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.

This study was aimed at comparing performance differences among three metagenomic sequencing platforms,MGISEQ-2000,Illumina NextSeq 2000,and Ion GeneStudio S5 Plus,to optimize the sequencing process for trace samples.The three sequencing platforms were used to perform high-throughput sequencing on DNA standards and simulated samples.Through analysis of the quality of raw data and microbial detection capabilities,systematic differences among platforms were compared.The sequencing results were optimized for trace samples by incorporation of exogenous nucleic acids during the li-brary preparation process.In terms of data output per batch and base quality,MGISEQ-2000 surpassed the other two plat-forms.Illumina NextSeq 2000 had the lowest proportion of duplicate reads,whereas Ion GeneStudio S5 Plus had the highest proportion,and significant differences were observed across platforms(P＜0.001).In sequencing uniformity,MGISEQ-2000 and Illumina NextSeq 2000 were superior to Ion GeneStudio S5 Plus.MGISEQ-2000 provided a substantial advantage in microbial detection capability(P＜0.001),but the advantage diminished with decreasing bacterial fluid concentration.Ion GeneStudio S5 Plus had the shortest duration for single-batch sequencing.Moreo-ver,for trace samples with DNA content ≤0.05 ng,the experi-mental group(with added exogenous nucleic acids)achieved a higher number of reads than the control group(without exogenous nucleic acids),with a 11.09±8.03 fold increase.In conclu-sion,the different sequencing platforms each had advantages and disadvantages,thus allowing researchers to choose the appro-priate platform according to specific needs.Furthermore,the addition of exogenous nucleic acids improved the microorganism detection efficiency,and provided better support for subsequent diagnosis and evaluation of results.

Objective:To evaluate the gene mutation profile and prognostic significance of adult cytogenetically normal acute myeloid leukemia (CN-AML) with CEBPA-bZIP mutation. Methods:Targeted sequencing was implemented on the diagnostic bone marrow DNA samples of 141 adult CN-AML subjects with CEBPA-bZIP mutation. The nomogram model for leukemia-free survival (LFS) rate was generated by combining genetic abnormalities and clinical data. Risk stratification was conducted based on prognostic variables and the effect of risk-adjusted consolidation therapy was investigated by Kaplan-Meier method. Results:Four variables were finally included in our nomogram model after multivariate Cox analysis,and an equation for risk score calculation was obtained,risk score=1.3002×white blood cell (WBC) (≥18.77×109/L)+1.4065×CSF3R mutation positive+2.6489×KMT2A mutation positive+1.0128×DNA methylation-related genes mutation positive. According to the nomogram model,patients were further divided into low-risk group (score=0,n=46) and high-risk group (score>0,n=95). Prognostic analysis showed that the 5-year LFS rate,5-year overall survival (OS) rate,and 5-year cumulative incidence of relapse (CIR) of patients who received allogeneic hematopoietic stem cell transplantation (allo-HSCT) in the high-risk group were 93.5％,97.1％,and 3.5％,while those in patients who received maintenance chemotherapy were 32.9％,70.5％,and 63.4％,respectively. The differences were statistically significant (all P<0.05). Allo-HSCT could significantly improve the prognosis of patients in high-risk group. However,no corresponding benefit was observed in the low-risk group. Conclusion:Adult CN-AML with CEBPA-bZIP mutation has a complex co-mutation pattern. The nomogram model based on mutations of CFS3R,KMT2A and DNA methylation-related genes together with WBC count can further divide this subset of patients into a relatively low-risk group and a relatively high-risk group. For individuals in the high-risk group,allo-HSCT is proposed as post-remission therapy. The above data will benefit the prognosis estimation and treatment decision for adult CN-AML with CEBPA-bZIP mutation.

Objective:To explore the gene mutations of Langerhans cell histiocytosis in children,and to analyze the correlation of BRAF V600E mutation with clinical features and prognosis of LCH,so as to provide reference for clinical diagnosis and treatment. Methods:Fluorescence PCR was used to detect gene mutations in paraffin-embedded tissue samples from 78 children with LCH,and the correlation of BRAF V600E mutation with clinical characteristics and prognosis of LCH in children was analyzed. Results:Among the 78 children,41 cases (52.6％) had BRAF V600E mutation,8 cases (10.3％) had MAP2K1 mutation,1 case (1.3％) had BRAF Exon 12 mutation,1 case (1.3％) had ARAF mutation,and 1 case (1.3％) had PIK3CA mutation. BRAF V600E mutation was not significantly correlated with sex,age,multisystem involvement,risk-organ involvement,CNS-risk lesions,and early treatment response in children with LCH (P>0.05),and it was also not significantly correlated with the recurrence and event-free survival (EFS) of children with LCH (P>0.05). Conclusion:LCH is an inflammatory myeloid tumor. BRAF V600E mutation is not correlated with clinical features,early treatment response,recurrence and prognosis of LCH.

