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

Acute Respiratory Syndrome Mimicking Shipping Sickness in Theileria buffeli Infected Buffalo Calf

Benign theileriosis, caused by the members of the Theileria orientalis complex, can develop fatal clinical outbreaks characterized by acute respiratory manifestation in stressful conditions. This report describes the molecular diagnosis and clinical management of a recently transported buffalo calf with severe Theileria buffeli infection and associated acute pneumonia. A five-month-old male buffalo calf having an inter-state travel history three days back was presented with pyrexia, anorexia, weakness, mucoid rhinorrhoea, dyspnoea and diarrhoea from the day of procurement. The history and physical examination revealed a clinical presentation similar to shipping fever. Whereas, severe parasitemia of Theileria spp. with anaemia, thrombocytopenia and granulopenia were evident on laboratory investigation. The Theileria spp. infection was confirmed by PCR method using specific primers and the authentication was made by detailed sequence analysis. The small subunit rRNA was amplified using universal apicomplexan primers and the phylogenetic analysis was carried out for further characterisation. The animal was stabilized by steroid nebulization therapy and the specific chemotherapy was instigated using buparvaquone and sulphamethoxazole-trimethoprim combination. Supportive medications like non-steroidal anti-inflammatory drugs, antihistamines, antidiarrhoeals and vitamins were provided symptomatically. The animal showed a good response to therapy and recovered from parasitemia by day 10 and the molecular clearance was later confirmed on day 70 of therapy. The present case of Theileria buffeli infected buffalo calf with acute respiratory signs points towards the possible hemoparasitic outbreaks in transport-stressed animals with the signs of shipping fever-associated syndrome.

Tick-borne Apicomplexa in wildlife and ticks of French Guiana

Tick-borne Apicomplexa encompass a group of parasites responsible for significant medical and veterinary diseases, including babesiosis, theileriosis, and hepatozoonosis. In this study, we investigated the presence and diversity of tick-borne Apicomplexa in wildlife and ticks inhabiting the Amazon rainforests of French Guiana. To this end, we conducted molecular screening and typing using 18S rRNA sequences on a collection of 1161 specimens belonging to 71 species, including 44 species of wild mammals, five species of passerines, and 22 species of ticks. We characterized eight genovariants of Babesia, Theileria, Hemolivia, and Hepatozoon parasites, some matching known species, while others suggested potential novel species. These parasites were detected in wild mammals, including opossums, sloths, armadillos, porcupines, margays, greater grisons, and ticks, but not in passerines. Finally, similarities with surveys conducted in Brazil highlight the specific sylvatic transmission cycles of South American tick-borne Apicomplexa.

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

Background and Aim

Theileria annulata infection in cattle causes major economic losses in livestock production in many Central Asian countries, including the southern region of Kazakhstan. This study aimed to obtain a recombinant T. annulata surface protein (TaSP) and to investigate its possible use as an antigen in an indirect enzyme-linked immunosorbent assay (ELISA) for the serological diagnosis of bovine theileriosis.

Materials and Methods

Recombinant TaSP was obtained by cloning a polymorphic region of the TaSP gene, expressing it in Escherichia coli strain BL21, and purifying it by metal chelating chromatography. An indirect ELISA using recombinant TaSP as an antigen was developed and evaluated for the detection of T. annulata-specific antibodies in plasma samples from 69 cows polymerase chain reaction (PCR)-positive or PCR-negative for T. annulata and/or Theileria orientalis from southern Kazakhstan.

Results

The obtained recombinant protein had a molecular weight of 32 kDa, and mass spectrometry analysis of the purified protein identified it as a fragment of the surface protein of T. annulata. Initial testing of 69 field plasma samples from cattle showed that the results of indirect ELISA using TaSP as an antigen agreed substantially with those of T. annulata PCR (κ: 0.78). The relative sensitivity and specificity of indirect ELISA were 88.7% and 100%, respectively, using PCR as a reference. There was no evidence of cross-reaction with T. orientalis.

Conclusion

Initial results using recombinant TaSP as an antigen in indirect ELISA are promising and support the widespread use of this assay for routine diagnosis and T. annulata seroprevalence studies in cattle in Kazakhstan and possibly neighboring countries.

