Fatal cases of Theileria annulata infection in calves in Portugal associated with neoplastic-like lymphoid cell proliferation

Isolation and propagation of an Egyptian Theileria annulata infected cell line and evaluation of its use as a vaccine to protect cattle against field challenge

Tropical theileriosis is an important protozoan tick-borne disease in cattle. Vaccination using attenuated schizont-infected cell lines is one of the methods used for controlling the disease. This study describes the production of attenuated schizont-infected cell lines from Egypt and an evaluation of its use as a vaccine to protect calves against clinical disease upon field challenge. Two groups of exotic and crossbred male calves were divided into vaccinated and control groups. The vaccinated groups were inoculated with 4 ml (1 × 106 cells/ml) of the attenuated cell line. Three weeks after vaccination, calves of both groups were transported to the New Valley Governorate (Egyptian oasis) where they were kept under field conditions and exposed to the natural Theileria annulata challenge. All animals in the control group showed severe clinical signs and died despite treatment with buparvaquone, which was administered after two days of persistent fever due to a severe drop in packed cell volume (PCV). Animals in the vaccinated group became seropositive without developing severe clinical signs other than transient fever. Post-mortem examinations revealed enlarged and fragile lymph nodes, spleen, and liver with necrosis and hemorrhages. These findings indicate that the Egyptian attenuated cell line was successful in protecting both exotic and crossbred animals against tropical theileriosis under field conditions.

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.

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.

Theileriosis in naturally infected roan antelope (Hippotragus equinus)

Cases of Theileria-associated mortality are rarely reported in African wild artiodactyls. Descriptions of lesions are limited, particularly in endangered hippotraginids. Here, we analyzed retrospectively the gross and histologic findings in 55 roan antelope (Hippotragus equinus) with fatal natural theileriosis. The most frequently recorded gross findings in 40 cases were widespread petechiae and ecchymoses (72.5%), probable anemia (67.5%), icterus (60%), splenomegaly (60%), hepatomegaly (52.5%), and pulmonary edema (50%). Histologic lesions in 34 cases were characterized by multi-organ infiltrates of parasitized and nonparasitized mononuclear leukocytes (MLs), and fewer multinucleate giant cells (MNGCs). Liver, lung, kidney, adrenal gland, and heart were most consistently infiltrated, followed by spleen and lymph nodes. Leukocytes were phenotyped in lung, liver, kidney, and heart specimens from 16 cases, using immunohistochemistry to detect CD20, CD3, myeloid/histiocyte antigen (MAC387), IBA-1, and CD204 surface receptors. A roan polyclonal anti-Theileria sp. (sable) antibody was applied to the same tissues to identify intraleukocytic parasite antigens. Similar proportions of intravascular and extravascular IBA-1-, CD204-, and MAC387-reactive putative monocyte-macrophages and fewer CD3-positive putative T-lymphocytes were identified in all organs, especially the lungs in infected roan. CD20-positive putative B-lymphocytes were significantly scarcer than in uninfected controls. Intraleukocytic Theileria parasites labeled consistently in affected tissues. Some parasitized and nonparasitized MLs and the MNGCs failed to label with selected leukocyte markers. Fatal theileriosis in roans may largely be the result of multi-organ monocyte-macrophage activation with associated tissue injury and overwhelming systemic inflammation. The identity of the parasitized leukocytes and characteristics of the lymphohistiocytic response require further clarification in roans.

Successful treatment of severe form of bovine tropical theileriosis in dairy cattle and genotyping of Theileria annulata isolates of Tamil Nadu, India

Bovine tropical theileriosis (BTT) is a tick-borne protozoan disease of cattle and responsible for major economic losses to the dairy farmers in India. This report describes diagnosis, genotyping and successful treatment of heavy infection of Theileria annulata in an organized dairy farm at Kattupakkam, Chennai. Four cross bred cows of 2 to 5 years of age showed clinical signs i.e., anorexia, salivation and panting. Clinical examination revealed pyrexia (40.0 °C to 40.1 °C), pale mucus membranes, enlarged prescapular lymph nodes and haemoglobinuria. The peripheral blood smear examination of infected cows revealed presence of piroplasm within the RBCs indicating high parasitemia. Haematology results suggested that decreased levels of Hb, RBC, WBC and PCV in the infected cows when compared with normal reference values. There were increased serum ALT and AST values and reduced serum total protein, albumin, calcium and phosphorous values in the infected cows. Semi-nested PCR using T. annulata specific oligonucleotide primers amplified 199 bp of the partial T. annulata 18S rRNA gene. Presence of four satellite markers TS6, TS8, TS9, and TS12 in the Theileria annulata isolates 1 and 2 indicating that the isolates were the same haplotype and suggested the infection in the farm was due to a single haplotype of T. annulata parasite. Based on the clinical signs, microscopic examination of blood smear and molecular diagnosis, the condition was diagnosed as tropical theileriosis. Infected cows were successfully treated with a single deep intramuscular injection of buparvaquone (Zubion®, INTAS pharmaceuticals LTD, Ahmedabad, India) along with supportive medication.

