Variation in cardiac markers and electrocardiographic alterations in young calves naturally infected with bovine tropical theileriosis

Clinical Findings, Laboratory Results, Electrocardiography and Echocardiography Findings in Dairy Buffaloes with Theileriosis

PURPOSE

Tropical theileriosis is a tick-borne haemoprotozoan disease, and cardiac function assessment in buffaloes with theileriosis was poorly documented.

METHODS

The Present study was carried out from April 2022 to December 2022. Theileriosis was confirmed by microscopic examination of stained blood smears and lymphnode smears further confirmed by PCR assay. Electrocardiography was performed by using the base apex lead system, and echocardiography was performed by using the right parasternal view.

RESULTS

The incidence of theileriosis was 16.25% by examination of stained blood smears, and 30.42% by PCR examination in 240 buffaloes. Repeatedly noted clinical signs were the absence of rumination, anorexia, loss of milk yield, depressed demeanour, emaciation, hyperthermia, lymphadenopathy, tick infestation, tachycardia, cardiac arrhythmia, and increased intensity of heartbeat. Haematological findings disclosed decreased haemoglobin, packed cell volume, total erythrocyte count, and neutrophils; increased eosinophils and monocytes. Serum biochemical findings revealed decreased albumin, albumin/globulin ratio, glucose, calcium, phosphorous, sodium, potassium, and chloride; increased globulin, aspartate aminotransferase, bilirubin, blood urea nitrogen, creatinine, cholesterol, lactate dehydrogenase, gamma-glutamyl transferase, and creatine kinase myocardial band isoenzymes. Electrocardiography explorations were sinus tachycardia, broad T wave, and sinus arrhythmia. Echocardiography examination showed ventricular wall thickening, cardiac chamber dilatation, valvular defects/valvular regurgitation, and pericarditis/cardiac tamponade.

CONCLUSION

The present research proposes the changes in the electrocardiography and echocardiography findings in buffaloes with theileriosis, which are essential in clinics to identify the secondary complications during theileriosis and formulate therapeutics.

An endpoint visualization loop-mediated isothermal amplification (LAMP) for detecting bubaline theileriosis

Background

Tropical theileriosis is a significant disease affecting the health and production levels of buffaloes in India. It is caused by an apicomplexan—Theileria annulata. The timely and accurate detection of infection is vital for implementing a mass vaccination or control programme in a given area under outbreak. Most of the literature concerned with diagnosis of theileriosis revolves around cattle, and practically, there are very limited assays available for detecting bubaline theileriosis. Loop-mediated isothermal amplification (LAMP) assay certainly amplifies the targeted deoxyribosenucleic acid (DNA) with a comparatively higher efficacy, rapidity and sensitivity. Alongside, minimal use of sophisticated instruments in performing LAMP assay is certainly an add on. The present study describes the application of LAMP assay in diagnosing tropical theileriosis in buffaloes alongside, its comparison with polymerase chain reaction (PCR) and blood microscopical examination.

Results

No cross-reaction was seen with DNA of other haemoprotozoan. LAMP was compared with blood microscopy and PCR. LAMP detected infection in 27 out of 100 buffaloes, while blood microscopy and PCR detected disease in 16 and 24 buffaloes, respectively.

Conclusion

The sensitivity, specificity and kappa value prediction of LAMP were found to be much higher than the PCR and blood microscopy. The present communication reports the first use of LAMP in detecting theileriosis in buffaloes in the world.

Evaluation of cardiovascular biomarkers and histopathological alterations in cattle naturally infected by Babesia bigemina

Hemolytic anemia and secondary hypoxia are characteristics of naturally occurring Babesia bigemina infection in cattle. The anemic phase comes with cardiovascular insufficiency due to hypoxia-induced system dysfunction; but to date there is no description of cardiac damage in the infected animals. Therefore, this study was undertaken to investigate hematological parameters, biomarkers of cardiac function and D-dimer in 13 cattle infected with B. bigemina which were unresponsive to standard treatment. The animals were necropsied and the cardiac tissue was examined for histopathologic alterations. A significant parasitemia burden-dependent increase in the cardiac biomarkers and D-dimer level were recorded in the infected cattle compared to the control animals. Thrombocytes count was also significantly lower in the infected animals than the control. Both macroscopic and microscopic hemorrhage, mononuclear infiltrates, and myocardial necrosis were the evident histopathologic findings. These findings suggest that B. bigemina infection can potentially induce cardiac dysfunction in cattle. Furthermore, mechanistic studies should be conducted to understand the mechanisms beyond cardiac complications.

Coexistence of Multiple Theileria annulata Genotypes Circulating in Neonatal Calves in Semi-arid India

BACKGROUND

Knowledge of local isolates and strains is a prerequisite for the development of either effective mass vaccination strategy or a suitable molecular marker-based diagnostic tool.

PURPOSE

The pathogenesis of Bovine tropical theileriosis (BTT), caused by Theileria annulata in susceptible ruminants, is known to vary depending upon the nature of isolate and strain involved. Therefore, RFLP and sequencing-based characterization of Indian isolates of T. annulata were attempted using TAMS gene.