Evaluation of haematological parameters in haemolytic anaemia caused by tick-borne pathogens in grazing cattle

BACKGROUND

No tick-borne pathogens (TBPs) causing haemolytic anaemia in cattle have been reported, except Theileria orientalis and complete blood count (CBC) profile is the only haematological parameter to determine the severity of regenerative haemolytic anaemia.

OBJECTIVES

To identify the causative agents of TBP-induced haemolytic anaemia and determine haematological parameters that indicate haemolytic anaemia in grazing cattle.

METHODS

Eighty-two Korean indigenous cattle (Hanwoo) were divided into two groups: grazing (n = 67) and indoor (n = 15) groups. CBC and serum biochemistry were performed. PCR was conducted using whole blood-extracted DNA to investigate the prevalence of TBPs.

RESULTS

TBP-induced haemolytic anaemia was observed in the grazing group. In grazing cattle, co-infection (43.3%, 29/67) was most frequently detected, followed by T. orientalis (37.6%, 25/67) and Anaplasma phagocytophilum infections (1.5%, 1/67). In indoor cattle, only co-infection (20%, 3/15) was identified. Grazing cattle exhibited regenerative haemolytic anaemia with marked monocytosis, mild neutropenia, and thrombocytopenia. According to grazing frequency, the 1st-time grazing group had more severe anaemia than the 2nd-time grazing group. Elevations in indirect bilirubin and L-lactate due to haemolytic anaemia were identified, and correlations with the respective markers were determined in co-infected grazing cattle.

CONCLUSIONS

Quantitative evaluation of haematocrit, mean corpuscular volume, and reticulocytes (markers of regenerative haemolytic anaemia in cattle) was performed for the first time. Our results show that, in addition to T. orientalis, A. phagocytophilum is strongly associated with anaemia. The correlation between haemolytic anaemia severity and haematological parameters (indirect bilirubin, reticulocytes, and L-lactate) was confirmed.

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.

In silico analysis of sporozoite surface antigen 1 of Theileria annulata (TaSPAG1) for multi-epitope vaccine design against theileriosis

Tropical theileriosis is a protozoan infection caused by Theileria annulata, which significantly affects cattle worldwide. This study was aimed to analyze the TaSPAG1 protein and design a novel multi-epitope vaccine candidate. Online tools were employed for the prediction of Physico-chemical properties, antigenicity, allergenicity, solubility, transmembrane domains and signal peptide, posttranslational modification (PTM) sites, secondary and tertiary structures as well as intrinsically disordered regions, followed by identification and screening of potential linear and conformational B-cell epitopes and those peptides having affinity to bind bovine major histocompatibility complex class I (MHC-I) molecules. Next, a multi-epitope vaccine construct was designed and analyzed. This 907-residue protein was hydrophilic (GRAVY: -0.399) and acidic (pI: 5.04) in nature, with high thermotolerance (aliphatic: 71.27). Also, 5 linear and 12 conformational B-cell epitopes along with 8 CTL epitopes were predicted for TaSPAG1. The 355-residue vaccine candidate had a MW of about 35 kDa and it was antigenic, non-allergenic, soluble and stable, which was successfully interacted with cattle MHC-I molecule and finally cloned into the pET28a(+) vector. Further wet studies are required to assess the vaccine efficacy in cattle.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40203-023-00153-5.

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

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

Pathogenesis of Anemia in Canine Babesiosis: Possible Contribution of Pro-Inflammatory Cytokines and Chemokines-A Review

Canine babesiosis is a tick-borne protozoan disease caused by intraerythrocytic parasites of the genus Babesia. The infection may lead to anemia in infected dogs. However, anemia is not directly caused by the pathogen. The parasite's developmental stages only have a marginal role in contributing to a decreased red blood cell (RBC) count. The main cause of anemia in affected dogs is the immune response to the infection. This response includes antibody production, erythrophagocytosis, oxidative damage of RBCs, complement activation, and antibody-dependent cellular cytotoxicity. Moreover, both infected and uninfected erythrocytes are retained in the spleen and sequestered in micro-vessels. All these actions are driven by pro-inflammatory cytokines and chemokines, especially IFN-γ, TNF-α, IL-6, and IL-8. Additionally, imbalance between the actions of pro- and anti-inflammatory cytokines plays a role in patho-mechanisms leading to anemia in canine babesiosis. This article is a review of the studies on the pathogenesis of anemia in canine babesiosis and related diseases, such as bovine or murine babesiosis and human or murine malaria, and the role of pro-inflammatory cytokines and chemokines in the mechanisms leading to anemia in infected dogs.