Genetic diversity in the Tams1 gene of Theileria annulata (Duschunkowsky and Luhs, 1904) infecting cattle

The present study describes the genetic diversity in the Tams1 gene (733 bp) of Theileria annulata along with the sequence, phylogenetic and haplotype analyses of the Indian isolates. The phylogenetic analyses displayed distinct clustering of the Indian isolates into three groups suggesting the presence of three genotypes, hitherto designated as T. annulata genotypes 1-3 (G1-G3). Genotype 3 seems to be novel containing only two newly generated sequences. Indian isolates displayed 88.4-100% and 82.2-100% similarity with each other at nucleotide (nt) and amino acid (aa) levels, respectively. However, the newly generated sequences (n = 36) showed 90.5-100% and 84.3-100% identity between them at nt and aa levels, respectively. The most diverse and heterogeneous genotype, G1, exhibited the highest number of polymorphic sites (S = 148), haplotypes (h = 16) and nucleotide differences (k = 43.23) besides haplotype (Hd = 0.903 ± 0.031) and nucleotide (π = 0.059 ± 0.005) diversities. Neutrality indices suggested a respective decrease and increase in population sizes of G1 and G2 genotypes in India. The nucleotide sequence analyses indicated the presence of extensive sequence variations between nucleotide positions 1-124, 194-257 and 396-494. The N-terminus of Tams1 protein displayed a considerable sequence variability with extensive variations in two regions, between amino acid positions 1-39 and 127-172, as compared to the conserved carboxyl terminus.

The phenotypic and haemato-biochemical appraisal of tropical theileriosis in newborn calves

Tropical theileriosis is one of the major causes of newborn calves mortality. Observation of clinical manifestations is important while making the presumptive/tentative diagnosis of tropical theileriosis in newborn calves. The phenotypic and haemato-biochemical appraisals of tropical theileriosis could be of great help to make a holistic therapeutic plan for diseased newborn calves. Therefore, the present study aimed to evaluate the haemato-biochemical and phenotypic diagnostic markers of tropical theileriosis in newborn calves. A total of 43 newborn calves naturally infected with Theileria annulata and 16 age-matched healthy calves were enrolled. The percentage distribution of clinical markers was generalized lymph nodes enlargement (100%), pyrexia (97.67%), respiratory distress (95.34%), tick infestation (90.69%), anorexia (88.37%), pica (81.39%), pallor mucous membrane (67.44%), hyperlacrimation (58.13%) and exophthalmia (30.22%). Haemograms including TEC, Hb and HCT were found to be significantly (P ≤ 0.001) lowered in diseased calves. Remarkable alterations in the leukogram panels were not observed. Serum glucose, total protein, albumin and globulin concentrations of calves with theileriosis were significantly (P ≤ 0.001) lower than healthy ones, whereas triglycerides and total cholesterol levels of diseased calves were significantly (P ≤ 0.001) higher. Significantly (P ≤ 0.001) elevated activities of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) enzymes were observed in diseased calves. An evaluation of clinical phenotypes could be helpful to initiate quick treatment of diseased calves in field conditions and save the lives of sick calves of economically poor farmers. Altered haemato-biochemical panels to be appraised by veterinary clinicians while making a therapeutic plan of tropical theileriosis.

