The impact of length variations in the L2 loop on the structure and thermal stability of non-specific porins: The case of OmpCs from the Yersinia pseudotuberculosis complex.

Porins are integral proteins of the outer membranes of gram-negative bacteria. In membranes, they exist as homotrimers and the L2 loops contribute to their stability. Comparison of OmpC porins of the Yersinia pseudotuberculosis complex with other enterobacterial porins demonstrated L2 loop length diversity, which is caused by varying numbers of dipeptide/tripeptide repeats. The OmpC porins are highly homologous to each other, and they can be subdivided into five isoforms based on their L2 loop structure. Optical spectroscopy and SDS-PAGE experiments revealed that particularities of the L2 loops affected the structure and thermal stability of the porins. Thermal denaturation studies showed that porins with shorter loops, compared to porins with longer loops, had more stable tertiary and less stable secondary and quaternary structures. According to our comparative modeling results, the L2 loops differ in their structure by adopting different spatial positions and forming different polar bonds with a neighbor monomer. The replacement of asparagine with arginine at the C-terminus of the L2 loop shifts the loop upwards and causes the loss of contacts with the arginine clusters within the pores. The increase in the length of these loops ensures that they shift down toward the pore and restore their contacts with arginines on the channel wall, as is the case in classical nonspecific porins. Despite the fact that the surface charge density varies considerably among the OmpC porins, the L2 loops form a typical negatively charged region in the center of the trimer.

Far East Scarlet-Like Fever Caused by a Few Related Genotypes of Yersinia pseudotuberculosis, Russia.

We used multivirulence locus sequence typing to analyze 68 Yersinia pseudotuberculosis isolates from patients in Russia during 1973-2014, including 41 isolates from patients with Far East scarlet-like fever. Four genotypes were found responsible, with 1 being especially prevalent. Evolutionary analysis suggests that epidemiologic advantages could cause this genotype's dominance.

[ON THE ORIGIN OF HYPERVIRULENCE OF THE CAUSATIVE AGENT OF PLAGUE].

The attempt to combine Yersinia pseudotuberculosis and Yersinia pestis into one species has been unsupported by microbiologists due to the specific features of the epidemiology and clinical presentations of their induced diseases and to basic differences in their virulence. Pseudotuberculosis is predominantly a relatively mild human intestinal infection transmitted through contaminated food and plague is an acute generalized disease with high mortality, which is most frequently transmitted by the bites of infected fleas. Y. pestis hypervirulence, the ability of single bacteria to ensure the development of predagonal bacteriemia in rodents, which is sufficient to contaminate the fleas, is one of the main events during pathogen adaptation to a new ecological niche. By analyzing the data of molecular typing of the representative kits of naturally occurring Y. pestis isolates, the authois consider the issues of formation of intraspecies groups with universal hypervirulence, as well as biovars that are highly virulent only to their major host. A strategy for searching for selective virulence factors, the potential molecular targets for vaccination and etiotropic treatment of plague, is discussed.

Generation of a CRISPR database for Yersinia pseudotuberculosis complex and role of CRISPR-based immunity in conjugation.

The clustered regularly interspaced short palindromic repeat - CRISPR-associated genes (CRISPR-Cas) system is used by bacteria and archaea against invading conjugative plasmids or bacteriophages. Central to this immunity system are genomic CRISPR loci that contain fragments of invading DNA. These are maintained as spacers in the CRISPR loci between direct repeats and the spacer composition in any bacterium reflects its evolutionary history. We analysed the CRISPR locus sequences of 335 Yersinia pseudotuberculosis complex strains. Altogether 1902 different spacer sequences were identified and these were used to generate a database for the spacer sequences. Only ∼10% of the spacer sequences found matching sequences. In addition, surprisingly few spacers were shared by Yersinia pestis and Y. pseudotuberculosis strains. Interestingly, 32 different protospacers were present in the conjugative plasmid pYptb32953. The corresponding spacers were identified from 35 different Y. pseudotuberculosis strains indicating that these strains had encountered pYptb32953 earlier. In conjugation experiments, pYptb32953-specific spacers generally prevented conjugation with spacer-positive and spacer-free strains. However, some strains with one to four spacers were invaded by pYptb32953 and some spacer-free strains were fully resistant. Also some spacer-positive strains were intermediate resistant to conjugation. This suggests that one or more other defence systems are determining conjugation efficiency independent of the CRISPR-Cas system.

