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Several animal species have been found to be susceptible to SARS-CoV-2 infection. The occurrence of infection in dogs and cats living in close contact with owners deserves particular attention from public health authorities in a One Health approach. In this study, we conducted serological screening to identify SARS-CoV-2 exposure in the sera from dogs and cats in three regions of southern Italy sampled during the years 2021 and 2022. We collected 100 serum samples in 2021 (89 from dogs and 11 from cats) and 640 in 2022 (577 from dogs and 63 from cats). Overall, the ELISA positivity rate was found to be 2.7% (20/740), with higher seroprevalence in dogs. Serum neutralization tests confirmed positivity only in two samples collected from dogs, and the assays, performed with serologically distinct SARS-CoV-2 variants, showed variant-specific positivity. This paper shows that monitoring SARS-CoV-2 exposure in animals might be affected by the viral antigenic evolution, which requires continuous updates to the serological tests used. Serological surveys are useful in understanding the true extent of exposure occurring in specific animal populations, not suffering the same limitations as molecular tests, and could help in identifying the infecting virus if tests able to characterize the immune response are used. The use of variant-specific validated serological methods should always be considered in serosurvey studies in order to determine the real impact of emerging variants on animal populations and its implications for veterinary and human health, as well as to identify potential reservoirs of the virus and its evolutionary changes. [ABSTRACT FROM AUTHOR]

Abstract: Verocytotoxin-producing Escherichia coli (VTEC) are foodborne pathogens that cause outbreaks linked to consumption of meat and raw milk. In this note the authors report results obtained from a survey conducted on minced beef and raw bovine milk samples using a Multiplex PCR (M-PCR) for the detection of eae, stx 1, stx 2 and hlyA genes as a screening step followed by a colony blot hybridization (CBH) technique for the isolation of the VTEC. Of 100 minced beef and 123 raw milk samples, 13 (13%) and 7 (5.7%) were positive in the M-PCR and among these 9 and 3 strains were isolated using CBH, respectively. All isolates showed the presence of the stx 2 gene, single or in association with the other investigated genes. None of the isolates belonged to the O157, O26, O91, O103, O111 and O145 serogroups. The study showed that the use of M-PCR for the screening of samples coupled with a sensitive and specific detection technique, could improve the possibility of detection of VTEC strains in foods. Moreover, the presence of VTEC in minced beef and in raw milk confirms their important role as putative vehicles of infection to humans. Stringent control of these foodstuffs is essential for food safety purposes. [Copyright &y& Elsevier]

Members of Bacillus cereus group are important food contaminants and they are of relevant interest in food safety and public heath due to their ability to cause two distinct forms of food poisoning, emetic and diarrhoeal syndrome. In the present study, 90 strains of B. cereus isolated from dairy products, have been typed using Multilocus Sequence Typing (MLST) analysis and investigated for the occurrence of 10 enterotoxigenic genes (hblA, hblC, hblD, nheA, nheB, nheC, cytK, entFM, entS and bceT) and one emetogenic gene (ces), to determine their genetic diversity. A total of 58 sequence types were identified and among these 17 were signalled as new profiles. Among the virulence genes, the majority of our strains carried the entS (92%), entFM (86%), nhe (82%) and cytK (72%) genes. All remaining genes were identified in at least one strain with different prevalence, stressing the genetic diversity, how even the different grade of pathogenicity of B. cereus isolated from dairy products. [ABSTRACT FROM AUTHOR]

