Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of national bloodstream infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:During the study period，9 035 strains of Gram-negative bacteria were collected from 51 hospitals，of which 7 895（87.4%）were Enterobacteriaceae and 1 140（12.6%）were non-fermenting bacteria. The top 5 bacterial species were Escherichia coli（ n=4 510，49.9%）， Klebsiella pneumoniae（ n=2 340，25.9%）， Pseudomonas aeruginosa（ n=534，5.9%）， Acinetobacter baumannii complex（ n=405，4.5%）and Enterobacter cloacae（ n=327，3.6%）. The ESBLs-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus spp. were 47.1%（2 095/4 452），21.0%（427/2 033）and 41.1%（58/141），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（58/4 510）and 13.1%（307/2 340）；62.1%（36/58）and 9.8%（30/307）of CREC and CRKP were resistant to ceftazidime/avibactam combination，respectively. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 59.5%（241/405），while less than 5% of Acinetobacter baumannii complex was resistant to tigecycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 18.4%（98/534）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of main Gram-negative bacteria resistance among different regions，with statistically significant differences in the prevalence of CRKP and CRPA（ χ2=20.489 and 20.252， P<0.001）. The prevalence of CREC，CRKP，CRPA，CRAB，ESBLs-producing Escherichia coli and Klebsiella pneumoniae were higher in provinicial hospitals than those in municipal hospitals（ χ2=11.953，81.183，10.404，5.915，12.415 and 6.459， P<0.01 or <0.05），while the prevalence of CRPA was higher in economically developed regions（per capita GDP ≥ 92 059 Yuan）than that in economically less-developed regions（per capita GDP <92 059 Yuan）（ χ2=6.240， P=0.012）. Conclusions:The proportion of Gram-negative bacteria in bloodstream infections shows an increasing trend，and Escherichia coli is ranked in the top，while the trend of CRKP decreases continuously with time. Decreasing trends are noted in ESBLs-producing Escherichia coli and Klebsiella pneumoniae. Low prevalence of carbapenem resistance in Escherichia coli and high prevalence in CRAB complex have been observed. The composition ratio and antibacterial spectrum of bloodstream infections in different regions of China are slightly different，and the proportion of main drug resistant bacteria in provincial hospitals is higher than those in municipal hospitals.

In recent years, the development of host-acting antibacterial compounds has gradually become a hotspot in the field of anti-infection. Through research on the interaction mechanism between hosts and pathogenic bacteria, it has been found that the immune system is one of the key targets of host-acting antibacterial compounds. There is a communication system called the quorum sensing system in microorganisms, which mainly adjusts the structure of multi-microbial community and coordinates the group behavior. When the quorum sensing molecules secreted by microorganisms reach a threshold concentration, the quorum sensing system is activated and the overall gene expression of the microorganism is changed. In addition to regulating the density of microorganisms, quorum sensing molecules can also act as a link between pathogenic microorganisms and hosts, entering the host immune system and playing a role in affecting the morphological structure of immune cells, secreting cytokines, and inducing apoptosis, leading to host immune injury and causing host immune dysfunction.The key mechanism of 3-oxo-C12-HSL and other acyl-homoserine lactone (AHL) molecules in the innate immune system has been extensively studied. The lipid solubility allows AHLs to pass through the plasma membrane of host immune cells easily and induce dissolution of lipid domains. Then, it acts through signaling pathways such as p38MAPK and JAK-STAT, further influencing the immune cell’s defense response to bacteria and potentially leading to cell apoptosis. Additionally, the human lactonase paraoxonase 2, which can degrade3-oxo-C12-HSL, has been found in macrophage. It acts as an immune regulator that promotes macrophage phagocytosis of pathogens and is hypothesized to have the ability to reduce bacterial resistance. The mechanism of quorum sensing molecules in the adaptive immune system is less studied, the current results suggest that 3-oxo-C12-HSL is closely related to the mitochondrial pathway in host immune cells. For example, 3-oxo-C12-HSL induces apoptosis of Jurkat cells by inhibiting the expression of three mitochondrial electron transport chain proteins; it can also trigger mitochondrial dysfunction and induce mast cell apoptosis through Ca²⁺ signaling.Among the quorum sensing molecules, the AHLs have the greatest impact on plant immune system. The different effects on plant resistance depends on the chain lengths of acyl groups in bacterial-produced AHLs. Short-chain AHLs (C4-HSL and C8-HSL) induce plant resistance to pathogenic bacteria mainly through the auxin pathway and jasmonic acid pathway. Long-chain AHL (3-oxo-C14-HSL) is commonly used in hosts against fungal pathogens by inducing stomata defense responses, and the reaction process is related to salicylic acid. Diffusible signal factor molecules also interfere with the stomatal immunity caused by pathogens. It may act through the formin nanoclustering-mediated actin assembly and MPK3 pathway to inhibit the innate immunity of Arabidopsis. In summary, AHLs induced different plant pathways and affects the plant-bacteria interactions to trigger plant immunity. As a quorum sensing molecule of fungi, farnesol has similar effects on host immunity as AHLs, such as stimulating cytokine secretion and activating an inflammatory response. It also plays a unique role on dendritic cell differentiation and maturation. In addition, studies have found that farnesol has a protective effect on autoimmune encephalomyelitis, which may be related to its effect on the composition of intestinal microorganisms of the host.Therefore, targeting the host immune system and quorum sensing molecules to develop antibacterial compounds can effectively inhibit the invasion of pathogens and subserve the host to resist the influence of pathogenic bacteria. This article will review the mechanism of host immune responses triggered by important quorum sensing molecules, aiming to explore the targets of host-acting antibacterial compounds and provide new directions for the prevention or treatment of causative infectious sources and the development of related drugs.

