Objective To investigate the repair mechanism of baicalin on gastric mucosa of chronic atrophic gastritis mice based on the network pharmacology and animal experiments.Methods(1)Applied network pharmacology to predict and analyze the potential key targets of baicalin in the treatment of chronic atrophic gastritis.(2)Animal experiment:40 C57BL/6N mice were randomly divided into normal group,model group,Vitacoenzyme group and baicalin group,10 mice in each group.Except for the normal group,the other three groups of mice were treated with N-methyl-N'-nitro-N-nitrosoguanidine(MNNG)by gavage combined with hunger and satiety disorder method to construct a chronic atrophic gastritis model.At the end of drug administration,the histopathological changes of gastric mucosa were observed by hematoxylin-eosin(HE)staining,the changes of gastrin(GAS)and prostaglandin E2(PGE2)levels in serum were detected by enzyme-linked immunosorbent assay(ELISA),and the mRNA and protein expression levels of Janus tyrosine kinase 1(JAK1),signal transducer and activator of transcription 3(STAT3)in the gastric mucosa were detected by real-time fluorescence quantitative polymerase chain reaction(qRT-PCR)and protein immunoblotting(Western Blot)methods,respectively.Results The results of network pharmacology showed that baicalin could spontaneously bind to the core targets JAK1 and STAT3.The results of animal experiments showed that compared with the normal group,the gastric mucosa of mice in the model group suffered from atrophy,disordered gland arrangement,the presence of a large number of lymphocytes,a significant increase in apoptotic index of the gastric mucosa(P＜0.05),a significant decrease in the levels of GAS and PGE2 in serum(P＜0.05),and a significant increase in the levels of mRNA and protein expressions of JAK1 and STAT3 in the gastric mucosa(P＜0.05);compared with the model group,the pathological changes of gastric mucosa in the Vitacoenzyme group and baicalin group were alleviated,the glands were arranged relatively neatly,the structure was more intact,the apoptosis index of gastric mucosal cells was significantly decreased(P＜0.05),the levels of GAS and PGE2 in serum were significantly increased(P＜0.05),and the mRNA and protein expression levels of JAK1 and STAT3 in gastric mucosa were significantly decreased(P＜0.05).There was no significant difference in the above-mentioned indexes between the baicalin group and the Vitacoenzyme group(P＞0.05).Conclusion Baicalin can effectively repair gastric mucosal lesions in mice with chronic atrophic gastritis,and its mechanism may be related to the down-regulation of mRNA and protein expressions of JAK1 and STAT3.

Objective To evaluate the molluscicidal effect of spraying different formulations of niclosamide ethanolamine salt with drones against Oncomelania hupensis in ditches. Methods A semi-dry and semi-wet ditch with O. hupensis snails was selected in the second branch field of Jiangbei Farm, Jiangling County, Hubei Province in May 2023, and divided into 4 experimental areas, named groups A1, A2, B1 and B2. Environmental cleaning was performed in groups A1 and B2, and was not conducted in groups A2 or B2. Then, 50% wettable powder of niclosamide ethanolamine salt was sprayed with drones at an effective dose of 2 g/m² in groups A1 and A2, and 5% niclosamide ethanolamine salt granule was sprayed with drones at an effective dose of 2 g/m² in groups B1 and B2. O. hupensis snails were surveyed using the systematic sampling method 1, 3, 5, 7, 14 days after spraying, and the natural mortality and corrected mortality of O. hupensis snails were calculated. Results The occurrence of frames with living snails, mean density of living snails and natural mortality of snails were 97.50% (117/120), 6.30 snails/0.1 m² and 1.18% (9/765) in the test ditch before spraying, respectively. There were significant differences in the mortality of snails among four groups 1, 3, 5, 7 and 14 days after spraying niclosamide formulations with drones (χ² = 17.230, 51.707, 65.184, 204.050 and 34.435, all P values < 0.01). The overall mortality rates of snails were 94.51% (1 051/1 112), 79.44% (908/1 143), 96.54% (977/1 012) and 88.55% (1 021/1 153) in groups A1, A2, B1 and B2 (χ² = 207.773, P < 0.05), respectively. In addition, there was no significant difference in the overall snail mortality between groups A1 and B1 (P > 0.05), and the snail mortality in groups A1 and B1 were both statistically different from that in groups A2 and B2 (all P values < 0.05). Conclusion Both 50% wettlable powder of niclosamide ethanolamine salt and 5% niclosamide ethanolamine salt granule sprayed with drones are active against O. hupensis snails in ditches, and environmental cleaning may improve the molluscicidal effect.

