oocytes, is essential for Vg uptake, egg development in the H. longicornis tick, and transovarial transmission of Babesia parasites.