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The recent identification in rabbits of hepatitis E viruses (HEV) related to viruses infecting humans raises the question of the role of this species as possible HEV reservoir. A serological survey on rabbit HEV infection was conducted in Italy during 2013-2014, including both farmed and pet rabbits. We found an anti-HEV antibody seroprevalence of 3.40 % in 206 farmed rabbits (collected on 7 farms) and 6.56 % in 122 pets. RNA was extracted from IgG-positive sera and analyzed by HEV-specific real-time RT-PCR. None of the samples were positive, confirming that no viremia was present in the presence of IgG. Only one serum sample from a farmed rabbit was positive for IgM, but no HEV RNA was detected in it. Pet rabbit feces were also tested for HEV RNA, with negative results. This finding suggests that HEV is circulating in rabbits in Italy. [ABSTRACT FROM AUTHOR]

Swine dysentery is a mucohaemorrhagic colitis of pigs caused by infection with Brachyspira hyodysenteriae. The disease can be controlled by treatment with antimicrobial agents, with the pleuromutilins tiamulin and valnemulin being widely used. In recent years, the occurrence of B. hyodysenteriae with reduced susceptibility to these drugs has been increasing. The aim of this study was to determine temporal changes in genetic groups and pleuromutilin susceptibility amongst B. hyodysenteriae isolates from Italy. Multilocus sequence typing (MLST) was performed on 108 isolates recovered from 87 farms in different regions of Italy from 2003 to 2012, and their minimum inhibitory concentrations (MICs) for tiamulin and valnemulin were determined. Logistic regression was performed to assess associations between susceptibility to the two antimicrobial agents and genetic group, year and region of isolation. The isolates were allocated to 23 sequence types (STs), with five clonal clusters (Ccs) and seven singletons. More than 50% of isolates were resistant to both pleuromutilins (MIC >2.0 pg/mL for tiamulin and >1.0 gg/mL for valnemulin). All 10 isolates in ST 83 were resistant; these were first isolated in 2011 and came from nine farms, suggesting recent widespread dissemination of a resistant strain. Significant associations were found between the proportion of pleuromutilin susceptible isolates and the genetic group and year of isolation. Although resistant isolates were found in all Ccs, isolates in Ccs 2 and 7 were over five times more likely to be susceptible than those in the other Ccs. A significant trend in the reduction of susceptibility over time also was observed. [ABSTRACT FROM AUTHOR]

Actinobacillus pleuropneumoniae is responsible for porcine pleuropneumonia, a highly contagious lung infection. The control of this respiratory disease remains heavily reliant on antibiotics, with phenicols being one of the primary classes of antibiotics used in pig farming. In the present study, we describe three isolates (B2278, B2176 and B2177) of A. pleuropneumoniae resistant to florfenicol attributed to the presence of the floR gene, which were obtained from two pig farms in Italy. Florfenicol susceptibility tests indicated that B2176 exhibited an intermediate susceptibility profile, while B2177 and B2278 were resistant. All three isolates belonged to serovar 6 and tested positive for the presence of the floR gene. Whole genome sequencing analysis revealed that isolates B2176, B2177 and B2278 harbored genes encoding the toxins ApxII and ApxIII, characteristic of strains with moderate virulence. Moreover, phylogenetic analysis demonstrated that these isolates were closely related, with single nucleotide polymorphisms (SNPs) ranging from 8 to 19. The floR gene was located on a novel 5588 bp plasmid, designated as pAp-floR. BLASTN analysis showed that the pAp-floR plasmid had high nucleotide identity (99 %) and coverage (60 %) with the pMVSCS1 plasmid (5621 bp) from Mannheimia varigena MVSCS1 of porcine origin. Additionally, at least under laboratory conditions, pAp-floR was stably maintained even in the absence of direct selective pressure, suggesting that it does not impose a fitness cost. Our study underscores the necessity of monitoring the spread of florfenicol-resistant A. pleuropneumoniae isolates in the coming years., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Contaminated pork is a significant source of foodborne Salmonella infections. Pork is contaminated at the slaughterhouse; however, the mechanisms driving Salmonella contamination of carcasses are still poorly understood. The aim of this study was to investigate whether the amount of Salmonella carried by slaughtered pigs in their guts has an influence on carcass contamination. On that account, we tested whether the number of carcasses contaminated during a slaughter day was associated with the prevalence of highly contaminated pigs (HCP: Salmonella caecal loads ≥3log/g), or with the prevalence of pigs that simply carry Salmonella spp. in their guts. Three hundred and six pigs were sampled in a slaughterhouse from Central Italy. Salmonella loads in the caecum and on the carcass of each pig were estimated by the most probable number (MPN) technique. The overall prevalence of Salmonella was 34.64% and 7.19% for the caeca and carcasses, respectively. S. Derby and Salmonella enterica 4,[5],12:i:- were the most frequently isolated serovars. The prevalence of HCP was 11.44%. We found a higher number of contaminated carcasses on days of high prevalence of HCP than on days of low prevalence of HCP (p=0.0011). Conversely, carcass contamination did not vary with the prevalence of pigs that simply carried Salmonella spp. in their guts (p=0.7970). Therefore, the prevalence of HCP, but not the prevalence of pigs carrying Salmonella spp., was related to carcass contamination. Taken together, these findings suggest that reduction of Salmonella loads in the guts of slaughtered pigs would result in fewer contaminated carcasses, and consequently, help to minimise the risk of human infection due to the consumption of contaminated pork., (Copyright © 2016 Elsevier B.V. All rights reserved.)