Theileria and Babesia infection in cattle - First molecular survey in Kazakhstan

Central Asia, including Kazakhstan, is an endemic area of Theileria and Babesia infections in cattle. Current data on the geographic distribution, prevalence, and genetic diversity of these pathogens in vertebrate hosts are lacking in Kazakhstan. The present study aimed to fill this gap, using molecular techniques for the first time. A cross-sectional survey was performed on adult cattle from 40 villages in nine administrative districts of the provinces of Turkistan and Zhambyl, southern Kazakhstan, in summer 2020. A total of 766 blood samples were screened for Theileria annulata (enolase gene), Theileria orientalis (major piroplasm surface protein gene, MPSP) and Babesia spp. (18 S ribosomal RNA gene) using polymerase chain reaction. The genetic variability of Theileria spp. was assessed by sequencing one amplicon from each village. All Babesia spp. positive amplicons were sequenced to identify the species involved. The overall prevalence of infections with T. annulata, T. orientalis and Babesia spp. was 83.0% (40 villages positive), 33.3% (31 villages) and 13.5% (36 villages), respectively. Co-infections with two or three species were present in 48.9% of all positive cattle. Theileria annulata showing a high polymorphism of the enolase gene occurred with similar frequency in both provinces. Theileria orientalis was detected for the first time in Kazakhstan being significantly (P = 0.014) more prevalent in Zhambyl than in Turkistan. Fourteen genotypes of T. orientalis were identified; two belonged to the moderately virulent MPSP-type 1 ('Chitose') and the others to MPSP-type 3 ('Buffeli') which is considered avirulent. The prevalence of Babesia infection was significantly (P < 0.000) higher in Turkistan than in Zhambyl. An unequivocal identification of the species involved was possible in 127 sequenced samples: Babesia occultans was the most common species, followed by Babesia bigemina and Babesia major, the latter being the first record in the country. The results show that Theileria and Babesia infections in cattle are widespread and occur with remarkably high prevalence in the southern Kazakhstan. They also provide first data on the genetic diversity of the species involved.

Tick-borne diseases in Egypt: A one health perspective

Background

Ticks are important arthropod vectors that transmit pathogens to humans and animals. Owing to favourable climatic and environmental conditions, along with animal importation from neighbouring countries, ticks and tick-borne diseases (TBDs) are widespread in Egyptian localities. Here, we review the current knowledge on the epidemiology of TBDs in Egypt in light of the One Health paradigm.

Methods and results

Five scientific databases, including "Web of Science", "Scopus", "PubMed", "Science Direct", and "Google Scholar", were searched for articles describing TBDs in Egypt. A total of 18 TBDs have been reported in humans and animals, including three protozoal diseases (babesiosis, theileriosis, and hepatozoonosis), 12 bacterial diseases (anaplasmosis, ehrlichiosis, Lyme borreliosis, bovine borreliosis, tick-borne relapsing fever, Mediterranean spotted fever, African tick-borne fever, lymphangitis-associated rickettsiosis, bartonellosis, tularaemia, Q fever, and aegyptianellosis), and three viral diseases (Crimean-Congo haemorrhagic fever, Alkhurma haemorrhagic fever, and Lumpy skin disease).

Conclusions

Despite the circulation of zoonotic tick-borne pathogens among livestock and tick vectors, human infections have been overlooked and are potentially limited to infer the actual communicable disease burden. Therefore, facility-based surveillance of TBDs, combined with capacity building for laboratory diagnostics in healthcare facilities, is urgently required to improve diagnosis and inform policy-making in disease prevention. Additionally, collaboration between expert researchers from various disciplines (physicians, biologists, acarologists, and veterinarians) is required to develop advanced research projects to control ticks and TBDs. Considering that domestic livestock is integral to many Egyptian households, comprehensive epidemiological studies on TBDs should assess all disease contributors, including vertebrate hosts (animals, humans, and rodents) and ticks in the same ecological region, for better assessment of disease burden. Additionally, upscaling of border inspections of imported animals is required to stop crossover movements of ticks and TBDs.

The control of Hyalomma ticks, vectors of the Crimean–Congo hemorrhagic fever virus: Where are we now and where are we going?

