Molecular diagnosis of Theileria and Babesia species infecting cattle in Northern Spain using reverse line blot macroarrays

Occurrence of ticks and tick-borne mixed parasitic microbiota in cross-bred cattle in District Lahore, Pakistan

The present study was focused on the incidence of ticks and tick-borne diseases (TTBD) in cross-bred cattle (Friesian x Sahiwal) of two farms (n = 2548) in district Lahore, Pakistan. We collected total of 572 ticks (adults and nymphs) and blood samples (10 ml) for microscopic i.e., blood smear test - Giemsa Stain (BST) and molecular analysis; Reverse Line Blot-General Primer-PCR (RLB-PCR) and Specie Specific Primer PCR (SP-PCR) from infested cattle (n = 100) from months of April to September. Results: The tick specie identified was Rhipicephalus microplus at both farms, with significant difference in infestations rate amongst both farms (p< 0.0001). The cross-bred cattle having higher ratio of Friesian blood and lower ratio of Sahiwal blood were mostly infested by ticks (p < 0.0458) and haemoparasites (p <0.474) and vice versa. The SP-PCR showed higher number of haemoparasites infection than BST, which revealed 16% T. annulata (p < 0.0001 and k value 0.485, 0.0001), 51% B. bigemina (p < 0.0001 and k value 0.485, 0.0001) and 15% A. marginale (p < 0.001 and k value 0.207, 0.001), respectively. The single infection with B. bigemina was 34% (n = 34/100) and A. marginale 6% (n = 6/100). The double infection with T. annulata/B. bigemina was 8% (n = 8/100) and B. bigemina/A. marginale 1% (n = 1/100). Whereas the triple infection with T. annulata/B. bigemina/A .marginale was 8% (n = 8/100). The phylogenetic study of isolated sequence of T. annulata revealed close homology to isolates from Iran (87%), B. bigemina to isolates from Cuba (94 to 100%) and A. marginale with isolates from Pakistan (99 to 98%).

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.

First detection of Anaplasma phagocytophilum and Babesia divergens and high infection rates of Anaplasma marginale and Babesia bigemina in cattle in extensive grazing systems of Central Spain

Bovine vector-borne diseases have a considerable economic impact worldwide and affect health of humans and animals. However, different aspects of their epidemiology and their pathogenesis remain unclear. Despite the frequent description of clinical cases reported by practitioners attending cattle from Madrid, Central Spain, molecular prevalence of Anaplasma spp. and Babesia spp. has not been described. The aim of this study was to assess the positivity rate of A. phagocytophilum, A. marginale, A. centrale, B. bigemina and B. divergens in livestock of this area and to evaluate the existence of associations between these pathogens and haematological, biochemical and epidemiological data. Babesia divergens and A. phagocytophilum were detected for the first time in cattle from Madrid. Their positivity percentages were low (2.2% ± 1.4% and 1.8% ± 1.2%, respectively), but this description is of special interest, as these agents are potentially zoonotic. Both agents were found in areas of higher altitude and relative humidity and lower temperature. The detection of ticks in livestock during the moment of sampling was confirmed as a risk factor for these infections. Anaplasma marginale showed the highest molecular infection rate (30% ± 4.1%) in this study, followed by B. bigemina (21.9% ± 3.7%). Higher positivity rates of A. marginale and B. bigemina were found in the areas of mountain climate and warm-summer continental Mediterranean climate. The use of ectoparasiticide treatment was found as a risk factor for infection by A. marginale and B. bigemina. This finding could lead to reconsider the ectoparasiticide protocols that are used nowadays. Grazing on pastures with domestic or wild ruminants and the presence of wild carnivores were associated with higher rates of infection by these four agents and coinfections were frequently found.

Phylogeography of Hyalomma (Euhyalomma) lusitanicum (Acarina, Parasitiformes, Ixodidae) in Andalusia based on mitochondrial cytochrome oxidase I gene

The genetic population structure relationships of Hyalomma (Euhyalomma) lusitanicum in Andalusia (the south of the Iberian Peninsula) were examined using mtDNA sequence data from 887 bp of cytochrome oxidase subunit I (COI) gene. The sequence for the COI region was determined for 84 individuals collected in several localities of Andalusia, and 10 for other localities (i.e., five from Toledo, central Iberian Peninsula, four from Sicily (Italy) and one from Canary Island). Seventeen haplotypes were detected, including 27 polymorphic sites. The number of amino acid substitutions per site from mean diversity calculations for the entire population was 0.017. AMOVA analysis revealed a low gene flow that characterises the genetic population structure of this species in South Iberian Peninsula, with a haplotype diversity (h) value of 0.815. No geographically induced differentiation was observed, and separate evolutionary units were not detected. Our results indicate low genetic diversity across the geographical range of H. lusitanicum tick in Andalusia. Our data do not show any genetic discontinuity between the tick populations studied, including specimens from Canary Island and Sicily (Italy).

