Influence of helicobacter pylori on composition and function of gastric microbiota in patients with chronic non-atrophic gastritis.

Objective: Helicobacter pylori (H. pylori) plays a major role in causing and advancing gastrointestinal illnesses. Our aim is to analyze the unique makeup and functional changes in the gastric microbiota of patients with chronic non-atrophic gastritis (CNAG), regardless of the presence of H. pylori, and to determine the potential signaling pathways. Methods: We performed metagenomic sequencing on gastric mucosa samples collected from 17 individuals with non-atrophic gastritis, comprising 6 cases were infected with H. pylori (H. pylori-infected case group) and 11 cases without (control group). The species composition was evaluated with DIAMOND software, and functional enrichment was assessed utilizing the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. We analyzed antibiotic resistance patterns using the Comprehensive Antibiotic Resistance Database as a reference (CARD). Results: The presence of H. pylori colonization in CNAG patients was associated with increased diversity in the gastric microbiota. The Phylum Firmicutes was found to be less prevalent, while the Phylum Proteobacteria showed an increase. Functionally, pathways associated with metabolic pathways, including vitamins, auxiliaries, amino acid residue, carbon hydrate, and metabolic energy pathways, were enriched in CNAG patients with H. pylori infection. Additionally, antibiotic resistance genes correlated with antibiotic efflux pump were enriched. Conclusions: From a holistic genomic perspective, our findings offer fresh perspectives into the gastric microbiome among CNAG patients carrying H. pylori, which is valuable for future research on CNAG.

The role of toll-like receptors in immune tolerance induced by Helicobacter pylori infection.

Helicobacter pylori (H. pylori) is a gram-negative, microaerobic bacterium that colonizes the gastric mucosa in about half of the world's population. H. pylori infection can lead to various diseases. Chronic infection by H. pylori exposes the gastric mucosa to bacterial components such as lipopolysaccharide (LPS), outer membrane vesicles (OMVs), and several toxic proteins. Infected with H. pylori activates the release of pro-inflammatory factors and triggers inflammatory responses that damage the gastric mucosa. As the only microorganism that permanently colonizes the human stomach, H. pylori can suppress host immunity to achieve long-term colonization. Toll-like receptors (TLRs) play a crucial role in T-cell activation, promoting innate immune responses and immune tolerance during H. pylori infection. Among the 10 TLRs found in humans, TLR2, TLR4, TLR5, and TLR9 have been thoroughly investigated in relation to H. pylori-linked immune regulation. In the present review, we provide a comprehensive analysis of the various mechanisms employed by different TLRs in the induction of immune tolerance upon H. pylori infection, which will contribute to the research of pathogenic mechanism of H. pylori.

Comparative analysis of the gut microbiota of wild adult rats from nine district areas in Hainan, China.

BACKGROUND: Wild rats have the potential to hold zoonotic infectious agents that can spread to humans and cause disease. AIM: To better understand the composition of gut bacterial communities in rats is essential for preventing and treating such diseases. As a tropical island located in the south of China, Hainan province has abundant rat species. Here, we examined the gut bacterial composition in wild adult rats from Hainan province. METHODS: Fresh fecal samples were collected from 162 wild adult rats, including three species (Rattus norvegicus, Leopoldamys edwardsi, and Rattus losea), from nine regions of Hainan province between 2017-2018. RESULTS: We analyzed the composition of gut microbiota using the 16S rRNA gene amplicon sequencing. We identified 4903 bacterial operational taxonomic units (30 phyla, 175 families, and 498 genera), which vary between samples of different rat species in various habitats at various times of the year. In general, Firmicutes were the most abundant phyla, followed by Bacteroidetes (15.55%), Proteobacteria (6.13%), and Actinobacteria (4.02%). The genus Lactobacillus (20.08%), unidentified_Clostridiales (5.16%), Romboutsia (4.33%), unidentified_Ruminococcaceae (3.83%), Bacteroides (3.66%), Helicobacter (2.40%) and Streptococcus (2.37%) were dominant. CONCLUSION: The composition and abundance of the gut microbial communities varied between rat species and locations. This work provides fundamental information to identify microbial communities useful for disease control in Hainan province.

Ultra-efficient multiple cross displacement amplification-lateral flow biosensor (MCDA-LFB) for serogroup identification of prevalent Neisseria meningitidis.

Meningococcal disease caused by Neisseria meningitidis remains a major global public health concern. Serogroup A, B, C and W135 were the major disease-causing serogroups. It is vital to timely and efficiently detect and differentiate these four serogroups. Herein, we developed multiple cross displacement amplification-lateral flow biosensor (MCDA-LFB) assays targeting ctrA, sacB, siaD, siaD and synG gene respectively for detection and subtyping of four N. meningitidis serogroups. This assay utilizes LFB to detect FITC and biotin-labeled target amplicons produced by MCDA through double antibody sandwich principle, to allow sensitive and specific detection under a constant temperature. The detection limit was as low as 10 fg or 100 fg genomic DNA in pure cultures and 5.5 CFUs or 36 CFUs in spiked cerebrospinal fluid (CSF) specimens, which were overall 100 to 1000-fold more sensitive than conventional PCR. High specificity of these assays was also validated through type strains and clinical isolates, with no cross-reactions. MCDA-LFB testing procedure can be finished within 1 h. In conclusion, the N. meningitidis- and serogroup-MCDA-LFB assays established in this study are simple, rapid and efficient, providing valuable molecular methods for diagnosis and surveillance of meningococcal disease, especially in resource-limited regions and when specimen culture fails.

COVID-19 Control in Community Hospitals: Experience From Four Community Hospitals in Beijing, China.

