Objective To examine the impact of different numbers of microsatellite markers on the analysis of population genetic diversity of Schistosoma japonicum, so as to provide insights into studies on the population genetic diversity of S. japonicum. Methods Oncomelania hupensis snails were collected from a wasteland in Gong’an County, Hubei Province, and 37 S. japonicum-infected O. hupensis snails were identified using the cercarial shedding method. A single cercaria released from each S. japonicum-infected O. hupensis snail was collected, and 10 cercariae were randomly collected from DNA extraction. Nine previously validated microsatellite loci and 15 additional microsatellite loci screened from literature review and the GenBank database and confirmed with stable amplification efficiency were selected as molecular markers. Genomic DNA from cercariae was subjected to three multiplex PCR amplifications of microsatellite markers with the Type-it Microsatellite PCR kit, and genotyped using capillary electrophoresis. The population genetic diversity of S. japonicum cercariae DNA was analyzed with observed number of alleles (Na), effective number of alleles (Ae), observed heterozygosity (Ho), expected heterozygosity (He), and polymorphism information content (PIC), and tested for Hardy-Weinberg equilibrium (HWE) and linkage disequilibrium (LD). To further investigate the impact of the number of microsatellite loci on the population genetic diversity of S. japonicum, the number of microsatellite markers was sequentially assigned from 1 to 24, and the mean and standard deviation of Na were calculated for S. japonicum populations at different locus numbers. In addition, the coefficient of variation (CV) of allelic number (defined as the ratio of the standard deviation to the mean) was determined, and the variation in Na with increasing microsatellite locus numbers was analyzed. Results Genomic DNA from 345 S. japonicum cercariae was selected for genotyping of 24 microsatellite markers, and all 24 microsatellite loci met linkage equilibrium (standardized linkage disequilibrium coefficient D′ < 0.7, r² < 0.3) and deviated from Hardy-Weinberg equilibrium (P < 0.001). The mean Na, Ae, Ho and He were 27.46 ± 2.18, 12.46 ± 0.95, 0.46 ± 0.03, and 0.91 ± 0.01 for 24 microsatellite loci in S. japonicum cercarial populations, respectively, and PIC ranged from 0.85 to 0.96, indicating high genome-wide representativeness of 24 microsatellite loci. The mean value of Na-Ae was higher in genotyping with 9 previously validated microsatellite loci (19.88 ± 8.43) than with all 24 loci (14.99 ± 8.09). As the number of microsatellite loci increased, the mean Na showed no significant variation; however, the standard deviation gradually decreased. Notably, if the locus number reached 18 or more, the variation in the standard deviation of Na remarkably reduced. In addition, the standard deviation of Na at 18 loci was less than 5% of the mean Na at 24 loci, with a CV of 4.6%. Conclusions The number of microsatellite loci significantly affects the population genetic diversity analysis of S. japonicum. Eighteen or more microsatellite loci are recommended for analysis of the population genetic diversity of S. japonicum under the current conditions of low-prevalence infection and unbalanced genetic distribution of S. japonicum.

