Detecção molecular e epidemiologia de Babesia vogeli em cães domiciliados da microrregião de Itaguaí, Estado do Rio de Janeiro, Brasil

Abstract

Canine vector diseases are frequently found in brazilian veterinary clinics. This group represents a varied complex of illness including anaplasmosis, ehrlichiosis, babesiosis, rangeliosis, hepatozoonosis among other diseases. Many of these pathogens cause severe clinical conditions, death of patients and in some cases, have zoonotic potential. There are a variety of diagnostic methods for these microorganism on the market. Molecular techniques are based on the detection of DNA from the etiological agents directly from the blood with high sensitivity and specificity, allowing the detection even under conditions of very low parasitemias, which are often characteristic of asymptomatic carriers. Also allows the distinction between different species of parasites. In this study, two molecular methods were developed for the detection of Babesia vogeli in blood samples from dogs from the Itaguai Microregion, based on quantitative real-time polymerase chain reaction (qPCR) technology and polymerase chain reaction (cPCR) with a specific target in hsp70 gene from B. vogeli. After the optimization and standardization of the techniques, it was observed that the qPCR developed in this study was efficient and presented high precision and sensitivity in the detection of B. vogeli. Comparative studies were performed between the 18S rDNA and hsp70 targets using cPCR, where it was possible to observe that there are no statistically significant differences between the two targets, but in the sequencing a false positive for B. vogeli was detected in the 18S rDNA sequence, a proximal hemoprotozoal related to Rangelia vitalli. The cPCR and qPCR techniques were compared for the detection of B. vogeli and it was observed that qPCR has higher sensitivity. In addition, an epidemiological study was carried out, which showed three factors associated with B. vogeli infection among these were young animals (less than 5 years old), the infestation by ticks and the absence of shelters.