Polyclonal antibody-based immunohistochemical detection of intraleukocytic Theileria parasites in roan and sable antelopes

Theileria parasites commonly infect African wild artiodactyls. In rare roan (Hippotragus equinus) and sable (H. niger) antelopes, Theileria sp. (sable)-associated calf mortalities constrain breeding programs. The pathogenicity of most leukocyte-transforming Theileria spp. originates in their invasion of and multiplication in various mononuclear leukocytes, the transformation of both infected and uninfected leukocytes, and their infiltration of multiple organs. Understanding the pathogenesis of theileriosis can be improved by the use of immunohistochemistry (IHC) to identify the localization of the parasites in tissue sections. Our aim was to develop a reproducible IHC assay to detect leukocyte-associated Theileria parasites in formalin-fixed, paraffin-embedded roan and sable tissues. Polyclonal antibodies were purified from the sera of 5 roans from an area endemic for Theileria sp. (sable) and tested for IHC reactivity in 55 infected and 39 control roan and sable antelopes, and for antigen and species cross-reactivity in an additional 58 cases. The 3 strongest antibodies consistently detected intraleukocytic theilerial antigens in known positive cases in roan and sable antelopes, and also detected other Theileria spp. in non-hippotraginid wild artiodactyl tissues. The antibodies did not cross-react with other apicomplexan protozoa, with the exception of Cryptosporidium. Given that PCR on its own cannot determine the significance of theilerial infection in wild ruminants, IHC is a useful laboratory test with which to confirm the diagnosis in these species.

Clinical and hematologic features of experimental theileriosis in roan calves (Hippotragus equinus)

Theileria sp. (sable) infection commonly causes significant calf mortality in endangered roan antelopes (Hippotragus equinus). Schizont-induced leukocyte transformation and systemic immune dysregulation with associated cytopenias characterizes theileriosis in livestock. Data on related hematologic alterations are scarce in roan antelopes. The objective of this study was to investigate temporal changes in selected clinical parameters and hematologic measurands in experimentally infected (EI) roan calves. Six of eight calves developed theileriosis after inoculation with a Theileria sp. (sable)-infected tick stabilate. Consecutive measures of rectal temperature, lymph node size, white blood cell count (WBC), packed cell volume (PCV), hemoglobin concentration, differential leukocyte counts, leukocyte and erythrocyte morphology and percentage parasitemia were recorded. Data were compared with 15 age-matched PCR-negative control calves and nine older immune animals that had recovered from natural infection. Two non-pyrexic EI calves recovered uneventfully. Six pyrexic calves were treated, four of which died. Time to pyrexia and/or observation of schizonts and piroplasms was approximately two weeks. Total WBCs were unchanged post-infection (PI); neutrophils and typical monocytes decreased whereas typical lymphocytes (Ls) and atypical mononuclear leukocytes (AMLs), which were grouped together, increased. Parasitized and non-parasitized lymphocyte and AML (L/AML) size increased significantly PI. Piroplasms occurred intermittently at low frequencies («1 % of erythrocytes) after infection. Fatally infected calves were dehydrated, anemic, and icteric with hemorrhages and multi-organ infiltration by AMLs. The PCV and hemoglobin concentration increased PI, and platelet clumps were consistently observed. Experimental acute theileriosis in roan antelopes follows a similar pattern of disease progression to that in domestic livestock. Parasitized and non-parasitized AMLs are pivotal to the pathogenesis and require phenotypic characterization if we are to further our understanding of disease progression and severity in roan antelopes.

Molecular detection of Theileria annulata infection in cattle by conventional PCR and quantitative real time PCR in India

Theileria annulata (T. annulata) is a tick-borne apicomplexan parasite that affects bovine. It is endemic in many tropical and subtropics areas, including Odisha, India. The objective of this study is to identify T. annulata infection in the peripheral blood of cattle as a biological sample by conventional PCR (cPCR) and quantitative PCR (qPCR). The phylogenetic analysis was done using the T. annulata merozoite surface antigen (Tams 1) gene. Out of 552 samples of examined blood smears by microscopy, 454 (82.24%) animals were positive for Theileria species. Out of 454 samples, 96 samples were further examined by both cPCR and qPCR, 52 samples (54.16%) were found positive for T. annulata in both PCR methodologies. Phylogenetic analysis revealed that T. annulata Odisha isolate was closely related to T. annulata Uttarakhand, India isolate (KM061799) and Hyderabad, India isolate (MK034702) with Nucleotide sequence identity 95.36%, 95.25%, respectively. This is the first study to detect T. annulata by qPCR in Odisha and supported that both PCR techniques were equally effective for the detection of Tams 1 gene of T. annulata in cattle's blood.

