Donatella Farina

In recent years, the wild boar population has increased in Italy. Wild boar is one of the most problematic species from a sanitary point of view because it represents a dangerous reservoir of pathogens and viruses. The aim of this study was to investigate the circulation of coronaviruses in wild boars, a group of viruses known for their ability to spill over between species. As part of the wild boar population control plan established by the Basilicata region relating to this species, 625 animals were analyzed from May 2024 to January 2026. Nasal swabs were collected at the slaughterhouse in the province of Potenza. Screening was conducted using pan-coronavirus PCR through a nested PCR assay targeting the conserved RNA-dependent RNA polymerase (RdRp) region. Out of all samples analyzed, 1.9% were positive for Porcine Hemagglutinating Encephalomyelitis Virus (PHEV), marking the first identification of this neurotropic coronavirus in wild boars in Italy. The detection of PHEV in free-ranging populations highlights the potential for viral circulation at the wildlife–livestock interface and underlines the importance of integrated surveillance systems to prevent possible interspecies transmission and minimize the risk of spillover to domestic pig herds.

The Bacillus cereus group (B. cereus group) comprises several closely related species that share high genetic similarity but display markedly different phenotypic traits and pathogenic potential. Reliable and rapid discrimination at the species level remains challenging using conventional microbiological and molecular methods. In this study, Fourier Transform Infrared (FTIR) spectroscopy was evaluated as a rapid phenotypic approach to differentiate seven members of the Bacillus cereus sensu stricto (B. cereus s.s.), Bacillus anthracis (B. anthracis), Bacillus thuringiensis (B. thuringensis), Bacillus mycoides (B. mycoides), Bacillus toyonensis (B. toyonensis), Bacillus wiedmannii (B. wiedmannii) and Bacillus weihenstephanensis (B. weihenstephanensis). A collection of 190 isolates previously characterized by whole genome sequencing was analyzed using the IR Biotyper system. Spectral data were processed through multivariate analyses, including principal component analysis and linear discriminant analysis, following a hierarchical classification strategy. FTIR spectroscopy enabled clear discrimination of B. anthracis from other members of the B. cereus group and allowed the separation of several additional species based on distinct spectral signatures. A further discrimination step permitted differentiation between B. cereus sensu stricto and B. thuringiensis, with minimal overlap. These findings demonstrate that FTIR spectroscopy represents a promising and rapid tool for species-level discrimination within the B. cereus group. While the results should be considered preliminary for species represented by a limited number of isolates, this approach shows strong potential as a complementary method to molecular techniques in routine diagnostics in food safety and veterinary microbiology.

The emergence and spread of swine coronaviruses represent a growing challenge for both veterinary medicine and public health. These viruses exhibit high mutation rates, recombination potential, and the capacity for cross-species transmission. Among the most relevant pathogens are PEDV, TGEV, PRCV, PHEV, PDCoV, and SADS-CoV, which have caused significant outbreaks in swine production systems worldwide, with severe economic consequences. Recent evidence demonstrates coronavirus circulation in wild boar populations across Europe, including Italy, Spain, and Germany. Although wild boars are not confirmed as primary reservoirs, their ecological behavior and increasing overlap with domestic pigs raise concern over their potential role in maintaining viral circulation. Future research priorities should focus on developing a more integrated and coordinated system for the control of swine coronaviruses, including strengthened surveillance in both domestic pigs and wild boar populations, the use of molecular epidemiology techniques to identify emerging variants, and structured collaboration among veterinary, ecological, health, and regulatory sectors. Finally, investment is needed in the development of next-generation vaccines and diagnostic tools to address the considerable genetic variability of swine coronaviruses and to improve the prevention and early detection of and response to future epidemic threats.

The emergence of colistin-resistant Enterobacteriaceae in food products is a growing concern due to the potential transfer of resistance to human pathogens. This study aimed to assess the prevalence of colistin-resistant Enterobacteriaceae in raw and ready-to-eat food samples collected from two regions of Italy (Apulia and Basilicata) and to evaluate their resistance phenotypes and genetic characteristics. A total of 1000 food samples were screened, with a prevalence of 4.4% of colistin-resistant Enterobacteriaceae. The majority of the isolates belonged to Enterobacter spp. (60%), followed by Moellerella wisconsensis, Atlantibacter hermannii, Klebsiella pneumoniae, and Escherichia coli, among others. Genomic sequencing and antimicrobial susceptibility testing revealed high levels of resistance to β-lactams, with most isolates exhibiting multidrug resistance (MDR). Notably, seven isolates harbored mcr genes (mcr-1, mcr-9, and mcr-10). Additionally, in four of them were predicted the IncHI2 plasmids, known to facilitate the spread of colistin resistance. Furthermore, 56 antimicrobial resistance genes were identified, suggesting the genetic mechanisms underlying resistance to several antibiotic classes. Virulence gene analysis showed that E. coli and other isolates carried genes linked to pathogenicity, increasing the potential risk to public health. This study emphasizes the role of food as a potential reservoir for colistin-resistant bacteria and the importance of monitoring the spread of AMR genes in foodborne pathogens.