Yersiniosis is the third most reported food-borne zoonosis in Europe. The aim of the present study was to perform the search for Yersinia enterocolitica in food samples collected from Apulia and Basilicata regions (Southern Italy) and to characterize any isolates by classical and modern analytical methods. A total of 130 samples were analyzed between July 2018 and July 2019: most of them were raw milk and dairy products made from it. Furthermore, 8 out of 130 samples were individual milk samples collected from bovines reared in a Brucella-free farm which showed false positive serological reaction for brucellosis due to the presence of pathogenic Y. enterocolitica O:9 biotype 2 in faeces. The Real Time PCR targeting the ail gene and the culture method were performed to detect pathogenic Y. enterocolitica. Isolates were subjected to API 20E (Biomerieux) and MALDI-TOF MS (Matrix Assisted Laser Desorption Ionization Time-of-Flight) for species identification. All samples were negative for the ail gene. The culture method allowed to isolate suspicious colonies from 28 samples. The API 20E system and the MALDI-TOF MS technique identified 20 Y. enterocolitica and 1 Y. intermedia in a concordant way. The remaining 7 strains were all identified as Y. enterocolitica by the API 20E system, while the MALDI-TOF MS recognized 4 Y. intermedia, 1 Y. bercovieri and 2 Y. massiliensis. Genotypic characterization of the discordant strains was performed by rMLST and it confirmed the MALDI-TOF MS' results. Only non-pathogenic Y. enterocolitica biotype 1A strains were found, although with a non-negligible prevalence (P = 0.15 with CI 95% = ± 0.06). This study indicates a poor circulation of pathogenic Y. enterocolitica in food products made and marketed in the investigated areas. However, the small number of samples, insufficient for some food categories such as meat and vegetable, does not allow to exclude the presence of pathogenic strains at all. [ABSTRACT FROM AUTHOR]

Methicillin-resistant Staphylococcus aureus (MRSA) is an important medical issue, since it causes serious and sometimes fatal infections in humans. Intensively reared swine may serve as reservoirs for MRSA that can infect swine workers, and also consumers (via contaminated meat). In this study, MRSA strains were isolated from 55 of the 85 (64.7%) intensive pig farms surveyed, and prevalence was greater on pig fattening farms than on breeding farms. In addition, we included in the study 63 foreign pigs imported for slaughter. Overall, the prevalence of MRSA in the 418 sampled swine was 59.1%; 12 genotypes were identified among the isolates; ST398 (96.4%) was most prevalent, followed by ST97 (2%), ST9 (0.8%) and ST1 (0.8%). MRSA isolates were also detected in 26 (17.3%) of the 150 operators included in the study; the genotypes detected were ST398 (85%), ST9 (7.6%), ST5 (3.8%) and ST1 (3.8%). All the strains were pvl negative and pia positive. Both swine and human strains displayed a multi-resistance pattern, and almost all were resistant to tetracycline. The results obtained in this study confirm the high prevalence of MRSA in swine reared and slaughtered in Italy, and underline the public health risk linked to the spread of antimicrobial-resistant Staphylococcus aureus among intensively reared pigs. • Our study shows genetic diversity of MRSA in pigs reared and slaughtered in Italy. • The foodborne risk linked to the consumption or handling the pig meat should be considered. • The professional risk for the farmers and the abattoir workers should be considered. • This is the first international report on the prevalence of MRSA in swine reared in Southern Italy. [ABSTRACT FROM AUTHOR]

The aim of the present study was to assess the prevalence and genetic characteristics of Arcobacter spp. in bovine bulk tank milk produced in Apulia Region (Italy). Samples collected from 396 dairy farms, after enrichment in a selective broth, were subjected to an Arcobacter genus - specific Real Time PCR. Positive broths, previously filtered, were seeded on Karmali, MCCD and Columbia Blood Agar plates; presumptive Arcobacter spp. colonies were identified using an amplification and sequencing method and then characterized by Multi-Locus Sequence Typing (MLST). Prevalence of Arcobacter spp. in bovine milk samples was 5% (20/396); A. butzleri was the only isolated species, in agreement with previous studies that reported A. butzleri as the most commonly recovered species in milk and dairy products. MLST analysis of the 20 A. butzleri strains identified 81 alleles and 16 STs. Consistent with previous studies, MLST revealed a high level of heterogeneity between the A. butzleri isolates and confirmed the high discriminatory power of this method and its suitability for epidemiological investigations. This study confirmed the importance of raw milk as a possible source of Arcobacter spp. for humans. [ABSTRACT FROM AUTHOR]