Objective To investigate the distribution of B cells in both tumor and non-tumor tissues of gastric cancer patients,analyze their phenotypic characteristics and explore the impact on T cell proliferation.Methods Immunohistochemical staining was utilized to detect the expression of B cell surface marker CD 19 in tumor and non-tumor tissues from 33 gastric cancer patients.The expression levels of chemokine receptors and immunoglobulin molecules on B cells in both tumor and non-tumor tissues were measured using flow cytometry.Chemotaxis experiments were conducted to examine the role of the CXCL12-CXCR4 axis in B cell chemotaxis.B cells isolated and purified from both tissue types were co-cultured with autologous peripheral T cells to assess their effect on T cell proliferation.Results There were significantly more B cells infiltrated in tumor tissues than those infitrated in the non-tumor tissues of gastric cancer patients(P＜0.01),and CXCR4 was highly expressed on tumor-infiltrating B cells compared with B cells derived from non-tumor tissues(P＜0.05).The Cancer Genome Atlas(TCGA)analysis indicated that the expression level of CXCL12 in tumor tissues was positively correlated with the expression level of CD19 in gastric cancer patients(r=0.15,P＜0.01).And the expression level of CXCL12 in tumor tissues of the gastric cancer patients was also positively correlated with the number of B cells infiltrated in tumor tissues.Chemotaxis experiments confirmed that the CXCL12-CXCR4 axis was involved in promoting B cell chemotaxis(P＜0.05).Although B cells in tumor and non-tumor tissues had similar levels of IgM,IgG,and IgA expression,tumor-infiltrating B cells significantly inhibited the proliferation of T cells when compared with B cells derived from non-tumor tissues(P＜0.01).Conclusion There are more B cells infiltrated in gastric cancer tissues,which may be recruited to tumor tissues through the CXCL12-CXCR4 axis,and then inhibit T cell proliferation to promote the progression of gastric cancer.

Objective:To investigate the influence of maternal autoimmune diseases and anticoagulants, including low-molecular-weight heparin (LMWH) and aspirin, on the fetal fraction of maternal plasma cell-free DNA of non-invasive prenatal testing (NIPT).Methods:A prospective cohort study was conducted on women with singleton pregnancies receiving NIPT in the Nanjing Drum Tower Hospital from March 2021 to July 2022. NIPT was carried out using a polymerase chain reaction (PCR)-free amplification platform. In this study, four types of maternal autoimmune diseases, which were antiphospholipid syndrome, undifferentiated connective tissue disease, Sj?gren's syndrome, and systemic lupus erythematosus (SLE), and two anticoagulants, LMWH and aspirin, were studied. Univariate and multivariate linear regression models were used to analyze the factors influencing fetal fraction of maternal plasma cell-free DNA.Results:A total of 4 102 singleton pregnant women were enrolled in the prospective cohort, and 3 948 were finally included after excluding the cases with unclear dosing time of LMWH or aspirin, other autoimmune diseases, conceiving through ovulation induction alone, and having true positive or failed NIPT result. There were 96 cases with antiphospholipid syndrome, 35 with undifferentiated connective tissue disease, 34 with Sj?gren's syndrome, and 18 with SLE. A total of 108 patients only received LMWH treatment, 121 only received aspirin treatment, and 113 received both LMWH and aspirin treatment. Univariate linear regression analysis showed that maternal body mass index at blood collection ( B=－0.423), conceived by assisted reproductive technology ( B=－0.803), male fetus ( B=－0.458), undifferentiated connective tissue disease ( B=1.774), and SLE ( B=3.467) had influence on the fetal fraction (all P<0.05). Multivariate linear regression analysis showed that maternal body mass index at blood collection ( B=－0.415), conceived by assisted reproductive technology ( B=－0.585), male fetus ( B=－0.322), SLE ( B=3.347) and undifferentiated connective tissue disease ( B=1.336) were factors influencing fetal fraction (all P<0.05). Conclusions:Maternal use of LMWH or aspirin does not affect fetal fraction when performing NIPT on a PCR-free amplification platform, but undifferentiated connective tissue disease and SLE are the influencing factors. Therefore, pregnant women should be informed before the NIPT that the fetal fraction of maternal plasma cell-free DNA may be affected by maternal autoimmune diseases.

