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Probiotics and Antimicrobial Proteins May 2024Commensal-derived peptidoglycan (PG) or lipoteichoic acid (LTA) can improve the growth, immunity, and intestinal health of fish, but it is not clear whether the two...
Commensal Bacillus pumilus SE5-Derived Peptidoglycan and Lipoteichoic Acid Showed Synergistic Effects in Improving Growth, Immunity, and Intestinal Health of Grouper (Epinephelus coioides).
Commensal-derived peptidoglycan (PG) or lipoteichoic acid (LTA) can improve the growth, immunity, and intestinal health of fish, but it is not clear whether the two components have synergistic effects. To clarify this, grouper (Epinephelus coioides) was fed basal diet (CG) or diets containing 1.0 × 10 CFU/g heat-inactivated SE5 (HIB), PG (21.30 mg/kg), LTA (6.70 mg/kg), mixture (PL1) of PG (10.65 mg/kg) and LTA (3.35 mg/kg), and mixture (PL2) of PG (21.30 mg/kg) and LTA (6.70 mg/kg). Improved growth performance and feed utilization were observed in groups PG, LTA, PL1, and PL2, and the optimum growth performance was recorded in group PL1. Furthermore, improved serum alkaline phosphatase (AKP) activity and immunoglobulin M (IgM) and complement C3 (C3) contents were observed in all treatments, and the AKP activity in group PL1 was significantly superior to that of groups PG and LTA. Although PG and LTA alone or in combination exert comparable effects on intestinal microbiota and physical structure, obviously enhanced intestinal protease activity was observed in group PL1. The combined efficacy of PL1 could further potentiate the immune response by modulating the nucleotide-binding oligomerization domain-containing protein 2 (NOD2) and upregulating the expression of antimicrobial peptides (epinecidin-1, hepcidin-1, and β-defensin) as well as IgM. At the same time, group PL1 could further mitigate intestinal inflammation by downregulating pro-inflammatory cytokines and upregulating anti-inflammatory cytokines. In conclusion, probiotic B. pumilus SE5-derived PG and LTA mixture (10.65 mg/kg PG and 3.35 mg/kg LTA) exhibits better potential for improving the growth performance, intestinal health, and immune function compared to another mixture (21.30 mg/kg PG and 6.70 mg/kg LTA) and PG or LTA alone in grouper.
PubMed: 38789900
DOI: 10.1007/s12602-024-10291-7 -
The Journal of Physical Chemistry. B Jun 2024The cell envelope of Gram-negative bacteria is composed of an outer membrane (OM) and an inner membrane (IM) and a peptidoglycan cell wall (CW) between them. Combined...
The cell envelope of Gram-negative bacteria is composed of an outer membrane (OM) and an inner membrane (IM) and a peptidoglycan cell wall (CW) between them. Combined with Braun's lipoprotein (Lpp), which connects the OM and the CW, and numerous membrane proteins that exist in both OM and IM, the cell envelope creates a mechanically stable environment that resists various physical and chemical perturbations to the cell, including turgor pressure caused by the solute concentration difference between the cytoplasm of the cell and the extracellular environment. Previous computational studies have explored how individual components (OM, IM, and CW) can resist turgor pressure although combinations of them have been less well studied. To that end, we constructed multiple OM-CW systems, including the Lpp connections with the CW under increasing degrees of strain. The results show that the OM can effectively resist the tension imposed by the CW, shrinking by only 3-5% in area even when the CW is stretched to 2.5× its relaxed area. The area expansion modulus of the system increases with increasing CW strain, although the OM remains a significant contributor to the envelope's mechanical stability. Additionally, we find that when the protein TolC is embedded in the OM, its stiffness increases.
Topics: Cell Wall; Peptidoglycan; Bacterial Outer Membrane Proteins; Bacterial Outer Membrane; Molecular Dynamics Simulation
PubMed: 38787347
DOI: 10.1021/acs.jpcb.3c08510 -
Marine Drugs May 2024The deep-sea bacterium CSC3.9 has significant inhibitory effects on agricultural pathogenic fungi and human pathogenic bacteria, especially , the notorious...
