Objective To gain insights into the biological characteristics of different populations of Culex tritaeniorhynchus within and around the Yellow Sea wetland from the perspective of the occurrence of resistance, we investigated the levels of resistance to deltamethrin and kdr gene mutation in the wetland and its peripheral areas. Methods Specimens were collected from Cx. tritaeniorhynchus populations at two monitoring sites in the Rare Bird National Nature Reserve and Tiaozi Ni Wetland Scenic Area, and also from two populations in Yancheng City and the Liuhe District of Nanjing, and the resistance of these mosquitoes to deltamethrin was determined using the CDC biotest bottle method. For each concentration of deltamethrin assessed, a random subset of exposed specimens was selected for amplification of the kdr gene fragment, followed by Sanger sequencing to identify and analyze resistance-associated mutations. Results The LC50 levels of deltamethrin among mosquitoes from the four populations in Luhe, Yancheng, the Rare Bird National Nature Reserve and the Tiaozi Ni Wetland Scenic Area were 2.048 5, 7.798 2, 3.473 3, and 17.695 5 mg/mL, respectively, with corresponding concentrations of deltamethrin ranging from 0.005 to 5.000,0.050 to 50.000,0.050 to 25.000 and 0.050 to 50.000 mg/mL, respectively. Furthermore, the ranges of the KT50 values were 11.76-107.43, 67.05-216.30,29.77-107.43 and 28.40-329.51 min; the 1-h knockdown rates were 34.58%-99.15%, 9.52%-43.80%, 55.09%-73.01%, and 10.09%-68.07%; and the 24-h mortality rates were 12.15%-67.52%,9.52%-79.56%,13.17%-82.21%, and 11.01%-78.99%, respectively. With respect to kdr gene mutation, we assayed a total of 63,70,59, and 57 mosquitoes for the four populations, for which we detected L1014F mutation frequencies of 14.29%, 35.00%, 20.34%, and 31.58%, respectively, with a majority of these mutations being heterozygous for resistance. In addition, five adult mosquitoes were identified has having synonymous mutations at site 1011[i. e. , AAT(asparagine)mutation to AAC(asparagine)]. Conclusions Our findings revealed the clear resistance of Cx. tritaeniorhynchus to deltamethrin in the Yancheng region of the Yellow Sea wetland, and the resistance phenotype and kdr frequency of Cx. tritaeniorhynchus in the wetland environment were comparable to those of Cx. tritaeniorhynchus in the wetland environment, thereby indicating that the resistance of different populations of Cx. tritaeniorhynchus was homogeneous under the pressure of different insecticide selection within and around the wetland. However, the underlying mechanisms need to be further studied.

In recent years,the microorganisms residues in endoscopes have frequently resulted in cross transmis-sion or even the outbreak of hospital-associated infections.It is of great importance to carry out standardized bio-logical surveillance of endoscopes,find out the high-risk links of cleaning and disinfection,and take targeted inter-vention measures to reduce the incidence of endoscopy-related infection.Based on the related guidelines in China and abroad as well as the latest clinical practice researches,the biological surveillance sampling and culture for en-doscopes were summarized in the article so as to enhance the surveillance quality,ensure the reprocessing effect and guarantee the endoscopy-related quality and safety.

Objective To explore the epidemiological characteristics and differences in antimicrobial resistance be-tween catheter-associated urinary tract infection(CAUTI)and non-CAUTI of healthcare-associated infection(HAI),and provide scientific basis for precise clinical prevention and control.Methods Based on the regional HAI surveillance platform in Suzhou City,urinary tract infection(UTI)surveillance data reported by 61 member units from January 2020 to December 2024 were analyzed retrospectively.Pathogen distribution,detection rate of multi-drug-resistant organisms(MDROs),and antimicrobial resistance spectrum characteristics of patients in the CAUTI group and non-CAUTI group were compared.Results The incidence of CAUTI in patients in CAUTI group was 0.99‰,the incidence of healthcare-associated UTI in patients in non-CAUTI group was 0.14％.There was statis-tically significant difference in the distribution of UTI pathogens between the two groups(P＜0.05).The patho-gens of the CAUTI group were mainly Gram-negative bacteria(56.1％),with high proportions of Escherichia coli(19.6％)and Klebsiella pneumoniae(15.0％).In the non-CAUTI group,the proportion of Gram-negative bacteria was higher(64.7％).Antimicrobial susceptibility testing results showed that the resistance rates of Escherichia co-li to tobramycin,cephalosporins,and carbapenems in the CAUTI group were all higher than those in the non-CAU-TI group(all P＜0.05).Except for tigecycline,the resistance rates of Klebsiella pneumoniae to other antimicrobial agents in the CAUTI group were all significantly different from the non-CAUTI group(all P＜0.05).The resis-tance rates of Acinetobacterbaumannii to ticarcillin/clavulanic acid,quinolones,most cephalosporins,carbapenems,and aminoglycosides in the CAUTI group were higher than those of the non-CAUTI group(all P＜0.05).The de-tection rates of MDROs were higher in the CAUTI group,especially that of carbapenem-resistant Klebsiella pneu-moniae,accounting for 57.8％.Conclusion There are significant differences in pathogen distribution and antimi-crobial resistance of UTI between the CAUTI group and the non-CAUTI group.It is necessary to establish a re-gional antimicrobial resistance surveillance system for pathogens in UTI,and provide basis for the rational use of an-timicrobial agents in clinical practice.

