Bovine Theileriosis Research Articles

First report of oriental theileriosis in the Intermediate Zone, Sri Lanka: Is Theileria orientalis type 7 always apathogenic?

PurposeTheileriosis in cattle has a significant economic implication for dairy production globally. Thus, it is crucial to investigate the prevalence of bovine theileriosis, the causative agent and genotypes of Theileria species in dairy cattle in the Kurunegala District in the Intermediate zone, where the third largest population of dairy cattle in Sri Lanka is present and experienced a substantial reduction in the cattle population recently. MethodsSixty blood samples and background data were collected from three dairy farms in Galpokuna (n = 20), Koulwewa (n = 20), and Andigama (n = 20) areas. Haematocrit was used to identify anaemia while Giemsa-stained blood smears demonstrated the presence of piroplasms. A Fisher's Exact Test (p < 0.05) compared the prevalence of infection among age groups and farms. PCRs using species-specific primers designed to amplify regions of MPSP and 18 s rRNA genes followed by sequencing of selected amplicons allowed phylogeny of the species detected. ResultsAll three farms had semi-intensive farming practices keeping animals in a ‘closed’ setup with limited movement. Theileriosis prevalence in dairy cattle was 55.0 % with no difference among the farms (Koulwewa: 65.0 %, Galpokuna: 50.0 %, Andigama: 50.0 %). One-third of the cattle (33.3 %) were anaemic based on haematocrit results but most showed mild anaemia. Anaemia was significantly higher in calves (45.0 %) than in adults (25.0 %; χ2 = 5.743; p = 0.03) tested positive for theileriosis. None of the animals showed any other signs of theileriosis. PCR revealed the presence of both T. orientalis (pathogenic or benign) and T. annulata (pathogenic). The sequencing data revealed that the T. orientalis genotype present in Kurunegala District is type 7. ConclusionThis is the first report on T. orientalis and T. annulata in dairy cattle in the Intermediate zone of Sri Lanka. The type 7 of T. orientalis was more common showing severe anaemia in calves while mild anaemia or no anaemia in adults and sub-adults. In immunologically intact animals, the reported genotype of the parasite can persist asymptomatically for life, occasionally causing a relapse, particularly under stressful conditions like pregnancy, lactation, and rapid changes in environmental conditions. However, the susceptibility of calves for pathogenic and apathogenic genotypes of T. orientalis and the carrier status of asymptomatic animals needs further investigation.

ROLE OF CALCIUM, VITAMIN D AND VITAMIN D RECEPTORS IN PATHOGENESIS OF THEILERIOSIS IN CATTLE

The present study was conducted to examine the levels of calcium, vitamin D and Vitamin D receptor (VDR) in naturally-infected cattle with bovine theileriosis for understanding their role in the pathogenesis of the disease. A total of 100 cattle were selected, based on clinical signs in three districts of Punjab, Pakistan. Fifteen healthy animals were kept as negative controls. Blood samples were collected in EDTA containing vacutainer for Giemsa staining to examine the intra-erythrocytic forms of Theileria. Serum was collected in yellow top vacutainer for Vitamin D and calcium determination while plasma was also extracted for the determination of VDR levels from EDTA containing tubes. Giemsa staining showed 23% positive animals by microscopy while 32% of animals were positive by PCR. Levels of calcium, vitamin D, and VDR were very significantly (P&lt;0.001) lower in Theileria affected animals in comparison to negative control. The results revealed that calcium, Vitamin D, and VDR might have a role in pathogensis of bovine theileriosis. Keywords: Bovine Tropical Theileriosis; Calcium; Vitamin D; VDRs; T.annulata

A novel recombinant Theileria annulata surface protein as an antigen in indirect enzyme-linked immunosorbent assay for the serological diagnosis of tropical theileriosis.