The deep-sea bacterium CSC3.9 has significant inhibitory effects on agricultural pathogenic fungi and human pathogenic bacteria, especially , the notorious multidrug-resistant pathogen affecting human public health. We demonstrate that the corresponding antibacterial agents against PAO1 are volatile organic compounds (VOCs, namely VOC-3.9). Our findings show that VOC-3.9 leads to the abnormal cell division of PAO1 by disordering the expression of several essential division proteins associated with septal peptidoglycan synthesis. VOC-3.9 hinders the biofilm formation process and promotes the biofilm dispersion process of PAO1 by affecting its quorum sensing systems. VOC-3.9 also weakens the iron uptake capability of PAO1, leading to reduced enzymatic activity associated with key metabolic processes, such as reactive oxygen species (ROS) scavenging. Overall, our study paves the way to developing antimicrobial compounds against drug-resistant bacteria by using volatile organic compounds.
Topics: Pseudomonas aeruginosa; Volatile Organic Compounds; Anti-Bacterial Agents; Biofilms; Quorum Sensing; Microbial Sensitivity Tests; Reactive Oxygen Species; Humans
PubMed: 38786624
DOI: 10.3390/md22050233 -
Antibiotics (Basel, Switzerland) May 2024Chlamydial infections and diseases caused by filarial nematodes are global health concerns. However, treatment presents challenges due to treatment failures potentially...
Chlamydial infections and diseases caused by filarial nematodes are global health concerns. However, treatment presents challenges due to treatment failures potentially caused by persisting and long regimens against filarial infections accompanied by low compliance. A new treatment strategy could be the targeting of the reduced peptidoglycan structures involved in cell division in the obligate intracellular bacteria and , the latter being obligate endosymbionts supporting filarial development, growth, and survival. Here, cell culture experiments with and showed that the nucleoside antibiotics muraymycin and carbacaprazamycin interfere with bacterial cell division and induce enlarged, aberrant cells resembling the penicillin-induced persistence phenotype in Enzymatic inhibition experiments with purified MraY revealed that muraymycin derivatives abolish the synthesis of the peptidoglycan precursor lipid I. Comparative in silico analyses of chlamydial and wolbachial MraY with the corresponding well-characterized enzyme in revealed a high degree of conservation, providing evidence for a similar mode of inhibition. Muraymycin D2 treatment eradicated persisting non-dividing cells from an established penicillin-induced persistent infection. This finding indicates that nucleoside antibiotics may have additional properties that can break bacterial persistence.
PubMed: 38786149
DOI: 10.3390/antibiotics13050421 -
Frontiers in Microbiology 2024
PubMed: 38784805
DOI: 10.3389/fmicb.2024.1329047 -
Journal of Agricultural and Food... Jun 2024Using as a food-grade carrier to create non-GMO whole-cell biocatalysts is gaining popularity. This work evaluates the immobilization yield of a chitosanase (CsnA, 30...
Using as a food-grade carrier to create non-GMO whole-cell biocatalysts is gaining popularity. This work evaluates the immobilization yield of a chitosanase (CsnA, 30 kDa) from and a mannanase (ManB, 40 kDa) from on the surface of WCFS1 using either a single LysM domain derived from the extracellular transglycosylase Lp_3014 or a double LysM domain derived from the muropeptidase Lp_2162. ManB and CsnA were fused with the LysM domains of Lp_3014 or Lp_2162, produced in and anchored to the cell surface of . The localization of the recombinant proteins on the bacterial cell surface was successfully confirmed by Western blot and flow cytometry analysis. The highest immobilization yields (44-48%) and activities of mannanase and chitosanase on the displaying cell surface (812 and 508 U/g of dry cell weight, respectively) were obtained when using the double LysM domain of Lp_2162 as an anchor. The presence of manno-oligosaccharides or chito-oligosaccharides in the reaction mixtures containing appropriate substrates and ManB or CsnA-displaying cells was determined by high-performance anion exchange chromatography. This study indicated that non-GMO chitosanase- and mannanase-displaying cells could be used to produce potentially prebiotic oligosaccharides.