Objectives:Comparative analysis of the beagles acute-phase electrocardiographic,hemodynamic,left ventricular flow field status,and energy consumption characteristics of pacing at different sites of conduction system may help to elucidate the scientific mechanism of left bundle branch pacing(LBBP)as a option of physiological pacing therapy.Methods:Eight healthy adult beagles were used in this study.Initially,an active fixation lead was implanted in the right atrial appendage,followed by implantation of another active fixation lead at the right ventricular apex,distal His bundle,and left bundle septal branch,respectively.After connecting a dual-chamber pacemaker,electrocardiographic and acute phase hemodynamic parameters under sinus rhythm,right ventricular apex pacing(RVAP),distal His bundle pacing(DHBP),and LBBP states were collected and analyzed.Three complete cardiac cycles of standard apical three-chamber color Doppler dynamic images were acquired under vector flow mapping(VFM)mode.Offline analysis was performed on obtained parameters including isovolumic contraction period,rapid ejection period,isovolumic relaxation period,rapid filling period,atrial contraction period,and left ventricular intracavitary energy consumption.These parameters were compared under pacing at different sites and the linear correlations of major parameters were analyzed.Results:The QRS duration of baseline intrinsic sinus rhythm,RVAP,DHBP and LBBP were(45.0±4.0)ms,(98.4±6.2)ms,(50.0±4.5)ms and(62.0±4.7)ms,respectively.The LBBP-QRS duration was significantly wider than intrinsic sinus rhythm and DHBP,but significantly narrower than RVAP(all P<0.01).Compared with baseline AOO mode(the pacing rate was performed at 10 beats/min above the intrinsic heart rate),the change of acute phase maximum left ventricular pressure rise rate(LVdP/dtmax)in RVAP,DHBP and LBBP was([-7.89±5.67]% ),([0.74±2.05]% )and([-0.14±3.59]% ),respectively.There was no significant difference in LVdP/dtmax changes between DHBP and LBBP(P=0.667),but both pacing modalities were significantly better than RVAP(all P<0.01).The average energy consumption of the left ventricle under RVAP was significantly higher than that of intrinsic sinus rhythm,DHBP,and LBBP in isovolumic contraction period,rapid ejection period,isovolumic relaxation period,rapid filling period,and atrial contraction period(all P<0.01).However,there was no statistically significant difference in energy consumption among intrinsic sinus rhythm,DHBP,and LBBP during the above five phases(all P>0.05).DHBP and LBBP did not show a significant increase in the number of left ventricular vortices,vortex area,and circulation intensity compared to intrinsic sinus rhythm,and LBBP did not show a significant increase in vortex area and circulation intensity compared to DHBP.Conclusions:Although LBBP canines significantly prolonged the paced QRS duration,it showed no significant differences in acute phase left ventricular hemodynamics,left ventricular flow field status,and energy consumption compared to intrinsic sinus rhythm and DHBP.Performance of LBBP was superior to RVAP.This study may contribute to revealing the theoretical basis of LBBP as a feasible physiological pacing therapy.