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 distribution and antimicrobial resistance profiles of the common pathogens isolated from urine from 2015 to 2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods The bacterial strains were isolated from urine and identified routinely in 51 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Antimicrobial susceptibility was determined by Kirby-Bauer method,automatic microbiological analysis system and E-test according to the unified protocol.Results A total of 261 893 nonduplicate strains were isolated from urine specimen from 2015 to 2021,of which gram-positive bacteria accounted for 23.8％(62 219/261 893),and gram-negative bacteria 76.2％(199 674/261 893).The most common species were E.coli(46.7％),E.faecium(10.4％),K.pneumoniae(9.8％),E.faecalis(8.7％),P.mirabilis(3.5％),P.aeruginosa(3.4％),SS.agalactiae(2.6％),and E.cloacae(2.1％).The strains were more frequently isolated from inpatients versus outpatients and emergency patients,from females versus males,and from adults versus children.The prevalence of ESBLs-producing strains in E.coli,K.pneumoniae and P.mirabilis was 53.2％,52.8％and 37.0％,respectively.The prevalence of carbapenem-resistant strains in E.coli,K.pneumoniae,P.aeruginosa and A.baumannii was 1.7％,18.5％,16.4％,and 40.3％,respectively.Lower than 10％of the E.faecalis isolates were resistant to ampicillin,nitrofurantoin,linezolid,vancomycin,teicoplanin and fosfomycin.More than 90％of the E.faecium isolates were ressitant to ampicillin,levofloxacin and erythromycin.The percentage of strains resistant to vancomycin,linezolid or teicoplanin was＜2％.The E.coli,K.pneumoniae,P.aeruginosa and A.baumannii strains isolated from ICU inpatients showed significantly higher resistance rates than the corresponding strains isolated from outpatients and non-ICU inpatients.Conclusions E.coli,Enterococcus and K.pneumoniae are the most common pathogens in urinary tract infection.The bacterial species and antimicrobial resistance of urinary isolates vary with different populations.More attention should be paid to antimicrobial resistance surveillance and reduce the irrational use of antimicrobial agents.

Objective To understand the distribution and changing resistance profiles of clinical isolates of Enterococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Enterococcus according to the unified protocol of CHINET program by automated systems,Kirby-Bauer method,or E-test strip.The results were interpreted according to the Clinical & Laboratory Standards Institute(CLSI)breakpoints in 2021.WHONET 5.6 software was used for statistical analysis.Results A total of 124 565 strains of Enterococcus were isolated during the 7-year period,mainly including Enterococcus faecalis(50.7％)and Enterococcus faecalis(41.5％).The strains were mainly isolated from urinary tract specimens(46.9％±2.6％),and primarily from the patients in the department of internal medicine,surgery and ICU.E.faecium and E.faecalis strains showed low level resistance rate to vancomycin,teicoplanin and linezolid(≤3.6％).The prevalence of vancomycin-resistant E.faecalis and E.faecium was 0.1％and 1.3％,respectively.The prevalence of linezolid-resistant E.faecalis increased from 0.7％in 2015 to 3.4％in 2021,while the prevalence of linezolid-resistant E.faecium was 0.3％.Conclusions The clinical isolates of Enterococcus were still highly susceptible to vancomycin,teicoplanin,and linezolid,evidenced by a low resistance rate.However,the prevalence of linezolid-resistant E.faecalis was increasing during the 7-year period.It is necessary to strengthen antimicrobial resistance surveillance to effectively identify the emergence of antibiotic-resistant bacteria and curb the spread of resistant pathogens.

Objective To examine the changing antimicrobial resistance profile of Enterobacter spp.isolates in 53 hospitals across China from 2015 t0 2021.Methods The clinical isolates of Enterobacter spp.were collected from 53 hospitals across China during 2015-2021 and tested for antimicrobial susceptibility using Kirby-Bauer method or automated testing systems according to the CHINET unified protocol.The results were interpreted according to the breakpoints issued by the Clinical & Laboratory Standards Institute(CLSI)in 2021(M100 31st edition)and analyzed with WHONET 5.6 software.Results A total of 37 966 Enterobacter strains were isolated from 2015 to 2021.The proportion of Enterobacter isolates among all clinical isolates showed a fluctuating trend over the 7-year period,overall 2.5％in all clinical isolates amd 5.7％in Enterobacterale strains.The most frequently isolated Enterobacter species was Enterobacter cloacae,accounting for 93.7％(35 571/37 966).The strains were mainly isolated from respiratory specimens(44.4±4.6)％,followed by secretions/pus(16.4±2.3)％and urine(16.0±0.9)％.The strains from respiratory samples decreased slightly,while those from sterile body fluids increased over the 7-year period.The Enterobacter strains were mainly isolated from inpatients(92.9％),and only(7.1±0.8)％of the strains were isolated from outpatients and emergency patients.The patients in surgical wards contributed the highest number of isolates(24.4±2.9)％compared to the inpatients in any other departement.Overall,≤ 7.9％of the E.cloacae strains were resistant to amikacin,tigecycline,polymyxin B,imipenem or meropenem,while ≤5.6％of the Enterobacter asburiae strains were resistant to these antimicrobial agents.E.asburiae showed higher resistance rate to polymyxin B than E.cloacae(19.7％vs 3.9％).Overall,≤8.1％of the Enterobacter gergoviae strains were resistant to tigecycline,amikacin,meropenem,or imipenem,while 10.5％of these strains were resistant to polycolistin B.The overall prevalence of carbapenem-resistant Enterobacter was 10.0％over the 7-year period,but showing an upward trend.The resistance profiles of Enterobacter isolates varied with the department from which they were isolated and whether the patient is an adult or a child.The prevalence of carbapenem-resistant E.cloacae was the highest in the E.cloacae isolates from ICU patients.Conclusions The results of the CHINET Antimicrobial Resistance Surveillance Program indicate that the proportion of Enterobacter strains in all clinical isolates fluctuates slightly over the 7-year period from 2015 to 2021.The Enterobacter strains showed increasing resistance to multiple antimicrobial drugs,especially carbapenems over the 7-year period.