Bovine Babesiosis Diagnosed in Formalin-Fixed, Paraffin-Embedded Tissues by Using In Situ Hybridization

Bovine babesiosis, caused by Babesia divergens, is in general a rare disease in Europe. Nonetheless, local outbreaks can cause severe economic damage, and postmortem identification represents a diagnostic challenge. During a recent outbreak in May 2018 in northern Germany, 21 animals of a herd of 150 cattle died within 40 days having had clinical signs of fever and hemoglobinuria. Gross examination of 4 of the 21 deceased animals revealed a tick infestation, jaundice, and dark brown staining of urine and kidneys. Histologically, there were iron-positive deposits, hyperplasia of the red pulp of the spleen, and centrilobular necrosis of hepatocytes. In several locations, small basophilic granules suggestive of intraerythrocytic parasites were visible in hematoxylin-eosin- and Giemsa-stained sections. Peripheral blood smears from a living cow from the herd and polymerase chain reaction (PCR) of feeding ticks revealed B. divergens infection. In situ hybridization (ISH) was applied on formalin-fixed, paraffin-embedded (FFPE) tissue of the necropsied cattle to confirm babesiosis in these animals postmortem. Digoxigenin-labeled DNA probes were generated based on a specific nucleotide sequence for B. divergens, obtained by PCR and sequencing of DNA isolates from infected Ixodes ricinus ticks from deceased cattle. ISH using these probes allowed postmortem diagnosis of B. divergens infection in routinely fixed FFPE tissues.

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.

Clinical Pathology, Immunopathology and Advanced Vaccine Technology in Bovine Theileriosis: A Review

Theileriosis is a blood piroplasmic disease that adversely affects the livestock industry, especially in tropical and sub-tropical countries. It is caused by haemoprotozoan of the Theileria genus, transmitted by hard ticks and which possesses a complex life cycle. The clinical course of the disease ranges from benign to lethal, but subclinical infections can occur depending on the infecting Theileria species. The main clinical and clinicopathological manifestations of acute disease include fever, lymphadenopathy, anorexia and severe loss of condition, conjunctivitis, and pale mucous membranes that are associated with Theileria-induced immune-mediated haemolytic anaemia and/or non-regenerative anaemia. Additionally, jaundice, increases in hepatic enzymes, and variable leukocyte count changes are seen. Theileria annulata and Theileria parva induce an incomplete transformation of lymphoid and myeloid cell lineages, and these cells possess certain phenotypes of cancer cells. Pathogenic genotypes of Theileria orientalis have been recently associated with severe production losses in Southeast Asia and some parts of Europe. The infection and treatment method (ITM) is currently used in the control and prevention of T. parva infection, and recombinant vaccines are still under evaluation. The use of gene gun immunization against T. parva infection has been recently evaluated. This review, therefore, provides an overview of the clinicopathological and immunopathological profiles of Theileria-infected cattle and focus on DNA vaccines consisting of plasmid DNA with genes of interest, molecular adjuvants, and chitosan as the most promising next-generation vaccine against bovine theileriosis.

Bovine babesiosis: An insight into the global perspective on the disease distribution by systematic review and meta-analysis

Bovine babesiosis is continuing as a great threat to the livestock sector causing havoc production losses with significant morbidity and mortality. Being a tick-borne disease, the great complexity in the agent-host- vector relationship has severely hampered the sincere efforts towards the development of an effective vaccine against bovine babesiosis. In these circumstances, assessing the global scenario of disease prevalence is a prerequisite to strategize the available control measures. Keeping this in view, the objective of this study was to estimate the pooled prevalence of bovine babesiosis globally. The literature search was conducted to identify all relevant published articles reporting the prevalence of bovine babesiosis and a total of 163 studies were found eligible for final systematic review and meta-analysis. Meta-analysis was conducted using meta package of R software and summary estimates of the prevalence were calculated. Meta analysis of 81099 samples from 62 countires representing six continents revealed pooled global prevalence of bovine babesiosis as 29% (95% CI = 24%-34%) with estimated prevalence of active infection as 16% (95% CI = 13%-20%) and seroprevalence as 50% (95% CI = 45%-56%) using random effects model. Continent wise highest prevalence of bovine babesiosis in South America 64% (95% CI = 49%-77%) and lowest in Asia 19% (95% CI = 14%-25%). Highest prevalence was estimated with B. bigemina 22% (95% CI = 18%-27%) and least prevalence was recorded with B. divergens 12% (95% CI = 2%-46%). The pooled prevalence estimates generated in the study is revealing an increase in disease trend and the need for immediate planning of mitigation strategies paralleled with the development of early diagnostic methods to reduce the impact of disease throughout the world.

Optimization of a suspension culture for a Theileria annulata-infected bovine cell line

Theileria annulata schizont transformed bovine lymphocytes show the feature of permanent proliferation in vitro culture. In this study, we optimized a suitable culture medium for transformed cells to ensure a high yield of quality cells in suspension culture. As the basis for the optimized medium, we combined 75% Gibco (GB) and 25% RPMI-1640 medium. Glucose, lactic acid, ammonia, growth factors and several kinds of amino acids at specific concentrations play important roles in maintaining the maximum growth rate and the quality of cells. The metabolic flow of 17 amino acids, glucose and nutrients was determined with high-performance liquid chromatography (HPLC) and cell viability analysis. The genetic stability of the TaSP and TaSE genes at different passages of the cell line in suspension culture was determined using PCR amplification. The optimal concentrations or tolerated levels of glucose, lactic acid and ammonia were 10-14, 2-5.5 and 3.5-5.5 mmol/L, respectively. Our data demonstrated that the potential utility of the medium optimized here to yield high quality cells compared with basal (normally used) medium. The medium also facilitated the easy maintenance of transformed cells with high yields and excellent quality for in vitro studies. This study also provides insight into the processes of optimization and vaccine development.