By September 20, 2021, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been pandemic in 237 countries and regions, resulting in 228,506,698 confirmed cases and 4,692,361 deaths. At the same time, a total of 1123 cases of COVID-19 had been confirmed in Beijing, China. Peking University Shougang Hospital has 4 community hospitals with 174 staff members, covering 230,000 residents in Shijingshan district, Beijing. The community hospitals were the basic units of China's healthcare system for public health services, as the main battlefield for screening and controlling of COVID-19. We reported our experience about the prevention of SARS-CoV-2. We suggest that community hospitals should change their process for admitting patients. While the screening of suspected cases of COVID-19 is vital, patients with suspected infections should be isolated immediately.

Highly flexible hydrogel dressing with efficient antibacterial, antioxidative, and wound healing performances.

Bacterial induced wound infection is very common in real life, but the abuse of antibiotics means that is poses a potential threat to human health. The development of non-antibiotic type antibacterial materials appears to be of importance. Herein, a microenvironment-responsive and biodegradable hydrogel complex, consisting of an acid-degradable antibacterial hydrogel and a hydrogen peroxide (H2O2)-responsive polymer/gold hybrid film with photothermal conversion ability was constructed based on polyethylenimine (PEI), polyethylene glycol (PEG), hexachlorocyclic triphosphonitrile (HCCP), and gold nanoparticles. The resultant hydrogel showed excellent adhesion to various surfaces, whether in air or underwater. However, a simple glycerine and water (v/v = 1/1) mixed solution could rapidly promote the detachment of the hydrogel from skin automatically, without any external force and no residue was left, exhibiting a manmade controllable flexible feature. Moreover, the in vitro antibacterial performance against methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus aureus (S. aureus), as well as wound healing investigations conducted in living mice confirmed that these hydrogels possessed excellent antibacterial, antioxidative, and wound healing abilities. We believe this proof of concept could create a novel pathway for the design and construction of highly efficient hydrogel dressings using readily available polymeric materials and that the resulting dressing have potential for clinical applications.

Self-Assembled Polymeric Materials: Design, Morphology, and Functional-Oriented Applications.

This Review focuses on the current research advances of the synthesis of various amphiphilic block copolymers (ABCs), such as conventional ABCs and newly presented polyprodrug amphiphiles, and the development of corresponding self-assemblies in selective solvents driven by the intermolecular interactions, like noncovalent hydrophobic interactions, π-π interactions, and hydrogen bonds, between ABCs or preformed small polymeric nanoparticles. The design of these assemblies is systematically introduced, and the diverse examples concerning the unique assembly structures along with the fast development of their exclusive properties and various applications in different fields are discussed. Possible perspectives on the existential challenges and glorious future are elucidated finally. It is hoped that this Review will provide a convenient way for readers to motivate more evolutional innovative concepts and methods to design next generation of novel polymeric nanoassemblies, and fill the gap between material design and practical applications.

Simultaneous detection of Streptococcuspneumoniae and prevention of carryover contamination using multiple cross displacement amplification with Antarctic thermal sensitive uracil-DNA-glycosylase and a lateral flow biosensor.

Streptococcus pneumoniae is an important clinical pathogenic bacterium that is the primary cause of meningitis, septicemia and community-acquired pneumonia. The mortality rate of pneumococcal disease is high, especially in children younger than 5-years-old. Rapid and accurate detection of S.pneumoniae is critical for clinical diagnosis. A ply gene-based multiple cross displacement amplification (MCDA) assay, amplifying DNA under 65°C for 40 min, was established to detect S.pneumoniae. Antarctic thermal sensitive uracil-DNA-glycosylase (AUDG) was applied to prevent carryover contamination. A lateral flow biosensor (LFB) was used to indicate the MCDA results. The ply-MCDA assay could detect as low as 10 fg of S. pneumoniae DNA and 447 colony forming units (CFU)/mL of spiked sputum samples. The analytical sensitivity of the ply-MCDA assay to detect clinical specimens was 100 times higher than that of PCR. The specificity of the ply-MCDA assay was evaluated using 15 S.pneumoniae strains and 25 non-S. pneumoniae strains, which confirmed the high selectivity of the ply-MCDA assay for S.pneumoniae. The AUDG enzyme could effectively eliminate carryover contamination and thus prevented false-positive results. In conclusion, ply-AUDG-MCDA-LFB is a simple, rapid and accurate method to detect S.pneumoniae.

Acid- and Thiol-Cleavable Multifunctional Codelivery Hydrogel: Fabrication and Investigation of Antimicrobial and Anticancer Properties.

Hydrogels serving as a drug carrier was realized by entrapping small-sized drug molecules within their cross-linked interstitial networks. After covering the targeted location, hydrogels interact with the physiological fluids and swell, resulting in an increased interspace between networks for the outside diffusion of drugs. However, inevitable in vivo inflammatory responses or bacterial infection on the implant materials and persistent cargo release are still challenging. Herein, we report the fabrication of dual-responsive hydrogels based on acid-sensitive poly(ethylenimine) (PEI) derivative (PEI(-COOH/-vinyl)), thiol-responsive camptothecin prodrug monomer (CPTM), and hydrophilic oligo(ethylene glycol) methyl ether acrylate (OEGMA) by a conventional radical polymerization. Curcumin was then solubilized into the hydrogels to endow them with antimicrobial and cancer resistance properties. The in vitro experiments exhibited sustained hydrogel dissolution and CPT release in a simulated physiological environment. The antimicrobial and cytotoxicity tests of drug-loaded hydrogels using methicillin-resistant Staphylococcus aureus (MRSA) strains and HeLa cancer cell lines, respectively, indicated that the hydrogels possessed efficient antimicrobial effects and could successfully inhibit the growth of cancer cells.