YERSINIA PSEUDOTUBERCULOSIS, SEROGROUP O:1A, INFECTION IN TWO AMAZON PARROTS (AMAZONA AESTIVA AND AMAZONA ORATRIX) WITH HEPATIC HEMOSIDEROSIS.

Necropsies were conducted on a female blue-fronted Amazon (Amazona aestiva) and a female yellow-headed Amazon (Amazona oratrix) that died after depression, ruffled feathers, diarrhea, and biliverdin in the urine. Gross and microscopic examinations revealed multifocal necrosis in the liver, spleen, lungs, kidneys, intestines, and heart caused by acute bacteremia. Yersinia pseudotuberculosis, serogroup O:1a, was isolated by culturing from the visceral lesions in the liver, intestines, and spleen. Virulence gene analysis showed the presence of the inv gene and the complete pathogenicity island: IS100, psn, yptE, irp1, irp2 ybtP-ybtQ, ybtX-ybtS, and int asnT-Int. Histopathologic findings and chemical analysis also demonstrated hepatic hemosiderosis. As has been demonstrated in other species, hemosiderosis may predispose Amazona spp. to systemic infection with Y. pseudotuberculosis after enteric disease.

Typing and clustering of Yersinia pseudotuberculosis isolates by restriction fragment length polymorphism analysis using insertion sequences.

Yersinia pseudotuberculosis is an enteropathogen that has an animal reservoir and causes human infections, mostly in temperate and cold countries. Most of the methods previously used to subdivide Y. pseudotuberculosis were performed on small numbers of isolates from a specific geographical area. One aim of this study was to evaluate the typing efficiency of restriction fragment length polymorphism of insertion sequence hybridization patterns (IS-RFLP) compared to other typing methods, such as serotyping, ribotyping, and multilocus sequence typing (MLST), on the same set of 80 strains of Y. pseudotuberculosis of global origin. We found that IS100 was not adequate for IS-RFLP but that both IS285 and IS1541 efficiently subtyped Y. pseudotuberculosis. The discriminatory index (DI) of IS1541-RFLP (0.980) was superior to those of IS285-RFLP (0.939), ribotyping (0.944), MLST (0.861), and serotyping (0.857). The combination of the two IS (2IS-RFLP) further increased the DI to 0.998. Thus, IS-RFLP is a powerful tool for the molecular typing of Y. pseudotuberculosis and has the advantage of exhibiting well-resolved banding patterns that allow for a reliable comparison of strains of worldwide origin. The other aim of this study was to assess the clustering power of IS-RFLP. We found that 2IS-RFLP had a remarkable capacity to group strains with similar genotypic and phenotypic markers, thus identifying robust populations within Y. pseudotuberculosis. Our study thus demonstrates that 2IS- and even IS1541-RFLP alone might be valuable tools for the molecular typing of global isolates of Y. pseudotuberculosis and for the analysis of the population structure of this species.

Homology analysis of pathogenic Yersinia species Yersinia enterocolitica, Yersinia pseudotuberculosis, and Yersinia pestis based on multilocus sequence typing.

We developed a multilocus sequence typing (MLST) scheme and used it to study the population structure and evolutionary relationships of three pathogenic Yersinia species. MLST of these three Yersinia species showed a complex of two clusters, one composed of Yersinia pseudotuberculosis and Yersinia pestis and the other composed of Yersinia enterocolitica. Within the first cluster, the predominant Y. pestis sequence type 90 (ST90) was linked to Y. pseudotuberculosis ST43 by one locus difference, and 81.25% of the ST43 strains were from serotype O:1b, supporting the hypothesis that Y. pestis descended from the O:1b serotype of Y. pseudotuberculosis. We also found that the worldwide-prevalent serotypes O:1a, O:1b, and O:3 were predominated by specific STs. The second cluster consisted of pathogenic and nonpathogenic Y. enterocolitica strains, two of which may not have identical STs. The pathogenic Y. enterocolitica strains formed a relatively conserved group; most strains clustered within ST186 and ST187. Serotypes O:3, O:8, and O:9 were separated into three distinct blocks. Nonpathogenic Y. enterocolitica STs were more heterogeneous, reflecting genetic diversity through evolution. By providing a better and effective MLST procedure for use with the Yersinia community, valuable information and insights into the genetic evolutionary differences of these pathogens were obtained.