Topics: Bacillus subtilis; Bacterial Proteins; Glycoside Hydrolases; Peptidoglycan; Enzymes, Immobilized; Protein Domains; Lactobacillus plantarum; Chitin
PubMed: 38775266
DOI: 10.1021/acs.jafc.4c01938 -
Insect Science May 2024C-type lectins (CTLs) act as pattern recognition receptors (PRRs) to initiate the innate immune response in insects. A CTL with dual carbohydrate recognition domains...
C-type lectins (CTLs) act as pattern recognition receptors (PRRs) to initiate the innate immune response in insects. A CTL with dual carbohydrate recognition domains (CRDs) (named immulectin-4 [IML-4]) was selected from the Ostrinia furnacalis transcriptome dataset for functional studies. We cloned the full-length complementary DNA of O. furnacalis IML-4 (OfIML-4). It encodes a 328-residue protein with a Glu-Pro-Asn (EPN) and Gln-Pro-Asp (QPD) motifs in 2 CRDs, respectively. OfIML-4 messenger RNA levels increased significantly upon the bacterial and fungal infection. Recombinant OfIML-4 (rIML-4) and its individual CRDs (rCRD1 and rCRD2) exhibited the binding ability to various microorganisms including Escherichia coli, Micrococcus luteus, Pichia pastoris, and Beauveria bassiana, and the cell wall components including lipopolysaccharide from E. coli, peptidoglycan from M. luteus or Bacillus subtilis, and curdlan from Alcaligenes faecalis. The binding further induced the agglutination of E. coli, M. luteus, and B. bassiana in the presence of calcium, the phagocytosis of Staphylococcus aureus by the hemocytes, in vitro encapsulation and melanization of nickel-nitrilotriacetic acid beads, and a significant increase in phenoloxidase activity of plasma. In addition, rIML-4 significantly enhanced the phagocytosis, nodulation, and resistance of O. furnacalis to B. bassiana. Taken together, our results suggest that OfIML-4 potentially works as a PRR to recognize the invading microorganisms, and functions in the innate immune response in O. furnacalis.
PubMed: 38772748
DOI: 10.1111/1744-7917.13382 -
Acta Veterinaria Scandinavica May 2024Bacteriophage-encoded endolysins, peptidoglycan hydrolases breaking down the Gram-positive bacterial cell wall, represent a groundbreaking class of novel antimicrobials... (Review)
Review
Bacteriophage-encoded endolysins, peptidoglycan hydrolases breaking down the Gram-positive bacterial cell wall, represent a groundbreaking class of novel antimicrobials to revolutionize the veterinary medicine field. Wild-type endolysins exhibit a modular structure, consisting of enzymatically active and cell wall-binding domains, that enable genetic engineering strategies for the creation of chimeric fusion proteins or so-called 'engineered endolysins'. This biotechnological approach has yielded variants with modified lytic spectrums, introducing new possibilities in antimicrobial development. However, the discovery of highly similar endolysins by different groups has occasionally resulted in the assignment of different names that complicate a straightforward comparison. The aim of this review was to perform a homology-based comparison of the wild-type and engineered endolysins that have been characterized in the context of bovine mastitis-causing streptococci and staphylococci, grouping homologous endolysins with ≥ 95.0% protein sequence similarity. Literature is explored by homologous groups for the wild-type endolysins, followed by a chronological examination of engineered endolysins according to their year of publication. This review concludes that the wild-type endolysins encountered persistent challenges in raw milk and in vivo settings, causing a notable shift in the field towards the engineering of endolysins. Lead candidates that display robust lytic activity are nowadays selected from screening assays that are performed under these challenging conditions, often utilizing advanced high-throughput protein engineering methods. Overall, these recent advancements suggest that endolysins will integrate into the antibiotic arsenal over the next decade, thereby innovating antimicrobial treatment against bovine mastitis-causing streptococci and staphylococci.