Prevalence of Piroplasma in Ticks Collected from Dogs and Cattle in Guangxi, South China Determined by Reverse Line Blot Hybridization Assay

Piroplasmosis is a disease of domestic and wild animals caused by tick-borne protozoa of the genera Theileria and Babesia. Piroplasmosis leads to substantial economic losses in the livestock industry. This disease has been frequently reported in subtropical and tropical regions worldwide. However, information regarding the prevalence of piroplasma in ticks collected from dogs and cattle is lacking in most areas. To assess the potential threat of piroplasmosis in South China, 671 ticks were collected in Guangxi Province. Deoxyribonucleic acid (DNA) was extracted from these ticks to evaluate the presence of piroplasma through a reverse line blot (RLB) hybridization assay using the hypervariable V4 region of the piroplasmic 18S ribosomal ribonucleic acid (r)RNA genes as probes to detect Theileria and Babesia species. The RLB results indicated that 144/671 (21.46%) ticks were infected with piroplasma species belonging to the genera Theileria or Babesia. Theileria buffeli, Babesia vogeli, Theileria annulata, and Theileria luwenshuni were present in the ticks at frequencies of 60/671 (8.94%), 21/671 (3.13%), 6/671 (0.89%), and 6/671 (0.89%), respectively. Mixed infections with 2 or more piroplasma species were present in 8/671 (1.19%) tick samples. The hypervariable V4 region of the piroplasmic 18S rRNA genes from 6 tick DNA samples with single infections was cloned, sequenced, and aligned to related sequences from GenBank. The Theileria and Babesia sequences were analyzed separately. 18S rRNA gene fragment sequences of T. annulata and T. buffeli were compared with previously reported homologous sequences. All 3 B. vogeli sequences examined in this study were grouped into the same cluster and belonged to the same genotype. The present study provides important epidemiological information regarding piroplasmosis occurrence in China. The existence of tick-borne piroplasma likely leads to high infection risks among the local animals in the studied areas.

Assessment of the prevalence of Theileria lestoquardi in sheep from the Sudan using serological and molecular methods

Malignant theileriosis of sheep and goats caused by Theileria lestoquardi is considered to be among the most important tick borne diseases in the Sudan. Information on the prevalence of the disease in different parts of the Sudan is limited. The purpose of this study was to estimate the prevalence of the disease in five states of the Sudan using molecular and serological assays. A total of 393 blood and serum samples from clinically asymptomatic sheep were analysed using nested reverse line blot (nRLB) and loop mediated isothermal amplification (LAMP), as well as an enzyme-linked immunosorbent assay (ELISA). The results indicated a sero-prevalence of 33.8% while RLB and LAMP assays revealed molecular prevalences of 29.5 and 22.6% respectively. The prevalence of Theileria lestoquardi varied significantly according to the geographical origin of the infected animals, whereas age and gender did not have a significant effect. RLB data indicated that T. lestoquardi usually occurred as a co-infection with the non-pathogenic Theileria ovis. Using RLB as a gold standard, a sensitivity of 68.1% and a specificity of 96.4% were recorded for LAMP and a sensitivity of 75.9% and a specificity of 83.8% for ELISA. The Kappa coefficient between nRLB and LAMP indicated a significant level of agreement (0.692), but only moderate concordance (0.572) between nRLB and ELISA. The results of the present study confirm and extend earlier findings regarding the widespread of T. lestoquardi infections in sheep in the Sudan. The data provide evidence that should enable the veterinary authorities to deploy appropriate control measures.

Co-infection with tick-borne disease agents in cattle in Russia

Tick-borne diseases cause significant livestock losses worldwide. In Russia, information concerning single or mixed infections with different Anaplasma, Theileria and Babesia species in cattle is very limited. This study was conducted to determine the level of co-infection with protozoan pathogens (Theileria spp. and Babesia spp.) and rickettsial pathogens (A. marginale and A. phagocytophilum) in cattle in central Russia. Blood samples were examined with real time polymerase chain reaction (RT-PCR) for A. marginale and A. phagocytophilum, and by amplifying the V4 hypervariable region of the 18S rRNA gene, followed by cloning, DNA sequencing, and phylogenetic analyses, for Babesia and Theileria species. In total 67% of examined blood samples were positive for Theileria spp. or A. marginale, and 19% of the animals were co-infected with Theileria spp. and A. marginale. Seasonal variation in prevalence was found for Theileria spp. Phylogenetic analysis based on 18S rRNA gene sequences revealed the presence of five Theileria species: T. annulata, T. orientalis, T. buffeli, T. sergenti, and T. sinensis. No samples were positive for Babesia spp. or A. phagocytophilum. The data obtained for prevalence of bovine theileriosis and anaplasmosis in the central part of Russia underscore the need for improved surveillance and control programs to reduce tick-borne diseases in cattle.