Theileria annulata infection in cattle causes major economic losses in livestock production in many Central Asian countries, including the southern region of Kazakhstan. This study aimed to obtain a recombinant T. annulata surface protein (TaSP) and to investigate its possible use as an antigen in an indirect enzyme-linked immunosorbent assay (ELISA) for the serological diagnosis of bovine theileriosis. Recombinant TaSP was obtained by cloning a polymorphic region of the TaSP gene, expressing it in Escherichia coli strain BL21, and purifying it by metal chelating chromatography. An indirect ELISA using recombinant TaSP as an antigen was developed and evaluated for the detection of T. annulata-specific antibodies in plasma samples from 69 cows polymerase chain reaction (PCR)-positive or PCR-negative for T. annulata and/or Theileria orientalis from southern Kazakhstan. The obtained recombinant protein had a molecular weight of 32 kDa, and mass spectrometry analysis of the purified protein identified it as a fragment of the surface protein of T. annulata. Initial testing of 69 field plasma samples from cattle showed that the results of indirect ELISA using TaSP as an antigen agreed substantially with those of T. annulata PCR (κ: 0.78). The relative sensitivity and specificity of indirect ELISA were 88.7% and 100%, respectively, using PCR as a reference. There was no evidence of cross-reaction with T. orientalis. Initial results using recombinant TaSP as an antigen in indirect ELISA are promising and support the widespread use of this assay for routine diagnosis and T. annulata seroprevalence studies in cattle in Kazakhstan and possibly neighboring countries.

Biochemical, Molecular, Postmortem and Histopathological Characterization of Bovine Theilerioses at Different Stages of Production and Reproduction

Theilerosis is the most important common vector (Tick) born and hemoprotozoan diseases (TBDS) which pose a serious threat to the livestock population in terms of mortality, reduced milk yield and lowered draft power. The disease is having impact on biochemistry and systemic functions affecting at different stages of production and reproduction of dairy cattle as well as there is lack of accurate diagnosis of this disease. A total 1900 cases were suspected for theileriosis on the basis of clinical signs and total 950 cases were found positive for theileriosis on the basis of blood smear examination. As per the stages of pregnancy and lactation, the cases were classified as cows in early pregnancy, cows in late pregnancy, cows in post parturient stage, cows in early and late lactation period. Biochemical alterations like increased AST, ALT and BUN level indicating liver and kidney dysfunctions in all the groups and significantly higher in post parturient group. The serum phosphorus, calcium and magnesium level decreased in all the affected groups and mostly in late pregnancy period and post parturient stage indicating metabolic disturbances during the disease which were aggravated during theileriosis. Through molecular diagnosis 114 cows (65.51%) were found positive for T. annulata and 41 cows (22.9%) were found positive for T. orientalis and 19 cows (10.9%) were found positive for both Theileria annulata and Theileria orientalis. Phylogenetic analysis revealed the accession number for Theileria annulata was OQ230445 which is having 100% similarity with puri isolate and 98% similarity with Khorda isolate and the accession number for T. orientalis was OQ 230446 having 85% similarity with Khorda isolate. On necropsy, the animals were weak, debilitated with atrophy of the muscles. In some cases, the liver was enlarged, markedly congested and in some cases yellowish tinged surface and cut edges with distension of gall bladder was evident. Abomasal ulcers were distinct and considered as pathognomonic. On histopathological examination, the liver revealed necrosis of hepatocytes with sinusoidal congestion and infiltration of mononuclear cells. In lymphnode, there was depletion of lymphocytes in lymphoid follicles with congestion and haemorrhage. Pulmonary edema was also evident in few cases. The combined approach involving biochemical, molecular, Post-mortem and histopathological characters were found to be fruitful in diagnosis of the bovine theileriosis at different stages of production and reproduction with optimum specificity.

The interplay of cytokines in bovine tropical theileriosis: a mini review.

