A molecular survey of bovine Theileria parasites among apparently healthy cattle and with a note on the distribution of ticks in eastern Turkey

Wide bovine tick-borne pathogen spectrum: Predominancy of Theileria annulata and the first molecular detection of Ehrlichia minasensis in Turkey

Vector-borne diseases indulge in severe economic losses in the livestock industry by adversely affecting cattle breeding in tropical and subtropical zone countries, including Turkey, encompassing a wide land area representing diverse climatic conditions. This study aimed to investigate significant bovine tick-borne piroplasm, rickettsia, and some other bacterial agents by genus- or species-specific PCR and nested PCR techniques in Turkey. A total of 210 cattle blood samples were collected from sixteen provinces in different geographical regions of Turkey. PCR analyses were performed targeting the detection of Babesia/Theileria/Hepatozoon sp. 18S rRNA, Babesia/Theileria sp. 18S rRNA (V4), B. bigemina RAP-1a, B. bovis SBP-4, B. ovata AMA-1, B. naoaki AMA-1, T. annulata Tams-1, T. orientalis MPSP, T. mutans 18S rRNA, Anaplasma/Ehrlichia sp. 16S rRNA, A. marginale MSP4, A. bovis 16S rRNA, A. phagocytophilum 16S rRNA, A. capra 16S rRNA, E. ruminantium pSC20, Mycoplasma sp. 16S rRNA, and Coxiella burnetii 16S rRNA genes. Overall, 133 (63.3%) cattle were found to be infected with at least one of the following protozoan or bacterial pathogens; B. bovis, B. bigemina, B. occultans, T. annulata, T. orientalis, A. marginale, A. phagocytophilum, and Mycoplasma sp. The total prevalence of pathogens was determined as follows; 0.5% B. bovis, 0.5% B. bigemina, 1.4% B. occultans, 41.0% T. annulata, 1.4% T. orientalis, 10.5% A. marginale, 13.8% A. phagocytophilum, 0.5% A. bovis, 2.9% Uncultured Anaplasma sp., 0.5% E. minasensis, 0.5% Uncultured Ehrlichia sp., and 23.3% Mycoplasma sp. Moreover, large part of the total infection (n:133) was composed of single infections (63.9%); however, double (24.8%), triple (7.5%), quadruple (2.3%), and quintuple (1.5%) co-infections were also encountered. In addition to some bovine pathogens such as B. occultans, T. orientalis, A. bovis, M. wenyonii, and Candidatus Mycoplasma haemobos, which were rarely reported in Turkey, sequencing and phylogenetic analysis revealed the first detection of Uncultured Ehrlichia sp. (0.5%), and E. minasensis (0.5%) with 100% nucleotide sequence identities. The study also indicates that the spectrum of pathogens harbored by Turkish cattle is quite wide, and these pathogens cause multiple co-infections with various combinations, and T. annulata stands out as the primary bovine pathogen among them.

Characterisation of field tropical Theileriosis and associated risk factors in two bioclimatic areas of Algeria

Tropical theileriosis (TT) is a tick-borne disease caused by Theileria annulata and commonly infects cattle in tropical and subtropical regions, including Algeria. It is a significant obstacle to cattle breeding programs established to improve production in Algeria. The present investigation aimed to estimate the current molecular prevalence, risk factors, and genetic characterisation of T. annulata in two bioclimatic areas of Algeria. In a cross-sectional study, 679 blood samples (629 from healthy cattle selected on farms and 50 from diseased cattle identified by veterinarians) were collected from the humid (n = 307+50) and semi-arid (n = 322) areas and screened by blood smear examination followed by polymerase chain reaction targeting cytochrome oxidase subunit 3 (cox III) mitochondrial and the 18S ribosomal RNA (18S rRNA) genes for Theileria spp. Seventy-six positive samples (56 clinically healthy and 20 with clinical signs) for Theileria spp. were confirmed to be T. annulata by the merozoïtes surface antigen-1 (Tams1) gene showing a rate of 8.9 % in clinically healthy and 40.0 % in suspected cattle. Among the 307 bloods samples collected from healthy cattle in the humid area, 25 cattle (8.1 %) were positive for T. annulata. Of the 322 healthy cattle from the semi-arid site, 31 (9.6 %) were carriers of T. annulata DNA. In subclinical population, demographic and environmental parameters analysis indicated that T. annulata infection was higher in adult crossbred cattle raised in the intensive and semi-intensive system (P<0.001). The multiple logistic regression analysis showed that age, breed, farming system, and bioclimatic area are potential risk factors for T. annulata infection in cattle (P<0.05). Multiple alignments of cox III sequences of T. annulata showed high heterogeneity with 25 polymorphic sites (nucleotide diversity π = 0.02402), resulting in two haplotypes with a low genetic diversity index (Hd) of 0.533. The 18S rRNA sequence alignment revealed only one T. annulata genotype with 100 % identity to the strains isolated from cattle and ticks in Mediterranean and Asian countries. Our preliminary results will serve as a basis for further studies on the genetic diversity and molecular epidemiology of T. annulata.

The Spatial Distribution of Crimean-Congo Haemorrhagic Fever and Its Potential Vectors in Europe and Beyond

Crimean-Congo haemorrhagic fever (CCHF) is considered to be spreading across the globe, with many countries reporting new human CCHF cases in recent decades including Georgia, Türkiye, Albania, and, most recently, Spain. We update a human CCHF distribution map produced in 2015 to include global disease occurrence records to June 2022, and we include the recent records for Europe. The predicted distributions are based on long-established spatial modelling methods and are extended to include all European countries and the surrounding areas. The map produced shows the environmental suitability for the disease, taking into account the distribution of the most important known and potential tick vectors Hyalomma marginatum and Hyalomma lusitanicum, without which the disease cannot occur. This limits the disease's predicted distribution to the Iberian Peninsula, the Mediterranean seaboard, along with Türkiye and the Caucasus, with a more patchy suitability predicted for inland Greece, the southern Balkans, and extending north to north-west France and central Europe. These updated CCHF maps can be used to identify the areas with the highest probability of disease and to therefore target areas where mitigation measures should currently be focused.

First molecular identification of multiple tick-borne pathogens in livestock within Kassena-Nankana, Ghana

The risk of pathogen transmission continues to increase significantly in the presence of tick vectors due to the trade of livestock across countries. In Ghana, there is a lack of data on the incidence of tick-borne pathogens that are of zoonotic and veterinary importance. This study, therefore, aimed to determine the prevalence of such pathogens in livestock using molecular approaches. A total of 276 dry blood spots were collected from cattle (100), sheep (95) and goats (81) in the Kassena-Nankana Districts. The samples were analyzed using Polymerase Chain Reaction (qPCR) and conventional assays and Sanger sequencing that targeted pathogens including Rickettsia, Coxiella, Babesia, Theileria, Ehrlichia and Anaplasma. An overall prevalence of 36.96% was recorded from the livestock DBS, with mixed infections seen in 7.97% samples. Furthermore, the prevalence of infections in livestock was recorded to be 19.21% in sheep, 14.13% in cattle, and 3.62% in goats. The pathogens identified were Rickettsia spp. (3.26%), Babesia sp. Lintan (8.70%), Theileria orientalis (2.17%), Theileria parva (0.36%), Anaplasma capra (18.48%), Anaplasma phagocytophilum (1.81%), Anaplasma marginale (3.26%) and Anaplasma ovis (7.25%). This study reports the first molecular identification of the above-mentioned pathogens in livestock in Ghana and highlights the use of dry blood spots in resource-limited settings. In addition, this research provides an update on tick-borne pathogens in Ghana, suggesting risks to livestock production and human health. Further studies will be essential to establish the distribution and epidemiology of these pathogens in Ghana.