A systematic review on modelling approaches for economic losses studies caused by parasites and their associated diseases in cattle

Parasites reside inside or outside their hosts and get host nutrition and blood. Here, we have emphasized economic losses in cattle caused by parasitic diseases due to ecto- and endo- parasites (flies, ticks, mites and helminths). We have outlined different methods/models including economic evaluation techniques and dynamic analysis as a major class, used for the calculation of economic losses caused by parasites in cattle. According to already conducted studies, a decrease in production is mentioned in quantity and percentage while financial losses are expressed in the form of account with respect to per head, herd or for the specific study area. The parasites cause the reduced production and financial losses due to control, treatment and mortality costs. We calculated the average decrease in milk production and organ condemnation as 1.16 L animal-1 day-1 and 12.95%, respectively, from overall cattle parasitic infections. Moreover, the average calculated financial and percentage losses were US$ 50.67 animal-1 year-1 and 17.94%, respectively. Economically important parasitic diseases mentioned here are caused by specific spp. of protozoans and helminths according to data collected from the literature. Protozoan diseases include tick-borne diseases, coccidiosis, neosporosis, trypanosomiasis and cryptosporidiosis. Losses due to tick-borne infections were encountered for decreased milk production, mortality, treatment and control. Losses from coccidiosis were due to decreased weight gain, treatment costs and mortality. While abortion losses were encountered in neosporosis. Trypanosomiasis caused losses due to a decrease in milk yield. Moreover, only diagnostic (conventional or molecular techniques) cost was taken into account for cryptosporidiosis. Economically important nematode parasites are Oesophagostomum spp., Cooperia spp., Trichostrongylus spp., Strongyloides spp., Ostertagia spp. and Haemonchus placei. Due to the zoonotic importance of echinococcosis, Echinococcus granulosus is the most economically important cestode parasite. Losses caused by echinococcosis were due to organ condemnation, carcass weight loss and decreases hide value, milk production and fecundity. While, fascioliasis is one of the most economically important trematodal disease, which causes cirrhosis of the liver due to parasite migration, and thus, the organ becomes inedible. So, it would be helpful for farmers and researchers to approach these methods/models for calculation of parasitic losses and should adopt suitable measures to avoid long-term economic losses.

Molecular, epidemiological, haematological and biochemical evaluation in asymptomatic Theileria annulata infected cattle from an endemic region in Spain

Mediterranean theileriosis is one of the most fatal theilerioses, with considerable economic impact on livestock production. The potential consequences of asymptomatic infection on the animal's health and on the epidemiology in endemic regions are still unclear. The objectives of this study were to determine the molecular prevalence of T. annulata in a representative population of asymptomatic cattle in extensive management in Madrid, Central Spain, an area where practitioners frequently report cases of clinical theileriosis, and to evaluate the existence of associations between infection by this pathogen and haematological, biochemical and epidemiological data. T. annulata DNA was detected in 22.4% of the study population. The age was statistically associated with T. annulata prevalence rates, with a higher prevalence in cows older than 8 years (26.1%). Introduction of new cattle to the farm, grazing on pastures with other herds of cattle and previous history of clinical cases were statistically related to a higher prevalence of T. annulata infection. Herds with more than one ectoparasiticide treatment per year and that used more than one drug had significantly lower prevalences of infection with T. annulata. The location of farms in areas with a mean temperature higher than 17.1°C and mean altitude lower than 962m was statistically associated with the presence of T. annulata. In our study, the mean values of haematological parameters were within the normal adult range, but it is noteworthy that some T. annulata-infected animals presented low values for red blood cell parameters.

Important hemoprotozoan diseases of livestock: Challenges in current diagnostics and therapeutics: An update

Hemoprotozoan parasites pose a serious threat to the livestock population in terms of mortality, reduced milk yield and lowered draft power. Diagnosis of these diseases often poses a challenging task. Needless to say that impact of disease in health and productivity is huge though a fair economic assessment on the quantum of economic loss associated is yet to be worked out from India. The diagnosis of hemoprotozoan infections largely depends on various laboratory-based diagnostic methods as the clinical manifestations are often inconspicuous and non-specific. Traditional diagnostic methods rely on microscopical demonstration of infective stages in blood or tissue fluids. However, it is laborious, lesser sensitive, and cannot differentiate between morphologically similar organisms. Recent development in the technologies has opened new avenues for improvement in the accurate diagnosis of parasitic infections. Serological tests are simple, fast but lack specificity. With advent of molecular techniques, as DNA hybridization assays, polymerase chain reaction and its modifications ensure the detection of infection in the latent phase of the disease. Nucleic acid-based assays are highly sensitive, free from immunocompetence and can differentiate between morphologically similar parasites. With the advent of newer diagnostics complemented with traditional ones will be of huge help for targeted selective treatment with better chemotherapeutic agents.

Reverse line blot hybridization with species-specific oligonucleotide probes: application to piroplasm detection

Reverse line blot (RLB) hybridization has become a well-established and widely used method for the multiplex identification of several Babesia and Theileria species in hosts and tick vectors. The procedure is based on the simultaneous PCR amplification of a polymorphic region of the 18S rRNA gene from different piroplasms followed by identification of the individual species by hybridization to species-specific oligonucleotide probes covalently linked to a nylon membrane in a macroarray format.

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.

Re-emergence of bovine piroplasmosis in Hungary: has the etiological role of Babesia divergens been taken over by B. major and Theileria buffeli?

BACKGROUND

The prevalence of bovine babesiosis caused by Babesia divergens has been declining during the past decades in northeastern Hungary, and no cases have been observed since 2008. Infections of cattle with B. major and Theileria buffeli were hitherto reported in southern and western Europe. In other parts of the globe, there is evidence of emergence and a growing clinical importance of T. buffeli and closely related genotypes of the T. orientalis complex.

FINDINGS

In a herd of 88 beef cattle kept in northeastern Hungary, bovine piroplasmosis was diagnosed in nine animals through the examination of blood smears or by molecular methods. B. major was identified in five animals, two of which died. In addition, four cattle harboured T. buffeli, and one of these animals was anaemic. Despite their presence, a contributory role of Anaplasma marginale and A. phagocytophilum could not be established in the disease cases.