Studying cytokine profiling in Theleria annulata infection enhances our understanding of how the immune response unfolds, the intricate interactions between the host and the parasite, the strategies employed by the parasite to evade the immune system, and potential avenues for developing treatments. The generation of pro-inflammatory cytokines plays a pivotal role in the immune response against T. annulata infection. Elevated concentrations of these cytokines potentially contribute to the manifestation of clinical symptoms associated with the disease, such as fever, anemia, exophthalmia, and weight loss. The production of anti-inflammatory cytokines potentially serves as a regulatory mechanism for the immune response, preventing the development of severe disease. Nevertheless, in animals afflicted by T. annulata infection, there is often a notable decrease in the levels of these cytokines, suggesting that they may not be as effective in mitigating the disease as they are in uninfected animals. This knowledge can be harnessed to develop improved diagnostic methods, treatments, and vaccines for tropical theileriosis. The objective of this current mini review is to achieve the same goal by consolidating the available knowledge of cytokine interactions in Bovine Tropical Theileriosis (BTT).

Phenology and habitat associations of the invasive Asian longhorned tick from Ohio, USA.

Geographically expanding and invading ticks are a global concern. The Asian longhorned tick (ALT, Haemaphysalis longicornis) was introduced to the mid-Atlantic US between 2010 and 2017 and recently invaded Ohio, an inland state. To date, ALTs in the US have been associated with livestock exsanguination and transmission of the agent of bovine theileriosis. To inform management, studies describing tick ecology and epidemiology of associated disease agents are critical. In this study, we described phenology, habitat and host associations, and tested for agents of medical and veterinary concern at the site of the first known established ALT population in Ohio, where pesticide treatment was applied in early fall 2021. In spring-fall 2022, we sampled wildlife (small mammals) and collected ticks from forest, edge, and grassland habitats. We also opportunistically sampled harvested white-tailed deer at nearby processing stations and fresh wildlife carcasses found near roads. Field-collected ALTs were tested for five agents using real-time PCR. We found that ALT nymphs emerged in June, followed by adults, and concluded with larvae in the fall. ALTs were detected in all habitats but not in wildlife. We also found a 4.88% (2/41) prevalence of Anaplasma phagocytophilum across ALT adults and nymphs. Host and habitat associations were similar to other studies in the eastern United States, but two potential differences in phenology were identified. Whether ALTs will acquire more endemic disease agents requires further investigations. Our findings provide the first evidence regarding ALT life history from the Midwest region of the United States and can inform exposure risk and guide integrated management.

Development of Low-Serum Culture Media for the in Vitro Cultivation of Theileria annulata S15 Cell Line.

The production of bovine theileriosis vaccine involves in vitro cultivation of Theileria annulata schizont-infected cell lines. Fetal bovine serum (FBS) is commonly used in animal cell culture, including the Theileria cell line. However, we aimed to reduce the amount of serum needed for cell culture by modifying the Stoker culture medium with supplements such as excretion factor and serum substitutes. To evaluate the effectiveness of these modifications, techniques such as cell counting, cell viability assays, and genomic analysis were employed in the Parasitic Vaccines Production Department of Razi institute of Iran, from 2020 to 2022. Statistical analysis was used to compare the results of different experimental conditions. The three experimental media were as effective as the commonly used 10% Stoker medium in supporting the growth and viability of cells. The significant reduction in the required amount of serum and the remarkable cell growth achieved by using defined serum replacements for the production of cell culture media is a significant step towards the preparation of a proper cell culture medium for the production of bovine Theileriosis vaccine.

Epidemiology, Clinical Signs, and Risk Factors Associated with Theileriosis in Australian Cattle (2006-2022).

For over a decade, bovine anaemia caused by Theileria orientalis Ikeda has been a significant disease in the Australian cattle industry. In this study, we conducted a spatial and temporal analysis of theileriosis in Australia using historic data from submissions to the New South Wales Department of Primary Industries (NSW DPI) from 2006 to 2022, where herd history, clinical signs, and PCR results were available. Since the first detections of bovine theileriosis in the Sydney area in 2006, the disease spread north- and southward and is now endemic to the southeast coast of Australia, closely mirroring the distribution of the principal vector Haemaphysalis longicornis. Across all years, the prevalence of the Ikeda genotype was 88%, while the prevalence of the benign Chitose and Buffeli genotypes was 55% and 38%, respectively. The majority of submissions were from beef cattle in coastal NSW, with anaemia, fever, jaundice, abortion, and lethargy the most frequently reported clinical signs. Transportation was identified as the major risk factor for disease. Until 2015, the majority of cases were reported in adult cattle, while in later years, calves made up the majority of cases, most likely due to the widespread acquisition of immunity in adults. Calves were significantly more likely to present with diarrhoea, lethargy, and anaemia, and to suffer mortality, while adults were significantly more likely to present with jaundice. Instances of abortion were observed to be significantly associated with beef cattle. The relationship between the level of parasitaemia and anaemia revealed a strong negative correlation for all animals examined.