High frequency of reactive arthritis in adults after Yersinia pseudotuberculosis O:1 outbreak caused by contaminated grated carrots.

OBJECTIVE: We describe the epidemiological and microbiological process in the clearing of a foodborne outbreak of Yersinia pseudotuberculosis O:1 linked to raw carrots and frequency of the associated reactive extra-gastrointestinal manifestations. METHODS: The patient samples were investigated by routine culture or antibody testing methods. The real-time bacterial PCR was used to detect Y pseudotuberculosis in samples from the grated carrots and in those taken from the carrot storage. Genotype of bacterial isolates was determined by pulsed-field gel electrophoresis. For case identification, we retrospectively looked over the laboratory files of the central hospital focusing on the time period of the outbreak. RESULTS: Altogether 49 case patients were identified. Y pseudotuberculosis was detected by real-time PCR analysis in samples taken from grated carrots and from the carrot distributor. Bacterial isolates originating from the farm environment showed identical serotype (O:1) and genotype (S12) with the patients' isolates. Among 37 adults, reactive arthritis (ReA) was found in 8 (22%) and three adults had probable ReA. Six (67%) out of nine human leucocyte antigen (HLA) typed patients with ReA were HLA-B27 positive. Erythema nodosum was found in 42% of the 12 children, whereas none of them had definite ReA. CONCLUSIONS: In this outbreak, Y pseudotuberculosis was for the first time detected in both patient and food samples. ReA was more common than earlier reported in the outbreaks associated with this pathogen; the reason may be that the previous outbreaks have occurred among children. HLA-B27 frequency was higher than usually reported in single-source outbreaks of ReA.

Relation between serology of meat juice and bacteriology of tonsils and feces for the detection of enteropathogenic Yersinia spp. in pigs at slaughter.

The association between positive serology and culture detection of Yersinia spp. in individual pigs was determined. Pieces of diaphragm from 370 pig carcasses were collected for serological analysis, and tonsils and feces of the same carcass were collected for bacteriological analysis. Detection of anti-Yersinia antibodies in meat juice samples was done using an indirect enzyme-linked immunosorbent assay (ELISA) based on Yops (Yersinia outer proteins). Tonsils and feces were tested for the presence of enteropathogenic Yersinia spp. by direct plating on cefsulodin-irgasan-novobiocin agar plates. Of the 370 meat juice samples, 241 (65.1%) gave a positive serological reaction using a cutoff value of 20%. Enteropathogenic Yersinia spp. (Yersinia enterocolitica serotype O:3 and Yersinia pseudotuberculosis) were found in tonsils of 161 pigs and feces of 30 pigs. Recovery of enteropathogenic Yersinia from the tonsils was highly correlated with positive serotiters, whereas no correlation was found between serology and fecal excretion. Results demonstrated that serology has an acceptable sensitivity, but a relatively low specificity for the rapid detection of enteropathogenic Yersinia spp. in tonsils of pigs at slaughter.

Proposed reclassification of Pasteurella lymphangitidis Sneath & Stevens 1990 as Yersinia pseudotuberculosis.

The 16S rRNA gene sequences of Pasteurella lymphangitidis, Yersinia pseudotuberculosis and Yersinia pestis were found to be identical and multilocus sequence analysis could not discriminate between the three species. The susceptibility to a Y. pseudotuberculosis phage and the presence of the Y. pseudotuberculosis-specific invasin gene in P. lymphangitidis indicate that the latter should be reclassified as Y. pseudotuberculosis.

Molecular typing of Yersinia pseudotuberculosis strains isolated from livestock in Brazil.

Yersinia pseudotuberculosis can infect a broad range of animals. In Brazil, this bacterium has been isolated from healthy and sick animals from sporadic cases and outbreaks of hemorrhagic gastroenteritis among livestock. However, the molecular diversity of these isolates is little understood. In this study, we used multilocus sequence typing, enterobacterial repetitive intergenic consensus PCR and pulsed-field gel electrophoresis to genotype 40 Y. pseudotuberculosis strains belonging to bio-serogroups 1/O:1a and 2/O:3 isolated between 1982 and 1990 in the southern region of Brazil. All three methodologies clustered the strains into two main clusters according to their bio-serogroups. Good correlations were observed between the clusters and the pathogenic potential of the strains. No correlation among the strains was observed according to geographical origin, host, place, or year of isolation. The grouping of the Y. pseudotuberculosis isolated in Brazil determined by these assays leads us to suggest that Brazilian livestock harbor two subpopulations of Y. pseudotuberculosis.

