Construction of the Enterococcal Strain Expressing Immunogenic Fragment of SARS-Cov-2 Virus

Contemporary SARS-Cov-2 pandemic, besides its dramatic global influence on the human race including health care systems, economies, and political decisions, opened a window for the global experiment with human vaccination employing novel injectable vaccines providing predominantly specific IgG response with little knowledge of their impact on the mucosal immunity. However, it is widely accepted that protection against the pathogens at the gates of the infection - on mucosal surfaces—predominantly rely on an IgA response. Some genetically modified bacteria, including probiotics, represent attractive vehicles for oral or nasal mucosal delivery of therapeutic molecules. Probiotic-based vaccines for mucous membranes are easy to produce in large quantities; they have low cost, provide quite a long T-cell memory, and gut IgA response to oral vaccines is highly synchronized and strongly oligoclonal. Here we present a study demonstrating construction of the novel SARS-Cov-2 vaccine candidate employing the gene fragment of S1 SARS-Cov-2 gene. This DNA fragment was inserted in frame into major pili protein gene with d2 domain of enterococcal operon encoding for pili. The DNA sequencing proved the presence of the insert in enterococcal genome. RNA transcription, immunoprecipitation, and immune electron microscopy with human sera obtained from the SARS-Cov-2 patients demonstrated expression of SARS-Cov-2 antigens in bacteria. Taken together the data obtained allowed considering this genetically modified probiotic strain as an interesting candidate for vaccine against SARS-Cov-2.

The role of yogurt enriched with lactobacillus rhamnosus GG culture in dental caries prevention

Introduction/Objective. Contemporary tendencies suggest that probiotics can significantly reduce the prevalence of caries in children, so it can be considered that they have a positive effect on general and oral health. Lactobacillus rhamnosus GG (LGG) is a probiotic culture of particular importance in preventive dentistry. The aim was to assess the effects of consumption of probiotic strain Lactobacillus rhamnosus GG on the dental plaque accumulation in children with mixed dentition. Methods. Research included 90 children with mixed dentition (5-12 years old). First study group consumed 200 ml of Lactobacillus rhamnosus GG-enriched yogurt (B-Activ LGG, Dukat) daily for a period of 14 days, while the remaining 30 formed the second study group who consumed 200 ml of yogurt (Jogurt 1,5% milk fat, Imlek) with manually added powder from probiotic capsule (Wayaforte LGG capsule, Medis) daily for14 days. The control group consisted of 30 children who had regular diet during examination period. Silness-L?e plaque index and saliva pH (pH-Fix-0-14, Macherey-Nagel) were determined at baseline and also upon intervention completion. Results. An increase in pH values was observed in both study groups. In general sample, there is a significant decrease of mean plaque index values (p ? 0.001). Both study groups had significant decrease of mean plaque index values on the baseline and after 14 days consumption of yogurt. In the control group the number of subjects with decrease plaque index values did not correlate and no association was found. Conclusion. Consistent consumption of LGG culture-enriched yogurt inhibits dental film accumulation and promotes saliva pH increase in children with mixed dentition.

Does Probiotic Consumption Enhance Wound Healing? A Systematic Review

The use of probiotics is one of the emerging lines of treatment for wound healing. This systematic review aimed to summarize currently available evidence on the effect of oral or enteral probiotic therapy on skin or oral mucosal wound healing in humans. To verify the developments in this field and the level of available scientific evidence, we applied a broad search strategy with no restrictions on wound type, target population, probiotic strain, or intervention protocol used. This review included seven studies involving 348 individuals. Four studies reported positive outcomes for healing improvement after probiotic therapy, and none of the studies reported adverse effects or a marked increase in wound healing time. The positive or neutral results observed do not generate strong evidence regarding the effectiveness of probiotics for wound healing. However, they suggest a promising field for future clinical research where the probiotic strains used, type of wounds, and target population are controlled for.