The need of accurate and reliable methods for DNA isolation and plant species identification in foodstuffs is of great importance, especially in the protection of high added value products. Fresh foods, which are not subjected to any modifications, are suitable for many kind of analysis; for processed products, such as musts, wines, olive oils, and pasta, the situation may be more complicated due to DNA fragmentation and, in the worst case, by its degradation. This work aimed to establish an exhaustive and reproducible analytical procedure for table grape DNA tracing in industrial musts. Three different DNA extraction methods were initially compared and DNA was tested in PCR for its suitability for the amplification reaction of microsatellite markers or simple sequence repeats (SSRs). An optimized DNA extraction method for microsatellite amplification was developed and adapted for industrial musts. Two SSR-based molecular methods, High Resolution Melting and capillary electrophoresis, were tested and the markers VrZAG62 and VrZAG79 were found to be the most informative. High Resolution Melting analysis, here applied for the first time on musts, proved to be the method of choice for a preliminary screening using four cultivars chosen as references and different DNA mixtures prepared in laboratory. Capillary electrophoresis, providing allele size, allowed a fine genotyping of musts in comparison with reference cultivars. The LOD 6 of a single grape cultivar in mixture with other varieties was also determined at 2.5 ng. Merging the information of the two molecular analyses applied to real samples, we demonstrated that is possible to discover case of musts adulterated with table grapes, and we propose our procedure in controlling musts quality and origin certification. [ABSTRACT FROM AUTHOR]

Historically, genome-wide and molecular characterization of the genus Listeria has concentrated on the important human pathogen Listeriamonocytogenes and asmall number of closely related species, together termed Listeria sensu strictu.More recently, a number of genome sequences for more basal, and nonpathogenic, members of the Listeria genus have become available, facilitating a wider perspective on the evolution of pathogenicity and genome level evolutionary dynamics within the entire genus (termed Listeria sensu lato). Here, we have sequenced the genomes of additional Listeria fleischmannii and Listeria newyorkensis isolates and explored the dynamics of genome evolution in Listeria sensu lato. Our analyses suggest that acquisition of genetic material through gene duplication and divergence as well as through lateral gene transfer (mostly from outside Listeria) is widespread throughout the genus. Novel genetic material is apparently subject to rapid turnover. Multiple lines of evidence point to significant differences in evolutionary dynamics between themost basal Listeria subclade and all other congeners, including both sensu strictu and other sensu lato isolates. Strikingly, these differences are likely attributable to stochastic, population-level processes and contribute to observed variation in genome size across the genus. Notably, our analyses indicate that the common ancestor of Listeria sensu lato lacked flagella, whichwere acquired by lateral gene transfer by a common ancestor of Listeria grayi and Listeria sensu strictu, whereas a recently functionally characterized pathogenicity island, responsible for the capacity to produce cobalamin and utilize ethanolamine/propane-2-diol, was acquired in an ancestor of Listeria sensu strictu. [ABSTRACT FROM AUTHOR]

