Probiotics and Antimicrobial Proteins最新文献

The main issue with clinical infections is multidrug resistance to traditional antibiotics. As they are essential to innate immunity, shielding hosts from pathogenic microbes, traditional herbal remedies are an excellent supplier of antimicrobial peptides (AMPs), vital parts of defensive systems. Nevertheless, little is known about the bioactive peptide components of most ethnobotanical species. Our goal in this study was to find new, likely AMPs from Portulaca oleracea (P. oleracea) using in silico studies. The P. oleracea transcriptome was gained from Sequence Read Archive (SRA) and quality controlled, then adapters and other low-quality reads were trimmed. Afterward, de novo assembled and translated open reading frames (ORFs) were determined. Next, the ORFs were filtered based on AMP physiochemical criteria and deep learning methods. Finally, the five selected putative AMPs docked with E. coli and S. aureus membranes that showed penetration in bilayers. In this step, PO2 was chosen as a candidate AMP to analyze with molecular dynamics (MD) simulations. Our data demonstrated that PO2 is more stable in E. coli than in S. aureus. Moreover, these predicted AMPs can be good candidates for in vitro and in vivo analysis.

Limosilactobacillus reuteri ZJ625 and Ligilactobacillus salivarius ZJ614 are potential probiotic bacteria with improved benefits when administered to the host as a multi-strain preparation. To elucidate the mechanisms of cell-to-cell crosstalk between these two strains, we studied their intracellular and extracellular proteomes in co-culture by liquid-chromatography mass-spectrometry (LC-MS) using Dionex Nano-RSLC and fusion mass spectrometer. The experiment consisted of five biological replicates, and samples were collected during the mid-exponential growth phase. The quantitative proteomic profiles revealed several differentially expressed proteins (DEPs), which are down- or up-regulated between and within groups for both the intracellular and extracellular proteomes. These DEPs include proteins synthesising autoinducer-2, a sensor compound for cell-to-cell bacterial crosstalk during quorum sensing in mixed culture. Other important DEPs identified include enolase, phosphoglycerate kinase, and l-lactate dehydrogenase, which play roles in carbohydrate metabolism. Proteins associated with transcription, ATP production and transport across the membrane, DNA repair, and those with the potential to bind to the host epithelium were also identified. The post-translational modifications associated with the proteins include oxidation, deamidation, and ammonia loss. Importantly, this study revealed a significant expression of S-ribosylhomocysteine lyase (luxS) involved in synthesising autoinducer-2 that plays important roles in quorum sensing, aiding bacterial cell-to-cell crosstalk in co-cultures. The proteome of L. salivarius ZJ614 was most affected when co-cultured with L. reuteri ZJ625. In contrast, omitting some medium components from the defined medium exerted more effects on L. reuteri ZJ625 than L. salivarius ZJ614.

Spiders produce webs, which are still a largely unexplored source of antibacterial compounds, although the reports of its application in the medical field. Therefore, this study aims to present an integrative review of the antibacterial activity of spider webs. The research was conducted using Google Scholar, Scielo, Web of Science, PubMed, ScienceDirect, Medline EBSCO, LILACS, and Embase. The inclusion criteria were original articles written in English that studied the antibiotic properties of the web or isolated compounds tested. The studies were compared according to the spider species studied, the type of web, treatment of the sample, type of antimicrobial test, and the results obtained. Nine hundred and seventy-three publications were found, and after applying the inclusion and exclusion criteria, sixteen articles were selected. Bacterial inhibition was found in seven studies against various species of bacteria such as Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Salmonella Typhi, Bacillus megaterium, Listeria monocytogenes, Acinetobacter baumannii, Streptococcus pneumoniae, Pasteurella multocida, and Bacillus subtilis. Additionally, there was no apparent relationship between the proximity of the spider species evaluated in the studies and the presence or absence of activity. Methodological problems detected may affected the reproducibility and reliability of the results in some studies, such as the lack of description of the web or microorganism strain, as well as the absence of adequate controls and treatments to sterilize the sample. Spider webs can be a valuable source of antibiotics; however, more studies are needed to confirm the real activity of the web or components involved.

