Valeria Rondinone

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.

Background: Staphylococcus pseudintermedius is a major opportunistic pathogen of dogs and the primary cause of canine pyoderma and other infections. The global emergence of methicillin-resistant S. pseudintermedius (MRSP) represents a significant challenge in veterinary medicine due to its frequent multidrug-resistant phenotype and limited therapeutic options. Methods: We describe the phenotypic and genomic characterization of an MRSP isolate recovered from a vaginal swab of an 11-year-old dog diagnosed with vulvovaginitis in southern Italy. Antimicrobial susceptibility testing was performed using broth microdilution according to CLSI VET01S guidelines. Whole-genome sequencing was conducted to determine sequence type and antimicrobial resistance determinants. Results: The isolate was identified as S. pseudintermedius by MALDI-TOF MS and confirmed by genomic analysis. Multilocus sequence typing assigned the strain to sequence type ST2333. Phenotypically, the isolate exhibited multidrug resistance, including resistance to β-lactams, macrolides, lincosamides, tetracyclines, aminoglycosides, fluoroquinolones, and trimethoprim–sulfamethoxazole, while remaining susceptible to amikacin, rifampicin, florfenicol, and vancomycin. Whole-genome sequencing confirmed the presence of mecA and additional resistance determinants consistent with the observed phenotype. Conclusions: This report suggests the possible occurrence of an MDR MRSP ST2333 lineage in southern Italy and highlights the importance of combined phenotypic and genomic surveillance to support antimicrobial stewardship in veterinary medicine within a One Health framework.

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.

Actinobacillus seminis is a gram-negative bacterium that affects reproductive organs, causing epididymitis, low fertility, and occasional abortions in sheep and goats. The virulence factors and the pathogenicity mechanisms of A. seminis have not been clearly elucidated yet. The aim of this study is to report a laboratory investigation performed on a sheep farm in the Basilicata region (southern Italy) following cases of abortion. Four samples of aborted fetuses taken from two sheep were analyzed to investigate the main pathogens causing abortions by bacterial isolation. In addition, serum samples belonging to the sheep have also been analyzed. Analysis by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) of the isolated colonies identified protein spectra referable to A. seminis. This result was also confirmed through the use of genome sequencing. Therefore, these data could explain cases of abortion that occurred on the farm and would confirm that MALDI-TOF MS technology is a rapid, accurate, and inexpensive method for identifying bacteria.

Salmonellosis is one of the most frequent foodborne zoonoses, and the consumption of contaminated poultry meat is considered the main source of Salmonella infections in humans. From 2021 to 2023, 384 chicken samples were collected from retailers in Apulia and Basilicata regions and analysed at the Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata (IZSPB) laboratories. The Salmonella isolates were investigated to evaluate their phenotypic characteristics of antimicrobial resistance. A total of 125 (32.55%) samples tested positive for Salmonella spp. Three samples were simultaneously infected with strains of two different serotypes. Strains were classified into nine serotypes. Out of 128 strains, 112 (87.5%) isolates showed multidrug-resistant (MDR) profiles. Moreover, 16 isolates (12.5%) were ESBL producers with MDR profiles. Our data confirm that chicken products are a common source of Salmonella and highlight how S. Infantis was the most prevalent serotype (85.93%). Furthermore, Salmonella isolates showed antimicrobial resistance, which is very worrisome for animals and consumers. The high rate of antibiotic resistance along with the appearance of numerous MDR isolates is considered an actual concern and requires a robust surveillance network in a One Health concept.

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.

A strain belonging to the genus Psychrobacter, named PraFG1^T, was isolated from the peritoneal effusion of a stray dog during necropsy procedures. The strain was characterized by the phylogenetic analyses based on the nucleotide sequences of 16S and 23S rRNA genes and of gyrB, which placed the strain in the genus Psychrobacter. The nucleotide sequence of the chromosome confirmed the placement, showing an average nucleotide identity of 72.1, 77.7, and 77.5 % with the closest related species, namely Psychrobacter sanguinis, Psychrobacter piechaudii, and Psychrobacter phenylpyruvicus, respectively, thus indicating a novel species. The polyphasic characterization by biochemical and fatty acid profiling as well as MALDI-TOF supported those findings. The strain was halotolerant, capable of growing within a temperature range between 4 and 37 °C, it was positive for catalase and oxidase, indole producing, nitrate reducing, and not able to use 5-keto-d-gluconic acid as a carbon source. Taken together, the data suggest that strain PraFG1^T could be considered as representing a novel species, with the name Psychrobacter raelei sp. nov. (type strain PraFG1^T=CIP 111873^T=LMG 32233^T).

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.