Thermotolerant Campylobacter spp. are frequently the cause of human gastroenteritis and have assumed more importance in Italy following the increased consumption of raw milk. Our objectives were to determine the prevalence and genotypes of Campylobacter spp. in dairy herds and to investigate the possible sources of bulk milk contamination. Bulk milk from dairy herds (n = 282) was cultured for Campylobacter spp. and Enterobacteriaceae. At three Campylobacter jejuni-positive farms, bovine feces, pigeon intestines, milk, and water points were also investigated. Isolates were identified by PCR and genotyped using multilocus sequence typing (MLST). C. jejuni was detected in 34 (12%) bulk milk samples. The strains belonged to 14 sequence types, and the most common clonal complexes were CC-21, CC-48, and CC-403. No association was demonstrated between the presence of C. jejuni and high levels of Enterobacteriaceae in bulk milk. At the three farms examined, C. jejuni was isolated from bovine feces (25/82 [30.5%]), pigeon intestines (13/60 [21.7%]), bulk milk (10/24 [41.7%]), and water points (4/16 [25%]). MLST revealed lineages that were common between milk and bovine feces but distinct between cattle and pigeons. In one herd, C. jejuni with the same genotype was isolated repeatedly from bulk milk and a cow with an udder infection. Our results showed a high prevalence of C. jejuni in bulk milk and suggested that udder excretion, in addition to fecal matter, may be a route of bulk milk contamination. MLST analysis indicated that pigeons are probably not relevant for the transmission of C. jejuni to cattle and for milk contamination. [ABSTRACT FROM AUTHOR]

Abstract: Standardized tools for typing Listeria monocytogenes isolates are required in epidemiological surveys investigating food-borne disease outbreaks and in the food-processing environment to identify the sources of contamination and routes by which the organisms are spread. In this survey Amplified Fragment Length Polymorphism (AFLP) and Multi-Locus Sequence Typing (MLST) have been used to study 103 L. monocytogenes isolates from food and environmental sources. A total of 62 AFLP types and 66 MLST Sequence Types were identified. AFLP and MLST produced similar results in terms of discriminating power. The Discrimination Index calculated for the two techniques was 0.976 for AFLP and 0.972 for MLST. These values were appreciably higher compared to serotyping (0.739). A good congruence was observed between AFLP and MLST. The present study demonstrated that AFLP and MLST subtyping are suitable tools for studying the epidemiology of L. monocytogenes. The great advantage of MLST over AFLP and other molecular typing methods based on fragment fingerprinting lies in the unambiguity of sequence data while AFLP is less costly and highly processive. In conclusion the two methods can be perfectly integrated for high-resolution genotyping of L. monocytogenes. [Copyright &y& Elsevier]

Abstract: The sequence of the full-length gene encoding for the main capsid protein VP2 of 58 canine parvovirus (CPV) type 2c strains, along with recent CPV-2a/2b strains, was determined and analysed in comparison with reference CPV isolates. The CPV-2c strains displayed a low genetic variability and shared amino acid changes already detected in recent CPV-2a/2b isolates, with a phylogenetic clustering accounting for their geographical distribution. Analysis of the selection pressure driving CPV evolution confirmed that the VP2 gene is under purifying selection. The emergence and global spread of the new CPV variant provides an interesting model to better understand virus evolution. [Copyright &y& Elsevier]

Abstract: Coxiella burnetii, an obligate intracellular parasite with a worldwide distribution, is the causative agent of acute and chronic Q fever in humans. Although infection is often unapparent in cattle, sheep and goats, there is increasing evidence that C. burnetii infection in these species is associated with abortion and stillbirth. This paper describes the introduction of a single-tube nested PCR protocol for the diagnosis of C. burnetii-related abortion in domestic ruminants in Italy. A total of 514 aborted foetuses from cattle (n =138) and sheep and goat (n =376), collected from 301 farms, were analyzed from January 2001 to March 2005. Ninety-seven of 514 (18.9%) animals tested PCR-positive, with 16/138 (11.6%) cattle and 81/376 (21.5%) sheep and goat. Eleven of 102 (10.8%) farms with reproductive disorders in cattle and 37/199 (18.6%) farms with reproductive disorders in sheep and goats were infected with C. burnetii. A greater incidence was observed in three of the seven investigated provinces (p <0.01), with rates of infected farms of up to 23.8%. Data showed that almost all the C. burnetii-related abortions were recorded between October and April (p <0.01). These findings suggest that Q fever in humans is largely underestimated in Italy, probably because its occurrence is obscured by flu-like symptoms in acute forms. [Copyright &y& Elsevier]