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.

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.

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.

Genomic analysis of Helicobacter himalayensis sp. nov. isolated from Marmota himalayana.

BACKGROUND: Helicobacter himalayensis was isolated from Marmota himalayana in the Qinghai-Tibet Plateau, China, and is a new non-H. pylori species, with unclear taxonomy, phylogeny, and pathogenicity. RESULTS: A comparative genomic analysis was performed between the H. himalayensis type strain 80(YS1)T and other the genomes of Helicobacter species present in the National Center for Biotechnology Information (NCBI) database to explore the molecular evolution and potential pathogenicity of H. himalayensis. H. himalayensis 80(YS1)T formed a clade with H. cinaedi and H. hepaticus that was phylogenetically distant from H. pylori. The H. himalayensis genome showed extensive collinearity with H. hepaticus and H. cinaedi. However, it also revealed a low degree of genome collinearity with H. pylori. The genome of 80(YS1)T comprised 1,829,936 bp, with a 39.89% GC content, a predicted genomic island, and 1769 genes. Comparatively, H. himalayensis has more genes for functions in "cell wall/membrane/envelope biogenesis" and "coenzyme transport and metabolism" sub-branches than the other compared helicobacters, and its genome contained 42 virulence factors genes, including that encoding cytolethal distending toxin (CDT). CONCLUSIONS: We characterized the H. himalayensis 80(YS1)T genome, its phylogenetic position, and its potential pathogenicity. However, further understanding of the pathogenesis of this potentially pathogenic bacterium is required, which might help to manage H. himalayensis-induced diseases.

Stopped-Flow Dynamics Study on the Escape Behavior of Polyelectrolyte Macromolecules from Microgels: The Influence of the Path Length and Size.

We reported the fabrication of several monodispersed poly(2-vinyl pyridine)-poly(N-isopropylacrylamide) (P2VP-PNIPAM) microgels including the P2VP core (non-cross-linked) and PNIPAM (cross-linked) shell by mature emulsion polymerization. The fast escape behavior (diffusion process) of linear P2VP chains through a porous PNIPAM layer was investigated by a pH jump stopped-flow apparatus. The time-dependent dynamic traces (corresponding to the scattered light intensity) decreased at the initial timescale of several seconds and then reached an apparent equilibrium, confirming the efficient escape of P2VP chains from microgels. Compared with the previously reported literature, such an accelerated escape process resulted from the sharply increased internal charge repulsive force caused by the protonation of P2VP moieties under acidic conditions. The obtained characteristic relaxation times by single exponential fitting of these kinetic traces were dependent on the final pH values, equilibrium temperatures, shell thickness (path length), and cross-linking density (mesh size). We believe that this work can provide an efficient way to investigate hindered diffusion, especially the initial rapid diffusion stage. Not only that, the proposed model can also provide theoretical guidance to some practical applications, such as membrane separation and the exocytosis phenomenon of intracellular proteins or macromolecular substances.

Pelistega ratti sp. nov. from Rattus norvegicus of Hainan island.

Two strains (NLN63T and NLN82) of Gram-stain-negative, oxidase- and catalase-positive, bacilli-shaped organisms were isolated from the faecal samples of two separate Rattus norvegicus in Baisha county of Hainan Province, Southern PR China. Phylogenetic analysis based on the near full-length 16S rRNA sequences revealed that strain NLN63T belongs to the genus Pelistega, having maximum similarity to Pelistega suis CCUG 64465T (97.1 %), Pelistega europaea CCUG 39967T (96.2 %) and Pelistega indica DSM 27484T (96.2 %), respectively. The phylogenomic tree built on 553 core genes from genomes of 20 species in the genus Pelistega and other adjacent genera further confirmed that strains NLN63T and NLN82 form a distinct subline and exhibit specific phylogenetic affinity with P. europaea CCUG 39967T. In digital DNA-DNA hybridization analyses, strain NLN63T showed low estimated DNA reassociation values (21.4-22.6 %) with the type strains of the species in the genus Pelistega. The DNA G+C contents of strains NLN63T and NLN82 were 37.3 and 37.1 mol%, respectively. Strain NLN63T had a unique MALDI-TOF MS profile, contained Q-8 as the major quinone and C16 : 0, summed feature 8 (C18 : 1 ω7c/C18 : 1 ω6c or both) and summed feature 3 (C16 : 1 ω7c/C16 : 1 ω6c or both) as the dominant fatty acids. Based upon these polyphasic characterization data obtained from the present study, a novel species of the genus Pelistega, Pelistega ratti sp. nov., is proposed with NLN63T (=GDMCC 1.1697T=JCM 33788T) as the type strain.

