Molecular Epizootiology and Diagnosis of Porcine Babesiosis in Sardinia, Italy

Abstract

The recent characterization of the 18S ribosomal RNA (rRNA) of a pathogenic Babesia species in a domestic sow paved the way for establishing diagnostic and epidemiological tools for porcine babesiosis. Here, we developed the first specific Babesia sp. Suis PCR, and we applied this test to a panel of samples collected from animals living in a typical Mediterranean environment (Sardinia, Italy), including domestic pigs, wild boars, and ticks. In domestic pigs, PCR coupled with sequencing revealed an estimated Babesia infection frequency of 26.2% and the presence of distinct 18S sequence types. The different distribution of sequence types in symptomatic and asymptomatic subjects might suggest the existence of phylogenetically closely related strains with variable pathogenicity in pigs. Moreover, molecular identification of tick species indicated Rhipicephalus sanguineus and Rhipicephalus bursa as candidate vectors potentially involved in the transmission of this pathogen. Collectively, the data reveal the suitability of 18S rRNA PCR/sequencing for molecular diagnosis of porcine babesiosis and for large-scale investigations on the presence and geographical distribution of Babesia sp. Suis genetic variants.

Coexistence of Tick-Borne Pathogens in Ticks Collected from their Hosts in Sardinia: an Update

“…Babesia sp. Anglona was previously identified in symptomatic and asymptomatic domestic pigs as well as in Rhipicephalus ticks in Sardinia [27]. In the present study, DNA of T. ovis was also identified in Rhipicephalus ticks.…”

Table_2.docx

“…Variation in disease severity and clinical manifestations may be due to pathogen factors or the response of the host to infection. Zobba et al speculated that different strains identified in clinically ill and in asymptomatic pigs may be responsible for different degrees of pathogenicity (12).…”

“…The sequences were compared to the GenBank database for homologous sequences using nucleotide blast BLASTN (18). Phylogenetic analyses were performed by aligning the partial 18S rRNA sequences obtained from this case with a set of 20 sequences ( Supplementary Table 2), mainly representative of the Babesidae clade VI, as previously described (6,12,19). The Ungulibabesids, as previously defined by Criado-Fornelio et al (16) fall within this clade of Babesiadae and is where Babesia sp.…”

“…The genetic diversity of Babesia species in pigs is largely unexplored, but recent molecular studies have identified a new subspecies, Babesia sp. Suis, in infected domestic pigs and ticks (6,12) This report describes the first recognition of porcine babesiosis due to B. sp. Suis in a pet pot-bellied pig from Gauteng province, South Africa.…”