Objective To investigate the drug resistance phenotype/genotype and virulence gene carrying status, serotype, and sequence typing (ST) of Campylobacter jejuni in Fengtai District in 2024. Methods The drug resistance phenotype was detected by agar dilution method, and serotyping was performed by real-time fluorescence quantitative polymerase chain reaction (PCR). The whole genome sequencing was used to analyze drug resistance genes, virulence genes, and other characteristics. Results Among the 35 Campylobacter jejuni strains analyzed, the antibiotics with the highest resistance rates were nalidixic acid and ciprofloxacin (both 82.86%), followed by tetracycline (74.89%). All strains exhibited a 100.00% sensitivity rate to erythromycin. The multiple drug resistance rate was 77.14%. The predominant drug resistance genes were gyrA-T86I (94.29%) and tetO (74.29%). The most common serotype was HS:2, accounting for 25 strains. A total of 132 virulence genes were detected. There were 12 clonal complexes (CC) and 24 ST types. Conclusion The drug resistance situation of Campylobacter jejuni in Fengtai District is relatively severe, and the drug resistance phenotype is related to specific genetic mutations to some extent. The serotypes are diverse, the virulence genes are complex, and the pathogenic potential is significant, posing a notable risk for inducing Guillain-Barré syndrome (GBS). The high number of ST types indicates substantial genetic diversity.

Arsenic is a semi-metal,and lipid-soluble arsenic compounds are one of the widespread forms in the environment and food chain,but there is a lack of standards for lipid-soluble arsenic compounds,which is one of the bottlenecks in the current analytical detection and toxicological studies of organic arsenic.In this study,four saturated arsenic-containing hydrocarbons,AsHC 318,AsHC 332,AsHC 346,and AsHC 374(The number is relative molecular mass),were successfully synthesized in three steps by using dimethylarsinic acid,potassium iodide,sodium hydroxide,and four brominated alkanes(1-Bromotetradecane,1-bromopentadecane,1-bromohexadecane,and 1-bromooctadecane)as raw materials.The structures of these four saturated arsenic-containing hydrocarbons were characterized by proton nuclear magnetic resonance(1H NMR)spectroscopy,13C nuclear magnetic resonance(13C NMR)spectroscopy,and high-resolution mass spectrometry(HR-MS).The yields of the method were 8%-10%,and the synthesized compounds could be used in subsequent toxicity evaluation experiments to assess the toxic effects and mechanisms of action of arsenic-containing hydrocarbons.This study provided an effective method for synthesis of arsenic-containing hydrocarbons,enriching the synthesis methods of arsenic-containing hydrocarbons,and provided raw materials for the subsequent toxicological studies of arsenic-containing hydrocarbons.

The traditional teaching model centered on courses has disadvantages such as interdisciplinary barriers, repetitive learning of content, and students being unable to enter clinical practice early. The Human Body Overview I is a core course at the basic stage under the integrated curriculum system centered on "organ-systems" at Chongqing Medical University. The course deeply integrates interdisciplinary resources and reconstructs the contents of systematic anatomy, embryology, and physiology under the traditional teaching model. The "Three in One" curriculum ideology and politics are implemented to assist students in their comprehensive development. By strengthening the cultivation of clinical application abilities and empowering with virtual simulation technology, the teaching effectiveness and quality have been improved. The teaching practice of the Human Body Overview I suggests that the teaching reform of integrated curriculum at the basic stage has broken interdisciplinary barriers, avoided repetitive learning of contents, and promoted the cultivation of students' interdisciplinary integration ability and clinical application ability. It can provide a reference for the teaching reform of integrated curriculum for other colleges.

