Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in tertiary hospitals in major regions of China in 2022.Methods Clinical isolates from 58 hospitals in China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2022 Clinical &Laboratory Standards Institute(CLSI)breakpoints.Results A total of 318 013 clinical isolates were collected from January 1,2022 to December 31,2022,of which 29.5％were gram-positive and 70.5％were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species(excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi)was 28.3％,76.7％and 77.9％,respectively.Overall,94.0％of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 90.8％of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis showed significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 94.2％in the isolates from children and 95.7％in the isolates from adults.The resistance rate to carbapenems was lower than 13.1％in most Enterobacterales species except for Klebsiella,21.7％-23.1％of which were resistant to carbapenems.Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.1％to 13.3％.The prevalence of meropenem-resistant strains decreased from 23.5％in 2019 to 18.0％in 2022 in Pseudomonas aeruginosa,and decreased from 79.0％in 2019 to 72.5％in 2022 in Acinetobacter baumannii.Conclusions The resistance of clinical isolates to the commonly used antimicrobial agents is still increasing in tertiary hospitals.However,the prevalence of important carbapenem-resistant organisms such as carbapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a downward trend in recent years.This finding suggests that the strategy of combining antimicrobial resistance surveillance with multidisciplinary concerted action works well in curbing the spread of resistant bacteria.

Objective To investigate the changing distribution and antibiotic resistance profiles of clinical isolates of Staphylococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Staphylococcus according to the unified protocol of CHINET(China Antimicrobial Surveillance Network)using disk diffusion method and commercial automated systems.The CHINET antimicrobial resistance surveillance data from 2015 to 2021 were interpreted according to the 2021 CLSI breakpoints and analyzed using WHONET 5.6.Results During the period from 2015 to 2021,a total of 204,771 nonduplicate strains of Staphylococcus were isolated,including 136,731(66.8％)strains of Staphylococcus aureus and 68,040(33.2％)strains of coagulase-negative Staphylococcus(CNS).The proportions of S.aureus isolates and CNS isolates did not show significant change.S.aureus strains were mainly isolated from respiratory specimens(38.9±5.1)％,wound,pus and secretions(33.6±4.2)％,and blood(11.9±1.5)％.The CNS strains were predominantly isolated from blood(73.6±4.2)％,cerebrospinal fluid(12.1±2.5)％,and pleural effusion and ascites(8.4±2.1)％.S.aureus strains were mainly isolated from the patients in ICU(17.0±7.3)％,outpatient and emergency(11.6±1.7)％,and department of surgery(11.2±0.9)％,whereas CNS strains were primarily isolated from the patients in ICU(32.2±9.7)％,outpatient and emergency(12.8±4.7)％,and department of internal medicine(11.2±1.9)％.The prevalence of methicillin-resistant strains was 32.9％in S.aureus(MRSA)and 74.1％in CNS(MRCNS).Over the 7-year period,the prevalence of MRSA decreased from 42.1％to 29.2％,and the prevalence of MRCNS decreased from 82.1％to 68.2％.MRSA showed higher resistance rates to all the antimicrobial agents tested except trimethoprim-sulfamethoxazole than methicillin-susceptible S.aureus(MSSA).Over the 7-year period,MRSA strains showed decreasing resistance rates to gentamicin,rifampicin,and levofloxacin,MRCNS showed decreasing resistance rates to gentamicin,erythromycin,rifampicin,and trimethoprim-sulfamethoxazole,but increasing resistance rate to levofloxacin.No vancomycin-resistant strains were detected.The prevalence of linezolid-resistant MRCNS increased from 0.2％to 2.3％over the 7-year period.Conclusions Staphylococcus remains the major pathogen among gram-positive bacteria.MRSA and MRCNS were still the principal antibiotic-resistant gram-positive bacteria.No S.aureus isolates were found resistant to vancomycin or linezolid,but linezolid-resistant strains have been detected in MRCNS isolates,which is an issue of concern.