Genome sequence of Corynebacterium Amycolatum ICIS 99 Isolated From Human Vagina Reveals Safety and Beneficial Properties

Corynebacterium amycolatum ICIS 99 was isolated from vaginal smears of healthy women and showed promising results in antimicrobial screenings. Here, we report the draft genome sequence of this strain and analyze its main features to assess its safety and useful properties. The genome is 2,532,503 bp long and contains 2,186 CDSs with an average G+C content of 59.0%. Analyses of the ICIS 99 genome revealed the absence of true virulence genes. The genome contains genes involved in the synthesis of secondary metabolites and bacteriocins of the class sactipeptide. In the genome of ICIS 99, we identified a large number of genes responsible for adaptation and survival in the vaginal environment, including acid and oxidative stress resistance genes. The genomic information of ICIS 99 provides a basis for understanding the safety and useful properties of ICIS 99 and for considering it as a potential probiotic strain. However, further research is needed to test its probiotic efficacy in vivo. The whole genome shotgun project has been deposited at DDBJ/ENA/GenBank under the accession number JAIUSU000000000.

Locked Nucleic Acid Hydrolysis Probes for the Specific Identification of Probiotic Strains Bifidobacterium animalis subsp. lactis DSM 15954 and Bi-07™

Probiotic health benefits are now well-recognized to be strain specific. Probiotic strain characterization and identification is thus important in clinical research and in the probiotic industry. This is becoming especially important with reports of probiotic products failing to meet the declared strain content, potentially compromising their efficacy. Availability of reliable identification methods is essential for strain authentication during discovery, evaluation and commercialization of a probiotic strain. This study aims to develop identification methods for strains Bifidobacterium animalis subsp. lactis DSM 15954 and Bi-07 (Bi-07™) based on real-time PCR, targeting single nucleotide polymorphisms (SNPs). The SNPs were targeted by PCR assays with locked nucleic acid (LNA) probes, which is a novel application in probiotic identification. The assays were then validated following the guidelines for validating qualitative real-time PCR assays. Each assay was evaluated for specificity against 22 non-target strains including closely related Bifidobacterium animalis subsp. lactis strains and were found to achieve 100% true positive and 0% false positive rates. To determine reaction sensitivity and efficiency, three standard curves were established for each strain. Reaction efficiency values were 86, 91, and 90% (R square values > 0.99), and 87, 84, and 86% (R square values > 0.98) for B. animalis subsp. lactis DSM 15954 and Bi-07 assays, respectively. The limit of detection (LOD) was 5.0 picograms and 0.5 picograms of DNA for DSM 15954 and Bi-07 assays, respectively. Each assay was evaluated for accuracy using five samples tested at three different DNA concentrations and both assays proved to be highly repeatable and reproducible. Standard deviation of Cq values between two replicates was always below 1.38 and below 1.68 for DSM 15954 and Bi-07 assays, respectively. The assays proved to be applicable to mono-strain and multi-strain samples as well as for samples in various matrices of foods or dietary supplement ingredients. Overall, the methods demonstrated high specificity, sensitivity, efficiency and precision and broad applicability to sample, matrix and machine types. These methods facilitate strain level identification of the highly monophyletic strains B. animalis subsp. lactis DSM 15954 and Bi-07 to ensure probiotic efficacy and provide a strategy to identify other closely related probiotics organisms.

Production and characteristic quality of probiotic Labneh cheese supplemented with broccoli florets