Isolation and characterization of Streptococcus respiraculi sp. nov. from Marmota himalayana (Himalayan marmot) respiratory tract.

Two bacterial strains were individually isolated from Marmota himalayana respiratory tracts; the animals were from the Tibet-Qinghai Plateau, PR China. The isolates were Gram-stain-positive, catalase-negative, coccus-shaped, chain-forming organisms. Analysis of 16S rRNA gene sequences indicated that the type strain HTS25T shared 98.0, 97.4, 97.2 and 97.1 % similarity with Streptococcus cuniculi, Streptococcus acidominimus, Streptococcus marmotae and Streptococcus himalayensis respectively. Sequence analysis of the sodA and rpoB genes indicated that HTS25T was closely related to S. marmotae (similarities of 94.7 and 91.4 % respectively). Analysis of groEL sequences showed interspecies similarity of 84.8 % between HTS25T and S. himalayensis. A whole-genome phylogenetic tree reconstructed from 81 core genes from the genomes of 17 members of the genus Streptococcus was used to validate that HTS25T forms a distinct subline from other recognized species of the genus Streptococcus. DNA-DNA hybridization of HTS25T showed a maximum estimated DNA reassociation value of 32.1 % to Streptococcus cuniculi CCUG 65085T. On the basis of the results of phenotypic and phylogenetic analyses, we propose that the two isolates be classified as representing a novel species of the genus Streptococcus, named Streptococcus respiraculi sp. nov. The type strain is HTS25T (=DSM 101998T=CGMCC 1.15531T). The genome of Streptococcus respiraculi sp. nov. strain HTS25T (2 067 971 bp) contains 2001 genes with an average DNA G+C content of 42.7 mol%.

Streptococcus himalayensis sp. nov., isolated from the respiratory tract of Marmota himalayana.

Five strains of Gram-positive-staining, catalase-negative, coccus-shaped, chain-forming organisms isolated separately from the respiratory tracts of five Marmota himalayana animals in the Qinghai-Tibet Plateau of China were subjected to phenotypic and molecular taxonomic analyses. Comparative analysis of the 16S rRNA gene indicated that these singular organisms represent a new member of the genus Streptococcus, being phylogenetically closest to Streptococcus marmotae DSM 101995T (98.4 % similarity). The groEL, sodA and rpoB sequence analysis showed interspecies similarity values between HTS2T and Streptococcus. marmotae DSM 101995T, its closest phylogenetic relative based on 16S rRNA gene sequences, of 98.2, 78.8 and 93.7 %, respectively. A whole-genome phylogenetic tree built from 82 core genes of genomes from 16 species of the genus Streptococcus validated that HTS2T forms a distinct subline and exhibits specific phylogenetic affinity with S. marmotae. In silico DNA-DNA hybridization of HTS2T showed an estimated DNA reassociation value of 40.5 % with Streptococcus. marmotae DSM 101995T. On the basis of their phenotypic characteristics and phylogenetic findings, it is proposed that the five isolates be classified as representatives of a novel species of the genus Streptococcus, Streptococcus himalayensis sp. nov. The type strain is HTS2T (=DSM 101997T=CGMCC 1.15533T). The genome of Streptococcus himalayensis sp. nov. strain HTS2T contains 2195 genes with a size of 2 275 471 bp and a mean DNA G+C content of 41.3 mol%.

Streptococcuspantholopis sp. nov., isolated from faeces of the Tibetan antelope (Pantholops hodgsonii).