AIM To study the Chemical constituents from Rhinacanthus nasutus(L.)Kurz and their in vitro antitumor and lipid-lowering activities.METHODS The ethyl acetate fraction from R.nasutus was isolated and purified by normal phase,reverse phase silica gel column and semi-preparative HPLC,then the structures of obtained compounds were identified by physicochemical properties and spectral data.The in vitro anti-tumor activity was determined by MTT assay,and the in vitro lipid-lowering activity was evaluated by oleic acid-induced HepG2 high-fat cell model.RESULTS Twenty compounds were isolated and identified as rhinacanthin A(1),rhinacanthin B(2),rhinacanthin C(3),rhinacanthin D(4),rhinacanthin E(5),rhinacanthin M(6),rhinacanthin N(7),rhinacanthin Q(8),rhinacanthin T(9),rhinacanthone(10),β-sitosterol(11),gallic acid(12),vanillic acid(13),syringic acid(14),lapachol(15),umbelliferone(16),sambucunlin A(17),17α,21-dihydroxy-1,4-pregnadiene-3,11,20-trione,21-acetate(18),1,8-dihydroxyanthraquinone(19),2,6-dimethoxy-1,4-benzoquinone(20).Compounds 3 and 7 inhibited the proliferation of HepG2,Hela,A549 and H22 tumor cells with IC50 values of(0.66±0.17)-(3.22±0.49)μmol/L in a time-and concentration-dependent manner.Compounds 3,7 and 9 had a lipid clearance rate of more than 50%in oleic acid-induced HepG2 high-fat cells.CONCLUSION Compounds 16-20 are isolated from this plant for the first time.Compounds 3 and 7 have good in vitro anti-tumor activities,and 3,7,9 have good in vitro lipid-lowering activities.

AIM To establish an LC-MS/MS method for the simultaneous content determination of guanine,adenosine,2′-deoxyuridine,uridine,uracil,thymine,cytidine,xanthine,hypoxanthine,guanosine,inosine and thymidine in Cervi Cornu slices.METHODS The analysis was performed on a 30℃thermostatic Waters X select HSS T3 column(2.1 mm×100 mm,5 μm),with the mobile phase comprising of methanol and 0.1%formic acid flowing at 200 μL/min in a gradient elution manner,and electron spray ionization source was adopted in positive ion scanning with multiple reaction monitoring mode.RESULTS Twelve nucleosides showed good linear relationships within their own ranges(r≥0.999 0),whose average recoveries were 92.46%-104.16%with the RSDs of 2.92%-6.14%.CONCLUSION This stable and feasible method can be used for the quality control of Cervi Cornu slices.

Objective:To analyze the immune microenvironment characteristics of human dental follicle tissues from the third molars and to explore the mutual communication and the effects of innate immune cells and adaptive immune cells within the dental follicle.Methods:Sequencing data(GSA-Human:HRA008022)in the GSA database were analyzed.Bioinformatics tools were employed for gene identification and GO enrichment analysis was performed to define the biological function of innate and adaptive immune cells.CellChat analysis was used for explaining intercellular communication among immune cell populations.Results:Using t-SNE dimen-sionality reduction analysis for immune cell populations,innate immune cell populations were obtained,including innate lymphoid cells,dendritic cells,mast cells and macrophages,and adaptive immune cell populations including T cells and B cells.Pearson corre-lation analysis showed that innate immune cells,specifically innate lymphoid cells and macrophages,had a strong correlation with adap-tive immune cell populations.GO enrichment analysis revealed mutual coordination among innate immune cell populations and regulato-ry effects on adaptive immune cell populations.Further CellChat analysis indicated biological signal transmission between innate and a-daptive immune cell populations,with CLEC,MIF,ADGRE5,COLLAGEN and MIF signaling pathways is the most significant.Con-clusion:Dental follicle tissues are rich in immune cells and innate immune cell populations interact with adaptive immune cells to regulate immune responses and participate in maintaining the homeostasis of dental follicle.

Further evidence is needed to explore the impact of high-altitude environments on the neurologic function of neonates.Non-invasive techniques such as cerebral near-infrared spectroscopy and amplitude-integrated electroencephalography can provide data on cerebral oxygenation and brain electrical activity.This study will conduct multiple cerebral near-infrared spectroscopy and amplitude-integrated electroencephalography monitoring sessions at various time points within the first 3 days postpartum for healthy full-term neonates at different altitudes.The obtained data on cerebral oxygenation and brain electrical activity will be compared between different altitudes,and corresponding reference ranges will be established.The study involves 6 participating centers in the Chinese High Altitude Neonatal Medicine Alliance,with altitude gradients divided into 4 categories:800 m,1 900 m,2 400 m,and 3 500 m,with an anticipated sample size of 170 neonates per altitude gradient.This multicenter prospective cohort study aims to provide evidence supporting the impact of high-altitude environments on early brain function and metabolism in neonates.[Chinese Journal of Contemporary Pediatrics,2024,26(4):403-409]