Evolution and virulence contributions of the autotransporter proteins YapJ and YapK of Yersinia pestis CO92 and their homologs in Y. pseudotuberculosis IP32953.

Yersinia pestis, the causative agent of plague, evolved from the gastrointestinal pathogen Yersinia pseudotuberculosis. Both species have numerous type Va autotransporters, most of which appear to be highly conserved. In Y. pestis CO92, the autotransporter genes yapK and yapJ share a high level of sequence identity. By comparing yapK and yapJ to three homologous genes in Y. pseudotuberculosis IP32953 (YPTB0365, YPTB3285, and YPTB3286), we show that yapK is conserved in Y. pseudotuberculosis, while yapJ is unique to Y. pestis. All of these autotransporters exhibit >96% identity in the C terminus of the protein and identities ranging from 58 to 72% in their N termini. By extending this analysis to include homologous sequences from numerous Y. pestis and Y. pseudotuberculosis strains, we determined that these autotransporters cluster into a YapK (YPTB3285) class and a YapJ (YPTB3286) class. The YPTB3286-like gene of most Y. pestis strains appears to be inactivated, perhaps in favor of maintaining yapJ. Since autotransporters are important for virulence in many bacterial pathogens, including Y. pestis, any change in autotransporter content should be considered for its impact on virulence. Using established mouse models of Y. pestis infection, we demonstrated that despite the high level of sequence identity, yapK is distinct from yapJ in its contribution to disseminated Y. pestis infection. In addition, a mutant lacking both of these genes exhibits an additive attenuation, suggesting nonredundant roles for yapJ and yapK in systemic Y. pestis infection. However, the deletion of the homologous genes in Y. pseudotuberculosis does not seem to impact the virulence of this organism in orogastric or systemic infection models.

Marathon of eponyms: 25 Yersiniosis.

The use of eponyms has long been contentious, but many remain in common use, as discussed elsewhere (Editorial: Oral Diseases. 2009: 15; 185). The use of eponyms in diseases of the head and neck is found mainly in specialties dealing with medically compromised individuals (paediatric dentistry, special care dentistry, oral and maxillofacial medicine, oral and maxillofacial pathology, oral and maxillofacial radiology and oral and maxillofacial surgery) and particularly by hospital-centred practitioners. This series has selected some of the more recognised relevant eponymous conditions and presents them alphabetically. The information is based largely on data available from MEDLINE and a number of internet websites as noted below: the authors would welcome any corrections. This document summarises data about Yersiniosis.

[Genetic analysis of biochemical differences of Yersinia pestis strains].

Literature data and results of our experimental studies on genetic base of biochemical differentiation of Yersinia pestis strains of various subspecies and biovars are summarized in the review. Data on variability of genes coding biochemical features (sugar and alcohol fermentation, nitrate reduction), the differential development of which are the base of existing phenotypic schemes of Y. pestis strains classification, are presented. Variability of these genes was shown to have possible use for the development of genetic classification of Y. pestis strains of various subspecies and biovars.

[Standard algorithm of molecular typing of Yersinia pestis strains].

AIM: Development of the standard algorithm of molecular typing of Yersinia pestis that ensures establishing of subspecies, biovar and focus membership of the studied isolate. Determination of the characteristic strain genotypes of plague infectious agent of main and nonmain subspecies from various natural foci of plague of the Russian Federation and the near abroad. MATERIALS AND METHODS: Genotyping of 192 natural Y. pestis strains of main and nonmain subspecies was performed by using PCR methods, multilocus sequencing and multilocus analysis of variable tandem repeat number. RESULTS: A standard algorithm of molecular typing of plague infectious agent including several stages of Yersinia pestis differentiation by membership: in main and nonmain subspecies, various biovars of the main subspecies, specific subspecies; natural foci and geographic territories was developed. The algorithm is based on 3 typing methods--PCR, multilocus sequence typing and multilocus analysis of variable tandem repeat number using standard DNA targets--life support genes (terC, ilvN, inv, glpD, napA, rhaS and araC) and 7 loci of variable tandem repeats (ms01, ms04, ms06, ms07, ms46, ms62, ms70). The effectiveness of the developed algorithm is shown on the large number of natural Y. pestis strains. Characteristic sequence types of Y. pestis strains of various subspecies and biovars as well as MLVA7 genotypes of strains from natural foci of plague of the Russian Federation and the near abroad were established. CONCLUSION: The application of the developed algorithm will increase the effectiveness of epidemiologic monitoring of plague infectious agent, and analysis of epidemics and outbreaks of plague with establishing the source of origin of the strain and routes of introduction of the infection.

