Letizia Cirasella

This study documents an outbreak of Salmonella enterica serovar Enteritidis (SE) on a commercial meat rabbit farm in Italy. Following the observation of increased mortality in kits and severe enteric symptoms across all age groups, SE was first isolated in early March 2024. A diagnostic and epidemiological investigation was subsequently undertaken to characterize the anatomo-histopathological features in deceased rabbits and to identify the source and transmission dynamics of the infection. Between March and December 2024, a total of 1550 rectal swabs from live rabbits, 60 environmental samples, and 168 carcasses were collected and subjected to microbiological analysis. SE-positivity rates ranged from 8.4% to 36.3%, depending on the sample type considered. Co-infections with Pasteurella multocida, Escherichia coli, and Staphylococcus spp. were also detected. Gross and histological lesions in SE-positive rabbits included fibrinonecrotizing enterocolitis, hepatosplenomegaly, and renal damage such as suppurative nephritis and tubulorrhexis. Despite the implementation of enhanced biosecurity protocols, SE re-emerged over time and across different pens. Given the zoonotic potential of SE, the outbreak described underscores the need for rabbit-specific Salmonella control programs to safeguard both animal and public health.

Trichinella spp. are zoonotic nematodes with a global distribution, primarily maintained through wildlife reservoirs which complicates eradication efforts. In Europe, four species—T. spiralis, T. britovi, T. nativa, and T. pseudospiralis—circulate in wild carnivores and omnivores, with T. britovi and T. spiralis being the most prevalent in wild and domestic hosts. This study aimed to assess the presence and species distribution of Trichinella spp. in wild mammals. This study presents the results of five years of wildlife surveillance carried out within the long-standing monitoring program implemented in the Emilia-Romagna region, northern Italy, which has been in place since 2006. Between 2020 and 2024, a total of 104,338 wild mammals, including red foxes, wolves, and wild boar, were tested using the magnetic stirrer digestion method in accordance with EU regulations. A total of 12 animals (0.011%) were found to be infected with Trichinella larvae. Molecular identification of positive samples, performed at the European Union Reference Laboratory for Parasites, showed the presence of T. britovi in 11 animals, while one isolate remained unidentified. T. britovi was detected primarily in wolves and red foxes. No infections were identified in wild boar during the study period. Overall, the low prevalence observed confirms that Trichinella spp. infections in wildlife in Emilia-Romagna are sporadic but persistently present. Only T. britovi was detected, supporting its role as the predominant species in this area. These findings highlight the importance of long-term surveillance for early detection and risk assessment within a One Health framework.

Objectives: To establish epidemiological cut-off values (ECOFFs) for the polyether ionophores narasin, salinomycin, lasalocid and monensin in Enterococcus faecium. Methods: MICs were measured using the broth microdilution method according to ISO 20776-1 (2019). Method validation involved ≥10 replicates of antimicrobial susceptibility testing of Enterococcus faecalis ATCC 29212. A total of 182 E. faecium isolates from various sources were tested in five European laboratories. The ECOFFinder tool from EUCAST was used to establish the ECOFFs for 122 WT isolates, verified by PCR or WGS. Results: Method validation showed consistency, with acceptable variation within ±1 2-fold dilution. The ECOFF for narasin was 0.5 mg/L, considerably below the current EUCAST ECOFF for E. faecium (ECOFF = 2 mg/L). Salinomycin and lasalocid ECOFFs were 1 and 2 mg/L, respectively. Strains carrying the previously identified narAB resistance genes clearly manifested a separate MIC distribution for narasin and salinomycin, but not for lasalocid, although a clear bias to the higher MIC values within the normal distribution could be observed. Monensin apparently displayed a broader MIC range (0.5–64 mg/L) with multiple modes, which precluded the establishment of an ECOFF for monensin. Conclusions: The study yielded novel ECOFFs for distinguishing WT E. faecium strains for the key veterinary ionophores, providing a mainstay for a better understanding of ionophore resistance in enterococci.

Caseous lymphadenitis is a chronic debilitating disease typical of small ruminants, but it is also noted in several other domestic and wild species. In this report, we present the first documented case in Italy of pseudotuberculosis in a roe deer (Capreolus capreolus, Linnaeus 1758) found dead in the mountains of Forlì-Cesena province, Emilia Romagna region. The carcass underwent necropsy according to standard protocols, revealing generalized lymphadenopathy and severe apostematous pneumonia with multifocal and encapsulated abscesses. Corynebacterium pseudotuberculosis was isolated from the lung parenchyma, lymph nodes and abscesses. Additionally, severe parasitic bronchopneumonia of the caudal lobes and gastrointestinal strongyle infestation were detected. To our knowledge, this is the first documented case of CLA referable to C. pseudotubercolosis in a roe deer in Italy.