Role of cytokines in the clinical manifestation of exophthalmia in newborn calves with tropical theileriosis

The present study aimed to evaluate the pathology of the exophthalmia and the host-immune response in naturally Theileria annulata-infected calves. The newborn calves detected positive for theileriosis were grouped into calves with theileriosis and absence of exophthalmia (n = 30), and calves with theileriosis and the presence of exophthalmia (n = 13). Sixteen healthy calves, free from any haemoprotozoal infection, were kept as healthy controls. A significantly (P ≤ .001) higher circulating levels of tumour necrosis factor-α (TNF-α) and interleukin-10 (IL-10) were estimated in diseased calves with and without exophthalmia as compared to healthy controls. Contrarily, significantly (P ≤ .01) lower interferon-γ (IFN-γ) level was estimated in diseased calves. The diseased calves with exophthalmia revealed significantly higher levels of TNF-α (P ≤ .001) and IL-10 (P ≤ .006) as compared to the diseased calves without exophthalmia. The diseased calves were not found to have an elevated intraocular pressure; rather they had significantly (P ≤ .001) lower intraocular pressure compared to the healthy controls. An elevated systemic TNF-α level might be attributed to the exophthalmia in calves with tropical theileriosis. The elevated circulatory IL-10 and reduced IFN-γ levels could be one of the strategies of Theileria annulata to escape the host immunity.

The Pathology of Pathogenic Theileriosis in African Wild Artiodactyls

The published literature on schizont-"transforming," or pathogenic theileriosis, in African wild artiodactyls is dated and based on limited information. Here the authors review the taxonomy, diagnosis, epidemiology, hematology, pathology, and aspects of control in various species. Molecular studies based on 18S and 16S rRNA gene sequences have shown that African wild artiodactyls are commonly infected with diverse Theileria spp., as well as nontheilerial hemoprotozoa and rickettsia-like bacteria, and coinfections with pathogenic and nonpathogenic Theileria species are often recorded. Although theileriosis is still confusingly referred to as cytauxzoonosis in many species, the validity of a separate Cytauxzoon genus in artiodactyls is debated. The epidemiology of theileriosis is complex; the likelihood of fatal disease depends on the interplay of parasite, vertebrate host, tick vector, and environmental factors. Roan calves (Hippotragus equinus) and stressed animals of all host species are more susceptible to fatal theileriosis. Even though regenerative anemia is common, peripheral blood piroplasm parasitemia does not correlate with disease severity. Other than anemia, common macroscopic lesions include icterus, hemorrhages (mucosal, serosal, and tissue), fluid effusions into body cavities, lung edema, and variably sized raised cream-colored foci of leukocyte infiltration in multiple organs. Histopathologic findings include vasocentric hyperproliferation and lysis of atypical leukocytes with associated intracellular schizonts, parenchymal necrosis, hemorrhage, thromboembolism, and edema. Immunophenotyping is required to establish the identity of the schizont-transformed leukocytes in wild ungulates. Throughout the review, we propose avenues for future research by comparing existing knowledge on selected aspects of theileriosis in domestic livestock with that in African wild artiodactyls.

Mortality and Morbidity of Beef Calves in Free-Range Farms in Alentejo, Portugal-A Preliminary Study

Extensive cow-calf beef cattle farms play a significant role in Portuguese livestock production, but records of important production variables, such as calf mortality, are scarce. To assess herd-level calf mortality and its potential economic impact, farmers from the Alentejo region were asked to fill a questionnaire regarding herd size, feeding and reproductive management practices, calf mortality (from birth to weaning), and detection of the main morbidity causes, as well as of sudden, unexplained deaths during the previous 12 months. Farmers were also requested to quantitatively assess the economic impact of calf mortality on their annual revenue. In the majority of farms, the herd size was larger than 100 animals. The median stocking rate was 0.41 adult animals/hectare, and 70% of farmers stated their farm was self-sufficient in forage. The percent of live births that resulted in weaned calves averaged 94.3%, which led to the assumption of a 5.7% calf mortality rate from birth to weaning. In the previous 12 months, 78.8% of the farms identified at least one case of calf diarrhea, 60.7% identified at least one case of respiratory disease, and 82.1% had at least one sudden, unexplained calf death. As expected, farmers that assessed a higher impact of calf losses on their annual economic revenue were also those who reported higher incidences of calf diarrhea, respiratory disease, and sudden, unexplained deaths. One-quarter of the farmers were unable to assess the economic impact of calf mortality on the farm's revenue. Herd size appears to have a predictive value on calf mortality in the first month of life, and from 30 days to weaning. The number of sudden, unexplained calf deaths seems to have a predictive value on overall calf mortality (from birth to weaning), suggesting that the farms' management practices probably play an important role in calf mortality throughout the suckling period. Further studies are needed to fully understand calf mortality in Portuguese extensive rearing systems.