Oriental theileriosis associated with a new genotype of Theileria orientalis in buffalo (Bubalus bubalis) calves in Uttar Pradesh, India

Theileria orientalis is known to cause a benign infection in cattle and buffalo (Bubalus bubalis). However, the Ikeda and Chitose genotypes of the parasite cause lethal disease in beef and dairy cattle. Recently an outbreak of clinical oriental theileriosis occurred in buffalo calves in a Government Animal Husbandry and Agricultural Farm located in Uttar Pradesh, India. Examination of Giemsa stained thin blood smears revealed typical rod-shaped T. orientalis piroplasms in the erythrocytes. The clinical signs included pyrexia, nasal discharge, lacrimation, lethargy, inappetence and anaemia with varying degrees of paleness of the visible mucous membranes. Vascular congestion in internal organs, pulmonary emphysema and consolidation of lungs, focal areas of necrosis in the heart with mononuclear cell infiltration, focal mononuclear cell aggregation in the cortex and tubular degeneration of the kidney were significant necropsy findings. The T. orientalis major piroplasm surface protein (MPSP) gene was amplified by polymerase chain reaction (PCR) using specific primers. The nucleotide sequence analysis of the PCR product revealed 84.8% identity between the T. orientalis Uttar Pradesh isolate and other reference genotypes available in the public domain. Furthermore, the phylogenetic analysis of the MPSP gene sequence ratified that this is a new genotype of T. orientalis. This is the first report of a clinical outbreak of oriental theileriosis in Indian buffalo calves caused by a novel genotype of T. orientalis.

Detection of Theileria orientalis Genotypes from Cattle in Kyrgyzstan

The ikeda and chitose genotypes of Theileria orientalis, which for many years were thought to be benign, cause a disease that results in significant economic losses in the cattle industry. This study was carried out in order to determine the genotypes of T. orientalis in cattle in Kyrgyzstan, and 149 archived DNA samples known to be T. orientalis were analyzed by the PCR amplification of the major piroplasm surface protein (MPSP) gene region. Single-Strand Conformation Polymorphism (SSCP) analysis was performed to uncover the nucleotide changes in the archived DNA samples, and 15 samples showing different band profiles were subjected to sequence analysis. As a result of the sequence analysis, it was seen that the samples belonged to the buffeli and chitose A genotypes. In order to identify mixed genotypes, PCR was performed using primers specific for these genotypes, and buffeli (type 3), chitose (type 1) and buffeli+chitose were found to be positive in 26.2%, 2% and 71.8% of samples, respectively. As a result of this study, we showed the presence of buffeli (type 3) and chitose (type 1) genotypes of T. orientalis in cattle in Kyrgyzstan. Comprehensive epidemiological studies are needed to understand the clinical infections caused by the pathogenic chitose A and to determine the geographical distribution and different genotypes of T. orientalis.

Seroprevalence and risk factors of tropical theileriosis in smallholder asymptomatic large ruminants in Egypt

Knowledge of the prevalence and epidemiological determinants of tropical theileriosis in large ruminants, particularly in the asymptomatic carrier, is crucial for designing and implementing effective host-specific control measures. This study aimed to estimate the seroprevalence of tropical theileriosis in asymptomatic cattle and water buffaloes and identify the potential risk factors of theileriosis in large ruminants raised under smallholder-production system in Egypt. A cross-sectional study was conducted in five districts of the Sharkia governorate from March 2019 to February 2020. In total, 350 serum samples were collected from cattle and water buffaloes under smallholder-production system and tested for Theileria annulata antibodies using the indirect antibody fluorescence test (IFAT). Data on species, host characteristics, presence of ticks, season, and districts were collected at sampling using a questionnaire. A multivariable mixed-effects logistic regression model was built to determine the potential risk factors associated with T. annulate seropositivity of the animals. The overall apparent seroprevalence of T. annulata in 350 tested animals was 70%. In the univariable analyses, cattle compared to buffaloes, younger animals compared to older ones, animals with ticks on their bodies, and warmer seasons were all associated with a higher likelihood of seropositive results in the study population while sex of the animals was not associated with seropositivity. The final multivariable model showed that animals with ticks on their bodies had 3.5× higher odds of seropositivity than those with no ticks (P < 0.001), and warmer seasons were associated with the higher odds of infection compared to winter (P = 0.003). The high seroprevalence of tropical theileriosis in the study region indicates that the disease is endemic among smallholders of large ruminants. The identified risk factors of T. annulata-seropositivity in asymptomatic carrier animals provides evidence-based guidance for adopting effective intervention measures.

Molecular epidemiology and genetic characterization of Theileria orientalis in cattle

Theileria orientalis (T. orientalis) is a benign species of Theileria that is found all throughout the world, including Egypt. The purpose of this work was to determine the current status of T. orientalis infection in cattle, as well as to define T. orientalis genetic diversity using the major piroplasm surface protein (MPSP) genes. In 2020, blood samples from 500 asymptomatic cattle were collected, which live in four different governorates at northern Egypt and examined using PCR assay based on MPSP gene. Overall, 44 blood samples (8.8%, 44/500) were positive for T. orientalis, and the highest prevalence rate was observed in Kafer ElSheikh while it was relatively low in Gharbia governorate. Moreover, based on multivariable analysis, the risk of infection with T. orientalis infection was higher in mixed breed cattle and in animals of age group more than 3 years compared to other. Additionally, absence of acaricide application, infestation with ticks, and communal grazing system were identified as potential risk factors for T. orientalis infection. Phylogenetic analysis revealed that the isolates studied belonged to two MPSP genotypes, types 1 and 2. These findings reveal that the MPSP genotypes discovered in the present work displayed genetic variation that was linked to geographic area. Therefore, further research should be focused on developing an effective T. orientalis monitoring and preventive program.

A Multi-copy Nucleic Acid-Based Diagnostic Test for Bovine Tropical Theileriosis

BACKGROUND

Bovine tropical theileriosis (BTT) is a haemoprotozoan tick-borne disease that implicates huge losses to livestock in terms of considerable mortality and morbidity in tropical and subtropical regions of the globe. Currently available diagnostic methods have less specificity and sensitivity towards the detection of Theileria species. Therefore, an attempt was made to diagnose Theileria annulata by targeting a multi-copy gene, viz. mitochondrially encoded cytochrome b (MT-CYB) gene via polymerase chain reaction (PCR) in different agro-zones of India.

METHODS AND RESULTS

129 cattle blood samples were collected from major livestock rearing regions of India and processed for both molecular and microscopic techniques. Screening of Giemsa-stained thin blood smears was able to detect 14 samples (10.85%) as positive for T. annulata. However, the MT-CYB gene-based PCR assay detected 107 samples (82.94%) positive for T. annulata out of 129 samples. Furthermore, the MT-CYB gene-based PCR assay was standardized in terms of its sensitivity and specificity. Specificity of PCR assay was evaluated against other common haemoprotozoan parasites of tropical countries viz. Babesia bigemina, Anaplasma marginale and Trypanosoma evansi. The multi-copy MT-CYB gene-based PCR assay provided an optimum level of sensitivity (up to the level of 10 femtogram) and high specificity. Haematological examination (Hb, PCV and TLC) of 113 samples revealed significantly (p < 0.05) decreased Hb and PCV levels in positive animals in comparison with the control group of healthy animals. However, the control group had significantly higher (p < 0.001) TLC levels than the positive group.

CONCLUSION

The MT-CYB gene-based PCR assay was found to be highly sensitive that can accurately detect the occurrence of T. annulata infection in carrier animals which are potential infection sources to healthier populations in naive demographic locations through infected ticks.

Emergence of Theileria species in ticks from free-ranging domestic animals in Raymond Mhlaba Local Municipality, South Africa

Ticks infestation and diseases associated with it, are becoming a major life threatening concern to wildlife, domesticated animals and human health in general. Besides causing skin damage, ticks infestations have become a growing burden in food security and transmission of multiple pathogens. There is paucity of data on the occurrence of etiologic agents of tick-borne diseases in the Eastern Cape Province South Africa. We therefore carried out a molecular surveillance on Babesia and Theileria species in ticks obtained from livestock in Raymond Mhlaba District Municipality of the Province. A total of 962 ticks were collected and were morphologically identified and processed for DNA extraction using commercial DNA extraction kit. The extracted DNA samples were used to molecular identification of the ticks, and also to assess the occurrence of the Babesia and Theileria spp by PCR using genus specific primers. Positive amplicons obtained were sequenced, processed and characterised using appropriate bioinformatics tools. The molecular and morphological identifications of ticks obtained from the domestic animals in the study areas revealed that they belong to three different genera namely: Haemophalis, Rhipicephalus, and Amblyomma in ascending order of their abundance. Furthermore, the DNA of Theileria spp. was detected from 10 out of 962 ticks screened, with an overall infection of about 1% for Rhipicephalus spp., while none of the ticks was positive for Babesia spp. The phylogenetic analysis of the 10 theilerial sequences showed that nine (9) clustered distinctly within the T. orientalis complex clade, while only one (1) sequence formed a cluster with reference sequences of T. velifera. The findings from this study therefore expand the knowledge on recent emergence of Theileria spp. in livestock reared in the study area. This calls for an urgent effort in curbing the further spread of the pathogens in the area and beyond.

