Development and Evaluation of a Loop-mediated Isothermal Amplification Assay for Rapid Detection of Theileria annulata Targeting the Cytochrome B Gene

Abstract

Background: Theileria annulata is an economically important cattle disease in North Africa that occurs in subtropical and tropical areas. Accurate and rapid, molecular diagnosis of tropical theileriosis is an important issue that allows early treatment and, prevents transmission. We developed and validated a Theileria annulata specific LAMP assay targeting the cytochrome b multicopy gene, in order to increase the DNA detection sensitivity. Methods: The methodology was used to evaluate the occurrences of T. annulata in 88 field samples collected in Northern Tunisia during 2013-2014. The specificity and sensitivity of the LAMP assays were compared to conventional cytochrome b PCR and routine microscopy commonly used on naturally infected cattle blood samples. Results: The PCR assay showed a sensitivity of 70% and specificity around 75%. Our LAMP assay showed a suitable sensitivity 78.7% and specificity 87.5%, with, however, positive (98.4%) and negative (29.1%) predictive values. Conclusion: The LAMP assay is a simple and convenient diagnostic tool for tropical theileriosis. Moreover, LAMP does not require experienced staff and specialized equipment for sampling procedures and it is practical outside laboratories and can be used for field diagnosis.

Keywords

• Theileria annulata
• LAMP
• Cytochrome b
• Tunisia
• Diagnosis