Leptospira fainei Detected in Testicles and Epididymis of Wild Boar (Sus scrofa)

SIMPLE SUMMARY: Genital leptospirosis is an important example of the neglected infectious zoonotic disease caused by Leptospira. The disease was just evaluated in bovine and domestic pig with important consequences for reproductive success. Recently, pathogenic Leptospira strains were also isolated and detected from reproductive system tissues collected from wild boar (Sus scrofa) free ranging in the Tuscany and Sardinia regions (Italy). This investigation aimed to understand this aspect in wild boar, describing the detection of intermediate Leptospira DNA belonging to Leptospira fainei for the first time in male reproductive organs of hunted wild boar. The obtained data shed significant light on this intermediate Leptospira species, because, other than circulating in wildlife, it can localize in testicles and epididymides of wild boar specimens. These findings add important information on genital leptospirosis epidemiology, especially among the wildlife that remains less investigated. ABSTRACT: Leptospirosis is a re-emerging and worldwide diffused zoonosis. Recently, the high importance of their epidemiology was explained by the intermediate Leptospira strains. Among these strains, Leptospira fainei was the first intermediate strain detected in domestic and wild swine. Wild boars (Sus scrofa) are well known as a reservoir, as well as all swine, for pathogenic Leptospira, but very little information is available concerning intermediate Leptospira infection. The investigation aim was to evaluate if intermediate Leptospira can infect the reproductive systems of wild boars hunted in the Tuscany region (Italy), as previously demonstrated for pathogenic ones. The reproductive system tissue (testicles, epididymides, uteri), and placentas and fetuses, were collected from 200 regularly hunted animals. Bacteriological examination and real-time PCR were performed to detect intermediate Leptospira DNA. Unfortunately, no isolates were obtained. Using real-time PCR, in six (3%) male organs (both testicles and epididymis), intermediate Leptospira DNA was found. The amplification of the 16S rRNA gene identified that all DNA obtained belong to Leptospira fainei. The results of this investigation highlighted for the first time the localization of Leptospira fainei in the male wild boar reproductive system, opening up a new avenue to further investigate.