CONCLUSIONS

In this study B. major and bovine theileriosis is reported for the first time in central-eastern Europe, where clinical cases were associated with a mild winter.

Retrospective study of hemoparasites in cattle in southern Italy by reverse line blot hybridization

Tick-borne diseases are widespread in tropical and temperate regions and are responsible for important economic losses in those areas. In order to assess the presence and prevalence of various pathogens in southern Italy, we retrospectively analyzed cattle blood samples collected for a previous study in 2000 using reverse line blot (RLB) hybridization. The study had been carried out in three regions of southern Italy on 1,500 randomly selected and apparently healthy adult cattle. RLB showed that 43.7% of the cattle were positive for nine different species of hemoparasites with either a single infection or a mixed infection. Theileria buffeli was the most common species found, being present in 27.3% of the animals, followed by Anaplasma marginale in 18.1%, Anaplasma centrale in 13.8%, Babesia bigemina and Anaplasma bovis in 4.2%, Anaplasma phagocytophilum in 1.7%, Babesia bovis in 1.6%, Babesia major in 0.2% and Babesia divergens in 0.1%. Complete blood counts showed different degrees of anemia in 363 animals (24.2%) and of these, 169 were RLB-positive for at least one pathogen. Among the ticks that were collected from the cattle, the following species were identified: Rhipicephalus bursa, Ixodes ricinus, Hyalomma marginatum, Boophilus annulatus, Dermacentor marginatus and Haemaphysalis (sulcata, parva, inermis and punctata). The results obtained confirmed the spread of endemic tick-borne pathogens in the regions studied.

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.

Monitoring piroplasms infection in three cattle farms in Minorca (Balearic Islands, Spain) with previous history of clinical piroplamosis

Bovine piroplasmosis are tick-borne protozoan diseases caused by parasites of the genera Theileria and Babesia. Three Friesian cattle farms (F1-F3) with previous history of clinical piroplamosis were selected in Minorca (Balearic Islands, Spain). Blood samples were collected from 8 to 11 animals every two months throughout a year and, a newly developed multiplex DNA bead-based suspension array based on the Luminex(®) xMAP technology was used to monitor for the presence of piroplasms. The assay incorporated probes for Babesia divergens, Babesia bovis, Babesia bigemina, Babesia major, Babesia occultans, Theileria annulata and Theileria buffeli, and a Catch-all Theileria and Babesia (TB) control probe. An internal amplification control that was detected with a Luminex probe was also included to monitor for inhibition. Infection was detected in 87.5% of the samples, 38.7% as single infections and 48.8% as mixed infections. T. annulata was widespread in Farm F1, with all animals positive over the whole study; albeit less frequently, T. annulata was also detected in Farms F2 and F3. T. buffeli was the overall most prevalent piroplasm, with a wide distribution in Farms F2 and F3 but only occasionally detected in F1. B. bigemina was the most frequent Babesia species, but was absent from Farm F1. B. bovis, previously reported in Minorca, was only sporadically detected in F2 and F3. A further 3 Babesia species not previously found in Minorca were also identified: B. major present in the 3 farms; B. divergens detected once in 2 animals in F2; and B. occultans found in 4 animals in F2 and in 1 Hyalomma marginatum female tick collected from a positive animal. Sequencing confirmed the identity of B. occultans thus extending the distribution of this species to Mediterranean Europe. This study confirmed the endemic situation for piroplasm infection in the region and detected the presence of a large number of chronic asymptomatic carriers. More importantly, 3 Babesia species not previously detected in the region were detected for the first time.

A highly sensitive DNA bead-based suspension array for the detection and species identification of bovine piroplasms

Piroplasms are among the most harmful tick-borne pathogens for livestock and sensitive and specific diagnostic methods for rapid detection and identification of the different species are needed for effective control. Reverse Line Blot has been the molecular technique of choice but it is laborious, time-consuming and highly susceptible to subjective variation in the interpretation of the hybridisation signal. Here, an oligonucleotide multiplex suspension microarray (Luminex® microsphere system) was developed for bovine piroplasms. Probes previously used in Reverse Line Blot for Babesia divergens, Babesia bovis, Babesia occultans, Babesia bigemina and Theileria buffeli, and a catch-all Theileria and Babesia control probe, were included in the Luminex assay together with newly designed probes for Theileria annulata and Babesia major. An internal amplification control that was detected with a Luminex probe was included to monitor for inhibition. Serially diluted linearised recombinant plasmids of the different species were used to assess the analytical sensitivity and specificity, and the detection limit of the Luminex assay was determined using serial dilutions of infected blood from an animal with a known level of T. annulata parasitaemia. The assay was then validated on 214 bovine blood samples analysed in parallel by Reverse Line Blot and Luminex. The Luminex assay proved to be highly specific and more sensitive than Reverse Line Blot, detecting 0.05 parasites/μl of blood. Technically, the Luminex procedure was rapid, provided high throughput screening, transformed the subjective interpretation of Reverse Line Blot results into numerical objective values, and allowed more flexibility in array preparation than Reverse Line Blot. The method described herein can substantially improve the detection of piroplasm carriers and thus better protect livestock trade and facilitate preventive control programs.