At a time of major global, societal, and environmental changes, the shifting distribution of pathogen vectors represents a real danger in certain regions of the world as generating opportunities for emergency. For example, the recent arrival of the Hyalomma marginatum ticks in southern France and the concurrent appearance of cases of Crimean–Congo hemorrhagic fever (CCHF)—a disease vectored by this tick species—in neighboring Spain raises many concerns about the associated risks for the European continent. This context has created an urgent need for effective methods for control, surveillance, and risk assessment for ticks and tick-borne diseases with a particular concern regarding Hyalomma sp. Here, we then review the current body of knowledge on different methods of tick control—including chemical, biological, genetical, immunological, and ecological methods—and the latest developments in the field, with a focus on those that have been tested against ticks from the genus Hyalomma. In the absence of a fully and unique efficient approach, we demonstrated that integrated pest management combining several approaches adapted to the local context and species is currently the best strategy for tick control together with a rational use of acaricide. Continued efforts are needed to develop and implement new and innovative methods of tick control.

Disease-bearing Hyalomma ticks are an increasingly emerging threat to humans and livestock worldwide. Various chemical, biological, genetic, and ecological methods for tick control have been developed, with variable efficiencies. Today, the best tick control strategy involves an integrated pest management approach.

Genetic Resistance of Bovines to Theileriosis

Diseases caused by ticks have a high impact on the health, welfare, and productivity of livestock species. They are also an important cause of economic losses in farms worldwide. An example of such diseases is theileriosis, which can be controlled by drugs or vaccines, although these are not fully efficient. Therefore, there is a need to develop alternative and more sustainable and efficient complementary strategies. These may involve the identification and selection of animals more resistant to the disease. Several previous studies have identified significant differences in resistance between different breeds, with resistant breeds typically identified as those native to the region where they are being studied, and susceptible as those from exotic breeds. These studies have indicated that resistance traits are intrinsically related to the modulation of the immune response to infection. This review aims to systematize the general knowledge about theileriosis, emphasize resistance to this disease as a sustainable control strategy, and identify which traits of resistance to the disease are already known in cattle.

Theileriosis in naturally infected roan antelope (Hippotragus equinus)

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

Identification and discrimination of Theileria annulata by polymerase chain reaction-restriction fragment length polymorphism

Background and Aim:

Theileria annulata infection is a tick-borne disease affecting ruminants in the tropical and subtropical regions causing severe economic losses. This study aimed to characterize circulating T. annulata isolates from four governorates (administrative districts) north and south of Egypt using polymerase chain reaction (PCR)-restriction fragment length polymorphism.

Materials and Methods:

Fifty samples were collected from the four governorates of Egypt and were examined by a PCR assay based on the heat shock protein 70 gene. The amplified product was subsequently digested using two restriction enzymes, Taq I and Alu I, to determine which pattern of T. annulata strains was involved.

Results:

The findings revealed that one distinct pattern was observed for T. annulata isolates in the northern governorates and another one in the southern governorates. The Taq I enzyme produced three fragments (100, 175, and 270 bp), and the Alu I enzyme produced four fragments (60, 90, 125, and 270 bp).

Conclusion:

This study determined the presence of two distinct circulating genotypes of T. annulata among cattle in Egypt based on PCR-RFLP using the HSP 70 gene. More studies are needed in different parts of the country to investigate the virulence and strain variance of T. annulata in cattle.

Babesia and Theileria Identification in Adult Ixodid Ticks from Tapada Nature Reserve, Portugal

This study, conducted in a nature reserve in southern Portugal, investigated the frequency and diversity of tick-borne piroplasms in six species of adult ixodid ticks removed from 71 fallow deer (Dama dama) and 12 red deer (Cervus elaphus), collected over the period 2012–2019. The majority of 520 ticks were Ixodes ricinus (78.5%), followed by Rhipicephalus sanguineus sensu lato, Hyalomma lusitanicum, Haemaphysalis punctata, Dermacentor marginatus, and Ixodes hexagonus. The R. sanguineus ticks collected from the deer were clearly exophilic, in contrast to the endophilic species usually associated with dogs. Four tick-borne piroplasms, including Theileria spp., and the zoonotic species, Babesia divergens and Babesia microti, were detected. B. divergens 18S rDNA, identical to that of the bovine reference strain U16370 and to certain strains from red deer, was detected in I. ricinus ticks removed from fallow deer. The sporadic detection of infections in ticks removed from the same individual hosts suggests that the piroplasms were present in the ticks rather than the hosts. Theileria sp OT3 was found in I. ricinus and, along with T. capreoli, was also detected in some of the other tick species. The natural vector and pathogenic significance of this piroplasm are unknown.

