Studies on Babesia infection of red foxes (Vulpes vulpes) shot in Hungary

Abstract

Red foxes have been recognized as potential reservoirs of several parasites and pathogens transmitted by arthropod vectors and a source of infection for all susceptible species sharing the same habitats, including dogs and humans (Dusher et al., 2015). Several studies have shown increasing prevalence of Babesia microti-like infections of red foxes in almost all European countries, suggesting that red foxes are the natural reservoirs of this pathogen (Baneth et al., 2015). Baneth et al. (2019) officially established and described a new species named as Babesia vulpes n. sp. among the Babesia microti-like spp. In Hungary, blood samples collected from red foxes in 2011 were screened by PCR for Babesia parasites (Farkas et al., 2015). Altogether 20% of the red foxes sampled were infected with piroplasms, and the positive samples sequenced were 100% identical to B. microti-like piroplasms isolated from foxes from Croatia or Italy. The aim of the present study was to screen more blood samples also collected in 2011 and to compare their partial 18S rRNA sequences to those parasites of domestic dogs and wild canids from other countries, especially with sequences of Babesia vulpes n. sp. recently described by Baneth et al. (2019). DNA was extracted from each blood sample and a conventional single step PCR was used to amplify a fragment of the 18S rRNA gene of piroplasms with primers BJ1 and BN2. PCR products were electrophoresed in agarose gel, stained and visualized under ultra-violet light. Altogether 85 red foxes out of 222 (38.3%; 95% CI: 31.9-44.7%) were found to be infected with piroplasms. The positive animals were shot in 17 of the 19 Hungarian counties, except Heves and Nógrád. The 18S RNA gene fragments from 37 positive foxes were sequenced and compared by BLAST. All of them were 99-100% identical to B. vulpes n. sp. This is the first time that infection of red foxes by B. vulpes n. sp was detected in Hungary. Further studies are needed to identify the tick vectors involved in its transmission, the mechanisms of transmission, its pathogenicity and whether or not it can be transmitted in between dogs and red foxes.