ObjectiveTo investigate microbial contamination status and distribution characteristics in laboratory animal barrier facilities, so as to provide a scientific basis for environmental quality control in barrier facilities. MethodsIn accordance with the national standard "Laboratory Animals—Environment and Housing Facilities" and the "Standard Operating Procedures" of the barrier facility, bacterial monitoring was performed on samples of air-settling bacteria, materials, and personnel gloves in the single-corridor barrier facility of the Animal Core Facility, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences (CEMCS). The monitoring data from January 2020 to December 2024 were collected, organized and statistically analyzed, and partial samples were subjected to species identification using PCR and sequencing methods. ResultsA total of 7 898 samples were collected from 2020 to 2024, including 3 175 air-settling bacteria samples, 3 353 material samples, and 1 370 glove samples. The overall compliance rate was 95.7% (7 559/7 898), among which the compliance rate of air-settling bacteria was 97.1% (3 084/3 175), that of materials was 93.2% (3 125/3 353), and that of personnel gloves was 98.5% (1 350/1 370). Over the five years, the compliance rates of all three types of monitored samples were above 90%. There were statistically significant differences in the compliance rates of air-settling bacteria and material samples among different quarters (P<0.05). Further investigation was conducted on samples collected from January to March 2024, and 190 bacterial strains were obtained through isolation and culture, including 126 strains from air-settling bacteria, 52 strains from materials, and 12 strains from personnel gloves. The strains were identified by PCR amplification and sequencing, and the 190 bacterial strains belonged to 9 genera and 20 species. Gram-positive bacteria accounted for the majority, with Staphylococcus as the dominant genus, accounting for 77.9% (148/190). ConclusionMicroorganisms carried by air, materials, and personnel gloves in barrier facilities are mainly Gram-positive bacteria. Regular monitoring of air-settling bacteria, materials, and personnel gloves in barrier facilities enables timely detection and control of potential risks during husbandry management and facility operation, which is of great significance for maintaining the sound operation of the barrier facility system and ensuring the quality of animal experiments.

Objective This study conducted molecular biological identification of the viruses carried by Culex pipiens pallens specimens collected in Shunyi District, Beijing in 2023, and observed the changes in the infection rate of the viruses carried by Cx. pipiens pallens at different collection times. Methods Cx. pipiens pallens were collected using carbon dioxide mosquito traps. The mosquito samples were ground in batches and analyzed by molecular biology technologies. The virus infection rate at different collection times was analyzed statistically. Results 17 strains of Culex pipiens pallens densovirus(CppDNV)were identified from Cx. pipiens pallens samples collected in Shunyi District, Beijing, in 2023. The nucleotide sequence analysis of the virus genome coding region showed that CppDNV was a single-stranded DNA virus with a total length of 3 335 nt, encoding 2 non-structural proteins(NS1, NS2)and 1 capsid protein(VP). The nucleotide(amino acid)sequence lengths of the three proteins were 2 376 nt(791 aa),1 092 nt(363 aa)and 1 071 nt(356 aa), respectively. Phylogenetic analysis showed that CppDNV was located in genus Brevihamaparvovirus. Statistical analysis showed no significant difference in infection rates across collection times(χ2=4.429, P=0.194). Conclusions CppDNV was identified in Cx. pipiens pallens in Beijing, and it was stably maintained in this natural population.

Objective To investigate the species composition of mosquitoes and breeding conditions of larvae in the rice planting areas of Beijing, and to provide a scientific basis for mosquito control in rice fields. Methods Adult mosquitoes were collected using CO2-baited light traps, and mosquito larvae(including pupae)were sampled via the dipping method. Results A total of 4 genera and 6 species of adult mosquitoes were captured in the study area. The dominant species were Culex pipiens pallens, Cx. tritaeniorhynchus, and Anopheles sinensis. The average adult mosquito density was 5.11 specimens per trap-hour, with slightly lower density in July compared to August. For larvae and pupae,3 genera and 4 species were identified, dominated by Cx. tritaeniorhynchus, An. sinensis, and Aedes vexans. Conclusions The mosquito species composition in Beijing′s rice planting areas is diverse. Mosquito control strategies should prioritize the management of adult mosquitoes, while density control of mosquito larvae in paddy fields can be achieved through intermittent irrigation techniques.

