# Characterization of Salmonella spp. Isolates from European Hedgehogs (Erinaceus europaeus) in Italy: Serotypes and Antimicrobial Susceptibility Profiles

## TL;DR

This study found that 30% of European hedgehogs in Italy carried Salmonella, with most strains being sensitive to antibiotics, but some showing resistance.

## Contribution

The study provides new insights into the role of European hedgehogs as potential reservoirs of zoonotic Salmonella in Italy.

## Key findings

- Salmonella was isolated from 30% of sampled hedgehogs, with S. Enteritidis and S. Typhimurium being the most common serovars.
- 90% of isolates were susceptible to all tested antibiotics, though some resistance and intermediate susceptibility were observed.
- The findings suggest the need for continued surveillance and integrated One Health strategies to monitor zoonotic Salmonella.

## Abstract

Background: Wildlife is increasingly recognized as an important component in the epidemiology of zoonotic pathogens. Salmonella spp., a leading cause of foodborne disease worldwide, can circulate across human, domestic animal, and environmental interfaces. European hedgehogs (Erinaceus europaeus), a synanthropic species frequently inhabiting urban and peri-urban areas, may act as reservoirs or sentinels for Salmonella. Objectives: The aim of this study was to investigate the prevalence, serotype distribution, and antimicrobial susceptibility profiles of Salmonella spp. isolated from European hedgehogs admitted to wildlife rehabilitation centers in Italy. Methods: Fecal samples were collected from 100 European hedgehogs housed in five wildlife rehabilitation centers located in four Italian regions. Salmonella spp. were isolated using standard bacteriological methods, serotyped according to the Kaufmann–White–Le Minor scheme, and tested for antimicrobial susceptibility by broth microdilution for ampicillin, enrofloxacin, and sulfamethoxazole-trimethoprim. Minimum inhibitory concentrations (MICs) were interpreted following CLSI guidelines. Results: Salmonella spp. was isolated from 30% of the animals sampled. Four serovars were identified, with S. Enteritidis (50%) and S. Typhimurium (36.7%) being the most prevalent, followed by S. Agona (10%) and S. Chester (3.3%). Antimicrobial susceptibility testing revealed a high level of susceptibility, with 90% of isolates sensitive to all tested antibiotics. One S. enteritidis strain showed resistance to enrofloxacin and sulfamethoxazole–trimethoprim, while two isolates exhibited intermediate susceptibility to enrofloxacin. Conclusions: The detection of Salmonella serovars commonly associated with human infections in European hedgehogs highlights the potential role of this species in the ecology of zoonotic Salmonella. Although antimicrobial resistance levels were low, the presence of resistant and intermediate strains underscores the importance of continued surveillance. Despite some limitations related to the study design and sample representativeness, these results support the need for further large-scale investigations, reinforcing the need for integrated One Health surveillance strategies.