Studies on alterations of clinical and hemato-biochemical parameters before and after treatment in calves naturally infected with theileriosis

Aim:

The aim was to determine hemato-biochemical alterations and to determine the better treatment of theileriosis in naturally infected calves.

Materials and Methods:

A total of 74 Holstein crossbred calves below 6 months of age, of either sex were included for present investigation in Bikaner. Based on the clinical examinations and laboratory results, 20 calves included for hemato-biochemical studies (before and after treatment) and divided into two groups (having 10 calves each).

Results:

The clinical examination of these calves revealed weakness, ticks infestations, high fever above 104°F, pronounced swelling of prescapular, prefemoral, parotid lymph nodes, loss of elasticity of skin, anemia, lacrimal discharges, pulpy cornea, tachycardia, and dyspnea. There was highly significant decrease (p<0.01) in hemoglobin, total erythrocyte count, packed cell volume and total leukocyte count, serum glucose, total protein, globulin and albumin level and highly significant increase in aspartate aminotransferase and alanine aminotransferase level as compared to healthy control animals in Group I and II. The animals of Group II treated with buparvaquone along with single blood transfusion shows better recovery then animals of Group I treated with bupavaqone and hematinic.

Conclusions:

Significant changes were found in hemato-biochemical parameters in theileria affected calves before treatment as compare to healthy control calves. Significant improvement was observed in hemato-biochemical parameters in buparvaquone and single blood transfusion treated calves as compare to another group, so it is concluded that buparvaquone and single blood transfusion is better combination for treatment of theileriosis.

An experimental ovine Theileriosis: The effect of Theileria lestoquardi infection on cardiovascular system in sheep

The malignant ovine theileriosis is caused by Theileria lestoquardi, which is highly pathogenic in sheep. Theileriosis involves different organs in ruminants, but the effect of the disease on the cardiovascular system is unclear. To understand the pathogenesis of T. lestoquardi on the cardiovascular system, Baluchi breed sheep were infected with the mentioned parasite by releasing unfed adults of Hyalomma anatolicum anatolicum, which were infected with T. lestoquardi. The infected sheep were clinically examined on days 0, 2, 5, 7, 10, 12, 14, 17, and 21, and the blood samples were collected for biochemical parameters measurement. At termination of the experiment, the infected sheep were euthanized and pathological examinations of heart tissue were conducted. During experimental infection of sheep with T. lestoquardi, activities of cardiac troponin I (cTnI), lactate dehydrogenase, and aspartate aminotransferase, were significantly increased (P˂0.05), while a conspicuous decrease (P˂0.05) was observed in creatine phosphokinase activities. Alterations made in biochemical factors almost coincided with the presence of piroplasm in the blood and schizont in lymph nodes. Maximum and minimum of parasitemia in the sheep stood between 3.3% and 0.28%, respectively. In addition, electrocardiography revealed sinus tachycardia, sinus arrhythmia, sino-atrial block and ST-elevation, atrial premature beat, and alteration in QRS and in T waves' amplitude. Heart histopathological examination showed hyperemia, infiltration of mononuclear inflammatory cells into interstitial tissue, endocarditis, and focal necrosis of cardiac muscle cells. In addition, in one of the sheep, definite occurrence of infarction was observed. The results indicate that T. lestoquardi infection has devastating pathological impacts on the cardiovascular system of sheep. Furthermore, measurement of the cTnI amount is a useful biochemical factor for diagnosis and for better understanding of the severity and progression of the disease and its effects on cardiac tissue.