Objective:To investigate teachers' evaluation and willingness and the influencing factors regarding the adoption of the flipped classroom teaching mode in undergraduate pediatrics education.Methods:From December 2022 to December 2024, a questionnaire survey was conducted among the teachers who were responsible for teaching Child Health and Disease（Pediatrics) to the eight-year clinical medicine students at Peking University Health Science Center. Their views, evaluation, and willingness of implementing the flipped classroom teaching mode were investigated. Logistic regression analysis was performed using SPSS 26.0 software to explore the factors influencing teachers' willingness to adopt the flipped classroom teaching mode.Results:A total of 102 questionnaires were collected. Among the teachers, 20.59%（ n=21) believed that the teaching effect of the flipped classroom was better than that of the traditional class, 58.82%（ n=60) considered its effectiveness comparable, and 20.59%（ n=21) found it less effective. The most influential factors affecting the effectiveness of flipped classroom were students' self-learning with online videos [(4.39±0.73) points], student participation in the flipped classrooms [(4.26±0.72) points], the adequacy of teachers' pre-class preparation [(4.18±0.65) points], and the suitability of the teaching content for the flipped classroom [(4.11±0.76) points]. Teachers believed that the flipped classroom significantly enhanced students' autonomous learning ability [(4.11±0.63) points], clinical thinking [(4.04±0.58) points], and expression skills [(3.80±0.61) points]. Additionally, 78.43%（ n=80) of the teachers expressed willingness to continue participating in flipped classroom teaching. Factors influencing teachers' willingness to adopt the flipped classroom included gender, satisfaction with students' classroom participation, and personal experience with the effectiveness of the flipped classroom（ P<0.05). Conclusions:The flipped classroom teaching mode is well-accepted by teachers. Students' classroom participation affects teachers' willingness to continue using the flipped classroom teaching mode. In the future, the content of flipped classroom should be arranged individually according to specific teaching objectives to increase students' classroom participation and promote the cultivation of students' ability.

Objective To investigate the role and mechanism of inflammatory marker C5a in regulating the polarization of M2 macro-phages as well as its clinical application value in the prognosis evaluation of lung cancer.Methods The phorbol 12-myristate 13-ace-tate(PMA)-pulsed human monocytic leukemia cell line THP-1 was stimulated with C5a for 0,6,12,24,and 48 h or 0,1,2,3,6,and 12 h,and then the expression levels of M2 markers CD163 and CD206 mRNA were determined by real-time fluorescence quantita-tive PCR(qRT-PCR).The expression level of general control non-repressed protein 5(GCN5)with histone acetyltransferase(HAT)activity was detected by Western blot.Co-immunoprecipitation(co-IP)was used to determine the acetylation of GATA binding protein 3(GATA3),a key transcription factor for macrophages,and its binding ability to GCN5 and E1A binding protein p300(Ep300/p300).After the macrophages pre-treated with GCN5 inhibitor butyrolactone 3(MB-3)were stimulated with C5a,the expression levels of CD163 and CD206,acetylation of GATA3,and its binding ability to GCN5 were determined by Western blot and co-IP.The clinical significance of the expression of C5a receptor 1(C5aR1)and GCN5 in lung cancer tissues in the prognosis of lung cancer patients was analyzed using the KM plotter database.Results C5a could significantly increase the expression levels of CD163 and CD206 mRNA,expression of GCN5,acetylation of GATA3,and its binding ability to GCN5 in PMA-induced adherent macrophages,but did not affect the binding of GATA3 to p300.Inhibiting the activity of GCN5 not only significantly reduced the acetylation of GATA3 and its binding ability to GCN5,but also down-regulated the expressions of CD163 and CD206.The overall survival rate of lung cancer patients with high expression of C5aR1 or GCN5 was significantly reduced.Conclusion C5a promotes the polarization of M2 macrophages by indu-cing GCN5 to acetylate GATA3.The expressions of C5aR1 and GCN5 in lung cancer tissues may have certain clinical application value for the prognosis of the patients.

