First detection of Cytauxzoon spp. infection in European wildcats (Felis silvestris silvestris) of Italy

Highlights

• Cytauxzoonosis is an emerging tick-transmitted protozoan disease.

• Mutual transmission of pathogens between wild and domestic cats is increasing.

• First paper focused on Cytaouxzoon spp. infection in F. s. silvestris.

• Cytauxzoon spp. may infect F. s. silvestris further than F. s. catus.

• Questions are raised on pathogenic role of Cytauxzoon spp. in F. s. silvestris.

Abstract

Cytauxzoonosis is an emerging, tick-transmitted, protozoan disease affecting domestic and wild felids and caused by Cytauxzoon felis, Cytauxzoon manul and Cytauxzoon spp. This study aimed to determine the presence of infection with Cytauxzoon spp. in Felis silvestris silvestris in Italy, in order to enhance the comprehension of its pattern distribution among domestic cat populations. In addition, wildcats were tested for other endemic vector-borne pathogens in Italy. The carcasses of 21 F. s. silvestris were collected from central and northern regions of Italy. All the animals were submitted to necropsy and samples of the spleens were collected. Cytauxzoon infection was surveyed by a conventional PCR amplifying a portion of the SSU-rDNA of species of Piroplasmida. The samples were also screened for Anaplasma spp., Ehrlichia spp., Rickettsia spp., Babesia spp., Theileria spp., and Leishmania spp. using SYBR Green Real-Time PCR (rPCR) assays. Four animals (19%) were positive for Piroplasmida-PCR assay and three sequenced amplicons were obtained (14.3%), clustering with the Italian, Spanish, French and Romanian Cytauxzoon spp. isolates and with C. manul found in Mongolia. The samples were negative for the other pathogens screened. The present results showed that Cytauxzoon spp. may infect both F. s. silvestris and F. s. catus.

Introduction

Cytauxzoonosis is an emerging, tick-transmitted, protozoan disease, affecting domestic and wild felids and caused by small piroplasms (Piroplasmida, Babesiidae), namely Cytauxzoon felis, Cytauxzoon manul and Cytauxzoon spp. (Lloret et al., 2015). C. felis is limited to the Americas (United States and Brazil) and is traditionally associated with wild felids (mainly bobcats − Lynx rufus), considered the natural reservoir in endemic areas, and domestic cats (Felis silvestris catus) (Shock et al., 2011, Maia et al., 2013, André et al., 2015). The cats infected with C. felis generally develop an acute and highly fatal disease (Kier et al., 1982). However, cases not only of domestic cats that survived after natural infection have been documented (Walker and Cowell, 1995, Meinkoth et al., 2000), but also of cats developing subclinical and persistent blood parasitaemia (Haber et al., 2007, Brown et al., 2008, Brown et al., 2010, Lewis et al., 2012).

In Europe, cytauxzoonosis in C. felis has not been reported, whereas other species are documented, i.e. C. manul in the Palla’s cat (Otocolobus manul) (Ketz-Riley et al., 2003, Reichard et al., 2005), Cytauxzoon spp. in the Iberian lynx (Lynx pardinus) (Luaces et al., 2005, Millán et al., 2007, Millán et al., 2009) and in cats from southern Europe (Criado-Fornelio et al., 2004, Criado-Fornelio et al., 2009, Millán et al., 2007, Carli et al., 2012).

In Italy, Cytauxzoon spp. has only recently been described, in 23% of cats from a north-eastern area (Carli et al., 2012) following three clinical cases, and in two clinical cases from a central area (Carli et al., 2014). No other information on Cytauxzoon spp. infection in cats or wild felids is currently published in Europe.

Three species of wild felids (the Iberian lynx, Lynx pardinus, the Eurasian lynx, Lynx lynx, and the European wildcat, Felis silvestris silvestris) are currently present in Europe (Otranto et al., 2015). In Italy, the wildcat is reported in the eastern Alps, in peninsular regions and in Sicily, where they are sharply differentiated. In central Italy, wildcats are split into two distinct groups, distributed in the Apennine mountain-hills and in the Maremma hill-plain and coastal areas, respectively (Mattucci et al. 2013).

The aim of this work was to determine the presence of an infection of Cytauxzoon spp. in F. s. silvestris, in regions of Italy where this wild felid has one of the highest densities (Anile et al., 2014), in order to enhance the comprehension of the distribution pattern of cytauxzoonosis among domestic cat populations. In addition, wild felids were screened for other vector-borne pathogens (Anaplasma spp., Ehrlichia spp., Rickettsia spp., Babesia spp., Theileria spp. and Leishmania spp.) known to be present or endemic in the same monitored areas (Capelli et al., 2012, Gramiccia et al., 2013).