Methods Applied to the Diagnosis of Cattle Trypanosoma vivax Infection: An Overview of the Current State of the Art.

Bovine trypanosomiasis caused by Trypanosoma vivax is a relevant disease in domestic ungulates in Latin America, causing different types of livestock losses, particularly in African and South American countries, leading to loss of millions of dollars/year related to dairy and meat production. In addition, T. vivax trypanosomiasis requires intensive veterinary care. While vector control is a feasible measure to manage disease spreading, the search for accurate diagnostic tools still represents a gap in routine veterinary practices and a challenge for the scientific community. The parasite is mechanically transmitted by fomites or by the saliva of haematophagous flies, such as Stomoxys sp. and Tabanus sp., infecting cattle as well as a number of animal hosts. The main symptoms of T. vivax bovine trypanosomiasis are apathy, fever, restricted growth, miscarriage, progressive weakness, neurological signs, pale mucous, loss of appetite, lethargy, and substantial weight loss. In most cases, the presence of animals with subclinical infections, nonspecific symptoms and without apparent parasitaemia presents a challenge when making a diagnosis, which requires accurate methods. Herein, we review state of the art concerning current methods available for the diagnosis of T. vivax bovine trypanosomiasis, focusing on clinical, parasitological, immunological and molecular approaches, highlighting the main features of each method, including "pros and cons". Overall, combining several diagnostic techniques is a better choice since it leads to fewer false negative results and contributes to better disease control.

Development of a chimeric protein based on a proteomic approach for the serological diagnosis of human tegumentary leishmaniasis.

Leishmania braziliensis is responsible for most cases of human tegumentary leishmaniasis (HTL) and has caused a wide range of clinical manifestations, including cutaneous (CL) and mucosal leishmaniasis (ML). The diagnosis is based on criteria that consider epidemiological data, clinical findings, and laboratory tests and is hard to establish. For laboratory tests, none of the assays available can be considered gold standards for disease detection. In addition, the Montenegro skin test, essential to supporting infectologists in the clinical management of the disease, is no longer available in Brazil. Thus, the aim of this study was to develop new targets to be used in diagnostic tests for HTL. In the first step, we carried out two-dimensional gel electrophoresis, followed by mass spectrometry, combined with heat map analysis and immunoproteomics approach, and disclosed eight proteins expressed in the amastigote stage specifically recognized by serum from CL and ML patients. A chimeric protein was designed based on the combination of thirteen linear B-cell epitopes, identified by immunoinformatics analysis, from L. braziliensis proteins. Our results showed that the strategy used in this work was successful in developing an antigen to be used in immunological assays (100.0% sensitivity and specificity) in the detection of HTL cases and in comparison with results obtained from an ELISA using soluble L. braziliensis antigen (SLb-Antigen) and immunofluorescence assay (Bio-Manguinhos/FIOCRUZ). The present technology opens the door for its use in field exams by means of an immunochromatographic test, which will be even more helpful in regions without laboratory structures.Key points• Rational strategy to develop antigens.• Integration between immunoproteomic and immunoinformatics analysis.• Chimeric protein shows high performance in HTL diagnosis.

Distinct immune response profile during rhipicephalus (boophilus) microplus infestations of guzerat dairy herd according to the maternal lineage ancestry (mitochondrial DNA).

Rhipicephalus (Boophilus) microplus ticks cause major constraints to public and livestock health, and serious economic losses. It is well known that the immune response to infestations with cattle ticks is influenced by the host genetic background leading to distinct immunological profiles between bovine hosts genetically susceptible and resistant. The influence of Bos indicus (Bi) and Bos taurus (Bt) maternal lineage ancestry of mitochondrial DNA in the profile of the immune response of Zebu cattle to ticks remains unknown. The present work evaluated the hematological parameters and the immune response profile in the peripheral blood of a Guzerat dairy herd, further categorized into two maternal lineage ancestry subgroups (Bi-mtDNA and Bt-mtDNA) after experimental infestation with larvae of R. microplus. Our data demonstrated that although hematological and erythrogram analysis showed a similar profile throughout, some cell populations present a distinct profile between the groups. Especially MON, CD335+ and CD8+ T-cells are predominant in Bi-mtDNA. Moreover, an overall picture of R. microplus infestation demonstrated that Bi-mtDNA presented a more efficient and earlier innate immune response. Bi-mtDNA showed a greater number of connections with R. microplus counts and also with the CD25+ activation marker of the immune response. Bi-mtDNA showed greater number of connections, with an important participation of the innate immune while Bt-mtDNA showed a delay in the immune response. Elucidating the mechanisms by which resistant animals prevent heavy tick infestation is a crucial step in the development of predictive biomarkers for tick resistance for use in selective breeding programs, and is also potentially useful for the development of anti-tick vaccines.

Parasitological and immunological evaluation of cattle experimentally infected with Trypanosoma vivax.

Trypanosoma vivax infection causes relevant economical impact due to high morbidity and mortality leading to negative impact on local livestock. Despite parasitological and serological methods are used for the diagnosis of T. vivax infection, gaps regarding sensitivity and specificity of these methods still represent a challenge. The present study aimed to compare the kinetics of parasitological and serological parameters in cattle experimentally infected with T. vivax along with immunophenotypic analysis of whole blood leukocytes. Based on the parasitemia profile the analysis were performed in three distinct periods, referred as pre-patent, patent and post-treatment. Distinct kinetics of anti-T. vivax IgM and IgG were observed during the pre-patent, patent and post-treatment periods. Increased levels of WC1+ γδ T-cells were observed throughout the infection with strong correlations with other biomarkers observed during post-treatment period. Our findings demonstrated that there is a important participation of Monocytes:CD14+; NK-cells:CD335+ and WC1+ γδ T-cells that coincide with the peak of parasitemia and also with the adaptive immunity, specially CD4+ T-cells in T. vivax infection. The knowledge of the immune response is important not only for understanding the biology of the parasite in the host, but for the design of new treatment strategies for trypanosome infections.