Population Genetic Analysis and Sub-Structuring of Theileria annulata in Sudan

Theileria annulata, which causes tropical theileriosis, is a major impediment to improving cattle production in Sudan. Tropical theileriosis disease is prevalent in the north and central regions of Sudan. Outbreaks of the disease have been observed outside the known endemic areas, in east and west regions of the country, due to changes in tick vector distribution and animal movement. A live schizont attenuated vaccination based on tissue culture technology has been developed to control the disease. The parasite in the field as well as the vaccine strain need to be genotyped before the vaccinations are practiced, in order to be able to monitor any breakthrough or breakdown, if any, after the deployment of the vaccine in the field. Nine microsatellite markers were used to genotype 246 field samples positive for T. annulata DNA and the vaccine strain. North and central populations have a higher multiplicity of infection than east and west populations. The examination of principal components showed two sub-structures with a mix of all four populations in both clusters and the vaccine strain used being aligned with left-lower cluster. Only the north population was in linkage equilibrium, while the other populations were in linkage disequilibrium, and linkage equilibrium was found when all samples were regarded as single population. The genetic identity of the vaccine and field samples was 0.62 with the north population and 0.39 with west population. Overall, genetic investigations of four T. annulata populations in Sudan revealed substantial intermixing, with only two groups exhibiting regional origin independence. In the four geographically distant regions analyzed, there was a high level of genetic variation within each population. The findings show that the live schizont attenuated vaccine, Atbara strain may be acceptable for use in all Sudanese regions where tropical theileriosis occurs.

Epidemiology and molecular characterization of Theileria annulata in cattle from central Khyber Pakhtunkhwa, Pakistan

Theileria annulata is a tick-borne hemoprotozoan parasite responsible for tropical theileriosis in the bovine population, which causes substantial economic losses to the livestock sector. The present study has investigated, characterized, and shaped epidemiologic and phylogenetic profiles of T. annulata infection in the cattle population of central Khyber Pakhtunkhwa, Pakistan. A total of 600 blood samples were collected from cattle. Microscopy and PCR (18S rRNA taxonomic marker) assays were performed to detect T. annulata infection in cattle from the study area. The overall relative prevalence rates of T. annulata in the examined cattle population were 12.8% (microscopy) and 23.7% (PCR). District-wise analysis (microscopy/PCR) showed that cattle from district Mardan were found more infected (16.0%/28.0%), as compared to cattle from district Charsadda (13.5%/25.5%) and district Peshawar (9.0%/17.5%). Based on host demographic and ecological parameters analysis, theileriosis was found to be higher in young, female, crossbred, freely grazing, tick-infested, and irregular/no acaricides treated cattle. The univariate logistic analysis showed that host age, tick infestation, acaricides use, and feeding method were significant risk factors (P<0.05) whereas multivariate analysis indicated that host age, gender, tick infestation, acaricidal application, and feeding method were potential risk factors (P<0.05) for tropical theileriosis in the cattle population. Phylogenetic and sequence analysis showed that T. annulata 18S rRNA isolates shared homology and phylogeny with other isolates from Asia and Europe. This study has addressed the epidemiology and phylogeny of T. annulata circulating in bovid in the study area where gaps were still present. These findings will serve as a baseline and will facilitate future large-scale epidemiological investigations on tropical theileriosis in the cattle population at a national level.

Bovine Cerebral Theileriosis: First Molecular Confirmed Report in Cross Bred Cattle Calf in India

Bovine tropical theileriosis caused by Theileria annulata, is a serious constraint to Indian dairy industry with more fatal infections in exotic cattle and substantial losses to cross-bred and indigenous zebu cattle. The present communication is to place on record the first report of molecular based confirmed case of cerebral theileriosis caused by T. annulata coupled with its morphological detection, clinical manifestations, haematological alterations and therapeutic management in a cross bred cattle calf from India. After preparation of peripheral thin blood smear from cross bred cattle calf at the site of collection and fixation with methanol, blood sample brought to Department of Veterinary Parasitology, College of Veterinary Science and A.H, Jabalpur and stained by standard protocol for Giemsa staining. Genomic DNA was isolated from the collected blood sample using QIAamp® DNA blood mini kit following the manufacturer’s recommendations and PCR was performed. The cross bred cow calf revealed high rise in temperature (105.5°F), increased heart rate, labored breathing with seromucous nasal discharge, enlargement of prescapular lymph node and animal exhibited tonic clonic convulsions in response to any sudden noise. Giemsa stained thin blood smear revealed intraerythrocytic piroplasm and Koch blue bodies of T. annulata within the cytoplasm of lymphocytes. The species of Theileria was confirmed by molecular amplification of genomic DNA as T. annulata.