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Distribution of ticks' species in domestic animals was described.

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Emergence of theilerial parasites in ticks from free-ranging domestic animals was observed

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Rhipicephalus spp. of ticks serve as the major transmission vector for Theileria spp. in the Eastern Cape Province, South Africa

Babesiosis and Theileriosis in North America

Babesia and Theileria are apicomplexan parasites that cause established and emerging diseases in humans, domestic and wild animals. These protozoans are transmitted by Ixodid ticks causing babesiosis or theileriosis, both characterized by fever, hemolytic anemia, jaundice, and splenomegaly. In North America (NA), the most common species affecting humans is B. microti, which is distributed in the Northeastern and Upper Midwestern United States (US), where the tick vector Ixodes scapularis is established. In livestock, B. bovis and B. bigemina are the most important pathogens causing bovine babesiosis in tropical regions of Mexico. Despite efforts toward eradication of their tick vector, Rhipicephalus microplus, B. bovis and B. bigemina present a constant threat of being reintroduced into the southern US and represent a continuous concern for the US cattle industry. Occasional outbreaks of T. equi, and T. orientalis have occurred in horses and cattle, respectively, in the US, with significant economic implications for livestock including quarantine, production loss, and euthanasia of infected animals. In addition, a new species, T. haneyi, has been recently discovered in horses from the Mexico-US border. Domestic dogs are hosts to at least four species of Babesia in NA that may result in clinical disease that ranges from subclinical to acute, severe anemia. Herein we review the pathogenesis, diagnosis, and epidemiology of the most important diseases caused by Babesia and Theileria to humans, domestic and wild animals in Canada, the US, and Mexico.

Molecular characterization and phylogenetic study of Theileria sp. parasites detected in cattle from the Moscow region of Russia

Theileriae are obligate intracellular protozoan parasites which are transmitted by ixodid ticks and infect both wild and domestic ruminants worldwide. Theileriosis causes significant economic losses to the livestock industry in many countries due to the high morbidity and mortality in cattle herds. In Russia, information concerning prevalence of Theileria spp. in cattle is very limited. This study reports on molecular characterization and phylogenetic analysis of Theileria spp. parasites detected in cattle from the Moscow region of Russia. Phylogenetic analysis based on the full length 18S rRNA gene revealed that the Russian Theileria parasites belong to the Theileria orientalis / Theileria buffeli / Theileria sergenti group and share a common genotype with T. buffeli Marula from Kenya, T. buffeli isolates from Japan and South Korea, T. orientalis isolate from Australia and T. sergenti isolate from Japan, which belong to the pathogenic Chitose genotype.

The role of sheep (Ovis aries) in maintaining Theileria orientalis Ikeda type infection

Theileria orientalis is a tick‒borne intracellular parasite of red blood cells that causes severe and mild infections in various ruminants worldwide. To date there have been 11 types identified within this species, of which 4 types are presently found in New Zealand cattle. Since 2012, New Zealand has suffered a substantial epidemic of infectious bovine anaemia in both dairy and beef cattle associated with the Ikeda type. The speed at which the disease spread through the North Island suggested that other species could have been involved in transmission. The aim of a series of related experiments was to test the null hypothesis that sheep cannot maintain T. orientalis Ikeda type infection or infect ticks that feed on them. Several studies were conducted over 2 years to address this hypothesis which together showed that sheep can have detectable levels of T. orientalis Ikeda type infection in both the acute and chronic phase and that Haemaphysalis longicornis larvae can become infected when feeding on sheep. No anaemia, weight loss or clinical disease was recorded in the sheep in the acute phase of infection. The levels of infection recorded in the sheep were much lower than those found in cattle, consistent with the sheep being asymptomatic carriers of T. orientalis Ikeda type infection.

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.

Endemic infection of cattle with multiple genotypes of Theileria orientalis on the Northern Tablelands of New South Wales despite limited presence of ticks

Bovine theileriosis, caused by the Theileria orientalis complex, causes a mild persistent infection with the severity dependent on the infecting genotype and host exposure status. Clinical theileriosis was first detected on the Northern Tablelands of NSW in 2009 and a high prevalence of infection in cattle reported in 2013. However, the parasite was not genotyped and likely vectors not investigated. In response to ongoing clinical cases, here we identify the Theileria genotypes present in the region and potential vectors. Genotype-specific multiplex qPCR of 90 blood samples from eight farms revealed a 100 % prevalence of T. orientalis in individual cattle with concurrent infection with all three genotypes present in 73 % of cases. The prevalence of the pathogenic genotype (Ikeda) differed significantly between farms; however, the level of parasitemia was not affected by genotype or associated with clinical disease. Parasitaemia levels were higher in heifers than cows. Questing tick collection on six of the farms between November 2017 and May 2019 yielded 358 questing ticks from one farm, all of which were morphologically identified as Haemaphysalis bancrofti. Larvae accounted for 59 % of the ticks followed by nymphs (34 %) and adults (7%). Theileria was detected only in nymphs with Ikeda and Buffeli genotypes each being detected in one of four pools of ticks. The high prevalence of co-infection with three genotypes of T. orientalis indicates that they are now endemic in the region and confirms the lack of cross-protection between genotypes. This is the first detection of T. orientalis in questing H. bancrofti ticks: indicating that it may be a vector for T. orientalis in this region. However, the high prevalence of bovine infection is at odds with the absence of captured ticks or history of tick infestation on five of the six farms raising the possibility that other vectors or transmission pathways play key roles.

Targeted Next-Generation Sequencing and Informatics as an Effective Tool to Establish the Composition of Bovine Piroplasm Populations in Endemic Regions

Protists of the genera Babesia and Theileria (piroplasms) cause some of the most prevalent and debilitating diseases for bovines worldwide. In this study, we established and used a next-generation sequencing-informatic approach to explore the composition of Babesia and Theileria populations in cattle and water buffalo in a country (Pakistan) endemic for these pathogens. We collected individual blood samples from cattle (n = 212) and water buffalo (n = 154), extracted genomic DNAs, PCR-amplified the V4 hypervariable region of 18S small subunit rRNA gene from piroplasms, sequenced amplicons using Illumina technology, and then analysed data using bioinformatic platforms. The results revealed piroplasms in 68.9% (252/366) samples, with overall occurrence being markedly higher in cattle (85.8%) than in water buffaloes (45.5%). Babesia (B.) occultans and Theileria (T.) lestoquardi-like species were recorded for the first time in Pakistan, and, overall, T. annulata was most commonly detected (65.8%) followed by B. bovis (7.1%), B. bigemina (4.4%), and T. orientalis (0.5%), with the genetic variability within B. bovis being pronounced. The occurrence and composition of piroplasm species varied markedly across different agro-ecological zones. The high detection of T. annulata in asymptomatic animals suggested a relatively high level of endemic stability of tropical theileriosis in the bovine population.

Molecular detection and phylogeny of Anaplasma spp. in cattle reveals the presence of novel strains closely related to A. phagocytophilum in Turkey

Anaplasma species are obligate intracellular rickettsial pathogens that affect the health of humans and animals. In this study, we investigated the presence and frequency of Anaplasma species by 16S rRNA PCR-RLB, RFLP, and DNA sequencing in 200 apparently healthy cattle. Anaplasma spp. overall infection rate was 38.5 % (77/200) by RLB. The frequency of single and mixed infections was 31.5 % (63/200) and 7% (14/200), respectively. The most common species was A. marginale (32.5 %), followed by A. centrale (5.5 %), Anaplasma/Ehrlichia catc-all (5.5 %) and Anaplasma sp. Omatjenne (2.5 %). No A. phagocytophilum and A. bovis were detected in the tested animals. Eleven of 77 PCR-positive amplicons gave positive reactions to the catch-all probes but did not show any signals to the species-specific probes, but PCR-RFLP results showed that these amplicons were A. phagocytophilum-like 1 and A. phagocytophilum-like 2 strains. Sequencing and phylogenetic analyses based on 16S rRNA gene validated RFLP findings and provided evidence for the circulation of A. phagocytophilum-like-1 and 2 strains in Turkish cattle. This is the first report of the presence of A. phagocytophilum-like strains in the country. These findings indicate that A. phagocytophilum-like 1 and 2 strains should be taken into account in the differential diagnosis with bovine anaplasmosis.

