Prevalence ofSalmonellaspp. in tonsils, mandibular lymph nodes and faeces of wild boar from Spain and genetic relationship between isolates

Abstract

Summary The importance of wild boars as game species in Spain is well known. Their feeding habits and intrusive behaviour, together with a progressively wider spreading of populations, increases the interactions of these animals with livestock and humans. Considering that wild boars could have a potential role in the transmission of certain pathogens as salmonellae, the aims of this study were to determine the prevalence of Salmonella spp. in wild boars hunted in central‐western Spain, the occurrence of this pathogen in tonsils, mandibular lymph nodes and faeces (as markers for transmission risk), and to define the phylogenetic relationships among isolated strains, in order to investigate the circulation pathways of bacteria among tissues, animals and estates. Samples from 1,041 hunted wild boars were analysed for the presence of Salmonella spp. by bacteriological culture. Isolates were confirmed by PCR and serotyped in the Spanish national reference laboratory. The genetic relationships between strains were determined by PFGE. The results showed a 7.7% of positive animals (81 wild boars), being tonsils the organ most frequently colonised by Salmonella spp. (18.7%), followed by lymph nodes (5.1%) and faecal samples (2.9%). Serovars Enteritidis and Newport were the most frequent amongst the 34 different serovars obtained. The pulsed‐field gel electrophoresis (PGFE) analysis showed a great genetic diversity, with serovars that exhibited different pulsotypes when isolated from different estates and multiple serovars in the same estate. In conclusion, this study reveals the importance of wild boars as carriers and possible transmitters of virulent and/or antimicrobial‐resistant clones of Salmonella spp. to livestock and humans.

Prevalence and Antimicrobial Resistances of Salmonella spp. Isolated from Wild Boars in Liguria Region, Italy

“…enterica is the most common subspecies isolated in our study. This observation is consistent with other studies conducted in wild boars [ 3 , 6 , 22 ]. The main location of Salmonella spp.…”

“…Our results are consistent with other studies on the presence of Salmonella spp. in wild mammals and in other territories, in which the majority of the resistances reported are against the same classes of antimicrobials [6,7,22,35] and in contrast with the results of a recent study conducted in central Italy in wild boars [8] where no resistances against tetracycline were observed, and a higher rate of antimicrobial resistance to streptomycin was reported. In our study, the antimicrobial susceptibility against molecules considered "Highest Priority Critically Important" antimicrobials for human medicine has been tested, among them, quinolones (nalidixic acid and ciprofloxacin) and cephalosporines of third generation (cefotaxime, ceftazidime).…”

Prevalence, Virulence and Antimicrobial Susceptibility of Salmonella spp., Yersinia enterocolitica and Listeria monocytogenes in European Wild Boar (Sus scrofa) Hunted in Tuscany (Central Italy)

“…infection. Very similar prevalence was reported in two studies carried out in the Lazio region (7.2%) and in North-West Italy (10.8%) [34,41], as well as in two studies performed in Spain (7.70%) and Sweden (10.0%) [42,43]. On the other hand, in research performed in Switzerland (12.0%) and Portugal (22.0%), the prevalence was higher than that reported in this investigation [44][45][46][47].…”

“…50:r:1,5,7 and Salmonella enterica subspecies houtenae serotype 1,40:z4,z23 were also isolated from the wild boar sampled in other northern (Lombardy, Piedmont, Liguria and Valle d'Aosta) and central (Latium) Italian regions, as well as in Spain [34,41,42,48], highlighting the circulation of these Salmonella serovars in North-Central Italy and in other Mediterranean countries. On the other hand, the serotype Newport was reported only in the Lombardy region and Spain [42,48], while the serotype Kottbus only in the Lombardy and Latium regions [34,48]. Moreover, the serotype Infantis was previously identified in the wild boar hunted in the North of Italy [41,48].…”

Foodborne Zoonoses Common in Hunted Wild Boars

“…There are no data available about Salmonella from wild boars in Finland. Wild boars frequently carry Salmonella in their tonsils, but Salmonella also colonizes the lymph nodes and is excreted in the feces (Sannö et al 2018 ; Bonardi et al 2019 ; Gil Molino et al 2019 ). In Belgium, Salmonella was recently detected in one third of wild boar meat samples (Peruzy et al 2019 ).…”