Achromobacter marplatensis strain YKS2 isolated from the yak rumen has the feature of producing cellulose. This study aims to analyze the genome and safety of strain YKS2 in vivo, considering its future research and application prospects. The genome of strain YKS2 was sequenced and used for genomic in silico studies. The administration of strain YKS2 in three doses was carried out on mice for 3 days of oral and 7 days of clinical observation tests. The BW, FI, organ indices, gut microbiota, and histological appearances of organs and intestines, along with hematological parameters and serum biochemistry, were measured in mice. The chromosome size of strain YKS2 was 6,588,568 bp, with a GC content of 65.27%. The 6058 coding sequences of strain YKS2 without plasmid were predicted and annotated and have multiple functions. The mice in all groups were alive, with good mental states and functional activities. Compared with the control group, there was no significant difference in the three dose groups on BW, FI, hematological parameters (WBC, LYM, etc.), and serum biochemistry (ALB, ALT, etc.). No abnormalities were observed in the main visceral organs, intestinal tissue, and V/C value in groups. However, the IEL number of duodenum and gut microbiota diversity (Shannon's index) in the high-dose group was significantly higher than in the control group (p < 0.05). Besides, the low dose of strain YKS2 also significantly affected the bacterial abundance of Firmicutes, Actinobacteria, and desulphurizing Bacteroidetes at the phylum level. There was no significant effect at genus levels in groups. In conclusion, the study revealed the genome and potential functional genes of strain YKS2, which is beneficial to understanding the features of the A. marplatensis strain and proved strain YKS2 to be without acute toxicity to mice. However, a long-term feeding toxicity experiment in vivo should be performed to further ensure its potential application value strain in the animal industry.

Xanthomonas oryzae causes tremendous damage in rice plants (Oryza sativa L). Therefore, this study is focused on siderophore-producing Bacillus albus (CWTS 10) for managing BLB disease caused by X. oryzae. Both B. albus and its crude siderophore (methanolic and diethyl ether) extracts inhibited X. oryzae (10-12 mm). Fourier transform infrared spectroscopy (FTIR) analysis of the extracts indicated the presence of catecholate siderophore functional groups. Liquid chromatography-mass spectrometry (LC-MS) analysis revealed the presence of antimicrobial compounds such as 2-deoxystreptamine, miserotoxin, fumitremorgin C, pipercide, pipernonaline, gingerone A, and deoxyvasicinone. Complete genome sequencing revealed the gene clusters for antibiotic, siderophore, antibacterial, antifungal, and secondary metabolite production. An in vivo study revealed that bacteria (CWTS 10) and their siderophore extracts effectively inhibited X. oryzae. The mode of application of bacterial or siderophore extracts in terms of DI and DSI percentage was as follows: soak method > inoculation method > spray method. In addition to providing enhanced antagonistic activity, there was a significant increase in root and shoot length and weight (wet and dry) of treated plants compared to control plants challenged with X. oryzae. Thus, the results clearly indicate that siderophore-producing B. albus and its siderophore extracts strongly inhibited X. oryzae. However, further field experiments are required before being formulated to protect rice crops from X. oryzae.

Fruit peels have potential as prebiotic sources thanks to their dietary fiber contents. This study aimed to determine the effects of freeze-dried banana (BPP) and watermelon (WPP) peel powders on bile salt resistance, growth kinetics, and survival of Lactobacillus acidophilus and Lactiplantibacillus plantarum. In the presence of 0.5-1% bile salt, L. plantarum counts were 0.52-1.13 log CFU/mL higher in MRS broth added with 5% peel powder than without peel powder. Lactobacillus acidophilus population was 2.47-2.79 log CFU/mL higher in MRS broth added with 5% peel powder than without peel powder in the presence of 0.5% bile salt. Both peel powders did not affect the growth kinetics of L. acidophilus in milk. Conversely, the growth of L. plantarum was promoted in milk supplemented with peel powders and yielded a shorter generation time (P < 0.05). The maximum population density of L. plantarum in milk supplemented with BPP (8.68 log CFU/mL) was higher than in milk without peel powder (7.72 log CFU/mL; P < 0.05). Survival of L. acidophilus improved during storage at 4 °C in milk added with peel powders. The results suggest that BPP and WPP can be functional ingredients in probiotic foods and may be used to improve the growth and survival of probiotic cultures.

The food industry has been developing new products with health benefits, extended shelf life, and without chemical preservation. Bacteriocin-producing lactic acid bacteria (LAB) strains have been evaluated for food fermentation to prevent contamination and increase shelf life. In this study, potentially probiotic LAB strains, Lactiplantibacillus (Lb.) plantarum ST8Sh, Lacticaseibacillus (Lb.) casei SJRP38, and commercial starter Streptococcus (St.) thermophilus ST080, were evaluated for their production of antimicrobial compounds, lactic acid and enzyme production, carbohydrate assimilation, and susceptibility to antibiotics. The characterization of antimicrobial compounds, the proteolytic activity, and its inhibitory property against Listeria (List.) monocytogenes and Staphylococcus (Staph.) spp. was evaluated in buriti and passion fruit-supplemented fermented milk formulations (FMF) produced with LAB strains. Lb. plantarum ST8Sh was found to inhibit List. monocytogenes through bacteriocin production and produced both L(+) and D(-) lactic acid isomers, while Lb. casei SJRP38 mainly produced L(+) lactic acid. The carbohydrate assimilation profiles were compatible with those usually found in LAB. The potentially probiotic strains were susceptible to streptomycin and tobramycin, while Lb. plantarum ST8Sh was also susceptible to ciprofloxacin. All FMF produced high amounts of L(+) lactic acid and the viability of total lactobacilli remained higher than 8.5 log CFU/mL during monitored storage period. Staph. aureus ATCC 43300 in fermented milk with passion fruit pulp (FMFP) and fermented milk with buriti pulp (FMB), and Staph. epidermidis KACC 13234 in all formulations were completely inhibited after 14 days of storage. The combination of Lb. plantarum ST8Sh and Lb. casei SJRP38 and fruit pulps can provide increased safety and shelf-life for fermented products, and natural food preservation meets the trends of the food market.