Population structure of the Yersinia pseudotuberculosis complex according to multilocus sequence typing.

Multilocus sequence analysis of 417 strains of Yersinia pseudotuberculosis revealed that it is a complex of four populations, three of which have been previously assigned species status [Y. pseudotuberculosis sensu stricto (s.s.), Yersinia pestis and Yersinia similis] and a fourth population, which we refer to as the Korean group, which may be in the process of speciation. We detected clear signs of recombination within Y. pseudotuberculosis s.s. as well as imports from Y. similis and the Korean group. The sources of genetic diversification within Y. pseudotuberculosis s.s. were approximately equally divided between recombination and mutation, whereas recombination has not yet been demonstrated in Y. pestis, which is also much more genetically monomorphic than is Y. pseudotuberculosis s.s. Most Y. pseudotuberculosis s.s. belong to a diffuse group of sequence types lacking clear population structure, although this species contains a melibiose-negative clade that is present globally in domesticated animals. Yersinia similis corresponds to the previously identified Y. pseudotuberculosis genetic type G4, which is probably not pathogenic because it lacks the virulence factors that are typical for Y. pseudotuberculosis s.s. In contrast, Y. pseudotuberculosis s.s., the Korean group and Y. pestis can all cause disease in humans.

Population structure and evolution of pathogenicity of Yersinia pseudotuberculosis.

Yersinia pseudotuberculosis is an enteric human pathogen but is widespread in the environment. Pathogenicity is determined by a number of virulence factors, including the virulence plasmid pYV, the high-pathogenicity island (HPI), and the Y. pseudotuberculosis-derived mitogen (YPM), a superantigen. The presence of the 3 virulence factors varies among Y. pseudotuberculosis isolates. We developed a multilocus sequence typing (MLST) scheme to address the population structure of Y. pseudotuberculosis and the evolution of its pathogenicity. The seven housekeeping genes selected for MLST were mdh, recA, sucA, fumC, aroC, pgi, and gyrB. An MLST analysis of 83 isolates of Y. pseudotuberculosis, representing 19 different serotypes and six different genetic groups, identified 61 sequence types (STs) and 12 clonal complexes. Out of 26 allelic changes that occurred in the 12 clonal complexes, 13 were mutational events while 13 were recombinational events, indicating that recombination and mutation contributed equally to the diversification of the clonal complexes. The isolates were separated into 2 distinctive clusters, A and B. Cluster A is the major cluster, with 53 STs (including Y. pestis strains), and is distributed worldwide, while cluster B is restricted to the Far East. The YPM gene is widely distributed on the phylogenetic tree, with ypmA in cluster A and ypmB in cluster B. pYV is present in cluster A only but is sporadically absent in some cluster A isolates. In contrast, an HPI is present only in a limited number of lineages and must be gained by lateral transfer. Three STs carry all 3 virulence factors and can be regarded as high-pathogenicity clones. Isolates from the same ST may not carry all 3 virulence factors, indicating frequent gain or loss of these factors. The differences in pathogenicity among Y. pseudotuberculosis strains are likely due to the variable presence and instability of the virulence factors.

Variation in the prevalence of enteropathogenic Yersinia in slaughter pigs from Belgium, Italy, and Spain.