Establishment and application of a qPCR diagnostic method for Theileria annulata

Bovine theileriosis caused by several Theileria species including Theileria annulata, Theileria parva, Theileria orientalis, Theileria mutans, and Theileria sinensis is a significant hemoprotozoan tick-borne disease. Among these, Theileria species, T. annulata, which causes tropical theileriosis (TT), is regarded as one of the most pathogenic and is responsible for high mortality. At present, most conventional diagnostic methods for tropical theileriosis are time-consuming and laborious and cannot distinguish newfound T. sinensis in China. Therefore, a high sensitivity and specificity real-time quantitative PCR method based on the TA19140 target molecule was developed, and the method was found to be specific for T. annulata. No cross-reaction was observed with T. sinensis, T. orientalis, Babesia bovis, Babesia bigemina, or Hyalomma anatolicum which is negative for T. annulata. A total of 809 field samples from different regions of China were analyzed by using the developed qPCR and conventional PCR. The positive samples for T. annulata detected by real-time qPCR and conventional PCR were 66/809 (8.16%) and 20/809 (2.47%), respectively, and all positive amplicons by qPCR were confirmed by Sanger sequencing. The results showed that the developed qPCR for the T. annulata 19,140 gene was more sensitive than conventional PCR. In addition, we first discovered that TA19140 was mainly expressed at the schizont and merozoite stages of T. annulata by relative quantification. The protein encoded by the TA19140 gene may be used as a potential diagnostic antigen for tropical theileriosis. In conclusion, a real-time quantitative PCR diagnostic method targeting the TA19140 gene was successfully established and could be used for both the quantitative and qualitative analysis of T. annulata infection from cattle and vector ticks, which will greatly help to control and diagnosis of tropical theileriosis.

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

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

Molecular detection of Theileria species, Anaplasma species, Candidatus Mycoplasma haemobos, Trypanosoma evansi and first evidence of Theileria sinensis-associated bovine anaemia in crossbred Kedah-Kelantan x Brahman cattle

BACKGROUND

Serious disease outbreaks in cattle are usually associated with blood pathogens. This study aims to detect blood pathogens namely Theileria species, Anaplasma species, Candidatus Mycoplasma haemobos and Trypanosoma evansi, and determine their phylogenetic relationships and haemato-biochemical abnormalities in naturally infected cattle.

METHODS

Molecular analysis was achieved by PCR amplification and sequencing of PCR amplicons of 18SrRNA gene of Theileria species, 16SrRNA genes of Anaplasma and Mycoplasma species, MPSP genes of T. orientalis and T. sinensis, MSP4 gene of A. marginale, 16SrRNA gene of Candidatus Mycoplasma haemobos, and RoTat1.2 VSG gene of Trypanosoma evansi, in sixty-one (61) clinically ill Kedah-Kelantan x Brahman cattle in Pahang, Malaysia.

RESULTS

A total of 44 (72.13%) cattle were infected with more than one blood pathogen. Theileria species was the blood pathogen with the highest molecular detection rate (72.13, 95% CI 59.83-81.81%). Nucleotide blast analyses of all sequences demonstrated high degree of molecular similarity (98-100%) in comparison with their respective reference sequences. Analysis of 18SrRNA gene sequences of Theileria species and 16SrRNA gene sequences of Anaplasma species revealed Theileria sinensis and Anaplasma platys respectively as additional species detected in these cattle. MPSP-PCR analysis was conducted for further confirmation of T. sinensis. The blood picture of eight infected cattle groups revealed poikilocytosis, anisocytosis, rouleaux formation and degenerative left shift. High mean erythrocyte fragility values were common in infected cattle groups. Anaemia of the macrocytic normochromic type and spherocytes were observed in the T. evansi and Anaplasma platys + Theileria sinensis double species co-infected cattle group. Normocytic normochromic anaemia was observed in the T. sinensis infected cattle group. Significant (p < 0.05) increases in serum liver and kidney parameters, total protein, globulin, total and unconjugated bilirubin and decreased albumin values were observed in the T. evansi infected cattle when compared to clinically healthy cattle.