The purpose of this study was to investigate the improvement of the intestinal barrier and gut microbiota in mice with antibiotic-associated diarrhea (AAD) using Lactiplantibacillus plantarum ELF051 combined with Astragalus polysaccharides. The amoxicillin, clindamycin, and streptomycin triple-mixed antibiotic-induced AAD models were administered with L. plantarum ELF051 or Astragalus polysaccharides or L. plantarum ELF051 + Astragalus polysaccharides for 14 days. Our findings revealed that the combination of L. plantarum ELF051 and Astragalus polysaccharides elevated the number of goblet cells and enhanced the proportion of mucous within the colon tissue. Furthermore, the expression of sIgA and IgG were upregulated, while the levels of IL-17A, IL-4, DAO, D-LA, LPS, and TGF-β1 were downregulated. L. plantarum ELF051 combined with Astragalus polysaccharides elevated the expression of tight junction (TJ) proteins, facilitating intestinal mucosal repair via Smad signaling nodes. Furthermore, their combination effectively increased the relative abundance of lactic acid bacteria (LAB) and Allobaculum, and decreased the relative abundance of Bacteroides and Blautia. Spearman rank correlation analysis demonstrated that LAB were closely related to permeability factors, immune factors, and indicators of intestinal barrier function. In summary, the effect of combining L. plantarum ELF051 and Astragalus polysaccharides on AAD mice was achieved by enhancing intestinal barrier function and regulating the composition of the gut microbiota.

The indiscriminate use of antibiotics in aquaculture has led to the emergence of resistance; hence, eco-friendly, host-specific alternatives to mitigate bacterial infections have become imminent. In this study, bacteria that could possibly serve as probiotics were isolated and evaluated for their efficacy with in vitro experiments and in vivo zebrafish gut model. One isolate from each of the 23 rohu fish (Labeo rohita) was shortlisted after preliminary screening of several isolates and tested for their ability to inhibit two important warm water bacterial fish pathogens, Aeromonas hydrophila, and Edwardsiella tarda. An isolate (RODK28110C3) that showed broad-spectrum inhibitory activity against a battery of different isolates of the two fish pathogens included in this study and maintained in our repository was selected for further characterization. The culture was identified phenotypically as Bacillus subtilis and confirmed by 16S rDNA sequencing. The isolate was able to hydrolyze fish feed constituents that include starch, protein, and cellulose. Further in vitro tests ensured that the potential isolate with probiotic attributes could tolerate different gut conditions, which included a range of pH, salinity, and varying concentrations of bile salt. Exposure of 4 days post fertilization zebrafish embryos to the RFP-tagged isolate confirmed the colonization of B. subtilis in the gut of the zebrafish embryo, which is an important attribute of a probiotic. The isolate was able to inhibit both A. hydrophila and E. tarda in gnotobiotic zebrafish embryo in triplicate. The study demonstrates the probiotic characteristics of the B. subtilis isolated from L. rohita and its ability to inhibit A. hydrophila and E. tarda using in vitro conditions and in the zebrafish gut and could serve as an effective alternative to antibiotics in aquaculture.

In this study, we aimed to produce a standard, more functional, and nutritious yogurt by using 5 different combinations of cow milk and goat milk and 2 types of starter cultures (classical yogurt culture and commercial probiotic culture). It was determined that the use of different milk types and different starter cultures in yogurt production had a statistically very significant effect (P < 0.01) on all physicochemical, microbiological, and biochemical properties. In addition, the storage period was effective on all parameters examined at varying rates. In the context, the use of goat milk in the experimental yogurt samples caused an increase in the ACE inhibitory activity values and the count of S. thermophilus, while the use of cow milk caused an increase in serum separation and pH values. On the other hand, serum separation, pH values, and ACE inhibitory activity and phenylalanine and leucine levels were found to be higher in the yogurts produced by using ABT-2 probiotic culture. It was observed that an increase in the levels of asparagine, aspartic acid, proline, and serine, as well as lactic acid, orotic acid, and citric acid, is higher in the yogurts produced by using classical yogurt culture. It has been concluded that the combination of goat milk and cow milk at different proportions and the use of probiotic culture together in yogurt production can produce yogurt that is more functional and richer in terms of organic compounds and essential amino acids.