Brucella suis biovar 2 multi locus sequence type ST16 in wild boars (Sus scrofa) from Abruzzi region, Italy. Introduction from Central-Eastern Europe?

Porcine brucellosis occurs in many countries where pigs are farmed, often representing an underrated problem. B. suis biovar 2 is the most common isolate in Europe, with high prevalence reported in wild boars in which it is generally isolated in the absence of gross lesions. In the last five years, we tested for Brucella spp. 389 lymph nodes of wild boars collected during hunting seasons or during necropsy procedures. In this paper, we describe the first case of isolation of B. suis biovar 2 from a wild boar aborted foetus, and we analyse the genomic relationships with B.suis biovar 2 strains isolated in the past five years in Abruzzi Region, Central Italy. The genetic fingerprint revealed that the isolates under study belong to the MLST ST16 and to the MLVA11 Gt 57, similar to the Central-Eastern European strains. Massive restocking (for hunting purpose) of wild boars from Eastern Europe have been done since 1950 in Italy contributing to the increasing of population size and distribution, as well as to the interbreeding between these foreign breeds and the local population. The contamination of pastures with infected material such as aborted wild boars foetuses can increase the risk of transmission of Brucella among wild and domestic animals. The contact of B. suis with domestic ruminants may also cause serological reactions to brucellosis serological testing, and even unapparent infection, thus hampering the efforts made in the brucellosis eradication campaign.