BACKGROUND:Previous studies have shown that Huosui Formula has a synergistic effect on the immune and hematopoietic regulation of patients with myelodysplastic syndrome,but the specific mechanism is not yet clear.OBJECTIVE:To explore the effect and mechanism of Huosui Formula on bone marrow hematopoiesis in rats with myelodysplastic syndrome.METHODS:A total of 70 SD rats were randomly divided into a normal control group(n=10),a model group(n=15),a western medicine group(n=15),a low-dose Huosui Formula group(n=15),and a high-dose Huosui Formula group(n=15).Except for the normal control group,the other four groups were injected with dimethyl benzanthracene via the tail vein to induce the establishment of rat myelodysplastic syndrome models.After modeling,the normal control group and the model group were given normal saline;the western medicine group was given thalidomide capsules 10 mg/kg and retinoic acid tablets 4 mg/kg,and the low-dose Huosui Formula group and the high-dose Huosui Formula group were given 1.5 and 6 g/kg Huosui Formula,respectively,by intragastric administration once a day for 28 consecutive days.Peripheral blood and femoral bone marrow tissue were collected to detect peripheral blood routine and bone marrow biopsy hematopoietic proliferation.Flow cytometry was used to detect T lymphocyte subsets and the expression of CTLA-4 and PD-1 on T lymphocytes.RESULTS AND CONCLUSION:(1)Compared with the normal control group,peripheral blood leukocyte,neutrophil,hemoglobin,platelet,and CD4+,CD4+/CD8+levels were decreased in the model group significantly(P＜0.05),while CD4+PD-1+,CD8+PD-1+,CD4+CTLA-4+,and CD8+CTLA-4+expressions were significantly upregulated(P＜0.05).(2)In all dosage groups,myelopoietic proliferation was increased compared with the model group,with no significant difference between the groups(P＞0.05).(3)Compared with the model group,leukocytes,hemoglobin,platelets,and CD4+,CD4+/CD8+were significantly elevated in the high-dose Huosui Formula group(P＜0.05),the expression of CD8+was significantly lower(P＜0.05),and the levels of CD4+PD-1+,CD8+PD-1+,CD4+CTLA-4+,and CD8+CTLA-4+were down-regulated but not statistically significant(P＞0.05).(4)The western medicine group and the high-dose Huosui Formula group showed similar efficacy.The improvement of each index in the high-dose Huosui Formula group was superior to that in the low-dose Huosui Formula group.These findings indicate that Huosui Formula can improve the bone marrow hematopoiesis in myelodysplastic syndrome model rats,increase the levels of CD4+,and CD4+/CD8+while down-regulate the expression levels of CD4+PD-1+,CD8+PD-1+,CD4+CTLA-4+,and CD8+CTLA-4+.These observations suggest a link to the negative immunoregulation mechanism.

Objective To examine the changing prevalence and antimicrobial resistance profiles of Burkholderia cepacia in 52 hospitals across China from 2015 to 2021.Methods A total of 9 261 strains of B.cepacia were collected from 52 hospitals between January 1,2015 and December 31,2021.Antimicrobial susceptibility of the strains was tested using Kirby-Bauer method or automated antimicrobial susceptibility testing systems according to a unified protocol.The results were interpreted according to the breakpoints released in the Clinical & Laboratory Standards Institute(CLSI)guidelines(2023 edition).Results A total of 9 261 strains of B.cepacia were isolated from all age groups,especially elderly patients.The proportion was 11.1％(1 032 strains)in children,significantly lower than the proportion in adults.About half(46.5％,4 310/9 261)of the strains were isolated from patients at least 60 years old and 42.3％(3 919/9 261)of the strains were isolated from young adults.Most isolates(71.1％)were isolated from sputum and respiratory secretions,followed by urine(10.7％)and blood samples(8.1％).B.cepacia isolates were highly susceptible to the five antimicrobial agents recommended in the CLSI M100 document(33rd edition,2023).B.cepacia isolates showed relatively higher resistance rates to meropenem and levofloxacin.However,the resistance rates to ceftazidime,trimethoprim-sulfamethoxazole,and minocycline remained below 8.1％.The percentage of B.cepacia strains resistant to levofloxacin was the highest compared to other antibiotics in any of the three age groups(from 12.4％in the patients＜18 years old to 20.6％in the patients aged 60 years or older).Conclusions B.cepacia is one of the clinically important non-fermenting gram-negative bacteria.Accurate and timely reporting of antimicrobial susceptibility test results and ongoing antimicrobial resistance surveillance are helpful for rational prescription of antimicrobial agents and proper prevention and control of nosocomial infections.

The traditional teaching model centered on courses has disadvantages such as interdisciplinary barriers, repetitive learning of content, and students being unable to enter clinical practice early. The Human Body Overview I is a core course at the basic stage under the integrated curriculum system centered on "organ-systems" at Chongqing Medical University. The course deeply integrates interdisciplinary resources and reconstructs the contents of systematic anatomy, embryology, and physiology under the traditional teaching model. The "Three in One" curriculum ideology and politics are implemented to assist students in their comprehensive development. By strengthening the cultivation of clinical application abilities and empowering with virtual simulation technology, the teaching effectiveness and quality have been improved. The teaching practice of the Human Body Overview I suggests that the teaching reform of integrated curriculum at the basic stage has broken interdisciplinary barriers, avoided repetitive learning of contents, and promoted the cultivation of students' interdisciplinary integration ability and clinical application ability. It can provide a reference for the teaching reform of integrated curriculum for other colleges.

