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Swine brucellosis due to Brucella suis biovar 2 (bv2) is enzootic in wild boar and hare in continental Europe and may cause major economic losses to the pig industry, mainly in free-ranged pig farms. The high nucleotide identity found among the B. suis biovar 2 isolates has long hindered the full understanding of the epidemiology and the phylogeography of the disease. Here, we used multilocus variable-number tandem-repeat (VNTR) analysis (MLVA) and whole-genome analysis to identify single-nucleotide polymorphisms (SNPs) in order to gain insights from the largest B. suis bv2 dataset analyzed so far composed of domestic pigs and wildlife isolates collected throughout Europe since the 1970s. We found four major clades with a specific phylogeographic pattern. The Iberian clade contains isolates exclusively from the Iberian Peninsula. The Central European clade includes most isolates from France, Northern Italy, Switzerland and an important proportion of those of Northern Spain. The Eastern European clade clustered isolates from Croatia and Hungary mainly but also from areas of France, Germany, Italy and Poland. Finally, a separated Sardinian clade grouped three isolates from this island. At fine scale, MLVA demonstrated an endemic status of the infection in Europe and it allowed tracking a large outbreak formed by different farms from Spain linked to the same infection source. The whole genome SNP analysis showed that the strains form genetically distinct clades, shared between wild boar and pigs, in agreement with the MLVA clades. Interestingly, all hare isolates clustered together within two groups composed exclusively of wildlife isolates. Our results support the hypothesis that maintenance and spread of B. suis bv2 in Europe is a dynamic process linked to the natural expansion of wild boar as the main wild reservoir of the infection, while spread over long distances is found largely dependent on anthropogenic activities., (Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.)

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., (Copyright © 2017 Elsevier B.V. All rights reserved.)

A female wild boar, aged approximately two years, was found dead by local veterinary services in Pianola di Roio in L'Aquila Province situated in the Abruzzo Region of central Italy. The carcass was submitted to the Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise 'G. Caporale' in Teramo for necropsy. Brucella suis biovar 2 was isolated from submandibular lymph nodes. This is the first report of isolation of B. suis in the Abruzzo Region. Several authors agreed in the past on the hypothesis that B. suis biovar 2 had been introduced into Italy through the importation of hares from European countries in which the infection is endemic in wild populations. This lead the Italian authorities to reinforce existing controls for hares imported for restocking purposes. However, no provisions for brucellosis control are currently in place (or have been in place in the past) for wild boar movements either at the national or the European level. The isolation of B. suis biovar 2 from wild boar in two different and distant regions of Italy may suggest that this infection may have been introduced to the affected areas by wild boar rather than by imported hares. National and European rules managing wildlife brucellosis should be adapted to control the health status of farmed wild boar before movement or release, with the aim of preventing the spread of this pathogen to free territories.