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 This study aimed to investigate the antimicrobial resistance profiles of bacterial strains isolated from pediatric intensive care units(PICU)in China for better antimicrobial therapy.Methods Clinical isolates were collected from 17 institutions,including tertiary care children's hospitals and pediatric department of tertiary general hospitals in China from January 1,2020 to December 31,2022.Antimicrobial susceptibility testing was carried out according to a unified protocol using Kirby-Bauer method or automated systems.Results were interpreted according to the breakpoints released by the Clinical and Laboratory Standards Institute(CLSI)in 2020.Results A total of 10 688 isolates were collected,including gram-positive organisms(39.2％)and gram-negative organisms(60.8％).The top three organisms were S.aureus(13.6％,1 453/10 688),A.baumannii(10.0％,1 067/10 688),and coagulase-negative Staphylococcus(9.9％,1 058/10 688).Multi-drug resistant organisms(MDROs)were very common in children.The prevalence of methicillin-resistant Staphylococcus aureus(MRSA),carbapenem-resistant Enterobacterales(CRE),carbapenem-resistant E.coli,carbapenem-resistant K.pneumoniae(CRKP),carbapenem-resistant A.baumannii(CRAB),and carbapenem-resistant P.aeruginosa(CRPA)was 41.1％,19.4％,8.8％,30.9％,67.4％,and 28.8％,respectively.Overall,more than 50％of Enterobacteriales isolates were resistant to cephalosporins,while nearly 25％of Enterobacteriales isolates were resistant to carbapenems.MDROs were highly resistant to commonly used antibiotics.More than 80％of CRE and CRAB strains were resistant to all beta-lactam antibiotics.CRE and CRAB showed low resistance rates to tigecycline and polymyxin.CRPA showed lower resistance rates to piperacillin,beta-lactamase inhibitor combinations than the resistance rates to third and fourth generation cephalosporins.All of the Staphylococcus and Enterococcus isolates were susceptible to vancomycin and tigecycline.None of PRSP strains isolated from meningitis and nonmeningitis samples were resistant to rifampicin,vancomycin,or linezolid.The prevalence of β-lactamase-negative ampicillin-resistant(BLNAR)strains was 43.3％in Haemophilus influenzae.Conclusions MDROs were prevalent in PICU.It is necessary to establish an effective multidisciplinary team(MDT)to control the antimicrobial resistance.

Objective:To observe the relationship between serum insulin-like growth factor binding protein-3(IGFBP-3),insulin-like growth factor-1(IGF-1)and cardiac function and short-term prognosis in patients with dilated cardiomyopathy(DCM)complicated with heart failure(HF).Methods:102 patients with DCM complicated with HF were selected as study group and they were divided into good prognosis group and poor prognosis group based on prognosis,and 100 patients with simple DCM during the same period were selected as the control group.The cardiac function indicators[left ventricular end systolic volume(LVESV),left ventricular ejection fraction(LVEF),left ventricular end diastolic volume(LVEDV)]and serum IGFBP-3 and IGF-1 levels between the control group and the study group were compared.The correlation between cardiac function and IGFBP-3,IGF-1 was analyzed by pearson analysis.The serum IGFBP-3 and IGF-1 leveles between good prognosis group and poor prognosis group were compared,the correlation between prognosis and IGFBP-3,IGF-1 was analyzed by spearman.Receiver operating characteristic(ROC)curves were used to analyze the predictive value of serum levels of IGFBP-3 and IGF-1 alone and in combination for the short-term prognosis of DCM complicated with HF patients.Results:Compared with control group,study group had higher LVEDV,LVESV,IGFBP-3,IGF-1,and lower LVEF(P＜0.05).Pearson analysis results showed that,IGFBP-3 and IGF-1 were positively correlated with LVEDV and LVESV,while which was negatively correlated with LVEF(P＜0.05).Compared with good prognosis group,poor prognosis group had higher IGFBP-3,IGF-1(P＜0.05).Spearman correlation analysis results showed that,the levels of IGFBP-3 and IGF-1 were positively correlated with the poor prognosis of DCM complicated with HF patients(P＜0.05).The area under the curve(AUC)of serum IGFBP-3,IGF-1 levels,and their combined use for short-term prognosis of DCM complicated with HF patients were 0.715,0.749,and 0.831,respectively.Conclusion:Serum IGFBP-3 and IGF-1 levels are elevated in patients with DCM complicated with HF,and the changes in these two indicators are associated with poor cardiac function and prognosis in patients.The combined detection of IGFBP-3 and IGF-1 levels has a high predictive value for the short-term prognosis of DCM combined with HF.