Genetic Diversity of Bovine Hemoprotozoa in South Korea

Tick-borne pathogens cause economically significant diseases in cattle. Theileria spp. are parasitic protozoa and the causative agent of bovine theileriosis. Here we report the distribution and risk factors of bovine Theileria using blood samples taken between 2018 and 2019. Of 737 tested cattle, nine animals (1.2%) were positive for Theileria orientalis infection by 18S rRNA gene amplification. Further analysis of the infected samples using the T. orientalis major piroplasm surface protein (MPSP) gene revealed five different genotypes circulating in the population: Types 1, 2, 3, 7, and N3. To the best of our knowledge, this is the first research to describe the existence of the T. orientalis MPSP genotype N3 in South Korea. Although the prevalence of bovine T. orientalis was low, our study offers data on the geographical distribution and prevalence of bovine Theileria spp. in South Korea. Further studies are warranted to determine the correlation of clinical symptoms with parasite MPSP genotypes. Our data provide epidemiological information to help control bovine theileriosis in South Korea.

Clinical and Pathological Studies on Cattle Experimentally Infected with Theileria annulata in China

Theileriosis is an important tick-borne protozoosis that causes high morbidity and mortality in cattle. In this study, the pathological and clinical characteristics of cattle experimentally infected with Theileria annulata were investigated. The clinical findings revealed typical signs of bovine theileriosis, including fever, enlargement of superficial lymph nodes, anemia, and respiratory distress. The most common pathological features were petechial and ecchymotic hemorrhages on the mucosa and serosal surface, severe jaundice, pulmonary edema and emphysema, multifocal necrosis and numerous ulcerations in the abomasum, congestion and marble-like discoloration of the spleen, and severe intestinal ecchymotic hemorrhages. The main histological characteristics were proliferation and infiltration of lymphocytes, plasma cells, and macrophages in the lymph nodes, spleen, and lymph node mass. Macroschizonts were observed in the cytoplasm of lymphocytes and macrophages of the lymph nodes and spleen. This study has significance for basic research and the clinical detection and diagnosis of Theileria annulata infection and can aid the prevention and control of theileriosis and future studies of the pathogenic mechanisms.

Molecular characterization and phylogenetic analysis of Babesia and Theileria spp. in Sardinian ruminants

Tick-borne diseases (TBDs) caused by Theileria and Babesia spp. are common in tropical and subtropical regions. This study investigates the presence of Theileria and Babesia spp. in ruminants from a subtropical Mediterranean region (Sardinia, Italy), a hotspot for ticks infestations. A total of 141 blood samples from healthy and symptomatic ruminants (showing symptoms consistent with tick-borne disease) were screened using a polymerase chain reaction test based on the amplification of the 18 s rRNA fragment. A total of 19/50 sheep (38%), 34/43 bovine (79.1%), and 5/48 goats (10.4%) tested positive to Babesia/Theileria. Phylogenetic analysis assigned all sequences obtained from sheep to the T. ovis cluster, while bovine and goats sequence types grouped in the Theileria buffeli/sergenti/orientalis group. One sequence type, isolated from a symptomatic bovine, clustered with B. major. Information on presence and frequency of piroplasms in ruminants increase our knowledge about the circulation of these pathogens in Sardinian animals and add up to previous studies conducted in ticks in the same area. Results also highlight the importance of subtropical Mediterranean environments as hotspots for ruminants piroplasmosis with potential impact on Veterinary Health.

Comparison of Viromes in Ticks from Different Domestic Animals in China

Ticks are involved in the transmission of various arboviruses and some tick-borne viruses pose significant threats to the health of humans or livestock. This study aimed to investigate the geographical distribution of tick species and tick-associated viruses in central and eastern China. Total 573 ticks from domestic animals including dogs, sheep and cattle were collected in 2017. Two genera of ticks were identified including Rhipicephalus and Haemaphysalis. Sequencing was performed on Miseq Illumina platform to characterize the tick viromes from the four different sampling locations. Following trimming, 13,640 reads were obtained and annotated to 19 virus families. From these sequences, above 37.74% of the viral reads were related to the RNA viruses. Virome comparison study revealed that the tick viral diversity was considerably different in the two identified tick genera. The viral diversity of R. microplus was significantly different from that of other Rhipicephalus species. On the other hand, substantial overlap in viral species was observed between the same genera. In addition, we found no evidence that the natural host played a major role in shaping virus diversity based on the comparison of their viromes. Rather, the geographic location seems to significantly influence the viral families. Phylogenetic study indicated that the novel negative-sense RNA viruses identified in this study was closely related to Bole tick virus 1 and 3 viruses. In conclusion, the present study provides a baseline for comparing viruses detected in ticks, according to species, natural hosts, and geographic locations.

An appraisal of oriental theileriosis and the Theileria orientalis complex, with an emphasis on diagnosis and genetic characterisation

Oriental theileriosis, a tick-borne disease of bovids caused by members of the Theileria orientalis complex, has a worldwide distribution. Globally, at least 11 distinct genotypes of T. orientalis complex, including type 1 (chitose), type 2 (ikeda), type 3 (buffeli), types 4 to 8, and N1-N3, have been described based on the sequence of the major piroplasm surface protein (MPSP) gene. Of these 11 genotypes, mainly ikeda and chitose are known to be pathogenic and cause considerable morbidity (including high fever, anaemia, jaundice and abortion), production losses and/or mortality in cattle. Mixed infections with two or more genotypes of T. orientalis is common, but do not always lead to a clinical disease, posing challenges in the diagnosis of asymptomatic or subclinical forms of oriental theileriosis. The diagnosis of oriental theileriosis is usually based on clinical signs, the detection of piroplasms of T. orientalis in blood smears, and/or the use of serological or molecular techniques. This paper reviews current methods used for the diagnosis of T. orientalis infections and the genetic characterisation of members of the T. orientalis complex, and proposes that advanced genomic tools should be established for investigations of these and related haemoparasites.

A longitudinal study of the effect of Theileria orientalis Ikeda type infection on three New Zealand dairy farms naturally infected at pasture

The aims of this study were to monitor the change in Theileria orientalis Ikeda type infection intensity, haematocrit, milk production and reproduction on three New Zealand spring calving dairy herds, over the 2014-2015 milking season. Three spring calving dairy farms, A, B and C, from high risk (endemically stable), low risk (endemically unstable), and zero risk (disease-free) tick areas respectively were followed through the 2014-2015 milking season. On Farms, A and B, 100 cows were randomly selected at the first visit, and the same cows blood sampled every month thereafter, whilst on Farm C, the whole herd was blood sampled bimonthly (140 cows). Blood samples were tested for haematocrit, by centrifugation, and Ikeda infection intensity, using qPCR. Animals that were Ikeda type PCR positive at the first sampling were described as prevalence cases and cows that were negative at the first sampling and became PCR positive during the sampling period were described as incidence cases. Production and reproduction data were accessed through LIC MINDA® and milk production data was standardised to energy corrected milk (ECM). In addition, the effect of buparvaquone (BPQ) treatment on milk production was estimated on Farm B. The prevalence of infection at the first sampling was 100 % on Farm A, 57 % on Farm B and 26 % on Farm C. The incidence risk of infection over the sampling period on Farms B and C was 25 % and 2 % and the incident rate was 0.026 and 0.002 cases per cow-month respectively. The average infection intensity for prevalence cases on all farms was low throughout the milking season, <7000 Ikeda organisms/μL however, cases of anaemia still occurred. There was no direct effect of infection intensity on milk production or from being a prevalence case compared to an uninfected cow on milk production, across all farms. However, on Farm B there was a loss of 266 kg (95 % CI 82 ̶ 450) ECM (∼20 kg milk solids) for incidence cases and a loss of 458 kg (95 % CI 211 ̶ 710) of ECM for buparvaquone treated cows, compared to uninfected cows. No significant effect of Ikeda infection on reproduction could be shown for Farms B and C, reproductive data for Farm A was not available. The effect of T. orientalis Ikeda type infection on production and reproduction appears to be minimal once animals have passed through the acute phase of infection and reached the chronic, asymptomatic carrier phase of infection.