Objective·To identify relevant biomarkers for patients with coronavirus disease 2019-associated kidney injury(COVID-19-associated KI)and explore the mechanisms underlying the involvement of severe acute respiratory syndrome coronavirus-2(SARS-CoV-2)proteins in infection-related KI by affecting the interactions between renal cells and macrophages.Methods·A retrospective analysis was conducted on the clinical characteristics of COVID-19 patients with KI treated in Shanghai Ninth,People's,hospital from December 2022 to February 2023.Serum levels of inflammatory factors and chemokines were measured by using enzyme-linked immunosorbent assay(ELISA).In vitro,human macrophage cell line THP-1 cells were stimulated with recombinant S1 subunit protein derived from SARS-CoV-2 spike protein.The cells and culture supernatants were collected to detect the levels of inflammatory factors and chemokines by using quantitative real-time PCR(qRT-PCR)and ELISA.Conditioned medium was prepared from the cell culture supernatants of S1-stimulated THP-1 cells and used to stimulate human renal epithelial cells(HK-2)in vitro to assess cytokine secretion.Antibody blocking experiments were performed to analyze the effects of the conditioned medium on the production of cytokines in HK-2 cells.Results·Among 39 patients with COVID-19,8(20.50%)had creatinine levels above the reference interval,which indicated the occurrence of KI.The levels of peripheral tumor necrosis factor-α(TNF-α)in the COVID-19 patient with KI group[(18.33±8.20)pg/mL]were significantly higher than those in the non-KI group[(11.88±6.50)pg/mL](P=0.015).In vitro assay has shown that S1-spike protein stimulation promoted the level of gene transcription and production of TNF-α,interleukin-1β(IL-1β)and chemokine C-X-C motif ligand 10(CXCL10)in THP-1 macrophage cells(P＜0.001).Furthermore,the conditioned medium from S1-stimulated THP-1 cells promoted the secretion of TNF-α,IL-1β and CXCL10 by HK-2 cells(P=0.005).When anti-TNF-α antibody(Infliximab)was used to block TNF-α in the culture supernatants from S1-stimulated THP-1 cells,the secretion level of TNF-α by HK-2 cells decreased dramatically(P＜0.001).Conclusion·TNF-α levels increase significantly in COVID-19 patients with KI,implying the significance of TNF-α in the occurrence of COVID-19-associated KI.In vitro experiments confirm that the S1 protein induces TNF-α secretion from THP-1 cells,leading to increased inflammatory responses in renal cells,which may contribute to the development of COVID-19-associated KI.Therefore,targeting TNF-α may become an alternative strategy to reduce the occurrence of COVID-19-associated KI.

