No abstract

A loop-mediated isothermal amplification (LAMP) assay was developed for the diagnosis of Theileria lestoquardi infection. The primers were designed based on the clone-5 sequence of T. lestoquardi. The specificity and sensitivity of the assay were established. Analysis of the specificity showed that the selected LAMP primers amplified the target sequence from T. lestoquardi DNA successfully, while no amplification was seen with DNA from Theileria annulata, Theileria ovis, Babesia ovis, Anaplasma ovis, or ovine genomic DNA. The specificity of the LAMP product was further confirmed by restriction digestion and sequencing. The sensitivity of the LAMP assay was analyzed in comparison to PCR resulting in a detection limit of 10 fg/μl of plasmid DNA containing the clone-5 sequence. The suitability for utilizing the LAMP assay in the field for the diagnosis of T. lestoquardi infection was tested on 100 field samples collected in Sudan and compared with results obtained by PCR. The relative specificity and sensitivity of the established LAMP assay was determined to be 92.1% and 87.5%, respectively, indicating that it may be regarded as an alternative molecular diagnostic tool to PCR which could be used for epidemiological surveys on T. lestoquardi infection.

Malignant Ovine Theileriosis (MOT) is a tick borne disease of sheep and goats, caused by Theileria lestoquardi and is considered a major constraint for sheep production in many areas of the world. It has been reported to infect lymphocytes in vivo and in vitro and the schizonts differentiate into macro-schizonts and micro-schizonts. To date, little is known about the mechanisms involved in the disease pathogenesis, but its high mortality is likely to be linked to the ability of T. lestoquardi to stimulate uncontrolled proliferation of the infected leukocyte. Consequently, severe tissue destruction and pulmonary oedema leading to respiratory failure are thought to be the cause of death. Despite an immense amount of small ruminant research, MOT remains an important disease of sheep and goats. Therefore, the present review outlines the current knowledge covering T. lestoquardi transmission, distribution, pathogenesis, diagnosis and control. The information may assist in filling the gaps in our knowledge about the economic impact of the disease and new research initiatives. We conclude that the development of a simple, affordable and applicable diagnostic test for an early detection at the field level, and the production of an effective vaccine could have a significant impact on the control of the disease.

Malignant Ovine Theileriosis (MOT), caused by Theileria lestoquardi, is a major constraint for sheep production in many areas of the world including Sudan. Export sheep and sheep products are a major component of Sudan national economy and foreign income. Despite the importance of the disease, there is a considerable lack of detailed information regarding the postmortem and histological manifestations in the infected sheep. To specify the macroscopic and microscopic findings in sheep infected with MOT, 45 Sudanese sheep, T. lestoquardi negative were selected and were maintained for 3 months under natural ticks challenge. Necropsy was performed on 15 dead infected and 4 euthanized non-infected control, all pathological lesions were recorded. Kidneys, liver, lungs, spleen, heart, lymph nodes, stomach, intestine, pancreas and brain from test and control groups were sampled, fixed and were processed for histopathological examinations. The 15 infected sheep displayed severe enteritis with scattered areas of petechial hemorrhages on the serosal and mucosal surface along the small and large intestines. In most animals (n = 7-14), their superficial lymph nodes, liver and spleen were enlarged and their gall bladder were distended. Heart showed petechial hemorrhages and kidneys were congested. All infected animals (100%) revealed sever pneumonia associated with edema and frothy exudates. Comparatively, the most remarkable microscopic lesions in infected sheep were obviously seen in the lungs which exhibited emphysema, congestion, collapse and proliferation of large mononuclear cells. The present study indicates that T. lestoquardi infections are accompanied by severe pulmonary involvements, suggesting that emphysema and interstitial pneumonia may lead to respiratory failure and could provide evidence for death. Our findings may assist our knowledge about the microscopic and macroscopic lesions caused by T. lestoquardi and could contribute to raise awareness among veterinary authorities regarding the pathognomonic lesions for early and/or differential diagnosis.