The rare-earth-elements-doped upconversion nanoparticles NaYF4:Yb3+,Er3+were synthesized by solvothermal method,and NaYF4:Yb3+,Er3+@SiO2 were prepared by coating SiO2 on the surface of NaYF4:Yb3+,Er3+by inverse microemulsion method in this work.Based on the fluorescence quenching principle between NaYF4∶Yb3+,Er3+@SiO2 and SQA-Fe3+,a NaYF4∶Yb3+,Er3+@SiO2-SQA-Fe3+fluorescence nanosensor was constructed for detection of trace hydrogen peroxide(H2O2).Under optimal conditions,the linear range of this method for detecting H2O2 was 1.8?84.0 μmol/L,with detection limit(3σ)of 0.47 μmol/L.The recoveries of H2O2 spiked in milk were 98.4%?99.7%.This method could be used for detection of H2O2 residue in milk samples,with advantages such as low detection limit,good stability and strong anti-interference ability.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-positive bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-positive bacteria from blood cultures in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:A total of 3 163 strains of Gram-positive pathogens were collected from 51 member units，and the top five bacteria were Staphylococcus aureus（ n=1 147，36.3%），coagulase-negative Staphylococci（ n=928，29.3%）， Enterococcus faecalis（ n=369，11.7%）， Enterococcus faecium（ n=296，9.4%）and alpha-hemolyticus Streptococci（ n=192，6.1%）. The detection rates of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）were 26.4%（303/1 147）and 66.7%（619/928），respectively. No glycopeptide and daptomycin-resistant Staphylococci were detected. The sensitivity rates of Staphylococcus aureus to cefpirome，rifampin，compound sulfamethoxazole，linezolid，minocycline and tigecycline were all >95.0%. Enterococcus faecium was more prevalent than Enterococcus faecalis. The resistance rates of Enterococcus faecium to vancomycin and teicoplanin were both 0.5%（2/369），and no vancomycin-resistant Enterococcus faecium was detected. The detection rate of MRSA in southern China was significantly lower than that in other regions（ χ2=14.578， P=0.002），while the detection rate of MRCNS in northern China was significantly higher than that in other regions（ χ2=15.195， P=0.002）. The detection rates of MRSA and MRCNS in provincial hospitals were higher than those in municipal hospitals（ χ2=13.519 and 12.136， P<0.001）. The detection rates of MRSA and MRCNS in economically more advanced regions（per capita GDP≥92 059 Yuan in 2022）were higher than those in economically less advanced regions（per capita GDP<92 059 Yuan）（ χ2=9.969 and 7.606， P=0.002和0.006）. Conclusions:Among the Gram-positive pathogens causing bloodstream infections in China， Staphylococci is the most common while the MRSA incidence decreases continuously with time；the detection rate of Enterococcus faecium exceeds that of Enterococcus faecalis. The overall prevalence of vancomycin-resistant Enterococci is still at a low level. The composition ratio of Gram-positive pathogens and resistant profiles varies slightly across regions of China，with the prevalence of MRSA and MRCNS being more pronounced in provincial hospitals and areas with a per capita GDP≥92 059 yuan.