OBJECTIVE To retrospectively investigate the incidence of surgical site infection(SSI),distribution and drug resistance of pathogens in 53 hospitals of Suzhou area from 2020 to 2023 so as to provide strategies for pre-vention and control of the hospital-associated infections in Suzhou area.METHODS The data regarding the SSI,distribution and drug resistance of pathogens were statistically analyzed through Suzhou City Regional Hospital In-fection Surveillance Platform.RESULTS The incidence of SSI was 0.24％among the 53 hospitals from 2020 to 2023.Staphylococcus aureus,Enterococcus faecalis,Staphylococcus epidermidis,Enterococcus faecium and Staphylococcus haemolyticus ranked the top 5 species of gram-positive bacteria;Escherichia coli,Klebsiella pneumoniae,Pseudomonas aeruginosa,Enterobacter cloacae and Acinetobacter baumannii ranked the top 5 spe-cies of gram-negative bacteria.There were significant differences in the distributions of S.aureus,K.pneumoniae and A.baumannii in the superficial,deep and organ cavities(P＜0.05).The isolation rate of carbapenem-resistant Acinetobacter baumannii(CRAB)was 69.23％,and the isolation rate of methicillin-resistant Staphylococcus au-reus(MRSA)was 42.14％.The drug resistance rate of the S.aureus strains to oxacillin reached up to 40.24％;the drug resistance rates of the A.baumannii to imipenem and meropenem reached up 63.00％and 65.80％,re-spectively.The drug resistance rates of the K.pneumoniae strains to imipenem and meropenem approximated to 30％,and the drug resistance rate to tigecycline was 19.84％.CONCLUSIONS The total incidence of SSI shows a downward trend in the 53 hospitals of Suzhou area.The S.aureus is the major species of pathogens,and some of the pathogens show high drug resistance rates.

OBJECTIVE To investigate the changes of etiological submission rates before the antimicrobial therapy after a series of intervention measures were taken so as to optimize the use and management of antibiotics.METHODS A total of 97,146 patients who were hospitalized and treated with antibiotics in the First Affiliated Hospital of Soochow University from Jul.2021 to Jun.2024 were recruited as the research subjects.Jan.2023 was set as the time node of intervention,the time period from Jul.2021 to Dec.2022 was assigned as the pre-interven-tion group,and the time period from Jan.2023 to Jun.2024 was assigned as the post-intervention group.The etio-logical submission rates before the antimicrobial therapy were observed by interrupted time series before and after the intervention measures were taken.The changes of isolation rates of multidrug-resistant organisms and inci-dence of hospital-associated infections were estimated by chi-square test.RESULTS The etiological submission rates before the antimicrobial therapy,etiological submission rates before combined use of major antibiotics and etiological submission rates relating to diagnosis of hospital-associated infections were higher after the intervention than before the intervention(all P＜0.05).The interrupted time series analysis showed that from the perspective of long-term benefit,the intervention measures could raise the etiological submission rates before the use of re-stricted,special grades of antibiotics and general antibiotics,and the net benefits were 0.85％,0.67％and 0.68％,respectively(all P＜0.05);there was no significant difference in the etiological submission rate before the com-bined use of major antibiotics.After the intervention,the incidence of multidrug-resistant organisms infection de-creased from 0.46％to 0.27％(P＜0.001);the isolation rate of multidrug-resistant organisms was 25.73％after the intervention,27.47％before the intervention,and there was no significant difference.CONCLUSIONS Scientif-ic and reasonable interventions may effectively raise the etiological submission rates before the antimicrobial thera-py,however,the etiological submission rate for combined use of major antibiotics and the isolation rate of multi-drug-resistant organisms are not improved remarkably.It is necessary to further formulate targeted interven-tion measures so as to push forward high-quality development of infection control.

In recent years,the microorganisms residues in endoscopes have frequently resulted in cross transmis-sion or even the outbreak of hospital-associated infections.It is of great importance to carry out standardized bio-logical surveillance of endoscopes,find out the high-risk links of cleaning and disinfection,and take targeted inter-vention measures to reduce the incidence of endoscopy-related infection.Based on the related guidelines in China and abroad as well as the latest clinical practice researches,the biological surveillance sampling and culture for en-doscopes were summarized in the article so as to enhance the surveillance quality,ensure the reprocessing effect and guarantee the endoscopy-related quality and safety.

