Limosilactobacillus reuteri L26 BiocenolTM and its exopolysaccharide: Their influence on rotavirus-induced immune molecules in enterocyte-like cells.

This study aimed to evaluate the immunomodulatory effect of the probiotic Limosilactobacillus reuteri L26 BiocenolTM (L26) and its purified exopolysaccharide (EPS) with respect to antiviral innate immune response. In our experiment, we used porcine epithelial IPEC-J2 cells as a model of the intestinal barrier in a homologous infection by porcine Rotavirus A strain OSU6 (RVA). The production of selected molecules of non-specific humoral immunity was evaluated at the mRNA level. The EPS alone significantly increased the level of interferon λ3 (IFN-λ3) mRNA in the non-infected IPEC-J2 cells (P < 0.001). We also tested whether the treatment of IPEC-J2 cells by L26 or EPS influences the replication of RVA by virus titration and real-time PCR. We found that a pre-treatment in combination with subsequent continuous stimulation has no influence on the RVA replication. However, both treatments significantly decreased the RVA-induced production of IFN-λ3 (P < 0.05) and the "SOS" cytokine interleukin 6 (IL-6; P < 0.01), already at the transcription level. In addition, the EPS treatment resulted in significantly increased IL-10 mRNA in the RVA-infected cells. In summary, we assume an immunoregulatory potential of L. reuteri L26 BiocenolTM and its EPS in the local intestinal antiviral immune response.

Antibacterial Effect and Therapy of Chronic Skin Defects Using the Composite Bioscaffold Polycaprolactone/GelitaSpon/Povidone-Iodine in Domestic Dogs.

Chronic wounds and the failure of conventional treatment are relatively common in veterinary medicine. Recently, there has been a growing interest in alternative therapeutic approaches and the utilization of biodegradable materials. Their potential application in wound therapy may offer a novel and more suitable option compared to conventional treatment methods. Biodegradable materials can be classified into two main categories: natural, synthetic, and a combination of both, which have the potential to have synergistically enhanced properties. In this study, four domestic dogs with clinical symptoms of chronic wounds were enrolled. These wounds underwent treatment utilizing a novel biodegradable composite material composed of gelatin sponge combined with two electrospun layers of polycaprolactone (PCL) along with polyvinylpyrrolidone (PVP) fibers containing povidone-iodine complex (PVP-I). The initial phase of the study was dedicated to evaluating the antibacterial properties of iodine against Staphylococcus aureus and Escherichia coli. On average, wound healing in domestic dogs took 22 days from the initial treatment, and iodine concentrations demonstrated a significant antibacterial effect against Escherichia coli and Staphylococcus aureus. Based on the favorable outcomes observed in wound management, we believe that the utilization of a blend of natural and synthetic biodegradable materials holds promise as an effective wound therapy option.

Beneficial Effect of Faecal Microbiota Transplantation on Mild, Moderate and Severe Dextran Sodium Sulphate-Induced Ulcerative Colitis in a Pseudo Germ-Free Animal Model.

Transplantation of faecal microbiota (FMT) is generally considered a safe therapeutic procedure with few adverse effects. The main factors that limit the spread of the use of FMT therapy for idiopathic inflammatory bowel disease (IBD) are the necessity of minimising the risk of infection and transfer of another disease. Obtaining the animal model of UC (ulcerative colitis) by exposure to DSS (dextran sodium sulphate) depends on many factors that significantly affect the result. Per os intake of DSS with water is individual for each animal and results in the development of a range of various forms of induced UC. For this reason, the aim of our study was to evaluate the modulation and regenerative effects of FMT on the clinical and histopathological responses and the changes in the bowel microenvironment in pseudo germ-free (PGF) mice of the BALB/c line subjected to chemical induction of mild, moderate and serious forms of UC. The goal was to obtain new data related to the safety and effectiveness of FMT that can contribute to its improved and optimised use. The animals with mild and moderate forms of UC subjected to FMT treatment exhibited lower severity of the disease and markedly lower damage to the colon, including reduced clinical and histological disease index and decreased inflammatory response of colon mucosa. However, FMT treatment failed to achieve the expected therapeutic effect in animals with the serious form of UC activity. The results of our study indicated a potential safety risk involving development of bacteraemia and also translocation of non-pathogenic representatives of bowel microbiota associated with FMT treatment of animals with a diagnosed serious form of UC.

Bacillus amyloliquefaciens-Derived Lipopeptide Biosurfactants Inhibit Biofilm Formation and Expression of Biofilm-Related Genes of Staphylococcus aureus.

Biosurfactants (BSs) are surface-active compounds produced by diverse microorganisms, including the genus Bacillus. These bioactive compounds possess biological activities such as antiadhesive, antimicrobial and antibiofilm effects that can lead to important applications in combating many infections. Based on these findings, we decided to investigate the antibiofilm activity of BSs from the marine Bacillus amyloliquefaciens against Staphylococcus aureus CCM 4223. Expression of biofilm-related genes was also evaluated using qRT-PCR. Isolated and partially purified BSs were identified and characterized by molecular tools and by UHPLC-DAD and MALDI-TOF/MS. Bacillus amyloliquefaciens 3/22, that exhibited surfactant activity evaluated by oil spreading assay, was characterized using the 16S rRNA sequencing method. Screening by PCR detected the presence of the sfp, srfAA, fenD and ituD genes, suggesting production of the lipopeptides (LPs) surfactin, fengycin and iturin. The above findings were further supported by the results of UHPLC-DAD and MALDI-TOF/MS. As quantified by the crystal violet method, the LPs significantly (p < 0.001) reduced biofilm formation of S. aureus in a dose-dependent manner and decreased expression of biofilm-related genes fnbA, fnbB, sortaseA and icaADBC operon. Data from our investigation indicate a promising therapeutic application for LPs isolated from B. amyloliquefaciens toward prevention of S. aureus biofilm infections.

Innovative Animal Model of DSS-Induced Ulcerative Colitis in Pseudo Germ-Free Mice.

The aim of this study was to investigate the use of a standardized animal model subjected to antibiotic treatment, and the effects of this treatment on the course of dextran sodium sulphate (DSS)-induced colitis in mice. By decontamination with selective antibiotics and observation of pathogenesis of ulcerative colitis (UC) induced chemically by exposure of mice to various concentrations of DSS, we obtained an optimum animal PGF model of acute UC manifested by mucin depletion, epithelial degeneration and necrosis, leading to the disappearance of epithelial cells, infiltration of lamina propria and submucosa with neutrophils, cryptitis, and accompanied by decreased viability of intestinal microbiota, loss of body weight, dehydration, moderate rectal bleeding, and a decrease in the selected markers of cellular proliferation and apoptosis. The obtained PGF model did not exhibit changes that could contribute to inflammation by means of alteration of the metabolic status and the induced dysbiosis did not serve as a bearer of pathogenic microorganisms participating in development of ulcerative colitis. The inflammatory process was induced particularly by exposure to DSS and its toxic action on compactness and integrity of mucosal barrier in the large intestine. This offers new possibilities of the use of this animal model in studies with or without participation of pathogenic microbiota in IBD pathogenesis.