CONCLUSION

We present the first evidence of Theileria sinensis-associated bovine anaemia (TSABA) in Malaysian cattle. Because of the high occurrence of bovine theileriosis and detection of A. platys, there is an urgent need for appropriate preventive and control measures against these blood pathogens.

Resistance to Ticks and the Path to Anti-Tick and Transmission Blocking Vaccines

The medical and veterinary public health importance of ticks and tick-borne pathogens is increasing due to the expansion of the geographic ranges of both ticks and pathogens, increasing tick populations, growing incidence of tick-borne diseases, emerging tick transmitted pathogens, and continued challenges of achieving effective and sustained tick control. The past decades show an increasing interest in the immune-mediated control of tick infestations and pathogen transmission through the use of vaccines. Bovine tick resistance induced by repeated infestations was reported over a century ago. This review addresses the phenomena and immunological underpinning of resistance to tick infestation by livestock and laboratory animals; the scope of tick countermeasures to host immune defenses; and the impact of genomics, functional genomics, and proteomics on dissecting complex tick-host-pathogen interactions. From early studies utilizing tick tissue extracts to salivary gland derived molecules and components of physiologically important pathways in tick gut and other tissues, an increased understanding of these relationships, over time, impacted the evolution of anti-tick vaccine antigen selection. Novel antigens continue to emerge, including increased interest in the tick microbiome. Anti-tick and transmission blocking vaccines targeting pathogen reservoirs have the potential to disrupt enzootic cycles and reduce human, companion, domestic animal, and wildlife exposure to infected ticks.

Effects of Theileria orientalis Infection on Health Status and Productivity of Dairy Cows Reared inside Barns

The objective of the present study was to investigate the effects of Theileria orientalis on the severity of anemia, the prevalence of disease within 21 days after calving and productivity in cows raised inside barns. This longitudinal observational study, which was conducted on a commercial dairy farm in Japan, involved 627 Holstein cows subjected to PCR analysis for T. orientalis. In study 1, we collected blood samples from 156 sick cows within 21 days after calving, and we found the prevalence of T. orientalis infection to be 65.4%. In study 2, we randomly selected 471 cows during the dry period and collected blood samples to conduct PCR analysis for T. orientalis and determined the prevalence of T. orientalis infection to be 69.0%. Compared with the values for the T. orientalis-uninfected group, the T. orientalis-infected cows had significantly decreased hemoglobin concentrations and hematocrit, but there were no differences in the other complete blood count indexes between the two groups. In addition, there were no differences in productivity and the prevalence of major diseases between the T. orientalis-infected and uninfected cows. In summary, T. orientalis had few effects on anemia, productivity and the health of cows raised inside a barn.

Toxic Effects of Docosahexaenoic Acid Treatment in the Rat Liver BRL-3A Cell

The cytotoxicity of docosahexaenoic acid (DHA) on normal cells is still unclear. This study investigated the effects of DHA on the cytotoxicity and possible mechanism in the BRL-3A cell. The cultured rat liver BRL-3A cell line was treated with 50, 100 and 200 μM DHA for 24 h. The cell viability was increased in the 50 and 100 μM DHA treatments, but decreased in the 200 μM DHA treatment. The 50, 100 and 200 μM DHA treatments increased the proportion of the apoptotic cells, the levels of lactate dehydrogenase (LDH), alkaline phosphatase (AKP) and IL-6 in the supernatant, and the ratio of the phosphonated p38MAPK to the p38MAPK (p-p38/p38) protein in the cells. The expression of TGF beta-activated kinase 1 (TAK1), nuclear transcription factor-κB p65 (NF-κB p65) and the inhibitor of NF-κB alpha (IκBα) mRNA, and the ratio of the phosphonated IκBα (p-IκBα) to IκBα protein were increased in the 200 μM DHA treatment, while the ratio of phosphonated extracellular regulated protein kinases (p-ERK) to ERK protein was decreased in the 200 μM DHA treatment. These results indicate that DHA-treated (50, 100 and 200 μM) BRL-3A cells for 24 h promotes cell apoptosis and inflammatory response, and the p38 MAPK, ERK and NF-κB signal pathways were involved in mediating the apoptosis and inflammatory response.