Haematobiochemical alterations in cattle infected with Bovine tropical theileriosis in and around Tirupati district

Haematobiochemical alterations in cattle infected with Bovine tropical theileriosis in and around Tirupati district

Dry LAMP: A point of care diagnostics for diagnosis of bovine tropical theileriosis.

Theileriosis is an important tick-bome hemoprotozoan disease of cattle which causes severe economic loss due to morbidity and mortality. A diagnostic test having high sensitivity, specificity and easy application at the field level is the need of the hour. In this regard Loop-mediated isothermal amplification (LAMP) is proven to be a sensitive, easy and time efficient method. One of the major obstacles for the application of LAMP is the difficulty in maintaining the cold chain to preserve reagents. Thus, the challenge is to develop a LAMP kit in a ready-to-use format with dried reagents useful for quick and simple application in field conditions. The optimized reaction of wet LAMP was followed for the standardization of dry LAMP with certain modifications which are needful. The major modification is vitrification technology of enzyme using trehalose. LAMP assay (dry and wet LAMP) was found to be more sensitive (100%) when compared to microscopy (69.5%) and PCR (86.9%). It was observed that the dry LAMP reaction tubes at room temperature as well as refrigeration temperature provided successful amplification till 7 weeks. The drying conditions of LAMP reagents were optimized, and finally managed to dry them in a single reaction tube without reducing the sensitivity. This technology enables us to transport LAMP kits to areas where the cold chain is not easily available.

Molecular Prevalence and Host Related Epidemiological Factors of Bovine Tropical Theileriosis in Semi-Arid Zone of Northern Plains of India

Molecular Prevalence and Host Related Epidemiological Factors of Bovine Tropical Theileriosis in Semi-Arid Zone of Northern Plains of India

Guardians of the Herd: Molecular Surveillance of Tick Vectors Uncovers Theileriosis Perils in Large Ruminants.

Theileria sp. (Piroplasmida: Theileriidae) is one of the most widely known infections transmitted by hard ticks (Acari: Ixodidae) and has been linked to significant economic losses across the globe. The study's main emphasis was theileriosis, a disease that is common in Pakistan and has an incidence ranging from 0.6% to 33%. Through DNA screening of the vector ticks and host blood, this study sought to determine the risk of tick-borne theileriosis in populations of buffalos (Bubalus bubalis) and cattle (Bos indicus) in Toba Tek Singh district of Punjab, Pakistan. Identified tick species include Hyalomma anatolicum (35.4%), Rhipicephalus (Boophilus) microplus (30.2%), and R. sanguineus (25%). Tick specimens were collected from animals and their respective microenvironments. PCR assays targeting Theileria annulata were used to investigate the infection in the DNA extracted from the collected blood samples from large ruminants and salivary glands (SGs) of the Hyalomma ticks. The 18S rRNA of T. annulata was amplified using specific primers. Positive T. annulata amplicons were sequenced and verified using BLAST analysis. Overall, 50% of SGs contained T. annulate DNA. Female ticks, and those collected from cattle and from riverine environments had significantly higher (p < 0.05) rates of Theileria infection in their acini. Overall prevalence of Theileria infection was 35.9% in blood collected from large ruminants. Cattle had a substantially greater frequency of bovine theileriosis (43.2%) than buffalos (28.7%). Age and sex of large ruminants were significantly positively associated (p < 0.05) with Theileria infection. Furthermore, compared to non-riverine cattle (35%) and buffalo (19.5%), riverine cattle (52.2%) and buffalo (36.2%) showed a considerably higher prevalence. The results of this study, which is the first in Pakistan to examine the blood of large ruminants and vectorial function of Ixodid ticks in the transmission of T. annulata along with associated risk factors, offer an important insight for risk assessment of Theileria infection in livestock using vectorial infectivity.