METHOD

In the present study, TAMS 1 gene of T. annulata was amplified from 25 naturally infected calves from the BTT endemic semi-arid zone of Northern India. The amplified products were then digested with three restrictions enzymes viz., Taq I, Rsa I, and Alu I to find out the variations in pattern of restriction digests, so as to have an idea about the various isolates of T. annulata present in the studied area. Around 14 samples covering all the variants (from the PCR-RFLP patterns) were sequenced and submitted in NCBI (MH277607-MH277620).

RESULT

Coexistence of 4 variant genotypes was detected upon in-silico analysis of RFLP and sequence variations.

CONCLUSION

The nucleotide variations alongside the chromatogram analysis revealed point mutations leading to presence of noticeable genetic diversity among the isolates.

Rapid diagnosis of Theileria annulata by colorimetric loop-mediated isothermal amplification (LAMP) assay

Theileria annulata the causative agent of bovine tropical theileriosis (BTT) is globally distributed. Rapid and accurate detection of the parasite is essential for the implementation and evaluation of mass drug administration and planned vaccination programs for controlling BTT. Loop mediated isothermal amplification (LAMP) amplifies targeted nucleic acid with a high efficacy, sensitivity and rapidity under isothermal conditions. In the present study, the internal transcriber space (ITS) gene of T. annulata was targeted for the development of a LAMP assay using pH-sensitive dye (phenol red) for enhanced visual detection of amplification. This method employed a set of specially designed four primers that recognized six distinct regions on the targeted gene. No amplification was detected with the DNA of other tested haemoprotozoans. Positive LAMP products were identified by a colour change from pink to yellow, and then rechecked by specific ladder pattern upon agarose gel electrophoresis. LAMP was able to detect infection in 63 out of 85 animals compared with blood microscopy, simple PCR and nested PCR which detected infection in 40, 49 and 64 animals, respectively. No difference in detection was seen in the colorimetric assay and the classical UV based LAMP assay.

Cardiac troponin I as a cardiac biomarker has prognostic and predictive value for poor survival in Egyptian buffalo calves with foot-and-mouth disease

Background and Aim:

Foot-and-mouth disease (FMD) causes huge economic losses in Egypt due to reductions in the production of red meat, milk, and milk by-products and can also lead to myocarditis in young animals. The aim of our study was to evaluate cardiac biomarkers, in particular cardiac troponin I (cTnI), and to reveal the relations of cardiac biomarkers with poor survival in FMD-infected Egyptian buffalo calves.

Materials and Methods:

Forty-two Egyptian buffalo calves were included in this study. The calves were divided into 12 apparently healthy control calves and 30 calves clinically diagnosed with FMD during a disease outbreak in Menofia and Behera Governorates, Egypt. The diseased calves were divided, according to age, into 13 calves <3 months old and 17 calves between 3 and 6 months old. The animals were examined clinically and subjected to analysis of cardiac biomarkers.

Results:

Biochemical analysis revealed significant elevations of cardiac biomarkers, especially creatine kinase myocardial band (CK-MB), lactate dehydrogenase (LDH), alanine aminotransferase (ALT), aspartate aminotransferase (AST), cardiac troponin T (cTnT), and cardiac troponin I (cTnI) in FMD-infected calves in comparison with control calves. There was a significant association between cTnI and poor survival in infected calves.

Conclusion:

Cardiac biomarkers could be used as a rapid method for diagnosis of myocarditis induced by FMD in Egyptian buffalo calves. In addition, cTnI is a very sensitive and accurate tool for determining myocardial cell damage in the earlier stages of the disease and a good predictor of poor survival in calves.

Molecular characterization and sequence phylogenetic studies on Theileria annulata Mathura isolate based on TAMS and 18S gene

The TAMS and 18S gene of local calf isolate from semiarid Mathura were amplified and used for phylogenetic analysis after custom sequencing. Results revealed phylogenetic association between Indian isolates in comparison to isolates across the world. Based on TAMS gene, the present isolates showed per cent homologies in the range 65.8–97.2% with various isolates across India and abroad. Likewise, 18S gene based per cent homologies of the present isolates varied from 70.5–100% with other isolates across India and abroad. The findings are important from molecular evolutionary point of view.

Comparison of different PCR protocols and respective primer sets from pool of TAMS 1 gene for diagnosis of calf theileriosis from semi arid India

The polymorphic nature of Theileria annulata merozoite surface antigen (TAMS 1) attributes to limitation in PCR based detection of various T. annulata genotypes present in different geographical domains across the globe. Multiple reports of failure of detection of tropical theileriosis using classical N516/517 primer set in the studied area were noticed. Hence, three single PCR protocols using N516/517, TAMS F/R and NTA F/R primer sets encoding different portions of TAMS 1 gene and two nested protocols, using combinations of these three primers, were compared to find out the most suitable primer set for diagnosis of calf theileriosis in studied area. The studied area constitutes the semi-arid theileriosis endemic area of Northern India. The various PCR protocols were tested on 75 clinically confirmed cases of calf theileriosis. Alongside, 25 confirmed theileriosis negative blood samples and DNA of other haemoprotozoa were also tested for specificity of these primer sets. Results revealed that the primer set NTA F/R to be more suitable in detecting the circulating T. annulata genotypes in the studied area in comparison to the classical N516/517 primer set. None of the primers gave false positive amplification with negative samples and/or DNA of other haemoprotozoa.