Tonsils of 829 fattening pigs originating from Belgium (n = 201), Italy (n = 428), and Spain (n = 200) were collected between 2005 and 2007 to study the prevalence of enteropathogenic Yersinia in slaughter pigs. Isolation of Yersinia enterocolitica and Yersinia pseudotuberculosis was done by selective enrichment and by cold enrichment for 7 and 14 days. Pathogenic Y. enterocolitica and Y. pseudotuberculosis isolates were identified by polymerase chain reaction targeting the chromosomal genes ail and inv, respectively, as well as the plasmid-encoded virF of both species. A significantly higher (p < 0.001) prevalence of ail-positive Y. enterocolitica in Spain (93%) than in Belgium (44%) or Italy (32%) was observed. virF-positive Y. enterocolitica was present in 77% of ail-positive samples. Bioserotype 4/O:3 was the most common type in all three countries. Bioserotypes 2/O:5 and 3/O:9 were found in Italy (1%) and Belgium (9%), respectively. The prevalence of inv- and virF-positive Y. pseudotuberculosis was 2% and 1% in Belgium and Italy, respectively. Y. pseudotuberculosis was not detected in pigs from Spain. Bioserotypes 1/O:1 (20%), 1/O:2 (20%), and 2/O:3 (60%) were found in Belgium, and 1/O:1 (60%) and 2/O:3 (20%) in Italy. The most efficient method for isolation of Y. enterocolitica was combined cold enrichment for 7 and 14 days; however, the isolation method for Y. pseudotuberculosis was cold enrichment for 14 days. Fattening pigs seem to be an important reservoir of pathogenic Y. enterocolitica in Belgium, Italy, and Spain. Bioserotype 4/O:3 of Y. enterocolitica and bioserotypes 2/O:3 and 1/O:1 of Y. pseudotuberculosis have been shown to predominate.

Cellular fatty acids as chemical markers for differentiation of Yersinia pestis and Yersinia pseudotuberculosis.

AIMS: Gas chromatography (GC) was utilized to investigate the cellular fatty acids (CFAs) composition of 141 Yersinia pestis isolates from different plague foci of China, and 20 Yersinia pseudotuberculosis strains as well. METHODS AND RESULTS: The whole cell fatty acid methyl esters (FAMEs) were obtained by saponification, methylation and extraction followed with analysis using a standardized Microbial Identification System (MIS). Y. pestis and Y. pseudotuberculosis strains are quite similar in major CFA profiles, which include 16:0, 17:0 cyclo, 3-OH-14:0, 16:1 omega 7c and 18:1 omega 7c, accounting for more than 80% of the total CFAs. CONCLUSIONS: Yersinia pestis could be easily differentiated from Y. pseudotuberculosis by plotting the ratios of some CFA pairs, i.e.,14:0/18:0 vs 18:1 omega 7c/18:0, 3-OH-14:0/18:0 vs 18:1 omega 7c/18:0, 16:1 omega 7c/18:0 vs 18:1 omega 7c/18:0, 12:0/18:0 vs 18:1 omega 7c/18:0 and 12:0 ALDE/18:0 vs 16:1 omega 7c/18:0 fatty acids. SIGNIFICANCE AND IMPACT OF THE STUDY: In the present study, the normalized Sherlock MIS and Sherlock standard libraries were used to analyse the fatty acid composition of different strains of Y. pestis and Y. pseudotuberculosis. Meanwhile, ratios of certain CFA components were found to serve as chemical markers for differentiating the two closely related bacteria that are difficult to be differentiated by simply comparing CFA profiles based on other researches.

Wild boars as an important reservoir for foodborne pathogens.

One hundred fifty-three wild boars shot in the canton of Geneva, Switzerland, were studied for the occurrence of foodborne pathogens. Tonsils and fecal samples of the animals were examined using real-time polymerase chain reaction, enzyme-linked fluorescent immunoassay, and cultural methods. The detection rate of Salmonella spp., Yersinia enterocolitica, Yersinia pseudotuberculosis, stx-positive Escherichia coli, and Listeria monocytogenes was 12%, 35%, 20%, 9%, and 17%, respectively, when tonsil samples were studied. Only Y. enterocolitica (5%) and L. monocytogenes (1%) were detected in fecal samples. None of the samples was positive for Campylobacter spp. Females (71%) and young animals (61%) carried more frequently one or more pathogens than males (53%) and older ones (44%). In total, 8 Salmonella spp., 14 Y. enterocolitica, 4 Y. pseudotuberculosis, and 26 L. monocytogenes strains were further characterized. Most of the Salmonella spp. strains were of serotype Salmonella Enteritidis (75%) followed by serotypes Salmonella Stourbridge (13%) and Salmonella Veneziana (13%). L. monocytogenes strains belonged to serotypes 1/2a (42%), 1/2b (19%), and 4b (38%). Serotypes O:3 (36%), O:5,27 (21%), and O:9 (29%) were identified among Y. enterocolitica strains and serotypes O:1 (75%) and O:2 (25%) among Y. pseudotuberculosis strains. This study shows that wild boars are frequent carriers of foodborne pathogens. High wild boar densities and increasing popularity of outdoor ranging of pigs may intensify the risk of transmission of these pathogens to fattening pigs.