Objective To investigate the distribution and antimicrobial resistance profiles of common pathogens isolated from cerebrospinal fluid(CSF)in CHINET program from 2015 to 2021.Methods The bacterial strains isolated from CSF were identified in accordance with clinical microbiology practice standards.Antimicrobial susceptibility test was conducted using Kirby-Bauer method and automated systems per the unified CHINET protocol.Results A total of 14 014 bacterial strains were isolated from CSF samples from 2015 to 2021,including the strains isolated from inpatients(95.3％)and from outpatient and emergency care patients(4.7％).Overall,19.6％of the isolates were from children and 80.4％were from adults.Gram-positive and Gram-negative bacteria accounted for 68.0％and 32.0％,respectively.Coagulase negative Staphylococcus accounted for 73.0％of the total Gram-positive bacterial isolates.The prevalence of MRSA was 38.2％in children and 45.6％in adults.The prevalence of MRCNS was 67.6％in adults and 69.5％in children.A small number of vancomycin-resistant Enterococcus faecium(2.2％)and linezolid-resistant Enterococcus faecalis(3.1％)were isolated from adult patients.The resistance rates of Escherichia coli and Klebsiella pneumoniae to ceftriaxone were 52.2％and 76.4％in children,70.5％and 63.5％in adults.The prevalence of carbapenem-resistant E.coli and K.pneumoniae(CRKP)was 1.3％and 47.7％in children,6.4％and 47.9％in adults.The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)and Pseudomonas aeruginosa(CRPA)was 74.0％and 37.1％in children,81.7％and 39.9％in adults.Conclusions The data derived from antimicrobial resistance surveillance are crucial for clinicians to make evidence-based decisions regarding antibiotic therapy.Attention should be paid to the Gram-negative bacteria,especially CRKP and CRAB in central nervous system(CNS)infections.Ongoing antimicrobial resistance surveillance is helpful for optimizing antibiotic use in CNS infections.

Objective To investigate the antimicrobial resistance of clinical isolates from elderly patients(≥65 years)in major medical institutions across China.Methods Bacterial strains were isolated from elderly patients in 52 hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program during the period from 2015 to 2021.Antimicrobial susceptibility test was carried out by disk diffusion method and automated systems according to the same CHINET protocol.The data were interpreted in accordance with the breakpoints recommended by the Clinical and Laboratory Standards Institute(CLSI)in 2021.Results A total of 514 715 nonduplicate clinical isolates were collected from elderly patients in 52 hospitals from January 1,2015 to December 31,2021.The number of isolates accounted for 34.3％of the total number of clinical isolates from all patients.Overall,21.8％of the 514 715 strains were gram-positive bacteria,and 78.2％were gram-negative bacteria.Majority(90.9％)of the strains were isolated from inpatients.About 42.9％of the strains were isolated from respiratory specimens,and 22.9％were isolated from urine.More than half(60.7％)of the strains were isolated from male patients,and 39.3％isolated from females.About 51.1％of the strains were isolated from patients aged 65-＜75 years.The prevalence of methicillin-resistant strains(MRSA)was 38.8％in 32 190 strains of Staphylococcus aureus.No vancomycin-or linezolid-resistant strains were found.The resistance rate of E.faecalis to most antibiotics was significantly lower than that of Enterococcus faecium,but a few vancomycin-resistant strains(0.2％,1.5％)and linezolid-resistant strains(3.4％,0.3％)were found in E.faecalis and E.faecium.The prevalence of penicillin-susceptible S.pneumoniae(PSSP),penicillin-intermediate S.pneumoniae(PISP),and penicillin-resistant S.pneumoniae(PRSP)was 94.3％,4.0％,and 1.7％in nonmeningitis S.pneumoniae isolates.The resistance rates of Klebsiella spp.(Klebsiella pneumoniae 93.2％)to imipenem and meropenem were 20.9％and 22.3％,respectively.Other Enterobacterales species were highly sensitive to carbapenem antibiotics.Only 1.7％-7.8％of other Enterobacterales strains were resistant to carbapenems.The resistance rates of Acinetobacter spp.(Acinetobacter baumannii 90.6％)to imipenem and meropenem were 68.4％and 70.6％respectively,while 28.5％and 24.3％of P.aeruginosa strains were resistant to imipenem and meropenem,respectively.Conclusions The number of clinical isolates from elderly patients is increasing year by year,especially in the 65-＜75 age group.Respiratory tract isolates were more prevalent in male elderly patients,and urinary tract isolates were more prevalent in female elderly patients.Klebsiella isolates were increasingly resistant to multiple antimicrobial agents,especially carbapenems.Antimicrobial resistance surveillance is helpful for accurate empirical antimicrobial therapy in elderly patients.

