Prevalence of Different Salmonella enterica Subspecies and Serotypes in Wild Carnivores in Emilia-Romagna Region, Italy

Abstract

Salmonella is a pathogen of considerable health concern, given its zoonotic potential, and, in Italy, is the most frequently reported causative agent for foodborne outbreaks. Wild animals and in particular wild carnivores may be carriers of different Salmonella enterica subspecies and serotypes. Given their potential role as reservoirs, surveillance activities are necessary. This study aims to investigate the presence of different Salmonella subspecies and serotypes in wild carnivores in the Emilia-Romagna Region. A total of 718 fox (Vulpes vulpes), 182 badger (Meles meles) and 27 wolf (Canis lupus) carcasses, submitted between 2016–2022, were included for the present work. Gender and age data were collected along with geographical coordinates of carcass’ discovery site. Contents of the large intestine were sampled and cultured according to ISO 6579-1 and both serogroup and serotype identification were performed according to ISO/TR 6579-3:2014. Salmonella was retrieved from 42 foxes (6%), 21 badgers (12%) and 3 wolves (12%), respectively. Isolated Salmonella enterica strains belonged to 4 different subspecies and 25 different serotypes. S. veneziana and S. typhimurium were the most frequent serotypes found (11/67 and 10/67, respectively). In conclusion, zoonotic serotypes were found in all these species of wildlife, thus confirming their potential role in the ecology of Salmonella spp.

Spatiotemporal Distribution of Salmonella enterica in European Hedgehogs in Northern Italy

“…Several Salmonella spp. serovars found in our study had not yet been described in hedgehogs, as in the case of S. Veneziana, which was previously found mostly in wild boars and other wild animals in Italy [ 36 , 47 , 48 , 49 ]. In particular, Veneziana was the most frequently detected S. enterica serovar in foxes and badgers, with a prevalence of 16.4% in the same area and in a similar year range as in the present investigation [ 36 ].…”

“…serovars found in our study had not yet been described in hedgehogs, as in the case of S. Veneziana, which was previously found mostly in wild boars and other wild animals in Italy [ 36 , 47 , 48 , 49 ]. In particular, Veneziana was the most frequently detected S. enterica serovar in foxes and badgers, with a prevalence of 16.4% in the same area and in a similar year range as in the present investigation [ 36 ]. The other S. enterica serovars detected were Hessarek, which has been described in avian species [ 50 , 51 ] and wild boars in Italy [ 52 ], and Zaiman, a rare serovar first detected in the Zaiman river and sporadically in humans in Argentina [ 53 , 54 ].…”

“…Salmonella spp. were isolated according to the ISO 6579:2002/Amd 1:2007 method (ISO 2007) [ 36 , 37 ]. Specifically, a pre-enrichment step was performed for the reactivation of the Salmonella spp.…”

“…serovars was conducted using a rapid slide agglutination test from pure cultures, after removing self-agglutinating serovars. An appropriate serum antigen for the detection of somatic (poly O, rabbit antiserum, SSI DIAGNOSTICS, Hillerød, Denmark) and flagellar (poly H, rabbit antiserum, SSI DIAGNOSTICS, Hillerød, Denmark) antigens was used [ 36 ].…”

One Health Approach: Invasive California Kingsnake (Lampropeltis californiae) as an Important Source of Antimicrobial Drug-Resistant Salmonella Clones on Gran Canaria Island

“…Subsp. salamae has previously been isolated from other animals, such as carnivores [40], wild boars [41], and poultry [42]. However, this subspecies has not frequently been associated with human infections [43][44][45].…”