RESUMO
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.
Assuntos
Vetores Aracnídeos/parasitologia , Babesia/isolamento & purificação , Babesiose/diagnóstico , Doenças do Cão/diagnóstico , Rhipicephalus sanguineus/parasitologia , Doenças dos Suínos/diagnóstico , Animais , Babesia/classificação , Babesia/genética , Babesiose/parasitologia , Babesiose/transmissão , Sequência de Bases , DNA de Protozoário/química , DNA de Protozoário/genética , Doenças do Cão/parasitologia , Doenças do Cão/transmissão , Cães , Feminino , Itália/epidemiologia , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase/veterinária , RNA Ribossômico 18S/genética , Sensibilidade e Especificidade , Análise de Sequência de DNA/veterinária , Especificidade da Espécie , Suínos , Doenças dos Suínos/parasitologia , Doenças dos Suínos/transmissão , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/parasitologia , Infestações por Carrapato/veterináriaRESUMO
We used serology to estimate the prevalence of exposure to chlamydiae in Italian populations of wild boars (Sus scrofa). Sera from 173 hunter-killed wild boars harvested during the 2006-2009 hunting seasons in three Italian regions were tested for antibodies to Chlamydia suis, Chlamydophila pecorum, Chlamydophila abortus, and Chlamydophila psittaci by the microimmunofluorescence test. Antibody titers to chlamydiae ≥ 1:32 were detected in 110 of the 173 samples tested (63.6%). Specific reactivity could be assessed only in 44 sera with antibody titers to C. suis that were two- to threefold higher than antibody titers against the other chlamydial species; the other 66 sera had similar reactivity against all the chlamydia species tested. Antibody to C. suis was detected in sera from wild boar populations with rare or no known contact with domestic pigs. These results suggest that the wild boar could be a chlamydia reservoir and may acquire chlamydiae independent of contacts with the domestic pig.