Objective To summarize the changing prevalence of carbapenem resistance in Enterobacterales based on the data of CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021 for improving antimicrobial treatment in clinical practice.Methods Antimicrobial susceptibility testing was performed using a commercial automated susceptibility testing system according to the unified CHINET protocol.The results were interpreted according to the breakpoints of the Clinical & Laboratory Standards Institute(CLSI)M100 31st ed in 2021.Results Over the seven-year period(2015-2021),the overall prevalence of carbapenem-resistant Enterobacterales(CRE)was 9.43％(62 342/661 235).The prevalence of CRE strains in Klebsiella pneumoniae,Citrobacter freundii,and Enterobacter cloacae was 22.38％,9.73％,and 8.47％,respectively.The prevalence of CRE strains in Escherichia coli was 1.99％.A few CRE strains were also identified in Salmonella and Shigella.The CRE strains were mainly isolated from respiratory specimens(44.23±2.80)％,followed by blood(20.88±3.40)％and urine(18.40±3.45)％.Intensive care units(ICUs)were the major source of the CRE strains(27.43±5.20)％.CRE strains were resistant to all the β-lactam antibiotics tested and most non-β-lactam antimicrobial agents.The CRE strains were relatively susceptible to tigecycline and polymyxins with low resistance rates.Conclusions The prevalence of CRE strains was increasing from 2015 to 2021.CRE strains were highly resistant to most of the antibacterial drugs used in clinical practice.Clinicians should prescribe antimicrobial agents rationally.Hospitals should strengthen antibiotic stewardship in key clinical settings such as ICUs,and take effective infection control measures to curb CRE outbreak and epidemic in hospitals.

Objective To characterize the changing species distribution and antibiotic resistance profiles of respiratory isolates in hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Commercial automated antimicrobial susceptibility testing systems and disk diffusion method were used to test the susceptibility of respiratory bacterial isolates to antimicrobial agents following the standardized technical protocol established by the CHINET program.Results A total of 589 746 respiratory isolates were collected from 2015 to 2021.Overall,82.6％of the isolates were Gram-negative bacteria and 17.4％were Gram-positive bacteria.The bacterial isolates from outpatients and inpatients accounted for(6.0±0.9)％and(94.0±0.1)％,respectively.The top microorganisms were Klebsiella spp.,Acinetobacter spp.,Pseudomonas aeruginosa,Staphylococcus aureus,Haemophilus spp.,Stenotrophomonas maltophilia,Escherichia coli,and Streptococcus pneumoniae.Each microorganism was isolated from significantly more males than from females(P＜0.05).The overall prevalence of methicillin-resistant S.aureus(MRSA)was 39.9％.The prevalence of penicillin-resistant S.pneumoniae was 1.4％.The prevalence of extended-spectrum β-lactamase(ESBL)-producing E.coli and K.pneumoniae was 67.8％and 41.3％,respectively.The overall prevalence of carbapenem-resistant E.coli,K.pneumoniae,Enterobacter cloacae,Pseudomonas aeruginosa,and Acinetobacter baumannii was 3.7％,20.8％,9.4％,29.8％,and 73.3％,respectively.The prevalence of β-lactamase was 96.1％in Moraxella catarrhalis and 60.0％in Haemophilus influenzae.The H.influenzae isolates from children(＜18 years)showed significantly higher resistance rates to β-lactam antibiotics than the isolates from adults(P＜0.05).Conclusions Gram-negative bacteria are still predominant in respiratory isolates associated with serious antibiotic resistance.Antimicrobial resistance surveillance should be strengthened in clinical practice to support accurate etiological diagnosis and appropriate antimicrobial therapy based on antimicrobial susceptibility testing results.