Objective To understand the changing distribution and antimicrobial resistance profiles of Proteus,Morganella and Providencia in hospitals across China from January 1,2015 to December 31,2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods Antimicrobial susceptibility testing was carried out following the unified CHINET protocol.The results were interpreted in accordance with the breakpoints in the 2021 Clinical & Laboratory Standards Institute(CLSI)M100(31 st Edition).Results A total of 32 433 Enterobacterales strains were isolated during the 7-year period,including 24 160 strains of Proteus,6 704 strains of Morganella,and 1 569 strains of Providencia.The overall number of these Enterobacterales isolates increased significantly over the 7-year period.The top 3 specimen source of these strains were urine,lower respiratory tract specimens,and wound secretions.Proteus,Morganella,and Providencia isolates showed lower resistance rates to amikacin,meropenem,cefoxitin,cefepime,cefoperazone-sulbactam,and piperacillin-tazobactam.For most of the antibiotics tested,less than 10％of the Proteus and Morganella strains were resistant,while less than 20％of the Providencia strains were resistant.The prevalence of carbapenem-resistant Enterobacterales(CRE)was 1.4％in Proteus isolates,1.9％in Morganella isolates,and 15.6％in Providencia isolates.Conclusions The overall number of clinical isolates of Proteus,Morganella and Providencia increased significantly in the 7-year period from 2015 to 2021.The prevalence of CRE strains also increased.More attention should be paid to antimicrobial resistance surveillance and rational antibiotic use so as to prevent the emergence and increase of antimicrobial resistance.

Objective To understand the changing distribution and antimicrobial resistance profiles of Klebsiella strains in 52 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Antimicrobial susceptibility testing was carried out according to the unified CHINET protocol.The susceptibility results were interpreted according to the breakpoints in the Clinical & Laboratory Standards Institute(CLSI)M100 document.Results A total of 241,549 nonduplicate Klebsiella strains were isolated from 2015 to 2021,including Klebsiella pneumoniae(88.0％),Klebsiella aerogenes(5.8％),Klebsiella oxytoca(5.7％),and other Klebsiella species(0.6％).Klebsiella strains were mainly isolated from respiratory tract(48.49±5.32)％.Internal medicine(22.79±3.28)％,surgery(17.98±3.10)％,and ICU(14.03±1.39)％were the top 3 departments where Klebsiella strains were most frequently isolated.K.pneumoniae isolates showed higher resistance rate to most antimicrobial agents compared to other Klebsiella species.Klebsiella isolates maintained low resistance rates to tigecycline and polymyxin B.ESBLs-producing K.pneumoniae and K.oxytoca strains showed higher resistance rates to all the antimicrobial agents tested compared to the corresponding ESBLs-nonproducing strains.The K.pneumoniae and carbapenem-resistant K.pneumoniae(CRKP)strains isolated from ICU patients demonstrated higher resistance rates to majority of the antimicrobial agents tested than the strains isolated from non-ICU patients.The CRKP strains isolated from adult patients had higher resistance rates to most of the antimicrobial agents tested than the corresponding CRKP strains isolated from paediatric patients.Conclusions The prevalence of carbapenem-resistant strains in Klebsiella isolates increased greatly from 2015 to 2021.However,the Klebsiella isolates remained highly susceptible to tigecycline and polymyxin B.Antimicrobial resistance surveillance should still be strengthened for Klebsiella strains.