Anaplasma marginale and Theileria annulata in questing ticks from Portugal

Ticks are ubiquitous arthropods and vectors of several pathogenic agents in animals and humans. Monitoring questing ticks is of great importance to ascertain the occurrence of pathogens and the potential vector species, offering an insight into the risk of disease transmission in a given area. In this study 428 host-seeking ticks, belonging to nine species of Ixodidae and collected from 17 of the 23 Portuguese mainland subregions, were screened for several tick-borne agents with veterinary relevance: Anaplasma marginale, Anaplasma ovis, Anaplasma centrale, Babesia spp., Coxiella burnetii and Theileria spp. Prevalence was assessed by PCR and amplified amplicons sequenced for validation of results. Twenty ticks, in a total of 428, were found positive: one Ixodes ventalloi for Theileria annulata and four Dermacentor marginatus, one Haemaphysalis punctata, five Ixodes ricinus, five I. ventalloi, and four Rhipicephalus sanguineus sensu lato for A. marginale. According to the reviewed literature, this is the first report of A. marginale and T. annulata detection in I. ventalloi. Furthermore, the amplification of A. marginale DNA in several tick species suggests a broad range for this agent in Portugal that might include other uncommon species as R. sanguineus s.l. This work provides new data towards a better understanding of tick-pathogen associations and also contributes to the surveillance of tick-borne agents in geographic areas with limited information.

[Sporadic cutaneous lymphosarcoma of T-cell origin with involvement of lymph nodes and internal organs in a Holstein cow]

Sporadic lymphosarcomas in adult cattle are rare entities with an unknown etiology. This case report describes the course of the disease in a 3.5-year-old cow of the breed German Holstein, which was presented to the veterinarian due to multifocal nodular skin lesions. Several superficial lymph nodes (Lymphonodi mandibulares, parotidei and mammariae) were enlarged, had a tight-elastic consistency and were freely movable. The histopathological and immunohistochemical examination of skin biopsies showed the presence of multifocal cutaneous T-cell lymphosarcomas consistent with a skin leukosis. Bovine leukemia virus infection was excluded by serological investigation of a milk sample and virological examination of a tissue sample, respectively. Seven weeks after the first clinical examination, the cow deteriorated rapidly and was euthanized. A post mortem examination revealed the presence of neoplastic cells within lymph nodes (all superficial lymph nodes of the carcass and Lymphonodi pulmonales), kidney and lungs as well as a liver rupture. Additionally, an overview of the case reports of sporadic bovine cutaneous lymphosarcomas published during the previous 15 years will be provided. The legal background for a further utilization of affected animals for milk and meat production will be discussed. This case report illustrates that sporadic bovine leukosis represents an important differential diagnosis for viral-, bacterial- and parasitic-induced skin lesions and enlargement of lymph nodes in adult cattle.

Salvage of Theileria infected calves with clinical manifestation of exophthalmia

Two crossbred female calves aged between 30 and 35 days were presented with bilateral exophthalmia, inappetence, pyrexia and cachexia since last 15 days. Clinical examination revealed mainly bilateral exophthalmia with dry and pulpy cornea, generalized enlargement of superficial lymph nodes, pallor mucous, petechiae, high rectal temperature and sternal recumbency. The calves were severely infested with Hyalomma anatolicum anatolicum ticks and thin layer blood smears revealed presence of piroplasm in the RBCs, while lymph nodes aspirate smear examination revealed presence schizonts in the mononuclear cells. The calves were treated with buparvaquone; meloxicam, nandrolone decanoate and vitamins A, D3, E and H. From day second post-therapy a remarkable improvement in the clinical condition was noticed and substantial reduction in the both protruded eyeballs was noticed by 7 days post-therapy in the both calves. Further at day 47 post-therapy the one calf was free from the parasite on blood smear examination and right eye was retracted in its orbits with full of sight. Moreover the left eye was also retracted in its orbit but there was loss of sight and opacity developed in this eye. While, the other calf also revealed remarkable improvement in the clinical condition and both eye balls retracted completely into the orbit at day 30 post-therapy. But, at day 86 the calf developed microphthalmia and complete loss of sight in both eyes. It can be concluded that adjunction of antioxidants and hematopoietic agents may salvage the calves suffering from fatal theileriosis.

Control and therapeutic management of bovine tropical theileriosis in crossbred cattle

Bovine tropical theileriosis (BTT) is a disease of worldwide economic importance in cattle, caused by Theileria annulata, a protozoan parasite, and transmitted cyclically by ticks. The disease is one of the serious constraints to dairy industry in endemic areas like India, leading to fatal infections in exotic cattle and significant mortality in cross-bred cattle and zebu cattle. The present report demonstrates the clinical manifestation, haematological alteration and therapeutic management of theileriosis cases in a cross-bred cattle dairy farm at district Bijnor, Uttar Pradesh. Clinical examination of affected animals revealed high rectal temperature (104-106 °F), generalized enlargement of superficial lymph nodes, pallor mucous, apathy and watery blood. The affected animals were severely infested with Hyalomma anatolicum ticks. The blood smears examination after staining with Leishman stain revealed the presence of typical Theileria organisms. Buparvaquone along with symptomatic and supportive therapy could cure all the animals.