Rapid detection and differentiation of Theileria annulata, T. orientalis and T. sinensis using high-resolution melting analysis

Bovine theileriosis, caused by protozoan parasites of the genus Theileria, presents with various clinical symptoms. In cattle, clinical presentations and outcomes of bovine theileriosis are closely correlated with the causative Theileria spp. Thus, accurate detection and discrimination of Theileria spp. are essential for epidemiological studies and for provision of clinical management strategies. High-resolution melting (HRM) analyses of two amplicons targeting the 18S rRNA indicated that T. annulata, T. orientalis, and T. sinensis isolated from China can be accurately detected and discriminated with the lowest detection limit of 1-10 copy numbers of plasmid bearing the 18S rRNA sequence. The approach was verified with DNA samples from experimentally infected cattle and field samples. Thus, this assay is useful for diagnosis of bovine theileriosis in field samples and experimentally infected animals, and could also be applicable for the survey of parasite dynamics, epidemiological studies.

Prevalence of bovine tropical theileriosis in sub-Himalyan region of northern India

The prevalence of bovine tropical theileriosis (BTT) caused by Theileria annulata was studied in large ruminants of sub-Himalyan region of northern India using thin blood smear examination (TBE), polymerase chain reaction (PCR) and loop mediated isothermal amplification (LAMP) assays. About 11.04% blood samples were found positive for BTT. Maximum seasonal prevalence of BTT was observed in summer followed by rainy season and winter. Month-wise maximum prevalence was recorded in May and minimum in January. Laboratory examination with Giemsa staining for Koch’s blue bodies (KBB) and piroplasms revealed that 3.75% samples were positive for theileriosis. LAMP method gave the highest level of sensitivity followed by AS-PCR and TBE. Hence, it is suggested that LAMP can be a better molecular diagnostic tool for large scale epidemiological studies of bovine tropical theileriosis. Our results provide better understanding of this haemoprotozoan parasite and hence may help in devising timely control measures.

First molecular survey of piroplasm species in cattle from Kyrgyzstan

Bovine piroplasmosis is a tick-borne disease caused by apicomplexan hemoparasites of the genera Theileria and Babesia. This study was carried out to assess the presence and frequency of piroplasm parasites in apparently healthy cattle in Kyrgyzstan. A total of 454 blood samples were collected from animals of various ages in eight villages located in the Chu valley and around the Lake Issyk Kul. The hypervariable V4 region of the 18S ribosomal RNA (rRNA) gene was amplified with a set of primers specific targeting members of the genera Theileria and Babesia. Amplified PCR products were hybridized onto a membrane to which generic and species-specific oligonucleotide probes were covalently linked. The results revealed the presence of three piroplasm species (Theileria orientalis, Babesia major, Theileria annulata). Theileria orientalis was the most prevalent species (32.8%; CI 28.5-37.3). Babesia major was the only species of Babesia found in any of the samples (1.3%; CI 0.5-2.8). The co-existence of Theileria annulata and T. orientalis was detected in nine animals (1.9%; CI 0.9-3.7). BLAST search revealed that the Theileria sequences shared 100% identity with the recently reported sequences for T. buffeli and T. annulata. The sequence of B. major was also 100% identical to an existing B. major sequence. This molecular survey provides important epidemiological data for control of bovine piroplasmosis caused by T. orientalis, B. major, and T. annulata in Kyrgyzstan.

Genetic diversity of Theileria orientalis from cattle in Turkey

Theileria orientalis is usually a benign parasite but some genotypes cause infection and economic losses to the cattle industry. This study was carried out to determine T. orientalis genotypes in cattle. T. orientalis positive 63 sample were analyzed by amplifying the MPSP gene region by PCR. As a result of the SSCP analysis, samples with different band profiles were sent to the sequence analysis and genotypes were determined. T. orientalis genotype-specific PCR was performed to determine the mix genotypes. Type 1 (chitose), type 3 and type 1-type 3 mix were found positive 11.1%, 46%, and 17.5% respectively. In addition, phylogenetic analysis was performed to separate the chitose genotypes, and two samples were found in chitose A, one sample was found in chitose B. Although chitose A genotype is suggested to be more pathogenic than chitose B, but there is little evidence for this. As a result of this study, we showed the presence of pathogenic genotype T. orientalis in Turkey. Therefore, extensive epidemiological studies are required to understand the geographic distribution, different genotypes and clinical pathologies of T. orientalis.

Prevalence studies for Theileria orientalis conducted during the early stages of the 2012 New Zealand epidemic of Theileria associated bovine anaemia

Since 1982 there have been two epidemics of bovine anaemia associated with Theileria orientalis infection (TABA) in New Zealand. The latest and more serious epidemic started in 2012 and is associated with the T. orientalis (Ikeda) type. In 2013 the Ministry for Primary Industries (MPI) carried out several epidemiological investigations on the TABA epidemic, which included a series of on-farm herd prevalence studies. The aims of this paper are to present and summarise the results of these herd prevalence studies. The data were collected from March 2013 to September 2013 and comprised 26 farms. For 21/26 of these farms, a T. orientalis (Ikeda) positive index case of TABA precipitated the follow-up herd prevalence study. Each herd prevalence study involved a random sample of 10 cows for haematocrit, for piroplasm counts (number of Theileria infected RBCs per 1000 RBCs) and for PCR molecular diagnosis. Animals were diagnosed anaemic if the haematocrit ≤0.24. The results showed that for the index cases, the average haematocrit = 0.10 L/L and the average piroplasm count = 10.9 Theileria infected RBCs per 1000 RBCs, and for the herd prevalence studies the average haematocrit = 0.26 and the average piroplasm count = 6.9. The average herd prevalence of T. orientalis (Ikeda) PCR positive cattle and of anaemic cattle was 87% and 26% respectively. For dairy herds (n = 7 herds) it took, on average, 80 days for the within herd prevalence of anaemia to return to zero after the initial diagnosis. In conclusion the prevalence studies showed that infection rates and anaemia rates were already high in herds when the index case of TABA was observed. At the time, these prevalence studies significantly added to our understanding of the epidemiology of the evolving T. orientalis (Ikeda) epidemic and furthermore met the New Zealand MPI objective of being rapid and applied, fit for purpose and completed at a relatively low cost.

A Molecular Survey of Rickettsias in Shelter Dogs and Distribution of Rhipicephalus sanguineus (Acari: Ixodidae) sensu lato in Southeast Turkey

Canine tick-borne pathogens are the source of emerging diseases and have important zoonotic relevance. Dogs play a major role in the transmission of several zoonotic tick-borne pathogens, as reservoirs and/or sentinels. To simultaneously detect Anaplasma and Ehrlichia species, a reverse line blot assay was conducted on 219 blood samples collected from autochthonous asymptomatic shelter dogs. One hundred and three (47.0%, CI 40.3-53.9) dogs were positive for one or both rickettsial pathogens. Seventy-one (32.4%, CI 26.3-39.0) dogs were infected with Anaplasma platys and 23 (10.5%, CI 6.8-15.3) with Ehrlichia canis. Concurrent infection with A. platys and E. canis was detected in nine (4.1%, CI 1.9-7.6) dogs. Partial sequences of the 16S ribosomal RNA gene shared 100% identity with the corresponding published sequences for A. platys and E. canis. Infection with Anaplasma phagocytophilum was not detected in the examined dogs. In total, 1018 (range 1-70, mean intensity 13.1, mean abundance 4.6) Rhipicephalus sanguineus (Latreille) (Acari: Ixodidae) sensu lato ticks (45.7% nymphs, 54.3% adults) were collected from the dogs. There was no significant association between Anaplasma/Ehrlichia infection and dog sex or age, but a significant correlation was found between rickettsia infection and presence of R. sanguineus. Improved tick control strategies to reduce the risk of these pathogens spreading among dogs and humans are needed in the region.