Growth inhibitory effect of selected quinones from Indian medicinal plants against Theileria annulata

Tropical Bovine Theileriosis, caused by the protozoan parasite Theileria annulata, poses a significant threat to cattle populations. Currently, Buparvaquone is the sole effective naphthoquinone drug commercially available for its treatment. In our research, we delved into the potential of naturally occurring quinones as alternative treatments. We isolated two quinones, emodin and chrysophanol, from Rheum emodi Wall, and two more, embelin and lawsone, from Embelia ribes Burm.f. and Lawsonia inermis L. respectively. We assessed the anti-Theileria efficacy of these quinones in vitro using MTT and flow cytometric assays on T. annulata-infected bovine lymphocytes. Additionally, we evaluated their safety on uninfected bovine Peripheral Blood Mononuclear Cells (PBMC) and Vero cells. Emodin emerged as a promising candidate, exhibiting an IC50 value of 4 μM, surpassing that of buparvaquone. Emodin also displayed relatively low LD50 values of 1.74 mM against uninfected PBMC and 0.87 mM against Vero cells, suggesting potential safety. Remarkably, emodin demonstrated a high cell absorption rate of 71.32%. While emodin's efficacy and bioavailability are encouraging, further research is imperative to validate its safety and effectiveness for treating Tropical Bovine Theileriosis.

Epidemiological situation of bovine tropical theileriosis in an arid region in central Tunisia with a phylogenetic analysis of Theileria annulata.

Tropical theileriosis, Theileria annulata infection, is the most prevalent summer disease in Tunisia. It is transmitted by Hyalomma scupense, a two-host tick known to be endophilic. The present study aimed to estimate the infection prevalence of cattle by T. annulata in two districts from central Tunisia. Blood samples collected from 270 Holstein cattle from the Sidi Bouzid (140 samples) and Kasserine districts (130 samples) were analysed by Giemsa staining and T. annulata-specific PCR. In both regions, PCR revealed a prevalence of 32.6%. This was significantly higher than the 6.3% prevalence obtained by Giemsa staining blood smears (p < 0.001). Giemsa staining also revealed a low parasitaemia of 0.05%. The PCR-based prevalence was not statistically different between the two districts (31.4 ± 0.04 and 33.8 ± 0.04% in Sidi Bouzid and Kasserine districts, respectively, p = 0.6). On the contrary, the results of blood smear examination (2.85 and 10% in Sidi Bouzid and Kasserine, respectively) differed significantly between the two sampling sites (p = 0.01). There was no evidence of a statistically significant difference between the overall molecular infection prevalence when the samples were segregated based on animals' age or gender (p = 0.1 and 0.2, respectively) and a similar trend was observed for Giemsa staining. Ten PCR amplicons of the Tams1 gene (721bp) were subsequently sequenced from the two regions. The phylogenetic analyses showed 100% similarity between all sequences. The unique conserved Tams1 sequence was deposited in GenBank under the accession number OP428816 and used to infer its phylogenetic relationships with those available in the GenBank repository. This is the first report of the presence of T. annulata in this region of central Tunisia which has no history of tropical theileriosis. Priority areas for future studies include understanding the origin of these T. annulata-positive animals in a region where the presence of a known natural vector tick, H. scupense, has not been reported. Given that the disease severely constrains cattle productivity, it would also be worthwhile to investigate if other potential vectors for T. annulata, such as Hyalomma dromedarii, are present in the arid regions.

Molecular investigation of bovine tropical theileriosis outbreak in an organized dairy cattle farm in Madhya Pradesh, India.