The flagellated protozoan Dientamoeba fragilis is often detected in humans with gastrointestinal symptoms, but it is also commonly found in healthy subjects. As for other intestinal protozoa, the hypothesis that genetically dissimilar parasite isolates differ in their ability to cause symptoms has also been raised for D. fragilis. To date, only two D. fragilis genotypes (1 and 2) have been described, of which genotype 1 largely predominates worldwide. However, very few markers are available for genotyping studies and therefore the extent of genetic variation among isolates remains largely unknown. Here, we performed metagenomics experiments on two D. fragilis-positive stool samples, and identified a number of candidate markers based on sequence similarity to the phylogenetically related species Trichomonas vaginalis. Markers corresponding to structural genes and to genes encoding for proteases were selected for this study, and PCR experiments confirmed their belonging to the D. fragilis genome; two previously described markers (small subunit ribosomal DNA and large subunit of RNA polymerase II) were also included. Using this panel of markers, 111 isolates of human origin were genotyped, all of which, except one, belonged to genotype 1. These isolates had been collected at different times from symptomatic and asymptomatic persons of different age groups in Italy, Denmark, Brazil and Australia. By sequencing approximately 160kb from 500 PCR products, a very low level of polymorphism was observed across all the investigated loci, suggesting the existence of a major clone of D. fragilis with a widespread geographical distribution., (Copyright © 2016 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.)