BACKGROUND:Previous studies have shown that Huosui Formula has a synergistic effect on the immune and hematopoietic regulation of patients with myelodysplastic syndrome,but the specific mechanism is not yet clear.OBJECTIVE:To explore the effect and mechanism of Huosui Formula on bone marrow hematopoiesis in rats with myelodysplastic syndrome.METHODS:A total of 70 SD rats were randomly divided into a normal control group(n=10),a model group(n=15),a western medicine group(n=15),a low-dose Huosui Formula group(n=15),and a high-dose Huosui Formula group(n=15).Except for the normal control group,the other four groups were injected with dimethyl benzanthracene via the tail vein to induce the establishment of rat myelodysplastic syndrome models.After modeling,the normal control group and the model group were given normal saline;the western medicine group was given thalidomide capsules 10 mg/kg and retinoic acid tablets 4 mg/kg,and the low-dose Huosui Formula group and the high-dose Huosui Formula group were given 1.5 and 6 g/kg Huosui Formula,respectively,by intragastric administration once a day for 28 consecutive days.Peripheral blood and femoral bone marrow tissue were collected to detect peripheral blood routine and bone marrow biopsy hematopoietic proliferation.Flow cytometry was used to detect T lymphocyte subsets and the expression of CTLA-4 and PD-1 on T lymphocytes.RESULTS AND CONCLUSION:(1)Compared with the normal control group,peripheral blood leukocyte,neutrophil,hemoglobin,platelet,and CD4+,CD4+/CD8+levels were decreased in the model group significantly(P＜0.05),while CD4+PD-1+,CD8+PD-1+,CD4+CTLA-4+,and CD8+CTLA-4+expressions were significantly upregulated(P＜0.05).(2)In all dosage groups,myelopoietic proliferation was increased compared with the model group,with no significant difference between the groups(P＞0.05).(3)Compared with the model group,leukocytes,hemoglobin,platelets,and CD4+,CD4+/CD8+were significantly elevated in the high-dose Huosui Formula group(P＜0.05),the expression of CD8+was significantly lower(P＜0.05),and the levels of CD4+PD-1+,CD8+PD-1+,CD4+CTLA-4+,and CD8+CTLA-4+were down-regulated but not statistically significant(P＞0.05).(4)The western medicine group and the high-dose Huosui Formula group showed similar efficacy.The improvement of each index in the high-dose Huosui Formula group was superior to that in the low-dose Huosui Formula group.These findings indicate that Huosui Formula can improve the bone marrow hematopoiesis in myelodysplastic syndrome model rats,increase the levels of CD4+,and CD4+/CD8+while down-regulate the expression levels of CD4+PD-1+,CD8+PD-1+,CD4+CTLA-4+,and CD8+CTLA-4+.These observations suggest a link to the negative immunoregulation mechanism.

AIM To study the chemical constituents from the stems and leaves of Dendrobium formosum Roxb.ex Lindl.and their biological activities.METHODS The 95％ethanol extract from the stems and leaves of D.formosum was isolated and purified by silica gel,Sephadex LH-20 and semi-preparative HPLC,then the structures of obtained compounds were identified by physicochemical properties and spectral data.Their inhibitory activities onα-glucosidase were determined by PNPG method,and their in vitro anti-inflammatory activities were evaluated by RAW264.7 model.RESULTS Fifteen compounds were isolated and identified as coniferyl p-coumarate(1),(-)-pinoresinol(2),2,5,7-trihydroxy-4-methoxy-9,10-dihydrophenanthrene(3),naringenin(4),spiropreussomerin A(5),7-hydroxy-14-de-O-methyl-lasiodiplodin(6),(4S,5S,6Z,8E)-5-hydroxydeca-6,8-dien-4-olide(7),(6S,9R)-blumenol C(8),p-hydroxybenzoic acid(9),m-hydroxybenzoic acid(10),p-hydroxy benzenepropanoic acid(11),5,7-dihydroxy-isobenzofuran(12),2-(4-hydroxyphenyl)-ethanol(13),β-sitostenone(14),β-sitosterol(15).The IC50 values of compounds 1 and 4 on α-glucosidase inhibition were(65.60±3.31)and(98.95±2.53)μmol/L,respectively.Compound 3 presented inhibitory activity on NO production in RAW 264.7 cells,with IC50 value of(3.97±0.12)μmol/L.CONCLUSION Compounds 5-6,8 and 12 are isolated from Orchidacae family for the first time,and 2-15 are first isolated from this plant.Compounds 1 and 4 have α-glucosidase inhibitory activities,and 3 has anti-inflammatory activity.