Objective To investigate the role and mechanism of inflammatory marker C5a in regulating the polarization of M2 macro-phages as well as its clinical application value in the prognosis evaluation of lung cancer.Methods The phorbol 12-myristate 13-ace-tate(PMA)-pulsed human monocytic leukemia cell line THP-1 was stimulated with C5a for 0,6,12,24,and 48 h or 0,1,2,3,6,and 12 h,and then the expression levels of M2 markers CD163 and CD206 mRNA were determined by real-time fluorescence quantita-tive PCR(qRT-PCR).The expression level of general control non-repressed protein 5(GCN5)with histone acetyltransferase(HAT)activity was detected by Western blot.Co-immunoprecipitation(co-IP)was used to determine the acetylation of GATA binding protein 3(GATA3),a key transcription factor for macrophages,and its binding ability to GCN5 and E1A binding protein p300(Ep300/p300).After the macrophages pre-treated with GCN5 inhibitor butyrolactone 3(MB-3)were stimulated with C5a,the expression levels of CD163 and CD206,acetylation of GATA3,and its binding ability to GCN5 were determined by Western blot and co-IP.The clinical significance of the expression of C5a receptor 1(C5aR1)and GCN5 in lung cancer tissues in the prognosis of lung cancer patients was analyzed using the KM plotter database.Results C5a could significantly increase the expression levels of CD163 and CD206 mRNA,expression of GCN5,acetylation of GATA3,and its binding ability to GCN5 in PMA-induced adherent macrophages,but did not affect the binding of GATA3 to p300.Inhibiting the activity of GCN5 not only significantly reduced the acetylation of GATA3 and its binding ability to GCN5,but also down-regulated the expressions of CD163 and CD206.The overall survival rate of lung cancer patients with high expression of C5aR1 or GCN5 was significantly reduced.Conclusion C5a promotes the polarization of M2 macrophages by indu-cing GCN5 to acetylate GATA3.The expressions of C5aR1 and GCN5 in lung cancer tissues may have certain clinical application value for the prognosis of the patients.

Objective To investigate the distribution and antimicrobial resistance profiles of common pathogens isolated from cerebrospinal fluid(CSF)in CHINET program from 2015 to 2021.Methods The bacterial strains isolated from CSF were identified in accordance with clinical microbiology practice standards.Antimicrobial susceptibility test was conducted using Kirby-Bauer method and automated systems per the unified CHINET protocol.Results A total of 14 014 bacterial strains were isolated from CSF samples from 2015 to 2021,including the strains isolated from inpatients(95.3％)and from outpatient and emergency care patients(4.7％).Overall,19.6％of the isolates were from children and 80.4％were from adults.Gram-positive and Gram-negative bacteria accounted for 68.0％and 32.0％,respectively.Coagulase negative Staphylococcus accounted for 73.0％of the total Gram-positive bacterial isolates.The prevalence of MRSA was 38.2％in children and 45.6％in adults.The prevalence of MRCNS was 67.6％in adults and 69.5％in children.A small number of vancomycin-resistant Enterococcus faecium(2.2％)and linezolid-resistant Enterococcus faecalis(3.1％)were isolated from adult patients.The resistance rates of Escherichia coli and Klebsiella pneumoniae to ceftriaxone were 52.2％and 76.4％in children,70.5％and 63.5％in adults.The prevalence of carbapenem-resistant E.coli and K.pneumoniae(CRKP)was 1.3％and 47.7％in children,6.4％and 47.9％in adults.The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)and Pseudomonas aeruginosa(CRPA)was 74.0％and 37.1％in children,81.7％and 39.9％in adults.Conclusions The data derived from antimicrobial resistance surveillance are crucial for clinicians to make evidence-based decisions regarding antibiotic therapy.Attention should be paid to the Gram-negative bacteria,especially CRKP and CRAB in central nervous system(CNS)infections.Ongoing antimicrobial resistance surveillance is helpful for optimizing antibiotic use in CNS infections.