New insights into the epidemiology of bovine piroplasmoses in Italy

Few studies have been published on bovine piroplasmoses in Italy, and therefore a clear picture of the epidemiology of these infections is difficult to obtain. Vertebrate and invertebrate hosts in Central and Northern Regions of Italy were investigated in 2005 and 2006, when microscopy, molecular tools and serological tests were applied to 468 blood samples drawn from cattle in order to evaluate the presence of these protozoa and identify possible risk factors. Ticks were also collected, identified and analyzed by molecular techniques. Microscopy identified 6.5% of the animals as positive, whereas PCR detected piroplasm DNA in 21.6%. BLAST analysis showed 67 amplicons (17.0%) referable to the Theileria sergenti/buffeli/orientalis group, 17 (4.3%) to Theileria annae, and 1 to Babesia divergens. Serology evidenced a prevalence of 45.4% for Babesia bovis, 17.4% for Babesia bigemina, and 34.9% for B. divergens. The 127 collected ticks were identified as belonging to 5 species, mostly represented by Rhipicephalus bursa, Hyalomma marginatum and Ixodes ricinus. Molecular analyses evidenced the presence of B. bovis and B. bigemina, in 3 and 5 ticks, respectively. Our findings suggest that different species of piroplasms are circulating in bovine populations in Central and Northern Italy, and provide new insights into the complex epidemiology of bovine piroplasmoses in Italy.

Molecular diagnosis of infections and resistance in veterinary and human parasites

Since 1977, >2000 research papers described attempts to detect, identify and/or quantify parasites, or disease organisms carried by ecto-parasites, using DNA-based tests and 148 reviews of the topic were published. Despite this, only a few DNA-based tests for parasitic diseases are routinely available, and most of these are optional tests used occasionally in disease diagnosis. Malaria, trypanosomiasis, toxoplasmosis, leishmaniasis and cryptosporidiosis diagnosis may be assisted by DNA-based testing in some countries, but there are very few cases where the detection of veterinary parasites is assisted by DNA-based tests. The diagnoses of some bacterial (e.g. lyme disease) and viral diseases (e.g. tick borne encephalitis) which are transmitted by ecto-parasites more commonly use DNA-based tests, and research developing tests for these species makes up almost 20% of the literature. Other important uses of DNA-based tests are for epidemiological and risk assessment, quality control for food and water, forensic diagnosis and in parasite biology research. Some DNA-based tests for water-borne parasites, including Cryptosporidium and Giardia, are used in routine checks of water treatment, but forensic and food-testing applications have not been adopted in routine practice. Biological research, including epidemiological research, makes the widest use of DNA-based diagnostics, delivering enhanced understanding of parasites and guidelines for managing parasitic diseases. Despite the limited uptake of DNA-based tests to date, there is little doubt that they offer great potential to not only detect, identify and quantify parasites, but also to provide further information important for the implementation of parasite control strategies. For example, variant sequences within species of parasites and other organisms can be differentiated by tests in a manner similar to genetic testing in medicine or livestock breeding. If an association between DNA sequence and phenotype has been demonstrated, then qualities such as drug resistance, strain divergence, virulence, and origin of isolates could be inferred by DNA-based tests. No such tests are in clinical or commercial use in parasitology and few tests are available for other organisms. Why have DNA-based tests not had a bigger impact in veterinary and human medicine? To explore this question, technological, biological, economic and sociological factors must be considered. Additionally, a realistic expectation of research progress is needed. DNA-based tests could enhance parasite management in many ways, but patience, persistence and dedication will be needed to achieve this goal.

Babesias of red deer (Cervus elaphus) in Ireland

Blood samples were obtained from 38 wild red deer (Cervus elaphus) at two sites in Ireland and subjected to PCR analysis of the 18S rRNA gene followed by sequencing. Two fragments of the 18S rRNA gene were generated by two different PCR protocols and subsequent sequencing suggested that at least six of the deer were infected by a babesia that, in those loci, is indistinguishable from Babesia divergens, an important tick-borne pathogen of cattle and of zoonotic significance. Additionally, a B. odocoilei-like parasite was detected in three samples and a babesia that did not match any sequences in the GenBank database was found in five samples. Neither B. capreoli nor B. venatorum (EU1) were found. There have been several reports of B. divergens occurring in deer species, including red deer, roe deer (Capreolus capreolus) and reindeer (Rangifer tarandus). However, in view of recent re-sequencing of bovine-origin samples deposited previously in GenBank, it is unlikely that any of these sequences from deer are B. divergens. The present study describes the only deer piroplasm detected so far that shows complete identity with B. divergens, in just over half of the 18S rRNA gene. The entire gene of this deer parasite should be analysed and transmission experiments undertaken before the infectivity of B. divergens for red deer can be confirmed.

Differences in questing tick species distribution between Atlantic and continental climate regions in Spain

Climate and vegetation in Spain vary from north to south, affecting tick distribution and consequently the presence of tick-borne diseases. The aim of this study was to investigate throughout a 2-yr study the distribution of the different exophilic questing tick species present in 18 areas: eight located in central and 10 in northern Spain. The same methodology was used in both areas, sampling vegetation on a monthly basis by blanket dragging for 20- to 30-min intervals. A total of 12 species belonging to the genera Ixodes, Haemaphysalis, Rhipicephalus, Dermacentor, and Hyalomma was identified. Differences in species distribution and prevalence were dramatically different. The most frequent and abundant species in northern Spain were Ixodes ricinus (67% of adult ticks) and Haemaphysalis punctata (8%), whereas Hyalomma lusitanicum (86%) and Dermacentor marginatus (12%) were the most abundant in central Spain. There were important differences in the monthly seasonal patterns for the different tick species. These results highlight important differences in tick distribution in neighboring areas and underline the need for ongoing surveillance programs to monitor tick population dynamics and the prevalence of tick-borne pathogens.

