Introduction: Periodontal diseases are the most frequently diagnosed problem in small animal veterinary medicine. Although their exact cause is not fully understood, bacteria play an important role in their development. Pseudomonas aeruginosa is a Gram-negative, rod-shaped, non-spore-forming bacterium. The living environment of this bacterium may be soil and water; however, it can also be found in humans and animals. Antibiotic treatment of periodontitis may be complicated by the carbapenem resistance of some P. aeruginosa strains, if these bacteria are found to be an aetiological agent. The aim of the study was to identify all bacterial strains isolated from dog with periodontitis. Material and Methods: After a clinical examination of a Schnauzer dog in the Department and Clinic of Animal Surgery in the University of Life Sciences in Lublin Faculty of Veterinary Medicine, periodontitis was diagnosed. A swab was taken from the diseased tissue and submitted for microbiological tests. Microorganisms were initially identified by colony morphology, haemolytic pattern and Gram staining, and subsequently by sensitivity tests, VITEK 2 and matrix-assisted laser desorption/ionisation–time-of-flight. Results: Pseudomonas aeruginosa was isolated and identified as a probable aetiological factor of periodontitis in dogs. Conclusion: In our opinion, attention should be paid to Pseudomonas aeruginosa as a possible aetiological factor of periodontal diseases in dogs.

Introduction: Lactococcus garvieae is a catalase-negative, Gram-positive coccus that occurs in pairs and short chains. It is present throughout the world and a causative agent of bovine mastitis. However, prior to writing, no case of mastitis caused by this bacterium had been reported in Poland. The aim of this research was to investigate the presence of L. garvieae in milk samples from Polish cows with inflammation of the mammary gland. Material and Methods: A total of 118 milk samples from 96 Holstein-Friesian cows were spread on blood agar plates for microbial analyses. Then analysis with matrix-assisted laser desorption/ionisation–time-of-flight mass spectrometry, biochemical identification and antibiotic susceptibility evaluation in the VITEK 2 system and a PCR with primers compatible with 16S ribosomal RNA of L. garvieae were performed. Results: The presence of three strains of L. garvieae was confirmed in milk samples. Analysis of antibiotic susceptibility showed the susceptibility of all isolates to moxifloxacin, erythromycin, linezolid, teicoplanin, vancomycin, tetracycline, tigecycline, chloramphenicol and trimethoprim-sulfamethoxazole. Lactococcus garvieae had high resistance to benzylpenicillin, clindamycin and rifampicin. One of the isolated strains was additionally resistant to tetracycline and had different minimum inhibitory concentrations. Conclusion: To the best of our knowledge, L. garvieae had not been identified as an aetiological factor of mastitis in cows in Poland before, and the presented research is the first report.

Background: Alkylresorcinols (ARs) are compounds belonging to the class of phenolic lipids. A rich source of ARs are cereal grains such as rye, wheat, triticale or barley. ARs found in plants are characterized by a variety of biological properties such as antimicrobial, antifungal and cytotoxic activity. Moreover, they are proven to have a positive influence on human health. Here, we aimed to find and characterize the gene with ARs synthase activity in the species Secale cereale. Methods and results: Using BAC library screening, two BAC clones containing the gene candidate were isolated and sequenced. Bioinformatic analyses of the resulting contigs were used to examine the structure and other features of the gene, including promoter, intron, 3’UTR and 5’UTR. Mapping using the FISH procedure located the gene on the 4R chromosome. Comparative analysis showed that the gene is highly similar to sequences coding for type III polyketide synthase. The level of gene expression in various parts of the plant was investigated, and the biochemical function of the gene was confirmed by heterologous expression in yeast. Conclusions: The conducted analyses contributed to a better understanding of the processes related to ARs synthesis. Although the research concerned the rye model, the knowledge gained may help in understanding the genetic basis of ARs biosynthesis in other species of the Poaceae family as well.

Using a positional candidate-gene approach, we show that semi-sterile desynaptic8 mutants are associated with deleterious variants of the barley homolog of XRCC2 (X-Ray Repair Cross Complementing 2). In barley XRCC2 mutants, the initial meiotic progression is normal, albeit with a small delay in initiation, with completion of synapsis. However, the absence of HvXRCC2 subsequently leads to a dramatic reduction in the number of crossovers, chromosome mis-segregation, and infertility, suggesting that HvXRCC2 plays a major role in recombination. This mutant phenotype is congruent with that reported in mammalian studies but contrasts with the XRCC2 mutant in Arabidopsis which is fertile, exhibits normal chromosome pairing and correct chromosome segregation, and is associated with an increased rate of crossovers. This observation indicates that the XRCC2 mutant phenotype in Arabidopsis is not representative of all plants and that XRCC2 is not a good candidate for the modulation of recombination in barley.

Using a positional candidate-gene approach we show that semi-sterile desynaptic8 mutants are associated with deletions in or complete knockout of the barley homolog of XRCC2 ( X-Ray Repair Cross Complementing 2 ). In barley XRCC2 mutants, the initial meiotic progression is normal, albeit with a small delay in initiation, with completion of synapsis. However, the absence of HvXRCC2 subsequently leads to a dramatic reduction in the number of crossovers, chromosome mis-segregation, and infertility, suggesting that HvXRCC2 plays a major role in recombination. This mutant phenotype is congruent with that reported in mammalian studies but contrasts with the XRCC2 mutant in Arabidopsis which is fertile, exhibits normal chromosome pairing and correct chromosome segregation, and is associated with an increased rate of crossovers. This indicates that the XRCC2 mutant phenotype in Arabidopsis is not representative of all plants and that XRCC2 is not a good candidate for the modulation of recombination in barley. Highlight: The mutants of the barley homolog of XRCC2 exhibit delays in replication leading to defective meiosis, altered RAD51 orthologue behaviour, and significant reduction in the number of crossovers as in canonical mammalian XRCC2 mutants but unlike those in Arabidopsis.