Objectives:To evaluate the incidence of neurological complications following left ventricular assist device(LVAD)implantation and to investigate related risk factors.Methods:A retrospective analysis was conducted on 151 patients who underwent LVAD implantation at Fuwai Hospital between June 2017 and September 2024.Clinical characteristics and postoperative survival outcomes were compared between patients with and without neurological complications.Results:Neurological complications occurred in 21 patients(13.9%)postoperatively,15 cases were ischemic strokes,5 cases were symptomatic intracranial hemorrhages or subarachnoid hemorrhages,and 1 case was transient ischemic attack(TIA).The total incidence of neurological complications was 0.08 events per person-year(EPPY),ischemic stroke was 0.06 EPPY and hemorrhagic stroke was 0.02 EPPY.Compared with patients without neurological complications,patients with neurological complications had a higher proportion of preoperative aortic regurgitation and tricuspid regurgitation,lower triglyceride levels,a lower rate of concurrent left atrial appendage resection and a higher rate of concurrent aortic valve replacement surgery.Multivariate cox regression analysis revealed that higher preoperative triglyceride levels(HR=0.21,95%CI:0.08-0.56,P=0.002)were associated with neurological complications.The median follow-up time was 508.0(186.5,931.5)days,12 out of 15 cases of ischemic stroke experienced no long-term sequelae,while 3 patients had varying degrees of residual deficits.All 5 patients with hemorrhagic stroke died,with 2 deaths directly attributed to hemorrhage.Kaplan-Meier survival curve analysis indicated that patients with neurological complications had a significantly lower survival rate(log-rank P=0.005).Conclusions:Neurological complications after LVAD implantation are predominantly ischemic strokes.Although less frequent,hemorrhagic strokes are associated with worse outcomes.Higher preoperative triglyceride levels is associated with neurological complications.

Objective This study aims to improve the evaluation index system for the operation of department levels in tertiary public hospitals,strengthen process management,and promote the comprehensive reform and high-quality development of public hospitals.Methods Through literature retrieval and theoretical analysis,a framework for the evaluation index system of department-level operation in tertiary general public hospitals was constructed,and evaluation indicators were initially proposed.Based on the Delphi method,a systematic sorting and adjustment of the evaluation indicators for department-level operation in public hospitals were carried out,and the evaluation index system was finally established.Results The response rates and effec-tive rates of the two rounds of questionnaires using the Delphi method were 90.00％and 83.33％,respectively.The authority co-efficient was 0.8,and the differences in coordination coefficients were statistically significant.The indicators passed the consis-tency test,and the final evaluation index system was composed of 5 first-level indicators,14 second-level indicators,and 43 third-level indicators.Conclusion The evaluation indicators for the operation of department levels in tertiary general public hos-pitals are conducive to guiding hospitals to improve their internal management level and providing support for the implementation of the high-quality development strategy of public hospitals.

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.

Objective To investigate the failure distribution characteristics of semiconductor coolers for medical devices and to analyze the failure mechanisms at different time periods.Methods Firstly,a sample of a pilot semiconductor cooler used in some medical device was used as the object,and all the failure data within the last 4 years were collected,screened and organized.Secondly,the failure data were fitted based on the Weibull distribution,and the failure distribution characteristics were analyzed by shape parameters.Finally,based on the failure distribution characteristics,mechanism analysis was carried out with the typical failure samples selected from three time periods of early failure,random failure and wear-out failure,and the causes of failure were found out.Results The failures of semiconductor coolers occurring in the three time periods presented different types of mechanisms,and the failure distribution conformed to the Weibull distribution.The causes included the mechanical stress damage for early failures,the process defect for random failures and water vapour penetration due to sealant aging after long-term operation of the semiconductor cooler.Conclusion The failure patterns of semiconductor coolers for medical devices are revealed effectively,providing a scientific basis for the design,improvement and reliability assessment of semiconductor coolers used in medical equipment.[Chinese Medical Equipment Journal,2025,46(5):34-38]

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.