The effect of month, farm type and latitude on the level of anaemia associated with Theileria orientalis Ikeda type infection in New Zealand cattle naturally infected at pasture

Commencing in 2012, an epidemic of infectious bovine anaemia associated with Theileria orientalis Ikeda type has been present in New Zealand. The aims of this study were to analyse the temporal and spatial effects of T. orientalis Ikeda type infection on the sample submission rates and haematocrits of infected cattle over the first two years of the New Zealand epidemic. The data were collected from 30/08/2012 to 28/11/2014 and included all samples that met the case definition for Theileria associated bovine anaemia (TABA) and tested positive for T. orientalis Ikeda type by PCR. The sample submission rates by month and farm type were highly seasonal with dairy farm submissions peaking in September a month before beef farm submissions peaked. A second lesser peak of dairy farm submissions in April was absent for beef farms. A mixed effects model was fitted to the data and showed a significant interaction between farm production type (dairy or beef) and month of sampling (p=0.006) and between latitude and month of sampling (p=0.024). The estimated haematocrit, adjusted for month and latitude, for dairy cattle=0.125 (95%CI 0.121-0.129) and for beef cattle=0.151 (95% CI 0.138-0.165), p<0.0001. This research shows that infected beef animals tend to be less severely affected than dairy animals and that the month of sampling and latitude of the sampled farm have significant and interacting effects on the level of anaemia associated with T. orientalis Ikeda type infection.

Molecular prevalence and phylogenetic analysis of Theileria annulata and Trypanosoma evansi in cattle in Northern Tunisia

The present study aimed to estimate the molecular prevalence of Theileria annulata and Trypanosoma evansi infection in cattle in Northern Tunisia. A total number of 96 cattle from five farms were evaluated. T. annulata and T. evansi prevalences were 61% [56/66] and 10% [7/13], respectively, at a confidence interval (CI) of 95%, while co-infection was present in 6% [4/8] of the tested animals at a CI of 95%. There was a significant correlation between age and the prevalence of T. annulata infection, whereas, there was no significant association shown with the age of cattle and T. evansi infection. Sequence and phylogenetic analyses showed that the T. annulata Tams1 gene and T. evansi ITS1 rDNA gene were highly conserved with 97.1-100% and 98.3-100% sequence identity, respectively.

Historical review and insights on the livestock tick-borne disease research of a developing country: The Philippine scenario

Tick-borne diseases (TBDs) remain to be a global animal health threat. Developing countries like the Philippines is not exempt to this. Despite the potential impact TBDs can give to these countries, local government initiatives and researches remain to be limited. In the Philippines, most epidemiological studies were confined only to specific areas, and predominantly in the Northern Area. Due to its unique geography and limited studies, the current nationwide status of most TBDs could not be clearly established. This review mainly covered published studies and presented challenges in the conduct of TBD research in the Philippines, which may be similar to other Southeast Asian or developing countries. To date, reported livestock TBD pathogens in the Philippines include Anaplasma, Babesia, Theileria, and Mycoplasma spp. With the ubiquitous presence of the Rhipicephalus microplus ticks in the country, it is highly probable that other pathogens transmitted by these vectors could be present. Despite studies on different TBDs in the livestock sector, the Philippine government has not yet heightened its efforts to implement tick control measures as part of the routine animal health program for local farmers. Further studies might be needed to determine the nationwide prevalence of TBDs and the presence of other possible tick species and TBD pathogens. The Philippine scenario may present situations that are similar to other developing countries.

Hematological Changes Associated with Theileria orientalis Infection in Korean Indigenous Cattle

Tick-borne pathogens can cause serious problems in grazing cattle. However, little information is available on tick-mediated diseases in cattle grazing on mountains. Thus, this study aimed to understand the potential problems related to tick-borne diseases in grazing cattle through the investigation of prevalent tick-transmitted infections, and their associated hematological changes, in terms of season and grazing type in Korean indigenous cattle (=Hanwoo). Hanwoo cattle from 3 regions of the Republic of Korea (=Korea) were either maintained indoors or placed on grassy mountains from spring to fall of 2014 and 2015. Cattle that grazed in mountainous areas showed a greater prevalence of tick-borne infections with an increased Theileria orientalis infection rate (54.7%) compared to that in non-grazing cattle (16.3%) (P<0.001). Accordingly, the red blood cell (RBC) count and hematocrit (HCT) values of grazing cattle were significantly lower than those of non-grazing cattle throughout the season (P<0.05). Moreover, RBC, hemoglobin (Hb), and HCT of T. orientalis-positive group were significantly lower than those of T. orientalis-negative group (P<0.05). T. orientalis is a widespread tick-borne pathogen in Korea. Grazing of cattle in mountainous areas is closely associated with an increase in T. orientalis infection (RR=3.4, P<0.001), and with consequent decreases in RBC count and HCT. Thus, these findings suggest that the Hanwoo cattle in mountainous areas of Korea are at a high risk of infection by T. orientalis, which can lead to hematological alterations. This study highlights the necessity of preventive strategies that target T. orientalis infection.

Pathogenic genotype of major piroplasm surface protein associated with anemia in Theileria orientalis infection in cattle

Serious disease outbreaks in cattle caused by Theileria orientalis have emerged in the Asia-Pacific region. Genetic variables of the major piroplasm surface protein (MPSP) expressed on the surface of the piroplasm inside T. orientalis-infected erythrocytes are considered to be associated with variation in the pathogenicity of T. orientalis. Our study describes the clinically relevant MPSP types associated with anemia in Theileria-infected cattle. These results revealed that MPSP expression plays an important role in hematological alterations in Theileria-infected cattle, and that MPSP type 1 is strongly associated with bovine anemia, which can be a potential target for the prevention of bovine theileriosis.

A field evaluation of an isothermal DNA amplification assay for the detection of Theileria annulata infection in cattle

A loop-mediated isothermal amplification (LAMP) assay was evaluated for the detection of Theileria annulata infection in cattle. The results were compared with a real-time PCR used for the quantification of T. annulata parasitaemia. One hundred bovine blood samples from 16 cattle farms were tested with LAMP and real-time PCR, with T. annulata DNA being detected in 66% and 67% of the samples, respectively. The results showed that the LAMP assay detects a parasitaemia as low as 0.00025%, indicating a high analytical sensitivity of LAMP for clinical diagnosis of bovine theileriosis.

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.

Genetic characterization of Theileria orientalis from cattle in the Republic of Korea

Theileria orientalis is the causative agent of benign theileriosis, which is distributed mainly in Asian countries, and causes serious economic losses in the livestock industry. The present study was performed to investigate the epidemiology of T. orientalis infections in cattle in the Republic of Korea (ROK) and to characterize the genetic diversity of T. orientalis based on the major piroplasm surface protein (MPSP) genes. In 2015, between July and August, blood samples were collected from 138 asymptomatic cattle in four different geographical regions (Hoengseong, Jeongeup, Namwon, and Jeju island) in the ROK. In total, 57 blood samples (41.3 %, 57/138) were positive for T. orientalis based on PCR amplification of the MPSP gene. A high prevalence of T. orientalis infection was observed in Jeju island, whereas the infection rate was relatively low in Jeongeup. Phylogenetic analysis showed that isolates identified in this study belonged to four MPSP genotypes, specifically types 1, 2, 3, and 7. The distribution of the four genotypes varied considerably among the four regions; types 1, 2, and 3 were detected in Jeju island, whereas types 1 and 7 were found in Namwon, types 1 and 2 in Jeongeup, and type 2 in Hoengseong. To our knowledge, this is the first report on the identification of type 7 T. orientalis in cattle in the ROK. These results suggest that the MPSP genotypes detected in this study showed genetic diversity related to geographical location. Our findings revealed that the T. orientalis infection rate was relatively high, indicating that T. orientalis infection is closely associated with grazing. Of the four MPSP genotypes, the prevalence of the most pathogenic type 2 was relatively high in the ROK. Therefore, further studies should focus on the development of an effective monitoring and prevention program for T. orientalis.

