A series of drugs which potentiate or antagonize transmission at cholinergic synapses have been tested on the slow depolarizing dorsal root potentials evoked by stimulation of adjacent dorsal and ventral roots. Some drugs acted specifically on the dorsal root potential evoked by ventral root stimulation. Dihydro‐β‐erythroidine, atropine and acetylcholine depressed this potential, whilst anticholinesterase substances in low concentrations potentiated and in higher concentrations depressed it. It is concluded that the results offer some evidence for a cholinergic link in the pathway responsible for the generation of depolarizing potentials in the dorsal root subsequent to ventral root stimulation.

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We found that the chokeberry and elderberry extracts rich in cyanidin glycosides possess better antioxidant and anticytotoxic activities in comparison to blueberry or bilberry extracts with complex anthocyanin profiles.

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Probiotic bacteria are frequently used for prevention of bacterial infections of the gastrointestinal tract, but there are only limited studies on their efficacy against viral gut infections in animals. The aim of this study was to investigate the effect of probiotic Lactobacillus reuteri L26 Biocenol on the innate and adaptive immune responses in germ-free Balb/c mice, experimentally infected by porcine circovirus type 2 (PCV2), which confers immunosuppressive effect. A total of 30 six-week-old female mice were divided into 3 groups and animals in experimental group LPCV (n=10) were inoculated with L. reuteri L26, animals in the control group (C; n=10) and experimental group PCV (n=10) received sterile De Man-Rogosa-Sharpe broth for 7 days. Subsequently, mice from both experimental groups were infected with PCV2; however, mice in the control group received virus cultivation medium (mock). Virus load in faeces, ileum and mesenteric lymph nodes (MLN); as well as gene expression of selected cytokines, immunoglobulin A (IgA) and polymeric Ig receptor (PIgR) in the ileum, and percentage of CD8+, CD19+ and CD49b+CD8- cells in the MLN were evaluated. Our results showed that L. reuteri significantly decreased the amount of PCV2 in faeces and in the ileum, and up-regulated the gene expression of chemokines, interferon (IFN)-γ, IgA and PIgR in the ileum. Increased IFN-γ mRNA level was accompanied by higher proportion of natural killer cells and up-regulated IgA and PIgR gene expressions were in accordance with significantly higher percentage of CD19+ lymphocytes in the MLN. These findings indicate that probiotic L. reuteri has an antiviral effect on PCV2 in the intestine which is mediated by stimulation of local gut immune response.

Background. Inflammatory periodontal diseases, including chronic periodontitis, are accompanied by a chronic persisting inflammatory process. The latter process and biofilm-forming potential are the factors that contribute to the formation of antibiotic-resistant microorganism strains. The purpose of our work was to study the biofilm-forming ability of antibiotic-resistant biofilm-forming Staphylococcus genus bacteria isolated from the oral cavities of patients suffering from periodontitis, and check the presence of the genes associated with biofilm formation in these bacteria. Material and methods. Isolates were obtained from patients suffering from chronic periodontitis using differentially diagnostic nutrient media. Chemotaxonomic identification of the antibiotic-resistant isolates was performed on the Microflex LT device. Biofilm-forming potential was studied in plastic Petri dishes by spectrophotometric method. The antibiotic sensitivity of the bacteria and microscopic fungi was identified by the disc diffusion method. The presence of icaA, icaD, icaC, icaB, agrA, srtA genes was detected in two multiplex polymerase chain reactions (mPCR). 16S rRNA gene and icaR genes were amplified in a separate PCR. Results. Opportunistic microbial associations dominate in the microbiom of the oral cavity under conditions of periodontitis; besides, in the majority of cases, Staphylococcus genus bacteria were present in associations. In 73 % (131/180) of cases, bacte ria from Staphylococcus genus represented by six species-S. aureus, S. haemolyticus, S. saprophyticus, S. epidermidis, S. xelosus, and S. hominis were isolated from the nidus during the inflammatory process. From the oral cavities of the patients with inflammatory periodontitis, 51 biofilm-forming strains of S. aureus, 29 strains of S. haemolyticus, 12 strains of S. saprophyticus, and 12 strains of S. epidermidis were isolated. It was established that antibiotic-resistant isolates of S. aureus possess the genetic determinants which are now believed to be connected with icaA, icaC, icaB icaA, icaR, agrA, and srtA biofilm-forming potential. Two non-biofilm forming strains of S. aureus were proven to lack the genes responsible for the biofilm-forming ability. Conclusion: It has been established that microbial associations with a prevailing share of Staphylococcus genus bacteria, most of which have a biofilm-forming potential, dominate in the microbiom of the oral cavity under conditions of periodontitis.

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.

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