Two bacterial strains were isolated from faecal samples of Tibetan antelopes. The isolates were Gram-stain-positive, catalase-negative, coccus-shaped organisms that were tentatively identified as representing a novel streptococcal species based on their morphological features, biochemical test results and phylogenomic findings. Comparative 16S rRNA gene sequencing studies confirmed that the organisms were members of the genus Streptococcus, but they did not correspond to any recognized species of the genus. The nearest phylogenetic relative of the unknown coccus was Streptococcus ursoris NUM 1615T (93.4 % 16S rRNA gene sequence similarity). Analysis of groEL and rpoB gene sequences of the novel isolates showed interspecies divergence of 27.0 and 22.2 %, respectively, from the type strain of its closest 16S rRNA gene phylogenetic relative, S. ursoris. The complete genome of strain TA 26T has been sequenced. Digital DNA-DNA hybridization studies between strain TA 26T and other species of the genus Streptococcus deposited in the GenBank database showed less than 70 % DNA-DNA relatedness, supporting a novel species status of the strain. On the basis of their genotypic and phenotypic differences from recognized Streptococcus species, the two isolates represent a novel species of the genus Streptococcus, for which the nameStreptococcus pantholopis sp. nov. (type strain TA 26T=CGMCC 1.15667T=DSM 102135T) is proposed.

Streptococcusmarmotae sp. nov., isolated from the respiratory tract of Marmota himalayana.

Five strains of a Gram-stain-positive, catalase-negative, α-haemolytic, coccus-shaped chain-forming organism were isolated separately from the lower respiratory tracts of five animals of Marmota himalayana in the endemic area of plague, the Qinghai-Tibet Plateau, China. Based on their morphological characteristics, biochemical features and molecular phylogenetic studies, the strains were placed as representing a new member of the genus Streptococcus. Comparative 16S rRNA gene sequence studies indicated that strain HTS5T shared 96.5, 96.2 and 96.0 % similarity with Streptococcus gallinaceus CCUG 42692T, Streptococcus parasanguinis ATCC 15912T and Streptococcus suis ATCC 43765T, respectively. Sequence analysis of its rpoB and sodA genes showed that strain HTS5T was most closely related to Streptococcus cuniculi CCUG 65085T with 9.2 and 10.9 % interspecies divergence, respectively. The whole genome phylogenetic tree based on 339 core genes of 65 Streptococcus genomes confirmed that HTS5T belongs to a distinct lineage that is well separated from recognized species of the genus Streptococcus. In silico DNA-DNA hybridization using 65 available genomes from GenBank showed that HTS5T displayed less than 70 % DNA-DNA relatedness with the other 65 species of the genus Streptococcus deposited in the GenBank database. The genome of strain HTS5T (2 322 791 bp) contained 2377 genes and had a G+C content of 41.6 mol%. Therefore, the five strains are considered to represent a novel species of the genus Streptococcus for which the name Streptococcusmarmotae sp. nov. is proposed. The type strain is HTS5T (=DSM 101995T=CGMCC 1.15534T).

Streptococcus halotolerans sp. nov. isolated from the respiratory tract of Marmota himalayana in Qinghai-Tibet Plateau of China.

Two Gramstaining-positive, catalase-negative, α-hemolytic, coccus-shaped organisms were isolated separately from the respiratory tracts of two Marmota himalayana animals from the Qinghai-Tibet Plateau, PR China. Morphological, biological, biochemical, and molecular genetic studies were performed on these two isolates (HTS9T and HTS12). Their biochemical characteristics, such as acid production from different sugars and enzymatic activities, indicated that they represented a member of the genus Streptococcus. They are most closely related to Streptococcus thoraltensis CIP 105518T based on sequence analysis of their 16S rRNA, groEL, sodA and rpoB genes, with similarities of 97.6, 89.9, 92.6 and 91.1 % the four genes respectively. The whole genome phylogenetic tree reconstructed using 372 core genes from 65 genomes of members of the genus Streptococcus validates that HTS9T forms a distinct subline and exhibits specific phylogenetic affinity with S. thoraltensis. In silico DNA-DNA hybridization of HTS9T showed a DNA reassociation value of 32.1 %, closest to that of S. thoraltensis CIP 105518T. Based on their phenotypic characteristics and in particular the phylogenetic findings (DNA-DNA hybridization, three phylogenetic trees built from the partial 16S rRNA/housekeeping genes, and from 372 core genes of 65 genomes of members of the genus Streptococcus), we propose with confidence that strains HTS9T and HTS12 should be classified as representing a novel species of the genus Streptococcus, Streptococcus halotolerans sp. nov. The type strain is HTS9T (=DSM 101996T=CGMCC1.15532T). Genome analysis of Streptococcus halotolerans sp. nov. shows that its genome is 1 823 556 bp long with a DNA G+C content of 39.9 mol% and contains 2068 genes.

