Genetic analysis and distribution of porcine parvoviruses detected in the organs of wild boars in Serbia

Abstract

Porcine parvoviruses (PPVs) are diverse and persistently evolving viruses found in domestic pigs and wild boars. Porcine parvovirus 1 (PPV1) causes reproductive problems in adult animals, although the veterinary relevance of PPV2, PPV3, and PPV4 has not been clarified. The detection and sequence analysis of PPVs circulating in wild boar populations in Serbia was performed to determine their phylogenetic relationships and prevalence in 122 organ samples collected during 2018. The DNA of PPV1, PPV2, and PPV3 was detected in 56.6% of the examined samples, whilst PPV4 was not identified. Overall, PPV3 was the most prevalent in 69.6% of the positive samples, followed by PPV1 in 63.8%, and PPV2 in 21.7% samples. Single infections were more common, although concurrent infections were confirmed in 34.8% samples for two, and 10.1% samples for three viruses. Sequence analysis of wild boar PPV1 showed no significant nucleotide differences from domestic pig PPV1 strains detected in Europe and the USA, however separate clustering from strains from China and the NADL-2 strain was demonstrated. Examination of the selected PPV2 sequences might suggest a certain geographical distribution of genetically diverse PPV2 strains considering high similarities to the strains from neighboring countries, and variability in comparison with other reported PPV2 sequences from different parts of the world. Wild boar PPV3 sequences clustered separately from most of the strains detected in wild boars, as well as the original porcine hokovirus strain. It is further noted that genetically different PPV3 strains circulate amongst Serbian domestic pigs and wild boars.

Parvovirusi svinja predstavljaju genetski različite viruse koji izazivaju infekcije doma-ćih i divljih svinja. Parvovirus svinja 1 (PPV1) dovodi do pojave reproduktivnih pro-blema kod odraslih jedinki, dok klinički značaj PPV2, PPV3 i PPV4 još uvek nije u potpunosti razjašnjen. Izvršena je detekcija i analiza genetskih sekvenci parvovirusa koji cirkulišu u populaciji divljih svinja u Srbiji u cilju njihove fi logenetske analize i određivanja zastupljenosti u ukupno 122 uzorka organa prikupljenih tokom 2018. go-dine. Prisustvo DNK PPV1, PPV2 i PPV3 detektovano je u 56,6% ispitanih uzoraka, pri čemu prisustvo PPV4 nije utvrđeno. Među pozitivnim uzorcima, PPV3 je pro-centualno najzastupljeniji virus detektovan u 69,6%, dok je prisustvo PPV1 i PPV2 utvrđeno u 63,8%, odnosno u 21,7% pozitivnih uzoraka. Infekcije jednim virusom su češće identifi kovane, međutim, prisustvo mešovitih infekcija sa dva, odnosno tri par-vovirusa zabeleženo je u 34,8% i 10,1% uzoraka. Analizom genetskih sekvenci PPV1 detektovanih kod divljih svinja nisu utvrđene značajnije razlike u odnosu na analogne sekvence PPV1 poreklom od domaćih svinja iz Evrope i SAD, međutim zabeleženo je izdvajanje u zaseban klaster u odnosu na kineske sojeve virusa i soj NADL-2. Ispi-tivanjem sekvenci PPV2 utvrđena je izvesna geografska distribucija genetski različitih sojeva navedenog virusa s obzirom na njihovu veliku sličnost sa sojevima virusa iz su-sednih zemalja. Sekvence PPV3 detektovanih kod divljih svinja su se na fi logenetskom stablu izdvajale u zaseban klaster u odnosu na većinu dostupnih sekvenci navedenog virusa detektovanih kod divljih svinja. Pored toga, zabeleženo je da genetski različiti sojevi PPV3 cirkulišu u populacijama divljih i domaćih svinja u Srbiji.