Theileria infection in domestic ruminants in northern Ethiopia

Piroplasmosis caused by different tick-borne hemoprotozoan parasites of the genera Theileria and Babesia is among the most economically important infections of domestic ruminants in sub-Saharan Africa. A survey for piroplasm infection was conducted in three locations in Northern Ethiopia. Of 525 domestic ruminants surveyed, 80% of the cattle, 94% of the sheep and 2% of the goats were positive for different Theileria spp. based on PCR of blood followed by DNA sequencing. Sheep had a significantly higher rate of infection compared with cattle (P<0.0003) and both sheep and cattle had higher rates of infection compared to goats (P<0.0001). Four species of Theileria were detected in cattle: T. velifera, T. mutans, T. orientalis complex and T. annulata with infection rates of 66, 8, 4, and 2%, respectively. This is the first report of T. annulata, the cause of Tropical Theileriosis in Ethiopia. Of the two Theileria spp. detected in small ruminants, T. ovis was highly prevalent (92%) in sheep and rare in goats (1.5%) whereas T. seperata was infrequent in sheep (2%) and rare in goats (0.4%). None of the animals were positive for Babesia spp.; however, Sarcocystis capracanis and S. tenella were detected in one goat and a sheep, respectively. The widespread distribution of Theileria spp. among cattle in northern Ethiopia including the virulent T. annulata and more mildly pathogenic T. mutans and T. orientalis, and the high infection rate in sheep with the usually sub-clinical T. ovis indicate extensive exposure to ticks and transmission of piroplasms with an important economic impact.

Recruitment of EB1, a master regulator of microtubule dynamics, to the surface of the Theileria annulata schizont

The apicomplexan parasite Theileria annulata transforms infected host cells, inducing uncontrolled proliferation and clonal expansion of the parasitized cell population. Shortly after sporozoite entry into the target cell, the surrounding host cell membrane is dissolved and an array of host cell microtubules (MTs) surrounds the parasite, which develops into the transforming schizont. The latter does not egress to invade and transform other cells. Instead, it remains tethered to host cell MTs and, during mitosis and cytokinesis, engages the cell's astral and central spindle MTs to secure its distribution between the two daughter cells. The molecular mechanism by which the schizont recruits and stabilizes host cell MTs is not known. MT minus ends are mostly anchored in the MT organizing center, while the plus ends explore the cellular space, switching constantly between phases of growth and shrinkage (called dynamic instability). Assuming the plus ends of growing MTs provide the first point of contact with the parasite, we focused on the complex protein machinery associated with these structures. We now report how the schizont recruits end-binding protein 1 (EB1), a central component of the MT plus end protein interaction network and key regulator of host cell MT dynamics. Using a range of in vitro experiments, we demonstrate that T. annulata p104, a polymorphic antigen expressed on the schizont surface, functions as a genuine EB1-binding protein and can recruit EB1 in the absence of any other parasite proteins. Binding strictly depends on a consensus SxIP motif located in a highly disordered C-terminal region of p104. We further show that parasite interaction with host cell EB1 is cell cycle regulated. This is the first description of a pathogen-encoded protein to interact with EB1 via a bona-fide SxIP motif. Our findings provide important new insight into the mode of interaction between Theileria and the host cell cytoskeleton.

The apicomplexan parasite Theileria can reprogram the cell it infects, inducing uncontrolled proliferation and clonal expansion. This is brought about by the schizont, which resides free in the host cell cytoplasm. As the schizont never leaves the cell to infect other cells, it can only persist provided it is distributed over the two daughter cells each time the host cell divides. This is achieved by interacting dynamically with microtubules (MTs) that form part of the host cell mitotic apparatus. How MTs are recruited to the schizont surface is not known. MTs are highly dynamic, undergoing continuous cycles of growth and shrinkage that is regulated to a large extent by an array of proteins, called +TIPs, that associate with the free plus-ends of MTs. End-binding protein 1 (EB1) is a master regulator and central adaptor that mediates MT plus-end tracking of potentially all other +TIPs. We established that a schizont surface protein, p104, provides a docking site for EB1, which critically depends on a consensus SxIP motif, present in p104. These finding provides important new insight into the complex interaction of the transforming schizont with host cell MTs. To our knowledge, p104 is the first pathogen-derived protein identified so far to join the SxIP family of EB1-binding proteins.