Rapid, Sensitive Detection of Bartonella quintana by Loop-Mediated Isothermal Amplification of the groEL Gene.

Trench fever, caused by Bartonella quintana, is recognized as a re-emerging and neglected disease. Rapid and sensitive detection approaches are urgently required to monitor and help control B. quintana infections. Here, loop-mediated isothermal amplification (LAMP), which amplifies target DNA at a fixed temperature with high sensitivity, specificity and rapidity, was employed to detect B. quintana. Thirty-six strains, including 10 B. quintana, 13 other Bartonella spp., and 13 other common pathogens, were applied to verify and evaluate the LAMP assay. The specificity of the LAMP assay was 100%, and the limit of detection was 125 fg/reaction. The LAMP assay was compared with qPCR in the examination of 100 rhesus and 20 rhesus-feeder blood samples; the diagnostic accuracy was found to be 100% when LAMP was compared to qPCR, but the LAMP assay was significantly more sensitive (p < 0.05). Thus, LAMP methodology is a useful for diagnosis of trench fever in humans and primates, especially in low-resource settings, because of its rapid, sensitive detection that does not require sophisticated equipment.

Escherichia marmotae sp. nov., isolated from faeces of Marmota himalayana.

The taxonomic position of a group of seven closely related lactose-negative enterobacterial strains, which were isolated from fresh faecal samples of Marmota himalayana collected from the Qinghai-Tibetan plateau, China, was determined by using a polyphasic approach. Cells were Gram-reaction-negative, non-sporulating, non-motile, short rods (0.5-1 × 1-2.5 µm). By 16S rRNA gene sequences, the representative strain, HT073016(T), showed highest similarity values with Escherichia fergusonii ATCC 35469(T) at 99.3%, Escherichia coli ATCC 11775(T) at 99.2%, Escherichia albertii LMG 20976(T) at 98.9%, Escherichia hermannii CIP 103176(T) at 98.4%, and Escherichia vulneris ATCC 33821(T) at 97.7%. Phylogenetic analysis based on the 16S rRNA gene sequences showed that the seven strains formed a monophyletic group with five other species of the genus Escherichia. Digital DNA-DNA hybridization studies between strain HT073016(T) and five other species of the genus Escherichia showed that it shared less than 70% DNA-DNA relatedness with all known species of the genus Escherichia, supporting the novel species status of the strain. The DNA G+C content of strain HT073016(T) was 53.8 mol%. On the basis of phenotypic and phylogenetic characteristics, strain HT073016(T) and the six other HT073016(T)-like strains were clearly distinct from the type strains of other recognized species of the genus Escherichia and represent a novel species of the genus Escherichia, for which the name Escherichia marmotae sp. nov. is proposed, with HT073016(T) ( = CGMCC 1.12862(T) = DSM 28771(T)) as the type strain.

Helicobacter himalayensis sp. nov. isolated from gastric mucosa of Marmota himalayana.