The interaction of drug and target protein is a critical part of new drug discovery. It is the premise for drugs to exert therapeutic effects by targeting specific binding sites of target proteins and thereby affecting its pharmacological activity. Currently, a variety of techniques are exploited to detect the interaction between drug ligands and target proteins. For example, cellular thermal shift assay (CETSA) and differential scanning fluorimetry (DSF) based on thermodynamics, mass spectrometry and nuclear magnetic resonance technology, etc. In addition, high-throughput ligand screening technology provides technical convenience for the search of specific ligand, and is a powerful tool to efficiently identify the interaction between drug ligand and target protein. Here, we summarize the detection techniques of interaction between small molecules and target proteins, and discuss the application of high-throughput ligand screening technology in drug research.

Target identification and verification of natural products is an important and challenging work in the field of chemical biology. It is also an important job for researchers to apply chemical proteomics technology to biomedicine in order to identify target proteins of natural products. Target identification is critical to understanding its mechanisms and developing natural products as molecular probes and potential therapeutic drugs. Traditional approaches of small molecule target identification based on affinity have been shown to be successful, such as click-chemical probes, radioisotope labeling or photosensitized small-molecule probes. Nevertheless, these technologies require purified candidate target proteins, and modified small molecules with probes or linkers, such as adding agarose beads, biotin labels, fluorescent labeling or photo-affinity labeling. Many structure-activity relationship studies should be performed to ensure that the addition of small molecule labels undisturbed the original biological activity of the small molecules. Unfortunately, all these modifications are likely to alter their biological activity or binding specificity. To overcome the bottleneck of "target recognition", researchers have developed a series of new techniques for unmodified drug target identification. In this article, we reviewed the target identification techniques of natural product without structural modification in order to provide reference for the development of natural products.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical bacterial isolates from bloodstream infections in China in 2021.Methods:The clinical bacterial strains isolated from blood culture from member hospitals of Blood Bacterial Resistant Investigation Collaborative System (BRICS) were collected during January 2021 to December 2021. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical Laboratory Standards Institute (CLSI). WHONET 5.6 was used to analyze data.Results:During the study period, 11 013 bacterial strains were collected from 51 hospitals, of which 2 782 (25.3%) were Gram-positive bacteria and 8 231 (74.7%) were Gram-negative bacteria. The top 10 bacterial species were Escherichia coli (37.6%), Klebsiella pneumoniae (18.9%), Staphylococcus aureus (9.8%), coagulase-negative Staphylococci (6.3%), Pseudomonas aeruginosa (3.6%), Enterococcus faecium (3.6%), Acinetobacter baumannii (2.8%), Enterococcus faecalis (2.7%), Enterobacter cloacae (2.5%) and Klebsiella spp (2.1%). The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus aureus were 25.3% and 76.8%, respectively. No glycopeptide- and daptomycin-resistant Staphylococci was detected; more than 95.0% of Staphylococcus aureus were sensitive to ceftobiprole. No vancomycin-resistant Enterococci strains were detected. The rates of extended spectrum B-lactamase (ESBL)-producing isolated in Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis were 49.6%, 25.5% and 39.0%, respectively. The prevalence rates of carbapenem-resistance in Escherichia coli and Klebsiella pneumoniae were 2.2% and 15.8%, respectively; 7.9% of carbapenem-resistant Klebsiella pneumoniae was resistant to ceftazidime/avibactam combination. Ceftobiprole demonstrated excellent activity against non-ESBL-producing Escherichia coli and Klebsiella pneumoniae. Aztreonam/avibactam was highly active against carbapenem-resistant Escherichia coli and Klebsiella pneumoniae. The prevalence rate of carbapenem-resistance in Acinetobacter baumannii was 60.0%, while polymyxin and tigecycline showed good activity against Acinetobacter baumannii (5.5% and 4.5%). The prevalence of carbapenem-resistance in Pseudomonas aeruginosa was 18.9%. Conclusions:The BRICS surveillance results in 2021 shows that the main pathogens of blood stream infection in China are gram-negative bacteria, in which Escherichia coli is the most common. The MRSA incidence shows a further decreasing trend in China and the overall prevalence of vancomycin-resistant Enterococci is low. The prevalence of Carbapenem-resistant Klebsiella pneumoniae is still on a high level, but the trend is downwards.

