Results and discussion
The blood sample of the guiña was CPV positive by PCR at the arrival to the Center for Rehabilitation of Wild Fauna. Post-mortem stool, stomach and spleen samples were also positive, confirming the CPV diagnosis and suggesting that the virus infected and established viremia in the host efficiently. The haemorrhagic diarrhoea and characteristic of the infected tissues collected in this case were similar to those found in protoparvovirus infections in other species (Allison et al ., 2013; Allison et al ., 2014; Oosthuizen et al ., 2019; Bucafusco et al ., 2019; Wang et al ., 2019; Viscardiet al ., 2019).
We obtained eight complete sequences of the CPV coding regions, one from the guiña and seven from domestic dogs. Details of these sequences are shown in Table 1. The guiña and Chilean dog sequences showed high genetic identity (99.8-99.9%). The sequence analysis of the VP2 region of the guiña sequence showed amino-acid changes associated with other 2c strains (Buonavoglia et al ., 2001; Decaro et al ., 2012), including 300G and 426E (Table 2). Three single nucleotide polymorphism lead to changes in the NS1 protein of three samples, CHL-17 V596A, CHL-71 E661K and CHL-guigna L582F (Table 3). Changes in the 582 NS1 position has been associated with neurological tissue tropism in FPV strains but the residue associated was different (L582S) (Gariglianyet al , 2016).
In South-America, Chile and Argentina have a predominance of 2c variant (Castillo et al ., 2020), but in Uruguay this variant is being replaced by a phylogenetically unrelated CPV-2a variant (Pérez et al ., 2014; Gallo-Calderón et al ., 2015). Phylogenetic analysis showed that the guiña parvovirus clustered with CPV-2c dog strains collected between 2009-2017 from Chile, Uruguay, Argentina, and Paraguay (Figure 1). Strains from guiña and coati diverged in different sub-clades, but both clustered in the Europe-I clade according to the recent classification by Grecco et al . (2018). Our results, suggests that the guiña virus is a recent acquisition of domestic dogs. Furthermore, apparently the 2c lineage may have a greater affinity for wildlife in South-America (Bucafusco et al ., 2019).
Several CPV infections in wild felids have been reported in Felis bengalensis (Nakamura et al ., 2001), Acinonyx jubatus ,Panthera tigris (Steinel et al ., 2000), Puma concolor , Lynx rufus (Allison et al ., 2013; Allisonet al ., 2014) and Leptailurus serval (Oosthuizen et al ., 2019). All of them showed high identity with domestic dog strains, and similar situation was described with the coati strain (Bucafuscoet al ., 2019). Recently, tiger parvovirus (TPV) has been described in captive tigers in China, and this has been the only variant described from a wild felid, showing greater similarity to FPV rather than to CPV (Wang et al ., 2019).
There are not many studies that show sequences comparison and analysis between domestic dogs and wild species (Chen et al., 2019; Oosthuizen et al ., 2019). Most reports only compare with sequences available in GenBank (Steinel et al ., 2000; Nakamuraet al., 2001; Allison et al., 2013; Allison et al ., 2014). For the conservation of this species, it will be important to consider the transmission of infectious agents from domestic animals. Likewise, infection by FeLV and FIV has been previously described in guiñas (Mora et al ., 2014). So, our finding might suggest that these animals would be at permanent risk of infection by these pathogens.