Detection of Babesia and Theileria species infection in cattle from Portugal using a reverse line blotting method

Babesiosis and Theileriosis are tick-borne diseases widespread in tropical and sub-tropical regions with high economic impact worldwide. In Portugal there are at least 4 tick vectors known to be competent for the transmission of Babesia and Theileria sp. identified: Rhipicephalus bursa, Rhipicephalus (Boophilus) annulatus, Ixodes ricinus and Haemaphysalis punctata. All these potential Babesia and Theileria tick vectors are widely distributed in Portugal, although they are predominant in the Southern region. In this study, 1104 cattle blood samples were randomly collected from Central and Southern regions of Portugal and analyzed by PCR-reverse line blotting (RLB) for the detection of Babesia and Theileria sp. Testing indicated that 74.7% of the bovines tested were positive for either Babesia and/or Theileria sp. In addition, five different apicomplexan species, namely, Theileria buffeli, Theileria annulata, Babesia divergens, Babesia bovis, and Babesia bigemina were detected by RLB among the bovines tested. T. buffeli was the most frequently found species, being present in 69.9% of the positive samples either as single infections (52.4%), or as mixed infections (17.5%). The Babesia specie most frequently found was B. divergens, detected in 4.2% of the infected bovines. Overall, infected bovines were found in all regions tested; however the highest number of infected bovines was observed in Évora district (96.2%) and in cattle from Limousin breeds (81.7%). The results indicate widespread Babesia and Theileria infections in Portuguese bovines, suggesting the need for improved control of ticks and tick-borne diseases.

A molecular survey of Piroplasmida and Hepatozoon isolated from domestic and wild animals in Burgos (northern Spain)

This study reports a molecular survey of Hepatozoon species and of the order Piroplasmida in the Province of Burgos, northern Spain. The diagnostic techniques employed included PCR and the sequencing of the 18S rRNA gene. Eighty-nine blood samples from domestic animals plus 138 blood/coagulated blood samples from wild mammals were examined. Theilerid protozoa were found at relatively high frequencies in bovines (14.6%) and horses (36%). Theileria buffeli, T. sergenti and T. annulata were diagnosed in cows. T. equi was common in horses and T. annae was found in a donkey for the first time. A new piroplasmid was found in the European badger (20%). This appears to be distantly related to both T. annae and a piroplasmid isolated from Lontra canadensis. A moderate prevalence (14%) for T. annae was recorded in red foxes. A species of hepatozoon was found in one bank vole (17%), while 28% of the red foxes examined were found to be infected with H. canis. Twenty-five wild house mice were studied and found not to be carriers of piroplasmids or Hepatozoon species. Wild boars, roe deer, hares, Apodemus sp. and moles were also negative for haematozoan infection. The present study indicates that piroplasmid protozoa are present at a low to moderate frequency in some domestic herbivores in the Burgos area. They also infect certain wild mammalian species, which may act as zoonotic carriers.

Detection and differentiation of ovine Theileria and Babesia by reverse line blotting in China

A reverse line blot (RLB) assay was developed for detection and specific identification of the different ovine Theileria and Babesia parasites. In a polymerase chain reaction (PCR), the hypervariable region 4 (V4 region) of the 18S ribosomal DNA gene was amplified with a set of general primers specific for members of the genera Theileria and Babesia. Meanwhile, specific oligonucleotide probes were designed and bound on membrane. After one single-PCR amplification, the amplified fragment was hybridized against different generic and species-specific probes. It was able to detect four species, i.e., Babesia motasi (Chengde, Lintan, Ningxian, Tianzhu), Babesia sp. (Kashi), Theileria luwenshuni (Lintan, Madang, Ningxian), Theileria uilenbergi (Longde, Zhangjiachuan) as defined previously. All probes bound to their respective target sequence only; therefore, no cross-reaction was observed, resulting in clear recognition of either individual strains, species, or groups in normal positive tests. Meanwhile, no signal was observed when ovine genomic DNA and water were used as a control, demonstrating that the signals are due to the presence of parasite DNA in the samples. Furthermore, the sensitivity of RLB could be considerably enhanced to detect a parasitemia level between10(-3)% and 10(-8)%. Finally, 117 samples from field were tested with RLB, PCR, and enzyme-linked immunosorbent assay (ELISA). The positive rate of RLB was higher than that of PCR and ELISA, and furthermore, RLB could determinate the species of piroplasms, the samples were infected with. Samples, 1,117, from five areas in Gannan Tibet Autonomous Region have been examined with RLB assay and compared with ELISA assay for corresponding samples. The results showed that the positive rate of RLB was higher than that of ELISA test obviously, and both T. luwenshuni and T. uilenbergi were widely distributed in these areas. RLB developed here could be used for differentiation of Babesia and Theileria infection and for epidemiological survey, which was difficult to achieve by classical methods. In conclusion, the RLB is a versatile technique for simultaneous detection and identification of all ovine piroplasms.

