Natural reservoirs of Yersinia (Y.) enterocolitica comprise different animal species, but little is known about the role of wild animals in the epidemiology of yersiniosis. The aim of the study was to evaluate the prevalence of Y. enterocolitica among game animals in Poland. The bio-serotypes and the pathogenicity markers of the analyzed isolates were determined. The experimental material comprised rectal swabs from 857 free-living animals hunter-harvested over a period of 2 years (2013–2014) in hunting districts across Poland. The isolates from bacteriological studies were confirmed by PCR and bio-serotyped based on the results of biochemical and agglutination tests. In the group of the 218 analyzed isolates of Y. enterocolitica, 133 were derived from wild boars, 70 from red deer, 11 from roe deer and 4 from fallow deer, and they accounted for 61.0%, 32.1%, 5.1% and 1.8% of all isolates, respectively. Bio-serotyping assays revealed that 91.7% of the examined isolates belonged to biotype 1A (200/218). The remaining 18 isolates belonged to bio-serotypes 1B/NI (3/218, 1.4%), 1B/O:8 (1/218, 0.5%), 2/NI (6/218, 2.8%), 2/O:27 (1/218, 0.5%), 2/O:3 (1/218, 0.5%), 2/O:9 (2/218, 0.9%), 3/NI (2/218, 0.9%), 4/O:3 (1/218, 0.5%) and 4/O:9 (1/218, 0.5%). The ail gene, a suggestive virulence gene for Y. enterocolitica, has been found in 30 isolates from 20 wild boars, in 6 isolates from red deer, and in 1 isolate from roe deer. Our study demonstrated that Y. enterocolitica is frequently isolated from game animals in Poland, which poses a risk of spreading these infectious agents to other animal species and humans.

Forty-five Yersinia enterocolitica strains isolated from aborted fetuses and placentas and from vaginal and rectal swabs of aborting sows were subjected to serotyping, biochemical typing and polymerase chain reaction multiplex analyses to detect the presence of the ail, yst A and ystB genes. The isolates were recovered from the internal organs (tonsil, lung, liver, spleen, kidney, mesentheric lymph nodes, small intestine and rectal intestine) of 18 (18.6%) of 97 aborted fetuses examined, two (8%) of 25 aborted placentas and 27 (15.8%) of 172 examined aborting sows. Serotyping of Y. enterocolitica revealed that only six (13.3%) of the examined isolates belonged to serotype O:3, with a considerable number of isolates (31.1%) having serotype O:5, while biochemical studies showed that as many as 40 of the 45 strains belonged to biotype 1A. As expected, the Y. enterocolitica strains of bioserotype 4/O:3 contained ail and ystA genes, while strains of biotype 1A contained only the ystB gene.

The objective of this study was to identify the bioserotypes and virulence markers of Yersinia enterocolitica strains isolated from wild boars in Poland. Bacteriological examination of 302 rectal swabs from 151 wild boars resulted in the isolation of 40 Y. enterocolitica strains. The majority of the examined strains (n = 30), belonged to bioserotype 1A/NI. The presence of individual Y. enterocolitica strains belonging to bioserotypes 1B/NI (3), 1A/O:8 (2), 1A/O:27 (2), 2/NI (1), 2/O:9 (1) and 4/O:3 (1) was also demonstrated. Amplicons corresponding to ail and ystA genes were observed only in one Y. enterocolitica strain--bioserotype 4/O:3. The ail and ystB gene amplicons were noted in 11 Y. enterocolitica biotype 1A strains, although single amplicons of ystB gene were found in 28 of the tested samples. In four out of eight cases when two Y. enterocolitica strains were isolated from the same animal, the strains differed in biotype, serotype or virulence markers. The European population of wild boars continues to grow and spread to new areas, therefore, wild boars harbouring potentially pathogenic Y. enterocolitica 4/O:3 strains pose a challenge to public health.

Yersinia (Y.) enterocolitica is the third etiological agent of human diarrhea in terms of the number of confirmed clinical cases. One of the important virulence markers is the yst gene which encodes the production of enterotoxins Yst (Yersinia stable toxins). However, not all strains with yst genes produce enterotoxins, what seems to be caused by the ymoA gene encoding the production of the YmoA protein inhibiting the expression of various genes. The purpose of our study was to evaluate the distribution of the ymoA and ystA genes and Yst production by Y. enterocolitica isolated from humans and pigs. All the studied strains obtained from pigs had the ystA gene which indicates that they belong to the group of strains commonly regarded as pathogenic, but the ability to produce YstA was detected in only 14 out of 96 examined strains. The fragments of ystA gene were also detected in all Y. enterocolitica strains isolated from human cases of diarrhea. Amplification of a fragment of the ymoA gene was detected in all the studied strains, both from humans and pigs, based on the presence of a 330 bp band. Thus no correlation was identified between the occurrence of the ymoA and ystA genes and the production of a specific type of enterotoxin.

The aim of the study was to analyse a part of the sequence of the E5 gene of bovine papillomaviruses (BPV) associated with equine sarcoids in Polish horses. Samples of 40 skin lesions obtained from 29 horses were collected for molecular examination. The PCR amplicons of BPV DNA were detected in 38 specimens. After phylogenetic analysis 37 specimens were recognized as BPV-1 and one as BPV-2. Phylogenetic analysis has allowed the classification of the amplicons into two phylogenetic groups (A1,) and four separate isolates (2, 10, 16, 17).

The objective of this study was to compare the effectiveness of the multiplex PCR method and traditional light microscopy in identifying and discriminating the species of Nosema spp. spores in worker bees from winter hive debris in the Province of Warmia and Mazury (NE Poland). A total of 1000 beesdead after from the bottom of the hive from bee colonies were analyzed. Spores were identified with the use of a light microscope (400-600x magnification). Spores were assigned to species by the multiplex PCR method. The microscopic evaluation revealed the presence of Nosema spp. spores in 803 samples (80.3%). Nosema ceranae spores were observed in 353 positive samples (43.96%), Nosema apis spores were found in 300 samples (37.35%), while 150 samples (19.67%) showed signs of a mixed infection. A multiplex PCR analysis revealed that 806 samples were infested with Nosema spp., of which 206 were affected only by Nosema ceranae, 600 showed signs of mixed invasion, while no samples were infected solely by Nosema apis parasites. In two cases, the presence of spores detected under a light microscope was not confirmed by the PCR analysis.The results of the study indicate that Nosema ceranae is the predominant parasitic species found in post-winter worker bees from the bottom of the hive in the region of Warmia and Mazury.

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Yersinia enterocolitica is the causative agent of yersiniosis in different animal species and in humans. Food contaminated with Y. enterocolitica is the main source of infection for humans, and swine plays a major role in the transmission of the disease. There are a limited number of reports of the prevalence of Y. enterocolitica in wild animals and birds. This study characterized virulence markers associated with Y. enterocolitica isolates recovered from mallards and pheasants. Y. enterocolitica strains were isolated from 5 (11.11%) of 45 mallards originating from a cold culture (peptone, sorbitol, and bile salts medium) belonging to biotype 1A. Serotyping showed that three of these five serotypes represented serotype O:8, one belonged to serotype O:5, and one did not agglutinate with any of the sera and was classified as nonidentified. Molecular analysis for virulence markers detected the ystB gene, which encodes an enterotoxin, in five isolates. Y. enterocolitica was not detected in any of the 16 examined pheasants.