: Bacteroides, as one of the most abundant and diverse genera in the human gut, is regarded as a window into the study of gut microbiota-host interactions. Currently, CRISPR/Cas-based gene editing systems targeting Bacteroides have been widely applied, while the large size of Cas nucleases limits their potential application scenarios (such as in situ gut Bacteroides editing based on phage delivery). Therefore, this study aims to develop a compact and highly efficient genetic editing tool in Bacteroides., We developed a miniaturized CRISPR/Cas gene editing system for human gut Bacteroides. First, the editing capabilities of different miniaturized CRISPR/Cas systems, including AsCas12f, CasΦ2, and ISDge10, were evaluated in Bacteroides fragilis. Subsequently, the editing capability of AsCas12f was assessed across various Bacteroides species, and the size of this system was further optimized. The results demonstrated that the CRISPR/AsCas12f genome editing system exhibited the highest editing efficiency in B. fragilis. The CRISPR/AsCas12f system achieved efficient genome editing in B. fragilis, Bacteroides thetaiotaomicron, and Phocaeicola vulgatus. Furthermore, with a repair template of 500 bp homologous arms, the editing efficiency remained as high as 94.7%. In conclusion, CRISPR/AsCas12f can serve as a chassis tool enzyme for the development of Bacteroides-based miniature gene editors and derivative technologies, laying a foundation for the further development of gene editing technology for Bacteroides.
CRISPR-Cas Systems/genetics* ; Gene Editing/methods* ; Bacteroides/genetics* ; Humans ; Gastrointestinal Microbiome/genetics* ; Bacteroides fragilis/genetics*

The enterobacterial common antigen (ECA) is a polysaccharide composed of polysaccharide repeats that are located in the outer membrane of almost all Enterobacteriaceae bacteria and has diverse biological functions. ECA is synthesized by the synergistic action of multiple genes that are present in clusters on the genome of Enterobacteriaceae bacteria, forming the ECA antigen gene cluster, an important virulence factor that plays a role in host invasion and survival of Enterobacteriaceae in vivo. ECA also plays an important role in the maintenance of the bacterial outer membrane permeability barrier, flagella gene expression, swarming motility, and bile salts resistance. In addition, ECALPS, anchored in the core region of bacterial lipopolysaccharide, is an important surface antigen for bacteria, stimulating high levels of antibody production in the host and could be a target for vaccine research. This review summarizes ECA purification, genes involved in ECA biosynthesis, its immunological characteristics, biological functions and clinical applications.
Antigens, Bacterial/genetics* ; Enterobacteriaceae/genetics* ; Lipopolysaccharides ; Polysaccharides

For promoting the quality evaluation of Gardenia resource,a UPLC method for the determination of 4 compounds (geniposidic acid,geniposide,crocin-1 and crocin-2) in Gardeniae Fructus was established.The UPLC separation was performed on an Waters Acquity UPLC BEH-C18 (2.1 mm× 100 mm,1.7 μm) column eluted with the mobile phases of acetonitrile-0.1％ formic acid solution in a gradient mode at a flow rate of 0.3 mL· min-1.The detection wavelengths were 240 nm and 440 nm,respectively.Under the optimum conditions,the calibration curves of four analysis were linear in the range of 0.0065-0.0096 μg· mL-1,with correlation coefficients more than 0.9995.The limits of detection (LODs) of four analysis were in the range of 0.0386-0.1875 μg· mL-1.As the results of determination of 4 compounds of 12 batches of Gardeniae Fructus showed,there was great differences between the contents of the 4 compounds,the contents of geniposide were 2.44％-6.96％,while the contents of crocin-1 were 1.26％-3.04％.In addition,fingerprints of 12 batches of Gardenia resources were built using ChemPattern software,and analysis and exploration over the detection results of several samples were carried out using multivariate statistical method (similarity analysis,principal component analysis and cluster analysis).The present study provided a reference to value the importance of this method in the quality evaluation and quality control of Gardeniae resources and slices.

Objective To observe the effectiveness and mechanism of Xiaoyao San (Xiaoyao Powder for Soothing Liver and Relieving Depression) in improving depression-like behavior of rats. Methods Male Wistar rats were randomized into normal group, model group, Xiaoyao San (1.9 g·kg-1·d-1) group, and fluoxetine (2 mg·kg-1·d-1) group. The rats were exposed to chronic unpredictable mild stress ( CUMS) to induce rat depression-like behavior. Field test was performed for the observation of effect of Xiaoyao San on rat depression-like behavior, Luminex liquid chip system was applied to detect the serum cytokines, and the amount and size of rat hepatic sinusoidal endothelial window were examined under electron microscope, and hepatic indoleamine 2, 3-dioxygenase ( IDO) and tryptophan 2, 3 -dioxygenaes ( TDO) expression levels were detected by immunohistochemical and Western blot methods. Results Xiaoyao San showed obvious effect on increasing sugar water consumption, the number of crossing the blocks and erection frequency in rats, decreasing serum levels of tumor necrosis factor alpha ( TNF-α) and interleukin 6 ( IL-6) , increasing the amount of hepatic sinusoidal endothelial window, promoting hepatic sinusoidal endothelial vascularization, and reducing TDO and IDO expression ( P<0.05 or P<0.01). Conclusion Xiaoyao San exerts obvious effect on improving rat depression-like behaviors, and the mechanism is probably related with the decrease of inflammatory factors, inhibition of IDO pathway, and improvement of hepatic sinusoidal endothelial function.

A novel antimicrobial peptide, named as perinerin (GenBank accession No. P84117), was isolated and characterized from Asian marine clamworms, Perinereis aibuhitensis Grube. Perinerin showes powerful and broad activity against both grampositive and gramnegtive bacteria in vitro, especially on Pseudemonas aeruginosa. To obtain large amounts of active perinerin and characterize its main physiochemical features, The perinerin weve expressed in Pichia pastoris. Intact perinerin gene amplified by the modified gene SOEing method(Gene splicing by overlap extension)was cloned into expression vector pPICZ?A and obtained recombinant vector pPICZ?APEN, then pPICZ?APEN was expressed in the Pichia pastoris GS115. The expressed sample was analyzed by TricineSDSPAGE. The results showed that Pichia pastoris was a suitable system producing the secreted form of perinerin. Bioactivity assay showed that the recombinant perinerin had marked antimicrobial effects.