Background: Bacillus cereus is a widespread environmental Gram-positive bacterium which is especially common in soil and dust. It produces two types of toxins that cause vomiting and diarrhea. At present, foodborne outbreaks due to Bacillus cereus group bacteria (especially Bacillus cereus sensu stricto) are rising, representing a serious problem in the agri-food supply chain. Methods: In this work, we analyzed 118 strains belonging to the Bacillus cereus group, isolated from several food sources, for which in vitro and in silico antibiotic resistance assessments were performed. Results: Many strains showed intermediate susceptibility to clindamycin, erythromycin, and tetracycline, suggesting an evolving acquisition of resistance against these antibiotics. Moreover, one strain showed intermediate resistance to meropenem, an antibiotic currently used to treat infections caused by Bacillus cereus. In addition to the phenotypic antimicrobial resistance profile, all strains were screened for the presence/absence of antimicrobial genes via whole-genome sequencing. There was inconsistency between the in vitro and in silico analyses, such as in the case of vancomycin, for which different isolates harbored resistance genes but, phenotypically, the same strains were sensitive. Conclusions: This would suggest that antibiotic resistance is a complex phenomenon due to a variety of genetic, epigenetic, and biochemical mechanisms.

Bacillus cereus is a gram-positive bacterium widespread in the environment, especially in soil and dust. It produces two types of toxins causing vomiting and diarrhea. Nowadays, food borne outbreaks due to Bacillus cereus group bacteria (especially Bacillus cereus sensu stricto) are increased, as reported by European Food Safety Authority, representing a very huge problem in agri-food chain. In this work, we analyzed 118 strains belonging to Bacillus cereus group, isolated from several food sources (fruit and vegetables, dairy products, bakery products) concerning their susceptibility to antibiotics currently most used to treat infections. Many strains showing an intermediate susceptibility to clindamycin, erythromycin, and tetracycline were detected, suggesting an evolving acquisition of resistance against these antibiotics. Moreover, one strain showed intermediate resistance to meropenem, another antibiotic currently used to treat infections caused by Bacillus cereus. Beside the antimicrobial characterization, all strains were studied comparing their antimicrobic phenotype with the presence/absence of antimicrobial genes in their genome. The analysis showed a not complete correlation between genes carried by the strains and their phenotype, demonstrating that the antibiotic resistance is due not only to genetic factors, but also to other factors such as the inappropriate use of antibiotics that can determine an acquired resistance for bacteria.

Fourier transform infrared spectroscopy (FTIRS) is a diagnostic technique historically used in the microbiological field for the characterization of bacterial strains in relation to the specific composition of their lipid, protein, and polysaccharide components. For each bacterial strain, it is possible to obtain a unique absorption spectrum that represents the fingerprint obtained based on the components of the outer cell membrane. In this study, FTIRS was applied for the first time as an experimental diagnostic tool for the discrimination of two pathogenic species belonging to the Bacillus cereus group, Bacillus anthracis and Bacillus cereus sensu stricto; these are two closely related species that are not so easy to differentiate using classical microbiological methods, representing an innovative technology in the field of animal health.

Brucella ceti infections have been increasingly reported in cetaceans. In this study, we analyzed all cases of B. ceti infection detected in striped dolphins stranded along the Italian coastline between 2012 and 2021 (N = 24). We focused on the pathogenic role of B. ceti through detailed pathological studies, and ad hoc microbiological, biomolecular, and serological investigations, coupled with a comparative genomic analysis of the strains. Neurobrucellosis was observed in 20 animals. The primary histopathologic features included non-suppurative meningoencephalitis (N = 9), meningitis (N = 6), and meningoencephalomyelitis (N = 5), which was also associated with typical lesions in other tissues (N = 8). Co-infections were detected in more than half of the cases, mostly involving Cetacean Morbillivirus (CeMV). The 24 B. ceti isolates were assigned primarily to sequence type 26 (ST26) (N = 21) and, in a few cases, ST49 (N = 3). The multilocus sequence typing (cgMLST) based on whole genome sequencing (WGS) data showed that strains from Italy clustered into four genetically distinct clades. Plotting these clades onto a geographic map suggests a link between their phylogeny and the topographical distribution. These results support the role of B. ceti as a primary neurotropic pathogen for striped dolphins and highlight the utility of WGS data in understanding the evolution of this emerging pathogen.