Yersinia pseudotuberculosis is a pathogen that infects both animals and humans worldwide. The epidemiology of infection caused by Y. pseudotuberculosis is poorly understood; however, its outbreaks have been traced back to a probable source in wildlife. This study aimed to characterise Y. pseudotuberculosis isolates collected from animals with yersiniosis. This study included 90 isolates of Y. pseudotuberculosis collected from different animals with yersiniosis between 1996 and 2013 in Italy. The isolates were tested for antimicrobial susceptibility and were biotyped. Genes associated with virulence plasmid pYV and those encoding O-antigen, high pathogenicity island (HPI), and superantigenic toxin (YPM) were determined by performing PCR. Pulsed-field gel electrophoresis (PFGE) was performed using NotI and SpeI enzymes, and 3 dendrograms were generated. No antibiotic resistance was found. The presence of pYV was shown in 57 out of 90 isolates. Virulence profiles of majority of the isolates indicated that they belonged to O:1a and O:1b serotypes, biotype 1, and genetic type 2. Isolates belonging to O:2a serotype were detected in sheep and cattle and were found to be associated (for the first time) with septicemia in hares. Y. pseudotuberculosis isolates belonging to O:5a and O:12-O13 serotypes were also detected in hares. To our knowledge, this is the first study to detect Y. pseudotuberculosis isolates belonging to the O:12-O13 serotype from a clinical case in Europe. Results of PFGE indicated that it was a reliable method for investigating the genetic relatedness of Y. pseudotuberculosis isolates. Thus, characterisation of Y. pseudotuberculosis infection in animals should be considered a possible tool for the surveillance of pseudotuberculosis., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Atypical Yersinia pseudotuberculosis serotype O:3 was isolated from rectal contents of two wild boars hunted in Italy within a regional wildlife management program. No outbreak of yersiniosis was reported in this area in the same period and no lesions were found by the veterinarian at post-mortem inspection. Nevertheless, after histological examination, granulomatous lesions were detected in submandibular lymph nodes of one of the two wild boars. Microbiological and bio molecular characterization of the isolates revealed a melibiose-negative, biotype 2, wbyK+O:3 genotype, carrying inv, yop (yopH and yopB), virF, and R-HPI. Strains showing the same profile, matching to the criteria of genetic group 5, have been recently reported in fatal cases of yersiniosis in cynomolgus macaques and in farmed deer and atypical O:3 serotype has been suggested as a pathogenic subtype of O:3. This is the third report of an atypical O:3 Y. pseudotuberculosis strain, the first outside the American continent and the first one not associated to fatal yersiniosis. Wild boars could be a possible reservoir of this emerging pathogen., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Meat contamination by Salmonella spp. is emerging as a major cause of human enteric infections in industrialized countries. The attempts to reduce human cases of salmonellosis encompass pre- and post-harvest interventions. In this context, vaccination of pigs may represent an effective instrument in eliminating/reducing Salmonella burden through the food chain. We have previously demonstrated that Salmonella Typhimurium lacking the ZnuABC transporter (S. Typhimurium ΔznuABC) is a promising candidate live vaccine in different mouse models of Salmonella Typhimurium infection. In this study, we confirmed in pigs the attenuation of S. Typhimurium ΔznuABC. Moreover, we evaluated the safety and immunogenicity of S. Typhimurium ΔznuABC administered to pigs by the oral route. We monitored clinical conditions of animals and we conducted a microbiological culture and a quantification of the humoral and cellular immune response, respectively, on fecal and blood samples of pigs. After vaccination with attenuated S. Typhimurium ΔznuABC, pigs showed a modest degree of hyperthermia. In addition, fecal shedding of S. Typhimurium ΔznuABC could not be detected 28 days after the inoculum. Furthermore, vaccination with S. Typhimurium ΔznuABC elicited a distinct production of anti-Salmonella antibodies and IFN-γ. Taken together, these results suggest that S. Typhimurium ΔznuABC is attenuated and immunogenic in pigs. Although the vaccine dosages do not guarantee complete safety there is ample margin to set up better conditions of use, suggesting that S. Typhimurium ΔznuABC could be a promising attenuated strain to be used as live mucosal vaccine for oral delivery., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

By screening rabbits with enterocolitis or enteritis complex and asymptomatic rabbits, we identified a novel astrovirus. The virus was distantly related (19.3%-23.7% aa identity) in the capsid precursor to other mammalian astroviruses within the Mamastrovirus genus. By using real-time reverse transcription PCR, with specific primers and probes and targeting a conserved stretch in open reading frame 1b, we found rabbit astrovirus in 10 (43%) of 23 samples from animals with enteric disease and in 25 (18%) of 139 samples from asymptomatic animals in Italy during 2005-2008. The mean and median titers in the positive animals were 10(2)× and 10(3)× greater, respectively, in the symptomatic animals than in the asymptomatic animals. These findings support the idea that rabbit astroviruses should be included in the diagnostic algorithm of rabbit enteric disease and animal experiments to increase information obtained about their epidemiology and potential pathogenic role.

Genotyping of Salmonella strains is an important tool to discriminate among isolates and to improve epidemiological studies when an outbreak occurs. No phagetyping scheme is available for Salmonella enterica subsp. enterica serovar Abortusovis (SAO) and molecular methods previously used were not standardized and were time consuming. Among the DNA-based methods of genotyping, pulsed field gel electrophoresis (PFGE) is currently in use to subtype Salmonella isolates. In this study we evaluated the feasibility of genotyping of SAO by XbaI and BlnI restrictions. Separation of restricted fragments was performed by PFGE. To test the possibility to apply this methodology to epidemiological investigation, a collection of 38 SAO strains isolated in different regions of Italy were analyzed. Eighteen and 29 different PFGE profiles were defined for XbaI and BlnI digestions, respectively. The method demonstrated an adequate typing ability and an excellent discriminatory power. Results from this study show that PFGE may represent a powerful tool to discriminate within the SAO serovar, and provide useful information in support of traditional epidemiological investigations. In particular, this method could be used to identify the origin of infection during outbreaks within a single flock or in different herds.