OBJECTIVE To investigate the characteristics of multidrug-resistant organisms(MDROs)infections in the patients of intensive care units(ICUs)so as to provide supportive data for precise prevention and control of in-fections.METHODS From Jan.2016 to Dec.2023,the case-time incidence of hospital-associated MDROs infec-tions,constituent ratios,infection sites and characteristics of drug resistance were observed and compared among the patients from 5 different ICUs of the First Affiliated Hospital of Suzhou University by means of real-time sur-veillance system of hospital-associated infection.RESULTS Among the ICU patients,there were 1322 case-times of hospital-associated infections with MDROs,and the case-time incidence rate was 4.67％,which varied in the ICUs.The patients with lower respiratory tract infections accounted for 66.51％,the patients with bloodstream infections 14.53％,the patients with urinary tract infections 10.78％.The distribution of infection sites,distribu-tion of pathogens and etiological spectrum of infection sites varied according to the ICUs.In general,the percenta-ges of carbapenem-resistant Klebsiella pneumoniae(CRKP)and carbapenem-resistant Acinetobacter baumannii(CRAB)infections were highest,which were 35.63％(471/1322)and 38.28％(506/1322),respectively.The drug resistance rates of the CRKP strains to polymyxin B and ceftazidime-avibactam were low,and the drug re-sistance rate to tigecycline was 38.44％.The drug resistance rates of the CRAB strains to polymyxin B and tigecy-cline were 10.00％and 21.64％,respectively.The carbapenem-resistant Pseudomonas aeruginosa(CRPA)strains showed high sensitivity to most of the antibiotics.The drug resistance rates of the methicillin-resistant Staphylococcus aureus(MRSA)strains to tetracycline,levofloxacin,gentamicin,moxifloxacin and ciprofloxacin were high.CONCLUSION It is necessary for the hospital to reasonably use antibiotics based on the result of sur-veillance of MDROs in the ICUs and take targeted prevention measures for the infections.

To enhance the emergency response capabilities of medical institutions and community public health,and strengthen the efficiency in handling major sudden infectious disease events.METHODS Relying on community grid management and under the integration of medical treatment and disease prevention,a multi-level medical service system was established,funding guarantees were implemented,and software and hardware supports were strengthened by emphasizing infection control training and introducing modern technological means like artifi-cial intelligence.In addition,stratified screening for infectious diseases among different populations was carried out in an orderly manner.RESULTS The grid management model for infectious diseases based on the integration of medical treatment and disease prevention in Suzhou was preliminarily formed and applied to the screening and treatment of COVID-19 and hepatitis C.The epidemic prevention teams,jointly established by medical institutions and community-based medical and preventive organizations,were critical for emergency response to major sud-den infectious diseases and became a key component of epidemic prevention and control.CONCLUSION The grid management strategy for infectious diseases based on the integration of medical treatment and disease preven-tion in Suzhou demonstrates certain reference value in enhancing emergency response capabilities and efficiency for major sudden infectious diseases,as well as in the field of disease prevention and control.

OBJECTIVE To investigate the current status and risk factors of carbapenem-resistant gram-negative or-ganisms(CRO)infections in neurosurgical ICU patients,and to construct and validate their prediction models.METHODS Clinical data and active screening microbiological results of 113 patients admitted to the Neurosurgical Intensive Care Unit(ICU)of The First Affiliated Hospital of Soochow University between Jul.2023 and Jan.2024 were retrospectively collected,and the patients were divided into a CRO-infected group(n=28)and a non-CRO-infected group(n=85).Predictive variables were screened using LASSO regression and logistic regression.Risk prediction models were constructed using random forest(RF)and logistic regression,the performance of the mod-el was evaluated by analyzing the area under the receiver operating characteristic(ROC)curve(AUC),calibration curves,and decision curves,and internal validation was performed using the bootstrap resampling method.RESULTS Among 113 neurosurgical ICU patients,28 cases developed CRO infections,with an infection rate of 24.78％.The highest infection rate was observed in lower respiratory tract infection,with 17 cases(15.04％).The predominant CRO pathogens were carbapenem-resistant Klebsiella pneumoniae(CRKP)and carbapenem-re-sistant Acinetobacter baumannii(CRAB),accounting for 50.00％and 42.86％of cases respectively.The AUC values for the RF prediction model and nomogram prediction modeling groups were 0.881 and 0.787 respectively,with Brier scores of 0.114 and 0.146,and threshold probabilities of net benefit ranging from 10％to 97％and 12％to 62％respectively.The RF prediction model exhibited superior discrimination,calibration,and clinical u-tility.The RF prediction model demonstrated that days of combined use of meropenem and vancomycin,GCS score,intestinal colonization,and hospitalization history were important predictors for CRO infections.CONCLUSION The prediction model for CRO infections in neurosurgical ICU patients established based on random forest algorithm has good predictive performance,and can be intervened with preventive and control measures for important predictive factors.