First report of Theileria annulata in Nigeria: Findings from cattle ticks in Zamfara and Sokoto States

Background Ticks and tick-borne pathogens (TBPs) represent a significant economic burden to cattle farming in sub-Saharan Africa including Nigeria. However, in the northern part of this country, where the largest livestock population resides, little is known about the contemporary diversity of ticks and TBPs. This area is particularly vulnerable to climate change, undergoing marked transformation of habitat and associated flora and fauna that is also likely to include ticks. This study aimed to document the occurrence of tick species and Apicomplexan TBPs in cattle from north-western Nigeria. Methods In 2017, ticks were collected from cattle in Zamfara and Sokoto States and identified morphologically. Additionally, a subset of ticks was screened molecularly for the detection of apicomplexan DNA. Results A total of 494 adult ticks were collected from 80 cattle in Zamfara and 65 cattle in Sokoto State. Nine tick species were encountered, among which the presence of one, Hyalomma turanicum, had not previously been recorded in Nigeria. Hyalomma rufipes was the most prevalent tick infesting cattle in Zamfara State (76%), while Hyalomma dromedarii was the most prevalent in Sokoto State (44%), confirming the widespread transfer of this species from camels onto livestock and its adaptation to cattle in the region. Of 159 ticks screened, 2 out of 54 (3.7%) from Zamfara State and 29 out of 105 (27.6%) from Sokoto State harboured DNA of Theileria annulata, the agent of tropical theileriosis. Conclusions This study confirms the presence of a broad diversity of tick species in cattle from north-western Nigeria, providing the first locality records for Zamfara State. The occurrence of H. turanicum indicates a distribution of this tick beyond northern Africa. This study provides the first report for T. annulata in Nigerian ticks. Given its enormous burden on livestock farming in north Africa and across Asia, further investigations are needed to better understand its epidemiology, vector transmission and potential clinical significance in cattle from northern Nigeria and neighbouring Sahelian countries.

Theileria annulata Subtelomere-Encoded Variable Secreted Protein-TA05575 Binds to Bovine RBMX2

Tropical theileriosis is the disease caused by tick-transmitted apicomplexan parasite Theileria annulata, which has ability to transform bovine leukocytes, including B cells, macrophage cells, and dendritic cells. The T. annulata transformed cells are characterized as uncontrolled proliferation and shared some cancer-like phenotypes. The mechanism of the transformation by T. annulata is still not understood well. In previous reports, the subtelomere-encoded variable secreted proteins (SVSP) of T. parva were considered to contribute to phenotypic changes of the host cell, but the role of SVSP of T. annulata in host-pathogen relationship remains unknown. In the present study, a member of SVSP family, TA05575 of T. annulata was selected as the target molecule to analyze its expression profiles in different life cycle stages of T. annulata by qPCR and investigate its subcellular distribution of different passages of T. annulata transformed cells using confocal experiments. From the results, the transcription level of TA05575 at schizont stage was significantly higher than the other two life stages of T. annulata, and the protein of TA05575 was mainly distributed in nucleus of T. annulata infected cells. In addition, the potential proteins of host cells interacting with TA05575 were screened by Yeast-two hybrid system. The results of Co-IP experiment confirmed that TA05575 interacted with RBMX2-like protein that participated in transcription regulation of cells. In addition, a novel BiFC assay and flow cytometry were carried out, and the results further revealed that TA05575-RBMX2-like pair was directly interacted in cell context. Moreover, this interacting pair was found to distribute in intracellular compartments of HEK293T cells by using confocal microscopy. The results of the present study suggest that TA05575 may contribute for cells transformation due its distribution. According to the function of RBMX2, the interaction of TA05575 and RMMX2-like will provide a new information to further understand the mechanisms of cells transformation by T. annulata.

Primary Tick-Borne Protozoan and Rickettsial Infections of Animals in Turkey

Parasitic diseases caused by ticks constitute a barrier on global animal production, mainly in tropical and subtropical regions. As a country with a temperate and subtropical climate, Turkey has topography, climate, and pasture resources, and these resources are suitable for animal breeding and parasite–host–vector relationships throughout the country. This geography restricts the regulations on animal movements in the southeastern and eastern Anatolia because of the close contact with the neighboring states. The livestock resources in Turkey are regulated by strong foundations. Almost 30% of the agriculture-based gross domestic product is provided by the livestock industry. Parasitic diseases arising from ticks are endemic in Turkey, and they have a significant impact on the economy and animal health, particularly for ruminants. The main and economically-important tick-borne diseases (TBDs) suffered by animals include theileriosis, babesiosis, hepatozoonosis, and cytauxzoonosis caused by protozoa, and anaplasmosis and ehrlichiosis caused by rickettsiae. The most common hemoprotozoan and rickettsial agents are Anaplasma marginale, Anaplasma ovis, Anaplasma phagocytophilum, Anaplasma platys, Babesia bigemina, Babesia caballi, Babesia ovis, Cytauxzoon felis, Ehrlichia canis, Hepatozoon canis, Theileria annulata and Theileria equi. These diseases are basically controlled through treatment and measures for tick control. Vaccination can be performed for only tropical theileriosis caused in Turkey. We reviewed the studies published in domestic and international journals to gather epidemiological data regarding the major TBDs suffered by animals in Turkey.