PurposeThe purpose of this study is to develop functional probiotic Labneh cheeses supplemented with broccoli florets.Design/methodology/approachProbiotic Labneh cheese was produced using broccoli florets paste at four different levels (0, 5, 10 and 15%), with Lactobacillus casei NRRL B-1922 as a probiotic strain, to evaluate its physicochemical, phenols, antioxidant activity, minerals, vitamins, textural, microbiological and sensory characteristics during storage for 15 days.FindingsThe results indicated that Labneh cheese with added broccoli paste exhibited significantly (p = 0.05) higher level of moisture, acidity, soluble nitrogen, phenols, antioxidant activity, minerals and B vitamins, and lower protein, fat, ash and pH values when compared to control Labneh cheese. Textural analysis of Labneh cheese indicated that Labneh with higher level of broccoli (15%) exhibited harder texture than others. Higher viable counts of Lactobacillus casei and Streptococcus thermophilus were detected in Labneh with broccoli paste, and the counts (107 cfu/g) were higher than the number should be present to achieve their health benefits. The most acceptable Labneh cheeses were those supplemented with 5 and 10% broccoli paste.Originality/valueThis study revealed broccoli florets could enhance the growth of Lactobacillus casei and Streptococcus thermophilus in the Labneh matrix, which resulted in a wider spectrum of health benefits of Labneh cheese to the consumers.

Bacillus subtilis natto Derivatives Inhibit Enterococcal Biofilm Formation via Restructuring of the Cell Envelope

Enterococcus faecalis is considered a leading cause of hospital-acquired infections. Treatment of these infections has become a major challenge for clinicians because some E. faecalis strains are resistant to multiple clinically used antibiotics. Moreover, the presence of E. faecalis biofilms can make infections with E. faecalis more difficult to eradicate with current antibiotic therapies. Thus, our aim in this study was to investigate the effects of probiotic derivatives against E. faecalis biofilm formation. Bacillus subtilis natto is a probiotic strain isolated from Japanese fermented soybean foods, and its culture fluid potently inhibited adherence to Caco-2 cell monolayers, aggregation, and biofilm production without inhibiting the growth of E. faecalis. An apparent decrease in the thickness of E. faecalis biofilms was observed through confocal laser scanning microscopy. In addition, exopolysaccharide synthesis in E. faecalis biofilms was reduced by B. subtilis natto culture fluid treatment. Carbohydrate composition analysis also showed that carbohydrates in the E. faecalis cell envelope were restructured. Furthermore, transcriptome sequencing revealed that the culture fluid of B. subtilis natto downregulated the transcription of genes involved in the WalK/WalR two-component system, peptidoglycan biosynthesis and membrane glycolipid biosynthesis, which are all crucial for E. faecalis cell envelope synthesis and biofilm formation. Collectively, our work shows that some derivatives present in the culture fluid of B. subtilis natto may be useful for controlling E. faecalis biofilms.

Draft Genome Sequence of Weissella cibaria P71, a Promising Aquaculture Probiotic Strain Isolated from Common Octopus (Octopus vulgaris)

Weissella cibaria P71 is a lactic acid bacterium that was isolated from common octopus ( Octopus vulgaris ) and previously showed interesting probiotic properties for turbot ( Scophthalmus maximus L.) farming. The draft genome sequence of this strain provides further data to support its potential as a probiotic for aquaculture.

Probiotic effect of Lactococcus lactis subsp. cremoris RPG-HL-0136 on intestinal mucosal immunity in mice

Lactococcus lactis subsp. cremoris is a lactic acid bacterium commonly used in the cheese manufacturing industry. It is known to produce antibacterial peptides and has recently received attention for its role as a probiotic strain. Here, we report the isolation of a new strain, Lactococcus lactis subsp. cremoris RPG-HL-0136 (RPG0136) from dried compost, which exhibits strong antibacterial activity. When RPG0136 was fed to mice, it increased the intestinal population of two beneficial bacteria, Lactobacillus and Bifidobacterium, whereas it decreased the intestinal population of two harmful bacteria, Bacteroides and Enterobacter. In addition, it increased the concentration of short-chain fatty acids, including acetic acid, propionic acid, and butyric acid, with a simultaneous decrease in pH, and accelerated the catabolic degradation of proteins, lipids, and starch. Lastly, RPG0136 increased the plasma IgG and intestinal mucosal SIgA concentrations and upregulated Reg3r, MUC1, and MUC2 expression to improve the intestinal mucosal immune function. The results of this study suggest that RPG0136 is a potential probiotic strain that supports the growth of a beneficial microbiome by promoting the synthesis of organic acids and enhancing intestinal immune function.