A Gram-stain-negative, microaerophilic strain, 80(YS1)T, with a spiral-shaped morphology and 1-2 sheathed flagella at each end of the cells was isolated from the gastric mucosa of Marmota himalayana, the animal reservoir of Yersinia pestis in China, on the Qinghai-Tibet Plateau. The strain grew at 30, 35 and 42 °C, but not at 25 °C. Growth was in the form of a thinly spreading film on brain heart infusion agar containing 8 % sheep blood under microaerobic conditions. The strain did not hydrolyse urea or hippurate, and did not grow on media containing 1 % glycine. It reduced nitrate to nitrite, and was catalase- and alkaline-phosphatase-positive, susceptible to nalidixic acid and resistant to cefalotin. It was positive for genus-specific PCR for the genus Helicobacter, but could not be classified to any recognized species according biochemical tests results. Therefore, a phylogenetic study based on 16S rRNA, 23S rRNA, 60 kDa heat-shock protein (hsp60) and gyrase subunit B (gyrB) genes was conducted. The 16S rRNA gene sequence (1468 bp) analysis showed that strain 80(YS1)T was most closely related to Helicobacter marmotae (96.7 % similarity). The 23S rRNA gene sequence (2879 bp) analysis showed that the strain was most closely related to Helicobacter canis (96 % similarity). The complete gyrB gene sequence (2325 bp) analysis showed that it was related phylogenetically to Helicobacter cinaedi (79.4 % similarity) and H. marmotae (79.1 % similarity). Analysis of the partial sequence of the hsp60 gene of strain 80(YS1)T showed closest similarity to the sequences of Helicobacter equorum (82 %) and H. cinaedi (81 %), respectively. However, there was no hsp60 sequence of H. marmotae available for analysis. The data of morphological, biochemical and phylogenetic characteristics all supported that this strain represents a novel species. The name Helicobacter himalayensis sp. nov. is proposed for this novel species with the type strain 80(YS1)T ( = CGMCC 1.12864T = DSM 28742T).

The Novel Multiple Inner Primers-Loop-Mediated Isothermal Amplification (MIP-LAMP) for Rapid Detection and Differentiation of Listeria monocytogenes.

Here, a novel model of loop-mediated isothermal amplification (LAMP), termed multiple inner primers-LAMP (MIP-LAMP), was devised and successfully applied to detect Listeria monocytogenes. A set of 10 specific MIP-LAMP primers, which recognized 14 different regions of target gene, was designed to target a sequence in the hlyA gene. The MIP-LAMP assay efficiently amplified the target element within 35 min at 63 °C and was evaluated for sensitivity and specificity. The templates were specially amplified in the presence of the genomic DNA from L. monocytogenes. The limit of detection (LoD) of MIP-LAMP assay was 62.5 fg/reaction using purified L. monocytogenes DNA. The LoD for DNA isolated from serial dilutions of L. monocytogenes cells in buffer and in milk corresponded to 2.4 CFU and 24 CFU, respectively. The amplified products were analyzed by real-time monitoring of changes in turbidity, and visualized by adding Loop Fluorescent Detection Reagent (FD), or as a ladder-like banding pattern on gel electrophoresis. A total of 48 pork samples were investigated for L. monocytogenes by the novel MIP-LAMP method, and the diagnostic accuracy was shown to be 100% when compared to the culture-biotechnical method. In conclusion, the MIP-LAMP methodology was demonstrated to be a reliable, sensitive and specific tool for rapid detection of L. monocytogenes strains.

Genomic portrait of the evolution and epidemic spread of a recently emerged multidrug-resistant Shigella flexneri clone in China.

Shigella flexneri is the major cause of shigellosis in developing countries. A new S. flexneri serotype, Xv, appeared in 2000 and replaced serotype 2a as the most prevalent serotype in China. Serotype Xv is a variant of serotype X, with phosphoethanolamine modification of its O antigen mediated by a plasmid that contained the opt gene. Serotype Xv isolates belong to sequence type 91 (ST91). In this study, whole-genome sequencing of 59 S. flexneri isolates of 14 serotypes (serotypes 1 to 4, Y, Yv, X, and Xv) indicated that ST91 arose around 1993 by acquiring multidrug resistance (MDR) and spread across China within a decade. A comparative analysis of the chromosome and opt-carrying plasmid pSFXv_2 revealed independent origins of 3 serotype Xv clusters in China, with different divergence times. Using 18 cluster-dividing single-nucleotide polymorphisms (SNPs), SNP typing divided 380 isolates from 3 provinces (Henan, Gansu, and Anhui) into 5 SNP genotypes (SGs). One SG predominated in each province, but substantial interregional spread of SGs was also evident. These findings suggest that MDR is the key selective pressure for the emergence of the S. flexneri epidemic clone and that Shigella epidemics in China were caused by a combination of local expansion and interregional spread of serotype Xv.

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.

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.

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.

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.