Staphylococcus aureus causes a wide range of life-threatening diseases. One of the powerful approaches for prevention and treatment is to develop an efficient vaccine as antibiotic resistance greatly increases. S. aureus type 8 capsular polysaccharide (CP8) has shown great potential in vaccine development. An understanding of the immunogenicity of CP8 trisaccharide repeating unit is valuable for epitope-focused vaccine design and cost-efficient vaccine production. We report the chemical synthesis of conjugation-ready CP8 trisaccharide 1 bearing an amine linker, which effectively served for immunological evaluation. The trisaccharide 1-CRM197 conjugate elicited a robust immunoglobulin G (IgG) immune response in mice. Both serum antibodies and prepared monoclonal antibodies recognized S. aureus strain, demonstrating that synthetic trisaccharide 1 can be an efficient antigen for vaccine development.

Helicobacter pylori, listed as a human carcinogen by the Department of Health and Human Services, colonizes the gastric mucosa of more than half of the world's population. The individuals infected with H. pylori have a high risk to develop chronic gastritis, peptic ulcers, and even gastric cancer. The conserved core structure of H. pylori lipopolysaccharide (LPS) has been regarded as a promising candidate structure for development of a glycoconjugate vaccine targeting multiple serotypes. Here, we report a total synthesis of the core undecasaccharide of H. pylori LPS and its subunit antigens. The match and mismatch between the glycosyl donor and acceptor caused by the inert hydroxyl groups were addressed by a judicious choice of orthogonal protection strategies and glycosylation conditions. A combination of acyl remote participation and solvent effects has been applied for selective formation of the five 1,2-cis-glucosidic bonds. The high steric hindrance induced by the high carbon sugars and trinacriform architecture required that the core undecasaccharide was synthesized through a finely tuned linear assembly [2 + (1 + (3 + (1 + (1 + 3))))] rather than convergent strategies. An antigenicity evaluation using glycan microarrays showed that an α-(1 → 6)-glucan trisaccharide is recognized by IgG antibodies in sera of H. pylori-infected patients. The phosphate group of the inner core trisaccharide key epitope is very important for IgG recognition. These findings are an important step toward designing carbohydrate-based vaccines against H. pylori.

Helicobacter pylori (H. pylori) infection is one of the most common causes of gastric disease. The persistent increase in antibiotic resistance worldwide has made H. pylori eradication challenging for clinicians. The stomach is unsterile and characterized by a unique niche. Communication among microorganisms in the stomach results in diverse microbial fitness, population dynamics, and functional capacities, which may be positive, negative, or neutral. Here, we review gastric microecology, its imbalance, and gastric diseases. Moreover, we summarize the relationship between H. pylori and gastric microecology, including non-H. pylori bacteria, fungi, and viruses and the possibility of facilitating H. pylori eradication by gastric microecology modulation, including probiotics, prebiotics, postbiotics, synbiotics, and microbiota transplantation.

BackgroundNetwork biology (systems biology) approaches are useful tools for elucidating the host infection processes that often accompany complex immune networks. Although many studies have recently focused on Haemophilus parasuis, a model of Gram-negative bacterium, little attention has been paid to the host's immune response to infection. In this article, we use network biology to investigate infection with Haemophilus parasuis in an in vivo pig model.ResultsBy targeting the spleen immunogenome, we established an expression signature indicative of H. parasuis infection using a PCA/GSEA combined method. We reconstructed the immune network and estimated the network topology parameters that characterize the immunogene expressions in response to H. parasuis infection. The results showed that the immune network of H. parasuis infection is compartmentalized (not globally linked). Statistical analysis revealed that the reconstructed network is scale-free but not small-world. Based on the quantitative topological prioritization, we inferred that the C1R-centered clique might play a vital role in responding to H. parasuis infection.ConclusionsHere, we provide the first report of reconstruction of the immune network in H. parasuis-infected porcine spleen. The distinguishing feature of our work is the focus on utilizing the immunogenome for a network biology-oriented analysis. Our findings complement and extend the frontiers of knowledge of host infection biology for H. parasuis and also provide a new clue for systems infection biology of Gram-negative bacilli in mammals.

The effects of NaOH pretreatment temperature on the physicochemical characteristics and methane production of anaerobically digested banana stems were investigated in this paper. With the increase of pretreatment temperature from 0 °C to 100 °C, the chemical oxygen demand (COD) of the soak liquid in the treated biomass approximately linearly increased from 5.9 g/L for the untreated stems to 34.0 g/L. A weight loss of 5.1% was observed for the untreated material, while it was up to 31.2% for the sample treated at 100 °C. The removal of lignin and hemicellulose accounted for the majority of the weight loss. The removal rates of lignin and hemicellulose increased from 15.0% to 41.6% and 1.9% to 23.6% when the treatment temperature increased from 0 °C to 100 °C, respectively. Moreover, the crystalline index (CI) of the banana stems also increased with rising temperature, resulting from the dissolution of amorphous cellulose with increasingly harsher alkaline environments. The optimal pretreatment temperature for banana stems was confirmed at 50 °C. In these conditions, methane was produced via anaerobic digestion with 239.9 mL/g total solid (TS) yield, which represented an increase of 66.7% over untreated banana stems.