Distribution and molecular detection of Theileria and Babesia in questing ticks from northern Spain

A total of 562 questing adult ixodid ticks, collected during 2003-05 in 10 recreational mountain areas in northern Spain, were analysed for piroplasm infection. Reverse line blot (RLB) analysis using a panel of probes for 23 piroplasm species identified 16 different piroplasms, with an overall prevalence of 9.3%. Most were Theileria spp.-positive (7.7%), 3.0% were positive for Babesia spp. and 1.4% of ticks harboured both genera. Ixodes ricinus (Linnaeus, 1758), the most abundant tick in the vegetation, ranked third with regard to piroplasm infection prevalence (11.4%) after Rhipicephalus bursa (Canestrini & Fanzago, 1878) (16.0%) and Haemaphysalis punctata (Canestrini & Fanzago, 1878) (13.5%). Infection was detected in 6.2% of Dermacentor reticulatus (Fabricius, 1794) and in 1.1% of Haemaphysalis inermis (Birula, 1895), but was absent from Haemaphysalis concinna (Koch, 1844). Ixodes ricinus carried more piroplasm species (13), followed by H. punctata (10), D. reticulatus (8), R. bursa (3) and H. inermis (1). Although most of the positive ticks harboured a single infection (76.9%), mixed infections with two or three different piroplasm species were also detected (23.1%). The various tick-pathogen associations found are discussed and prevalences of infection in ticks are compared with previous results on piroplasms infecting animals in the same region.

Hemoprotozoa of domestic animals in France: prevalence and molecular characterization

Very limited information is available on epizootiology of haematozoan infections in French domestic animals. In an attempt to address this issue, prevalence of piroplasmida was studied in carnivores and ruminants, whereas prevalence of Hepatozoon spp. was only investigated in carnivores. In total, 383 animals were included in the survey (namely 116 cats, 108 dogs, 91 sheep and 68 cows). Parasite diagnosis was carried out using molecular methods such as PCR and sequencing of the 18S rRNA gene. In addition, ruminant samples were analyzed with the reverse line blotting technique (RLB). Results of RLB and PCR plus sequencing were in total agreement. In carnivores, haematozoan prevalence was close to 1%. Two cats were infected by H. canis (1.7% prevalence) and one of them was co-infected by Cytauxzoon sp. (0.8%). This represents the first finding of both pathogens in French cats. One dog was infected by H. canis (0.9%) and another by Babesia canis vogeli (0.9%). In ruminants, haematozoan prevalence (piroplasmida) was significantly higher than in carnivores (4.8% in sheep and 8.8% in cow). Theileria ovis was found in 1 sheep, Theileria sp. in 2 sheep, Theileria buffeli in 5 cows and B. major in 1 cow. Evidence presented in this contribution indicates that haematic protozoa are not widely distributed in domestic mammal populations of France.

A molecular survey of Theileria and Babesia parasites in cattle, with a note on the distribution of ticks in Tunisia

Between October and November 2006, a total of 278 bovine blood samples were examined, and 104 (37.4%) were positive for piroplasms by microscopy. A reverse line blot hybridisation with polymerase chain reaction detected Theileria annulata, T. buffeli, Babesia bovis and B. bigemina in cattle accounting for 48.6% of positive samples. The most frequently found species was T. buffeli, which was present in 39.2% of the samples. T. annulata was found in 48 samples (17.3%). Babesia infections were less frequently detected: B. bovis was found in 6.8% of the samples and B. bigemina in 4.3%. Mixed infections were detected in 45 samples, accounting for seven different combinations of species. Seven Ixodid tick species (Boophilus annulatus, Ixodes ricinus, Hyalomma marginatum, Hyalomma excavatum, Hyalomma detritum, Haemaphysalis punctata and Haemaphysalis sulcata) were collected from examined cattle in the 23 visited farms. I. ricinus was the dominant species (36%), mainly collected in the humid zone, while it seemed to be very rare in the semi-arid zone (where only 15 specimens were collected), whereas B. annulatus was the most commonly collected species in the sub-humid area (68.5% of ticks collected in this zone).

Molecular detection and characterization of piroplasms infecting cervids and chamois in Northern Spain

Wildlife can act as reservoir of different tick-borne pathogens of veterinary and zoonotic importance. To investigate the role of wild ruminants as reservoir of piroplasm infection, 28 red deer, 69 roe deer and 38 chamois from Northern Spain were examined by reverse line blot (RLB) hybridization. The survey detected a prevalence of 85.7% in red deer, 62.3% in roe deer and 28.9% in chamois. Four different piroplasms were identified: Theileria sp. OT3 (previously described in sheep) as the most prevalent (85.7% in red deer, 46.4% in roe deer and 26.3% in chamois); Theileria sp. 3185/02 (previously described in a red deer in Central Spain) more abundant in red deer (53.6%) than in roe deer (10.1%) but absent from chamois; Babesia divergens detected in 6 roe deer; Theileria ovis present in 1 chamois. Mixed infections (Theileria sp. OT3 and Theileria sp. 3185/02) were only found in red and roe deer. Sequencing analysis of the 18S rRNA gene confirmed the RLB results and showed 99.7% identity between Theileria sp. 3185/02 and T. capreoli, suggesting that they are the same species. Tick distribution and contact of wild ruminants with domestic animals are discussed in terms of piroplasm infection. The results suggest that a considerable number of wildlife ruminants are asymptomatic carriers that may serve as reservoirs of the infection posing a serious concern in terms of piroplasmosis control.