The present study aimed to investigate an outbreak of Theileria annulata (T. annulata) infection in an organized dairy cattle farm in Madhya Pradesh, India, using clinical and molecular techniques. Following the deaths of two crossbred cattle in March 2021, 43 blood samples were collected from infected and apparently healthy animals and examined by blood smear and polymerase chain reaction (PCR) techniques. The blood smear examination showed that 23.25% of samples were positive for Theileria organisms, while conventional PCR targeting the 18S ribosomal RNA (18S rRNA) and T. annulata merozoite surface antigen-1 (TAMS-1) genes revealed that 32.55% of samples were positive for T. annulata. PCR targeting cytochrome b (Cytb) gene showed 46.51% of samples were positive for T. annulata. Haematological analysis confirmed clinical signs of infection in affected animals, which were treated with buparvaquone @ 2.5mg/kg body weight intramuscularly along with supportive medicine. Two 18S rRNA gene amplicons were sequenced and analysed in a phylogenetic tree and haplotype network with 54 Indian and 38 foreign sequences. The phylogenetic tree revealed two groups with a high posterior probability and bootstrap value, while the haplotype network revealed 35 haplotypes, with haplotype 1 (H1) being the most abundant and several single haplotypes clustering around it, indicating fast and widespread expansion. Genetic diversity indices and neutrality tests confirmed that the population was expanding. These studies highlight the significance of prompt and precise diagnosis and management of T. annulata outbreaks and provide insights into its evolutionary history and population dynamics of T. annulata in India, which could aid improving disease preventive and control strategies.

Phylogenetic Analysis and Detection of Drug Resistance Gene in Theileria annulata Isolated from Buffaloes

Bovine theileriosis, caused by Theileria annulate, is disease affecting cattle and buffaloes worldwide. The current study aimed to screen the blood samples of 30 naturally suspected local buffaloes infected with Theileria species. The blood samples were initially examined by light microscopic and then the positive samples were subjected to PCR reactions. All 30 animals indicated clinical symptoms, such as high fever, loss of appetite, the presence of the hard tick, and enlargement of lymph nodes. The amplified products of 18S rRNA were analyzed, along with molecular detection of the drug-binding site alterations and interrelated changes in the cytochrome b (cyto b) gene. Blood smears revealed the presence of infected erythrocytes with Theileria spp. The PCR results confirmed infection in samples when DNA amplified with partial 18S rRNA and cyto b genes. The sequencing data were obtained from GeneBank using the accession numbers OM937770.1, ON207523.1, ON207525.1, ON207524.1, ON207526.1, and ON207527.1 Following BLAST analysis (Basic Local Alignment Search Tool), genetic differences were observed between the Iraqi isolate OM937770.1 and strains from India, Iran, and Turkey. The data obtained from the current study may reveal the genetic alteration of the local strain in the drug-target codons, which are found in one isolate and are different from the GenBank isolates. The results suggest that the failure of buparvaquone therapy might be due to the resistance to cyto b gene.

Prevalence and Risk Factors Associated with Theileria annulata Infection in Two Bovine Portuguese Autochthonous Breeds.

Tropical Bovine Theileriosis is an important tick-borne disease. This study aims to assess the occurrence of Theileria annulata infection in two indigenous Portuguese cattle breeds. A total of 843 blood samples collected from animals of Alentejana (n = 420) and Mertolenga (n = 423) breeds were analyzed. The detection of Theileria annulata was determined by amplification of a fragment of the merozoite-pyroplasm surface antigen gene with 319 base pairs (bp). The prevalence found (10.8%) is lower than that reported in previous studies (21.3%). A statistically significant difference was found for positivity between breeds (p < 0.05). There is also a higher probability of older animals being positive compared to younger ones (p < 0.05). The region where Mertolenga animals are located is shown to have a significant impact on positivity (p < 0.05). Thus, the development of sustainable T. annulata control strategies and their implementation, adapted to the epidemiological conditions of higher risk, will be extremely important.