Topics: Animals; Mastitis, Bovine; Cattle; Endopeptidases; Staphylococcus; Bacteriophages; Staphylococcal Infections; Streptococcus; Female; Streptococcal Infections; Anti-Bacterial Agents
PubMed: 38769566
DOI: 10.1186/s13028-024-00740-2 -
International Journal of Systematic and... May 2024A Gram-stain-positive actinomycete, designated REN17, was isolated from fermented grains of Baijiu collected from Sichuan, PR China. It exhibited branched substrate...
A Gram-stain-positive actinomycete, designated REN17, was isolated from fermented grains of Baijiu collected from Sichuan, PR China. It exhibited branched substrate mycelia and a sparse aerial mycelium. The optimal growth conditions for REN17 were determined to be 28 °C and pH 7, with a NaCl concentration of 0 % (w/v). ll-Diaminopimelic acid was the diagnostic amino acid of the cell-wall peptidoglycan and the polar lipids were composed of phosphatidylethanolamine, phosphatidylinositol, an unidentified phospholipid, two unidentified lipids and four unidentified glycolipids. The predominant menaquinone was MK-9 (H), MK-9 (H), MK-9 (H) and MK-9 (H). The major fatty acids were iso-C. The 16S rRNA sequence of REN17 was most closely related to those of SUN 51 (99.8 %), BH-SS-21 (99.6 %) and JCM 4521 (98.9 %). The digital DNA-DNA hybridization, average nucleotide identity and average amino acid identify values between REN17 and its closest replated strain, of SUN 51, were 35.9, 88.9 and 87.3 %, respectively. Therefore, REN17 represents a novel species within the genus , for which the name sp. nov. is proposed. The type strain is REN17 (=GDMCC 4.193=JCM 34712). While exploring the function of the strain, REN17 was found to possess the ability to transform major ginsenosides of (Burk.) F.H. Chen (Araliaceae) into minor ginsenoside through HPLC separation, which was due to the presence of β-glucosidase. The recombinant β-glucosidase was constructed and purified, which could produce minor ginsenosides of Rg3 and C-K. Finally, the enzymatic properties were characterized.
Topics: RNA, Ribosomal, 16S; Phylogeny; Fatty Acids; Streptomyces; Vitamin K 2; DNA, Bacterial; Nucleic Acid Hybridization; China; Sequence Analysis, DNA; Fermentation; Panax notoginseng; Bacterial Typing Techniques; Ginsenosides; Peptidoglycan; Edible Grain; Diaminopimelic Acid; Phospholipids; Base Composition
PubMed: 38767616
DOI: 10.1099/ijsem.0.006392 -
Vaccine May 2024Mucosal vaccination presents a promising complement to parenteral vaccination. Bacterium-like particles (BLPs), peptidoglycan structures prepared from lactic acid...
Mucosal vaccination presents a promising complement to parenteral vaccination. Bacterium-like particles (BLPs), peptidoglycan structures prepared from lactic acid bacteria, are explored as potential nasal vaccine adjuvants for respiratory infections. To date, studies on BLP-adjuvanted nasal vaccines against intestinal infections have remained limited. In this study, we demonstrated the efficacy of intranasal BLP-adjuvanted vaccination in controlling intestinal infections using the Citrobacter rodentium (C. rodentium) model in C57BL/6 mice. Intranasal vaccination of Intimin, an adhesin critical for intimate bacterial adhesion to colonic epithelial cells, combined with BLP (BLP+I) elicited robust Intimin-specific intestinal secretory IgA production, reduced bacterial load in feces and almost completely inhibited colonic hyperplasia, a characteristic symptom of C. rodentium infection in mice. Conversely, parenteral vaccination with Alhydrogel-adjuvanted Intimin failed to induce intestinal Intimin-specific IgA production, resulting in poor protection against C. rodentium infection. This underscores the pivotal role of mucosal IgA responses elicited by intranasal immunization in its protective efficacy. As this study did not delineate the precise protective mechanism conferred by BLP+I intranasal immunization against C. rodentium infection, further elucidation of the mechanisms underlying intranasal BLP+I immunization is required.
PubMed: 38763852
DOI: 10.1016/j.vaccine.2024.05.023