Detection of Theileria and Babesia infections amongst asymptomatic cattle in Portugal

Piroplasmosis caused by tick-borne hemoprotozoans of several Theileria and Babesia species has a major impact on livestock production worldwide. A reverse line blotting assay that includes genus- and species-specific probes for Theileria and Babesia species was used to assess the occurrence of these parasites in blood samples collected from 1407 healthy bovines throughout mainland Portugal. The global prevalence of piroplasm-infected animals was 36.8%, although significant differences were found between various regions. Higher prevalence was found in the southern regions (42.4% in Lisbon and Tagus Valley, 51.6% in Alentejo, and 40.0% in Algarve) compared to central (23.1%) and northern (12.8%) Portugal. Theileria annulata was the most frequently found species with a prevalence of 21.3%. The prevalence values of this pathogenic species were higher in the southern regions. The second most prevalent species was T. buffeli that infected 10.1% of the bovines. A low prevalence was found for Babesia infections (7.9%) with B. bigemina as the most frequent species. Some animals were infected with T. ovis and B. occultans. Veterinary practitioners and stakeholders should be made aware of the existence of a relatively high prevalence of carrier animals infected with T. annulata in Portugal, given the potential threat this pathogenic parasite represents to the cattle industry.

Parasites and malignancies, a review, with emphasis on digestive cancer induced by Cryptosporidium parvum (Alveolata: Apicomplexa)

The International Agency for Research on Cancer (IARC) identifies ten infectious agents (viruses, bacteria, parasites) able to induce cancer disease in humans. Among parasites, a carcinogenic role is currently recognized to the digenetic trematodes Schistosoma haematobium, leading to bladder cancer, and to Clonorchis sinensis or Opisthorchis viverrini, which cause cholangiocarcinoma. Furthermore, several reports suspected the potential association of other parasitic infections (due to Protozoan or Metazoan parasites) with the development of neoplastic changes in the host tissues. The present work shortly reviewed available data on the involvement of parasites in neoplastic processes in humans or animals, and especially focused on the carcinogenic power of Cryptosporidium parvum infection. On the whole, infection seems to play a crucial role in the etiology of cancer.

Corpuscular oxidation in newborn crossbred calves naturally infected with Theileria annulata

Erythrocytic lipid peroxidation has been implicated as a cause of anemia in Theileria annulata infection in cattle. The present study aimed to evaluate oxidative damage of membrane lipids and proteins in addition to hemoglobin (Hb) as three criterions of erythrocyte oxidation and their relation to erythrocyte deformability and anemia of newborn crossbred calves (Friesian × Egyptian Balady breed) naturally infected with T. annulata. Twenty-five T. annulata-infected calves (aged 20-30 days) along with 15 age matched healthy controls were used. Percentage of parasitemia varied from 12% to 63% (34.76 ± 3.05%). In comparison to controls, infected calves showed increased levels (P<0.001) of lipid peroxidation (malondialdehyde; MDA, 52%) and protein oxidation (protein carbonyls; PCs, 132%) in erythrocyte membrane as well as increased values of Hb oxidation (methemoglobin; MetHb, 186%), corpuscular osmotic fragility (15.1%) and hemolysis (free Hb; 195.5%). Parasitemia was positively correlated with MDA (r=0.41, P=0.039), PCs (r=0.45, P=0.023) and MetHb (r=0.40, P=0.042). Also, percent of erythrocytic deformability (echinocytosis) was positively correlated with MDA (r=0.49, P=0.013) and PCs (r=0.63, P<0.001). On the other hand, erythrocytic packed cell volume was negatively correlated with MDA (r=-0.44, P=0.028), PCs (r=-0.72, P<0.001) and MetHb (r=-0.42, P=0.037). In conclusion, T. annulata infection is associated with a parasitic burden-dependant oxidative damage to the erythrocyte membrane protein and lipid contents in addition to Hb. This oxidative damage is linked to the morphological changes of the erythrocyte and may act as mechanisms contribute to pathogenesis of anemia in T. annulata infection in newborn calves.