Multiplex ddPCR: A Promising Diagnostic Assay for Early Detection and Drug Monitoring in Bovine Theileriosis

Accurate quantification based on nucleic acid amplification is necessary to avoid the spread of pathogens, making early diagnosis essential. Droplet digital PCR (ddPCR) stands out for absolute parasite quantification because it combines microfluidics with the TaqMan test. This helps deliver maximum accuracy without needing a reference curve. This study assessed the efficacy of ddPCR as a detection tool for the bovine theileriosis (BT) caused by Theileria parasites. We developed and validated a duplex ddPCR method that detects and quantifies the Theileria genus (18S rRNA) and identifies clinically significant Theileria annulata parasites (TaSP) in experimental and clinical samples. ddPCR was shown to be as effective as qPCR throughout a 10-fold sample dilution range. However, ddPCR was more sensitive than qPCR at lower parasite DNA concentrations and reliably assessed up to 8.5 copies/µL of the TaSP gene in the infected DNA (0.01 ng) samples. The ddPCR was very accurate and reproducible, and it could follow therapeutic success in clinical cases of theileriosis. In conclusion, our ddPCR assays were highly sensitive and precise, providing a valuable resource for the study of absolute parasite quantification, drug treatment monitoring, epidemiological research, large-scale screening, and the identification of asymptomatic parasite reservoirs in the pursuit of BT eradication.

Association between proliferation status of infected and non-infected mononuclear cells with tissue lesions in acute bovine theileriosis.

Tropical or Mediterranean theileriosis in dairy cattle is widely distributed in many tropical regions of the world. The purpose of this study was to evaluate the proliferation status of mononuclear cells infected with Theileria annulata schizonts in different tissues and its relationship with the pathogenesis of the parasite in cattle by histopathology, immuno-histochemistry and polymerase chain reaction (PCR). Blood and tissue samples of eight Holstein cattle that had been lost due to theileriosis and eight healthy slaughtered cattle of the same breed were collected as a control group after necropsy. The piroplasms in the blood smears and the schizonts in the cytoplasm of the lymphocytes and macrophages of the lymph nodes were microscopically detected. Histopathologically, the proliferation of macrophages, lymphocytes, and plasma cells in lymph nodes and the heart, congestion, and bleeding in the red pulp of the spleen, portal tracts of the liver, interstitial tissue of the kidneys, multifocal necrosis and ulceration in the abomasum together with hyperemia and hemorrhages and lymphoblastic infiltration in the submucosa and lamina propria adjacent to these lesions and emphysema with ecchymotic hemorrhage in the lungs were evident. Immunohistochemistry identified the proliferated cells as mostly Cluster of Differentiation 3- Positive T lymphocytes and macrophage marker antibody 387- positive macrophages. Positive results of PCR for the Tams1 30.00 kDa gene were observed in lymph nodes, liver, lung and abomasum. It was concluded that the pathological changes were the result of schizont-infected macrophage proliferation leading to severe uncontrolled proliferation of uninfected T lymphocytes.

Clinico-morphological and Molecular Detection of Bovine Tropical Theileriosis in Cattle

Background: Theileria spp. were targeted for detection and differentiation from clinical samples using PCR in the current investigation and the diagnostic sensitivity of this method was evaluated in comparison to microscopic observations. The clinical characteristics of bovine tropical theileriosis as clinical markers were also analysed based on the PCR data. Methods: On the basis of clinical evaluation and microscopic inspection of blood smears, 200 blood samples from cattle suspected of having theileriosis were examined. To confirm the disease, the PCR method was employed by using 18S rRNA and Cyto b1 gene to confirm Theileria spp. and Theileria annulata respectively in clinical samples. Result: The results showed that microscopic examination detected 65/200 (32.50%), whereas, the PCR assay identified 120/200 (60.00%) for Theileria spp. Of the total 200 samples studied, 77 (38.50.3%) were positive for T. annulata specific PCR. Based on PCR confirmation of T. annulata infection in cattle, the predominant clinical signs were pyrexia, ticks’ infestations, anorexia, enlargement of lymph node, pale mucous membrane, lacrimation, coughing, drop in milk production and emaciation. The other clinical signs were observed as icterus, nasal discharge, salivation, melena and exophthalmia.