Seasonal changes in hemograms and Theileria orientalis infection rates among Holstein cattle pastured in the mountains in the Republic of Korea

In the current study, we compared seasonal changes in complete blood counts (CBCs) and rates of infection with a tick-borne pathogen between Holstein cattle housed indoors and those maintained outside on pasture. There were differences in white blood cell (WBC) parameters, but the changes were not associated with seasons or the housing type. Analysis of red blood cell (RBC) parameters showed lower values in August and November versus March, and in the cattle maintained on pasture versus the housed cattle. In comparison with the RBC count of the housed cattle in March (10.1M/μL), the RBC counts of the pastured cattle were significantly lower in August (7.8M/μL; p<0.01) and November (7.5M/μL; p<0.01). The hematocrit (HCT) also showed a decrease in March (33.5%), August (30.0%, p<0.01) and November (28.5%, p<0.01). According to PCR analysis, the Theileria infection rate among the pastured cattle in March was only 11%, but this rate increased to 22% and 60% in August and November, respectively. The RBC count (7.4M/μL) and HCT (27.7%) values in Theileria-positive pastured cattle in November showed a dramatic decrease compared to those of cattle examined in March. Phylogenetic analysis revealed that these Theileria isolates correspond to T. orientalis. These results suggest that a remarkable increase in tick infestation in mountainous areas in the summer may cause increased rates of infection with T. orientalis, leading to significant changes in the RBC profile after grazing. Therefore, these hematological changes may be associated with T. orientalis infection caused by tick-biting; thus, additional studies on the pathogenicity of T. orientalis are needed.

Molecular characterization of Theileria orientalis from cattle in Ethiopia

This study reports the first molecular characterization of Theileria orientalis in local breeds of cattle in Ethiopia. A conventional PCR utilizing major piroplasm surface protein (MPSP) gene and an established multiplexed tandem PCR (MT-PCR) were used to characterize T. orientalis and to assess the infection intensity, respectively. Of 232 blood samples tested, T. orientalis DNA was detected in only 2.2% of samples using conventional PCR; two genotypes buffeli (1.3%; 3/232) and type 5 (0.9%; 2/232) of T. orientalis were detected. Phylogenetic analysis revealed that the buffeli MPSP sequences from Ethiopia were closely related to those reported from Kenya, Sri Lanka and Myanmar, and type 5 sequences from Ethiopia grouped with those from Korea, Japan, Vietnam and Thailand. A higher number of samples (3.9%; 9/232) were test-positive by MT-PCR and four genotypes (buffeli, chitose, ikeda and type 5) of T. orientalis were detected. The average intensity of infections with genotypes buffeli (DNA copy numbers 11,056) and type 5 (7508) were significantly higher (P<0.0001) than the pathogenic genotype ikeda (61 DNA copies). This first insight into T. orientalis from cattle in Ethiopia using MPSP gene provides a basis for future studies of T. orientalis in various agroclimatic zones and of the impact of oriental theilerosis on cattle in this and other countries of Africa.

Comparison of molecular and microscopic technique for detection of Theileria annulata from the field cases of cattle

AIM

Tropical theileriosis is fatal hemoprotozoal disease of dairy animals caused by Theileria annulata. The aim of the present study was to detect the T. annulata and comparison of results of molecular and microscopic techniques.

MATERIALS AND METHODS

A total of 52 blood samples were collected from the cattle suspected for theileriosis across the Banaskantha district. All the samples were screened for theileriosis using Giemsa's staining technique and polymerase chain reaction (PCR).

RESULTS

Total of 17 (32.69%) and 24 (46.15%) samples were found positive for theileriosis by microscopic examination and PCR test, respectively. It revealed that the study area is endemic for theileriosis, and the microscopic technique has 70.83% sensitivity and 100% specificity with respect to PCR technique.

CONCLUSION

It may be concluded from the present study that the PCR is comparatively sensitive technique than microscopic examination and may be recommended to use in the field for screening of theileriosis in the study area, where a high prevalence of diseases have been reported due to intensive dairy farming.

Assessment of the First Commercial ELISA Kit for the Diagnosis of Theileria annulata

The present study assesses the efficacy of SVANOVIR Theileria annulata-Ab, the first commercial ELISA kit for the diagnosis of Theileria annulata infection in cattle based on a recombinant protein known as T. annulata surface protein (TaSp). As a reference test, a polymerase chain reaction (PCR) assay depending on T. annulata merozoite surface antigen (Tams-1) was applied. A total of 468 blood samples as well as serum samples were randomly collected from cattle and tested in the PCR as well as in the ELISA developed in this study. Moreover, all samples were also analyzed by conventional Giemsa-stained blood smear. The results of this study revealed a good correlation between the results obtained by PCR and the ELISA, whereas all PCR positive samples scored correctly positive in the ELISA and 73 of the 125 PCR negative samples scored correctly negative. Taken together, a sensitivity of 91.25% and a specificity of 78.4% were recorded, when compared to the PCR data. In conclusion, the SVANOVIR Theileria annulata-Ab is a suitable diagnostic assay for use in the diagnosis and epidemiological surveys of Theileria annulata infection in chronic and carrier animals.

FatalTheileria orientalisN2 genotype infection among Asian water buffaloes (Bubalus bubalis) in a commercial dairy farm in Kerala, India

Fifteen dairy buffaloes of a farm in the state of Kerala, India developed fatal oriental theileriosis within 2 months of their procurement. Typical piroplasms ofTheileria orientaliswere observed in the erythrocytes of all affected animals by Giemsa–Leishman staining of blood smears. Case fatality rate was 87·5% (seven out of eight) in the clinically progressed cases. Therapeutic management with anti-theilerial drugs buparvaquone and oxytetracycline led to recovery of seven other animals in less advanced stages of the disease. The aim of this study was to determine the reasons for increased virulence of this pathogen, hitherto considered to be benign. Acute haemolytic anaemia was the predominant haematological finding in the affected animals. Lymphocytic infiltration and degeneration of vital organs leading to functional derangement was the cause of the high mortality. Identification ofT. orientaliswas confirmed by polymerase chain reaction (PCR). DNA sequencing of the PCR products revealed close identity with already reported sequences ofT. orientalis/buffeliN2 genotype. The sequences were deposited in GenBank with accession number KM609973 and KM043772.Rhipicephalusticks, previously not reported as vectors for oriental theileriosis, were identified as the potential vectors. This is the first report of fatal oriental theileriosis in Asian water buffaloes.

Molecular and Parasitological Survey of Bovine Piroplasms in the Black Sea Region, Including the First Report of Babesiosis Associated with Babesia divergens in Turkey

Clinical cases of babesiosis were evaluated, and the frequency of bovine Babesia and Theileria parasites was determined in cattle. Blood samples and thin blood smears were collected from 23 cattle exhibiting clinical signs of babesiosis. In addition, tick and blood samples were collected from 100 apparently healthy cattle cograzing from the same area. Egg masses obtained from fully engorged female ticks were included. DNA isolated from blood and tick samples was screened for Babesia and Theileria by reverse line blot assay. Piroplasms compatible with Babesia spp. were observed microscopically for symptomatic cattle as circular, oval, elongated, or pear-shaped bodies. Parasitemia ranged from 0.08 to 0.9% for Babesia bovis, 2.5 to 15.4% for Babesia bigemina, and 7.4% for Babesia divergens. Reverse line blot showed positivity in 13 (13%) of the sampled clinically normal cattle and revealed the presence of three Babesia species. Babesia bovis was the most prevalent (9/100, 9%), followed by Babesia occultans (3/100, 3%) and B. bigemina (1/100, 1%). One animal infected with B. bigemina was also infected with B. bovis. The single animal infected with B. divergens showed symptoms of babesiosis. Ticks were identified as Rhipicephalus annulatus, Rhipicephalus turanicus, and Ixodes ricinus. One female R. annulatus and its egg mass were infected with B. bigemina. Neither Theileria annulata nor Theileria buffeli/orientalis infections were observed in cattle or ticks. This is the first report of clinical babesiosis caused by B. divergens in cattle from Turkey.

Epidemiology of the epidemic of bovine anaemia associated with Theileria orientalis (Ikeda) between August 2012 and March 2014

AIMS

To describe the epidemiology of the epidemic of bovine anaemia associated with Theileria orientalis infection (TABA) in New Zealand between 30 August 2012 and 4 March 2014.

METHODS

Blood samples and associated data were obtained from cases of TABA. The case definition for TABA was met when piroplasms were present on blood smears and the haematocrit was ≤0.24 L/L. Samples were analysed using quantitative PCR (qPCR) assays for the detection of T. orientalis Ikeda type. Only cases that were positive in the qPCR assays were included in the analysis. A case herd was defined as a herd that had ≥1 animal positive for T. orientalis Ikeda. Movement records for farms were accessed through the national animal identification and tracing scheme. The OR for cattle movements onto a case farm compared to a non-case farm was estimated using a generalised estimating equation model and the geodesic distance for movements onto case and non-case farms compared using Student's t-test. The kernel-smoothed risk of disease at the farm level was calculated using an extraction map and the clustering of diseased farms in time and space was measured using the spatial temporal inhomogeneous pair correlation function.