Objective:To investigate the effects of insulin glargine administration by jet injection versus conventional insulin pen on glucose profile using professional mode flash glucose monitoring(FGM) system in type 2 diabetic patients with poor glucose control.Methods:In this randomized, controlled, crossover study, 40 patients with T2DM who treated with insulin glargine were enrolled. The patients were randomly divided into group A(jet injector-conventional pen, n=20) and group B(conventional pen-jet injector, n=20). Each patient wore FreeStyle Libre sensor from day 4 to day 17. The specialist nurse instructed patients how to master the injection techniques. Professional FGM system was applied to assess glucose profile. Results:The fasting blood glucose(FBG) of the enrolled patients was(9.37±1.84) mmol/L. In contrast to conventional insulin pen, treatment with the jet injector significantly decreased the 24h MBG [(9.06±2.13 vs 9.98±2.67) mmol/L, P=0.001], MaxBG [(16.69±3.01 vs 17.95±3.48) mmol/L, P=0.001], AUC>10 mmol/L [95.93(21.12, 129.02) vs 142.66( 27.88, 198.46), P=0.002], TAR(31.10±21.89 vs 39.49±25.93, P=0.003), MAGE and SDBG. It was observed that patients using jet injector had significant increased TIR(65.94±20.47 vs 58.32±25.00, P=0.001). There were no difference in the risk of hypoglycaemia between two groups. Conclusion:Insulin jet injector was more effective than the insulin pen on glycaemic control and glucose fluctuation without increasing the risk of hypoglycemia in type 2 diabetic patients with uncontrolled glycemia.

According to the theory of 'Xingben Dazao' of Psoralea corylifolia Linn. (BL), the susceptible syndromes and biomarkers of liver injury caused by BL were searched. Rat models of kidney-yin deficiency syndrome (M_yin) and kidney-yang deficiency syndrome (M_yang) were established, and all animal experimental operations and welfare following the provisions of the First Affiliated Experimental Animal Ethics and Animal Welfare Committee of Henan University of Traditional Chinese Medicine (No. YFYDW2020017). The results showed that BL significantly decreased the body weight, water intake, and urine weight of M_yin rats and increase the organ indexes of the liver, testis, adrenal gland, and spleen and the expression of alanine aminotransferase (ALT). Meantime, BL significantly increased the urine weight of M_yang rats and decreased the expression of ALT and aspartate aminotransferase (AST). Hematoxylin and eosin (HE) staining showed that BL could aggravate inflammatory infiltration of hepatocytes in rats with M_yin and alleviate liver injury in rats with M_yang. Metabolomics identified 17 BL co-regulated significant differential metabolic markers in M_yin and M_yang rats. Among them, 8 metabolites such as glutamine, quinolinate, biliverdin, and lactosylceramide showed opposite trends, mainly involving cysteine and methionine metabolism, tyrosine metabolism, tryptophan metabolism, purine metabolism, sphingolipid metabolism, glycerol phospholipid metabolism, glutamine metabolism, and other pathways. M_yin/M_yang may be the susceptible constitution of BL for liver damage or protection, which may be related to the regulation of amino acid metabolism and sphingolipid metabolism. The study can provide some experimental data support for the safe and accurate use of BL in the clinical practice of traditional Chinese medicine.

Abstract: Objective　To analyze the influencing factors of mother-to-child transmission of hepatitis B virus after combined immunological blockade, and to evaluate the effect of mother-to-child blockade, and to provide a basis for health policies and health interventions for preventing mother-to-child blockade of hepatitis B virus. Methods A total of 11 363 pairs of HBsAg positive pregnant women and their infants aged 7-12 months in Hainan Province from 2015 to 2020 were included in the study. The general situation, the situation of health care and delivery in this pregnancy and perinatal period, the detection of hepatitis B markers, the situation of antiviral therapy, the general situation of mother and infant during delivery and the implementation of blockade measures for mother-to-child transmission of hepatitis B were collected and analyzed. Results Among the 11 363 pairs of HBsAg positive pregnant women and their infants delivered in hospitals in Hainan province from 2015 to 2020, the positive rate of HBsAg in children at 7-12 months after birth was 1.47 %, and the difference in HBsAg positive rate of infants born in different years was not statistically significant (P>0.05). There were no significant differences in the positive rate of HBsAg among children born to pregnant women with different nationalities, educational levels, occupations, delivery modes, delivery places, obstetric operations and perineal laceration, abnormal perinatal period, children with different genders and premature delivery and perinatal (all P<0.05). There was significant difference in HBsAg positive rate among infants born to pregnant women of different ages, the positive rate of HBsAg of infants born to young pregnant women was higher than that of older pregnant women (P<0.05). The rate of antiviral therapy was low in HBeAg positive pregnant women, and the positive rate of HBsAg in their infants was 2.54%, which was higher than 0.83% in HBeAg negative pregnant women (P<0.05). Conclusions Combined immunological blockade with hepatitis B vaccine and hepatitis B immunoglobulin can effectively prevent the mother-to-child transmission of HBV. HBsAg-positive women can give birth at the right age, and HBeAg-positive pregnant women can be treated with antiviral therapy to block mother-to-child transmission, providing the important basis for the formulation of hepatitis B prevention and control strategies and measures.