Objective:To investigate the diagnosis value of serum levels of soluble B7-H3(sB7-H3),trefoil factor 1(TFF1)and lipocalin-2(LCN-2)in breast cancer(BC)patients.Methods:From March 2020 to March 2023,196 newly diagnosed BC patients accepted by Huanghe San-menxia hospital were regarded as the study subjects and assigned to the BC group;84 patients with benign breast lesions and 76 physically healthy individuals served as the benign lesion group and the control group,respectively;clinical data were collected.ELISA method was applied to de-tect the serum levels of sB7-H3,TFF1,and LCN-2 in each group,and the relationship between the serum levels of the three and the clinical and pathological characteristics of BC patients was analyzed;Spearman method was applied to analyze the correlation between serum sB7-H3,TFF1,LCN-2 levels and clinical pathological characteristics in BC patients;receiver operating characteristic(ROC)curve was plotted to evaluate the diagnostic value of serum sB7-H3,TFF1,and LCN-2 levels for BC.Results:Compared with the reference group,the serum levels of sB7-H3,TFF1,and LCN-2 in the benign lesion group and BC group were obviously increased(P＜0.05),the serum levels of sB7-H3,TFF1,and LCN-2 in the BC group were obviously higher than those in the benign lesion group(P＜0.05);the serum levels of sB7-H3,TFF1,and LCN-2 were obviously elevated in BC patients with tumour diameter＞2 cm,TNM stage Ⅲ+Ⅳ,lymph node metastasis,and negative ER expression(P＜0.05),the serum levels of sB7-H3,TFF1 and LCN-2 were positively correlated with tumor diameter(r=0.463,0.442,0.481,P＜0.001),positive correla-tion with TNM stage(r=0.474,0.394,0.562,P＜0.001),positive correlation with lymph node me-tastasis(r=0.567,0.488,0.409,P＜0.001),and negative correlation with ER expression(r=-0.575,-0.534,-0.538,P＜0.001);the AUC for serum sB7-H3,TFF1,and LCN-2 alone for BC diagnosis were 0.817,0.814,and 0.830,respectively,and the combined diagnosis was superior to the separate diagnosis(AUC=0.911,95％CI:0.871-0.942).Conclusion:The serum levels of sB7-H3,TFF1 and LCN-2 in BC patients were significantly increased,which is of high clinical value for the diagnosis of BC.

Objective:To explore the changes in early postpartum pelvic floor muscle strength following the implementation of the new labor process.Methods:This retrospective cohort study selected 1 834 primiparous women with singleton, full-term pregnancies who delivered at Peking University First Hospital from February 2011 to March 2016 and had a pelvic floor re-examination 6-8 weeks postpartum. Out of these, 738 cases who followed the old labor process before 2014 were categorized as the old process group, and 1 096 cases who followed the new labor process after 2014 were categorized as the new process group. Basic data, childbirth information, and postpartum pelvic floor muscle strength of the two groups were compared. Data were statistically analyzed using t-test, Chi-square test, Mann-Whitney U test, Wilcoxon rank-sum test, and ordered multicategory logistic regression to assess the impact of the new and old labor process and other factors on pelvic floor muscle strength. Results:The total duration of labor, as well as the duration of the first, second, and third stages of labor, were longer in the new process group than in the old process group [549.0 min (360.0-768.0 min) vs. 482.5 min (328.0-635.0 min), 465.0 min (297.5-672.5 min) vs. 420.0 min (285.0-555.0 min), 42.0 min (24.0-74.0 min) vs. 27.0 min (18.0-45.0 min), with Z-value of－5.72,－3.95, and－9.28, all P<0.05). The rates of vaginal delivery and labor analgesia were higher in the new process group [72.1% (790/1 096) vs. 67.2% (496/738), χ2=7.41; 67.4% (739/1 096) vs. 53.4% (394/738), χ2=36.82; both P<0.05]. There were no statistically significant differences in the comparison of Class Ⅰ and Class Ⅱ muscle strength grades between the two groups (all P>0.05). Conclusion:There was no significant decline in early postpartum pelvic floor muscle strength following the implementation of the new labor process standards.