RESULTS

In the first 18 months there were 496 case herds; 392 (79%) were dairy and 104 (21%) beef herds. Of 882 individual cases, 820 (93.0%) were positive for T. orientalis Ikeda in the qPCR assays. Case herds were initially clustered in the Northland, then the Waikato regions. The OR for a case farm compared to a non-case farm having ≥1 inward cattle movements was 2.03 (95% CI=1.52-2.71) and the distance moved was 26 (95% CI=20.8-31.3) km greater for case farms. The risk of disease was highest in a north, north-eastern to south, south-western belt across the Waikato region. The spatial-temporal analysis showed significant clustering of infected herds within 20-30 days and up to 15 km distant from a case farm.

CONCLUSIONS

Theileria orientalis Ikeda type is likely to have been introduced into regions populated with naïve cattle by the movement of parasitaemic cattle from affected areas. Local spread through dispersed ticks then probably became more important for disease transmission between herds once the disease established in a new area.

CLINICAL RELEVANCE

Dairy and beef farming in the North Island of New Zealand will be significantly changed in the coming years by the incursion of this new disease.

Molecular detection and genetic identification of Babesia bigemina, Theileria annulata, Theileria orientalis and Anaplasma marginale in Turkey

Babesia spp., Theileria spp. and Anaplasma spp. are significant tick-borne pathogens of livestock globally. In this study, we investigated the presence and distribution of Babesia bigemina, Theileria annulata, Theileria orientalis and Anaplasma marginale in cattle from 6 provinces of Turkey using species-specific PCR assays. The PCR were conducted using the primers based on the B. bigemina rhoptry-associated protein 1a (BbiRAP-1a), T. annulata merozoite surface antigen-1 (Tams-1), T. orientalis major piroplasm surface protein (ToMPSP) and A. marginale major surface protein 4 (AmMSP4) genes, respectively. Fragments of B. bigemina internal transcribed spacer (BbiITS), T. annulata internal transcribed spacer (TaITS), ToMPSP and AmMSP4 genes were sequenced for phylogenetic analysis. PCR results revealed that the overall infections of A. marginale, T. annulata, B. bigemina and T. orientalis were 29.1%, 18.9%, 11.2% and 5.6%, respectively. The co-infection of two or three pathogens was detected in 29/196 (15.1%) of the cattle samples. The results of sequence analysis indicated that BbiRAP-1a, BbiITS, Tams-1, ToMPSP and AmMSP4 were conserved among the Turkish samples, with 99.76%, 99-99.8%, 99.34-99.78%, 96.9-99.61% and 99.42-99.71% sequence identity values, respectively. In contrast, the Turkish TaITS gene sequences were relatively diverse with 92.3-96.63% identity values. B. bigemina isolates from Turkey were found in the same clade as the isolates from other countries in phylogenetic analysis. On the other hand, phylogenetic analysis based on T. annulata ITS sequences revealed significant differences in the genotypes of T. annulata isolates from Turkey. Additionally, the T. orientalis isolates from Turkish samples were classified as MPSP type 3 genotype. This is the first report of type 3 MPSP in Turkey. Moreover, AmMSP4 isolates from Turkey were found in the same clade as the isolates from other countries. This study provides important data for understanding the epidemiology of tick-borne diseases and it is expected to improve approach for diagnosis and control of tick-borne diseases in Turkey.

Molecular and Phylogenetic analysis revealed new genotypes of Theileria annulata parasites from India

Background

Tick borne diseases impinge cattle worldwide causing mortality and resulting in huge economic losses. Theileriosis is one of the important tick borne diseases mainly caused by Theileria annulata and one of the commonly occurring infections among the livestock. T. annulata causes immense loss to the livestock industry and therefore, efficacious eradication and control strategies are needed for the control of the disease. Genetic diversity among T. annulata parasites is another important aspect which is overlooked in India. Thus, the present study aims to evaluate the prevalence along with genetic diversity and phylogeny of the prevailing T. annulata population of India.

Methods

Genomic DNA was extracted from cattle blood samples (n = 862) from different regions of Andhra Pradesh. Molecular diagnosis using T. annulata 18S rRNA based PCR was performed to detect parasites in cattle. Further, 18S rRNA gene was cloned and sequenced to determine similarity and diversity from the known T. annulata sequences.

Results

We observed an overall prevalence rate of 32.40 % T. annulata infection in Andhra Pradesh based on PCR assay. The sequence analysis revealed novel genotypes among the T. annulata strains from India. Thirteen strains showed closed proximity with a strain from China whereas one Indian strain showed similarity with a South African strain [Theileria sp (buffalo)] based on phylogenetic analysis. Nucleotide heterogeneity of the 18S rRNA sequence among the strains examined varied from 0.1 to 8.6 % when compared with the published strains.

Conclusion

The present study provides us with the molecular prevalence of theileriosis, and will support the accomplishment of actions or in design of strategy to control theileriosis transmission to cattle. Additionally, it highlights the emergence of strains with novel genotypes from India.

The global distribution of Crimean-Congo hemorrhagic fever

BACKGROUND

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne infection caused by a virus (CCHFV) from the Bunyaviridae family. Domestic and wild vertebrates are asymptomatic reservoirs for the virus, putting animal handlers, slaughter-house workers and agricultural labourers at highest risk in endemic areas, with secondary transmission possible through contact with infected blood and other bodily fluids. Human infection is characterized by severe symptoms that often result in death. While it is known that CCHFV transmission is limited to Africa, Asia and Europe, definitive global extents and risk patterns within these limits have not been well described.

METHODS

We used an exhaustive database of human CCHF occurrence records and a niche modeling framework to map the global distribution of risk for human CCHF occurrence.

RESULTS

A greater proportion of shrub or grass land cover was the most important contributor to our model, which predicts highest levels of risk around the Black Sea, Turkey, and some parts of central Asia. Sub-Saharan Africa shows more focalized areas of risk throughout the Sahel and the Cape region.

CONCLUSIONS

These new risk maps provide a valuable starting point for understanding the zoonotic niche of CCHF, its extent and the risk it poses to humans.

Direct detection of Theileria annulata in bovine blood samples using standard and isothermal DNA amplification approaches

Tropical theileriosis is a tick-borne disease responsible for important health problems in cattle, caused by the hemoprotozoan Theileria annulata. Traditionally, detection of Theileria pathogens in infected animals requires the microscopic examination of stained-blood smears and serological methods. Molecular diagnostic assays have been developed for the detection of Theileria parasites, including PCR-based and reverse line blotting approaches, but these methods usually demand qualified personnel, complex instrumentation, and expensive materials. Loop-mediated isothermal amplification (LAMP) can facilitate the design of molecular assays independent of the use of sophisticated equipment. In this chapter we describe the application of two molecular assays for the direct detection of T. annulata in bovine blood samples, based in real-time PCR and LAMP, both targeting the Tams1-encoding gene of this parasite.

Assessment of sequence variability in a p23 gene region within and among three genotypes of the Theileria orientalis complex from south-eastern Australia

Oriental theileriosis is a tick-borne, protozoan disease of cattle caused by one or more genotypes of Theileria orientalis complex. In this study, we assessed sequence variability in a region of the 23kDa piroplasm membrane protein (p23) gene within and among three T. orientalis genotypes (designated buffeli, chitose and ikeda) in south-eastern Australia. Genomic DNA (n=100) was extracted from blood of infected cattle from various locations endemic for oriental theileriosis and tested by polymerase chain reaction (PCR)-coupled mutation scanning (single-strand conformation polymorphism (SSCP)) and targeted sequencing analysis. Eight distinct sequences represented all DNA samples, and three genotypes were found: buffeli (n=3), chitose (3) and ikeda (2). Nucleotide pairwise comparisons among these eight sequences revealed considerably higher variability among the genotypes (6.6-11.7%) than within them (0-1.9%), indicating that the p23 gene region allows the accurate identification of T. orientalis genotypes. In the future, we will combine this gene with other molecular markers to study the genetic structure of T. orientalis populations in Australasia, which will pave the way to establish a highly sensitive and specific PCR-based assay for genotypic diagnosis of infection and for assessing levels of parasitaemia in cattle.