Objective To investigate the incidence rate,clinical characteristics,and prognosis of neonatal stroke in Shenzhen,China.Methods Led by Shenzhen Children's Hospital,the Shenzhen Neonatal Data Collaboration Network organized 21 institutions to collect 36 cases of neonatal stroke from January 2020 to December 2022.The incidence,clinical characteristics,treatment,and prognosis of neonatal stroke in Shenzhen were analyzed.Results The incidence rate of neonatal stroke in 21 hospitals from 2020 to 2022 was 1/15 137,1/6 060,and 1/7 704,respectively.Ischemic stroke accounted for 75％(27/36);boys accounted for 64％(23/36).Among the 36 neonates,31(86％)had disease onset within 3 days after birth,and 19(53％)had convulsion as the initial presentation.Cerebral MRI showed that 22 neonates(61％)had left cerebral infarction and 13(36％)had basal ganglia infarction.Magnetic resonance angiography was performed for 12 neonates,among whom 9(75％)had involvement of the middle cerebral artery.Electroencephalography was performed for 29 neonates,with sharp waves in 21 neonates(72％)and seizures in 10 neonates(34％).Symptomatic/supportive treatment varied across different hospitals.Neonatal Behavioral Neurological Assessment was performed for 12 neonates(33％,12/36),with a mean score of(32±4)points.The prognosis of 27 neonates was followed up to around 12 months of age,with 44％(12/27)of the neonates having a good prognosis.Conclusions Ischemic stroke is the main type of neonatal stroke,often with convulsions as the initial presentation,involvement of the middle cerebral artery,sharp waves on electroencephalography,and a relatively low neurodevelopment score.Symptomatic/supportive treatment is the main treatment method,and some neonates tend to have a poor prognosis.

Objective To study the clinical and pathological characteristics,as well as diagnosis,treatment methods and prognosis of adult patients with chronic active Epstein-Barr virus infection(CAEBVI).Methods Clinical and pathological data of 8 adult patients with CAEBVI admitted to a hospital in Gansu Province from January 2017 to December 2022 were collected retrospectively,clinical and histopathological characteristics,EBV-related test re-sults,as well as treatment and prognosis of patients were analyzed.Results Among 8 CAEBVI patients,3 were males and 5 were females,with the median age of 21.5 years.The median time from onset to diagnosis of CAEBVI was 7 months.The main manifestations were fever,pancytopenia(involving two or three peripheral blood lines),as well as lymph node enlargement,hepatomegaly and splenomegaly.The quantifications of plasma EBV nucleic acid(DNA)were all＞1.0 × 103.The sorting results of EBV infected cells showed that 3 cases were T lymphocytes in-fection,2 were NK cell infection,and 3 were co-infection of T lymphocytes and NK cells.Bone marrow cytological examination of 8 patients showed no atypical lymphocytes,while 6 patients showed hemophagocytic cells.Flow cy-tometey(FCM)typing results showed that no abnormal cell population was detected in all the 8 patients,and no myeloid,B lymphocyte,T lymphocyte and NK cell markers were expressed.The positive rate of T cell receptor(TCR)gene rearrangement was 37.5％(n=3).Histopathology showed that most cases(n=6,75.0％)expressed CD3,partial cases expressed CD4,CD8,CD56,TIA-1,and EBV encoded RNA(EBER),all were positive.The survival rate of patients after treatment was 50.0％(n=4),the follow-up time was 6-51 months,the 1-year sur-vival rate was 85.7％,and the median survival time was 24 months.Conclusion CAEBVI is characterized by varia-ble clinical manifestations that may lead to fatal complications.Early diagnosis and individualized treatment should be performed to reduce mortality of patients.

Butyric acid is a type of short chain fatty acid and an important nutrient in intestinal epithelial cells.In addition to its important role in intestinal health,it has application value in anti-tumor,treatment of neuritis and di-abetes.At the same time,based on the demand for green development in the livestock industry,its anti-inflammato-ry effect can avoid the abuse of antimicrobial agents.As a green,pollution-free,and residue-free new feed,butyric acid ensures the sustainable and healthy development of the livestock industry.This article mainly summarizes the production of butyric acid in the intestine,its effects on the balance of gut microbiota,digestion ability,and inflam-mation in humans and animals,elaborates its application in human health and animal production.

In recent years, polysaccharides have received much attention because of their high safety and good immunological activity. The study of polysaccharide in vivo process is a key scientific problem that needs to be solved for polysaccharide drug development. Some progress has been made in the field of polysaccharide pharmacokinetics and immunomodulation. However, due to the lack of both chromogenic and light-absorbing groups and the complex molecular structure of polysaccharides, the in vivo processes and immunomodulatory mechanisms of polysaccharides have been slow to be investigated. The effective combination of multiple techniques can break the bottleneck of difficult tracing and unknown immunomodulatory mechanism of polysaccharides in vivo, and promote the development and utilization of polysaccharides. In this paper, we systematically summarize the key techniques in the study of polysaccharide in vivo processes and immunomodulatory mechanisms in order to provide technical references and research ideas for the study of polysaccharide in vivo processes and immunomodulatory mechanisms.