Objective To investigate the correlation between serum indirect bilirubin(IBIL)levels and carotid intima-media thickness(CIMT)of acute cerebral infarction patients.Methods A total of 229 patients with acute cerebral infarction at Wuxi No.2 Chinese Medicine Hospital from July 2021 to November 2023 were divided into the intima-media thickness group(CIMT≥0.9mm,n=108)and intima-media normal group(CIMT<0.9mm,n=121)according to CIMT values.The differences in gender,age,body mass index,smoking history,history of alcohol drinking,hypertension,coronary heart disease,diabetes,hyperlipidemia,total bilirubin(TBIL),direct bilirubin(DBIL),indirect bilirubin(IBIL),total cholesterol,high-density lipoprotein cholesterol,low-density lipoprotein cholesterol,triglyceride,fasting blood glucose,uric acid,and cystatin C were compared between the two groups.To further elucidate the association between serum bilirubin levels and CIMT using both univariate and multivariate analysis.Results The two groups showed significant differences in gender,body mass index and IBIL in the results(P<0.05).However,there was no significant difference in age,history of alcohol drinking,smoking history,diabetes,coronary heart disease,hypertension,hyperlipidemia,TBIL,DBIL,total cholesterol,high-density lipoprotein cholesterol,low-density lipoprotein cholesterol,triglyceride,fasting blood glucose,uric acid and cystatin C levels(P>0.05).Binary Logistic regression analysis indicated that gender,body mass index and IBIL were significant independent predictors of CIMT values(P<0.05).Conclusion Serum indirect bilirubin level is inversely associated with CIMT in acute cerebral infarction patients,which may be one of the protective factors of atherosclerosis.

Objective To explore the current status of H.pylori infection in the natural population of Sanya City,analyze its influencing factors,and provide a reference basis for the prevention and control of H.pylori infection.Methods A total of 677 residents from four districts of Sanya City were selected by overall stratified random sampling method,and were subjected to urea 14C breath test and questionnaire survey to calculate the positive rate of H.pylori in the natural population and analyze the influencing factors of H.pylori infection.Results A total of 606 residents were included,and the number of H.pylori positive detections was 261,with a positive detection rate of 38.5％.Among them,different ethnicity,marital status,smoking,eating vegetables and fruits,and literacy level were associated with H.pylori infection(P＜0.05);gender,age,BMI,alcohol consumption,drinking water source,betel quid chewing,and the number of cohabitants were not significantly associated with H.pylori infection(P＞0.05).Family infection was an independent risk factor for H.pylori infection in the natural population of Sanya City,and Li ethnicity,frequent consumption of fruits and vegetables,and college and higher education level were independent protective factors for H.pylori infection in the natural population of Sanya City.Conclusion The rate of H.pylori infection in the natural population of Sanya City is lower than the national average.Consuming more fruits and vegetables and improving the awareness of hygiene protection are conducive to the prevention of H.pylori infection;and the promotion of the family and related members with the same examination and treatment is important to avoid aggregation of infection within the family.

Objective To develop a portable collection device of human exhaled breath condensate(EBC)based on natural breathing to meet the needs for rapid screening of human respiratory tract(especially lower respiratory tract)infections.Methods The device consisted of a refrigeration unit,a heat dissipation unit and a condensation unit.The refrigeration unit adopted a TES1-7102 thermoelectric Peltier cooler semiconductor as the refrigeration element;the heat dissipation unit was composed of a high thermal conductivity aluminum heat sink and a high-speed brushless cooling fan;the condensation unit was made up of a cold guide plate and a condenser,in which the cold guide plate was made of thin sheet of aluminum alloy,and the condenser was prepared by 3D printing technology and made of hydrophobic polylactic acid,with primary and secondary 2-stage guide grooves and an ultra-thin condensing surface.The performance of the device was verified in terms of cooling,thermal conductivity,condensation and human EBC collection and content analysis.Results Performance analysis showed that after refrigeration began the temperature difference between the condenser surface and the exhaled gas met the requirements of the condenser,and no obvious thermal resistance was found on the condensing surface so that large droplets could be formed rapidly and then be collected after the gas-liquid phase change of the exhaled gas on the condensing surface.Human EBC collection and content analysis indicated the device realized home self-collection of EBCs from people of all ages,and the concentrations of interleukins,C-reactive protein and other inflammation-related indexes and the pH value of the collected EBC samples were all correlated with respiratory infections in the subjects.Conclusion The device developed with easy operation avoids the discomfort of blowing collection and the risk of saliva contamination,and is worthy promoting for rapid diagnosis and dynamic monitoring of respiratory tract infection and other related diseases.[Chinese Medical Equipment Journal,2024,45(8):32-37]