Molecular detection of Leptospira spp. in wild boar (Sus scrofa) hunted in Liguria region (Italy)

Leptospirosis is a re-emerging and widespread zoonosis, worldwide distributed, due to a wide variety of wild and domestic animal species able to act as natural or accidental hosts. During last years, in Europe, as in Italy, wild boar (Sus scrofa) population is increased. This animal represents a reservoir for different etiological agents, such as Leptospira. The aim of this investigation was to evaluate the prevalence of Leptospira spp. in wild boar hunted in Liguria region (Italy) during two-year hunting seasons. From 611 hunted wild boar, kidneys were collected. DNA was extracted from each organ and different targets were used to detect pathogenic (lipL32 gene), intermediate (16S rRNA gene) and saprophytic (23S rRNA gene) Leptospira by Taqman-based RealTime-PCR assays. Overall, kidneys were sampled from 282 adults, 155 sub-adults and 174 young wild boar (in total 314 males and 298 females). By RealTime PCR 77 kidneys were positive and, among these, 74 resulted positive for pathogenic (96.10%) and 3 (3.90%) for intermediate Leptospira. No significant differences in pathogenic Leptospira infection ratio were detected between male (11.50%) and female (12.75%). Only 13 sub-adult animals (8.39%) resulted infected by pathogenic Leptospira; 23 young animals (13.22%) and 38 adult animals (13.47%) were positive. The results of this study confirmed the importance of wild boar in the epidemiology of leptospirosis, which is able to infect other animal species (domestic and wild) including humans. Rarely, intermediate Leptospira could be able to infect wild boar with a renal localization that can contribute to their shedding and circulation.