Evaluation and comparison of Loop-mediated Isothermal Amplification (LAMP), PCR and nested PCR for detection of Ehrlichia canis in naturally infected dogs

Background The detection of parasites in blood samples by DNA based assays is mostly performed by using the PCR technique, but due to the time of the reactions and costs involved, they still cannot be used in large-scale in routine laboratories. Recently, an alternative are assays based on the technique of Loop-mediated Isothermal Amplification (LAMP), which requires a shorter reaction time, higher specificity and has a lower cost [1]. This study aimed to develop a LAMP assay for the detection of Ehrlichia canis, a Gram-negative endobacteria and the etiologic agent of canine monocytic ehrlichiosis (CME), a major disease transmitted by ticks to dogs [2]. DNA extracted from blood samples of dogs presented to veterinary clinics and laboratories in the city of Ribeirão Preto, showing clinical signs indicative of EMC, were used in the assays. The samples were also previously diagnosed by PCR for presence of E.canis. Two sets of LAMP primers were used for the amplification of a fragment of the genes p30 (P30) and Heat-shock operon groESL (GRO).