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.

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.

Objective To construct a deep learning-based artificial intelligence model to automatically quantify left ventricular ejection fraction (LVEF) using static views of echocardiography. Methods The study included data of 1, 902 adults with left ventricular multi-slice echocardiographic views at end-systole and end-diastole. The collected dataset was divided into development set (1, 610 cases, with 1, 252 cases for model training and 358 cases for parameter adjustment), internal test set (177 cases for internal validation), and external test set (115 cases for external validation and generalization testing). The model achieved left ventricular segmentation and automatic quantification of LVEF through precise identification of the left ventricular endocardial boundary and inspection of key points. The Dice coefficient was employed to evaluate the performance of the left ventricular segmentation model, while the Pearson correlation coefficient and the intraclass correlation coefficient were used to assess the correlation and consistency between the automatically measured LVEF and the reference standard. Results The left ventricular segmentation model performed well, with Dice coefficients ≥ 0.90 for both the internal and external independent test sets; the agreement between the automatically measured LVEF and the cardiologists' manual measurements was moderate, with Pearson correlation coefficients ranging from 0.46 to 0.71 and intragroup correlation analysis agreements from 0.39 to 0.57 for the internal test set; and Pearson correlation coefficients for the independent external test set were 0.26 to 0.54 and intra-group correlation analysis agreement of 0.23 to 0.50. Conclusion In this study, a left ventricular segmentation model with better performance is constructed, and initial application of the model for automatic quantification of LVEF for two-dimensional echocardiography has general performance, which requires further optimisation of the algorithm to improve the model generalisation.

Objective:To investigate the epidemiological and clinical characteristics of human parainfluenza viruses (HPIVs) infection among hospitalized children with community-acquired pneumonia (CAP) in China, and provide basic data for diagnosis, treatment and prevention of HPIVs infection.Methods:From November 2014 to February 2020, 5 448 hospitalized children with CAP were enrolled in 14 hospitals in 11 provinces and municipalities directly under the Central Government in southern China and northern China. Nasopharyngeal aspirates or throat swabs were collected, and the nucleic acids of 18 types respiratory viruses including HPIV1-4 were screened by suspension array technology. Demographic data and clinical information were collected for statistical analysis.Results:The total detection rate of HPIVs in 5 448 children with CAP was 8.83% (481/5 448), and the detection rate in males was higher than that in females (62.79% vs. 37.21%; χ2=0.000, P=0.992). The detection rate of HPIVs in 1~< 3 years age group was higher than that in other age groups, and the difference was statistically significant ( χ2=61.893, P<0.001). The detection rate of HPIVs in the northern region was higher than that in the southern region (9.02% vs 8.65%), but the difference was not statistically significant ( χ2=0.239, P=0.625). The prevalence of HPIV1-4 in northern and southern China was not completely same. HPIV1 was mainly prevalent in autumn in both northern and southern regions. HPIV2 was prevalent in summer in northern China, and the detection rate was low in southern China. HPIV3 reached its peak in both spring and summer in both northern and southern China, but its duration was longer in southern China than in northern China. HPIV4 is mainly popular in autumn in both southern China and northern China. Among 481 children infected with HPIVs, 58.42% (281/481) were infected with HPIV alone, and the main clinical manifestations were cough (90.75%) and fever (68.68%). Out of the HPIV-positive cases, 42.62% (205/481) were co-infected with another type of HPIV or a different virus, while 11.43% (55/481) had co-infections with two or more different viruses. HPIV3 was the most common type of co-infection with other viruses. HPIV3 infection accounted for the largest proportion (76.80%) in 47 HPIVs-positive children with severe pneumonia. Conclusions:HPIVs is one of the most important pathogens causing CAP in children in China, and children under 3 years of age are the main populations of HPIVs infection. The prevalence characteristics of all types of HPIVs in children in the north and south are not completely same. HPIV3 is the dominant type of HPIV infections and causes more severe diseases.

Objective: To evaluate the safety of simultaneous administration of quadrivalent influenza split virion vaccine and 23-valent pneumococcal polysaccharide vaccine in adults aged 60 years and older. Methods: From November 2021 to May 2022, eligible participants aged 60 years and older were recruited in Taizhou City, Jiangsu Province, China, and a total of 2 461 participants were ultimately enrolled in this study. Each participant simultaneously received one dose of quadrivalent influenza split virion vaccine and one dose of 23-valent pneumococcal polysaccharide vaccine. The safety was observed within 28 days after vaccination. Safety information was collected through voluntary reporting and regular follow-ups. Results: All 2 461 participants completed the simultaneous administration of both vaccines and the safety follow-ups for 28 days after vaccination. The mean age of the participants was (70.66±6.18) years, with 54.61% (1 344) being male, and all participants were Han Chinese residents. About 22.51% (554) of the participants had underlying medical conditions. The overall incidence of adverse reactions within 0-28 days after simultaneous vaccination was 2.07% (51/2 461), mainly consisting of Grade 1 adverse reactions [1.83% (45/2 461)], with no reports of Grade 4 or higher adverse reactions or vaccine-related serious adverse events. The incidence of local adverse reactions was 0.98% (24/2 461), primarily presenting as pain at the injection site [0.93% (23/2 461)]. The incidence of systemic adverse reactions was 1.42% (35/2 461), with fever [0.85% (21/2 461)] being the main symptom. In the group with underlying medical conditions and the healthy group, their overall incidence of adverse reactions was 2.53% (14/554) and 1.94% (37/1 907), respectively. The incidence of local adverse reactions in the two groups was 1.62% (9/554) and 0.79% (15/1 907), respectively, and the incidence of systemic adverse reactions was 1.44% (8/554) and 1.42% (27/1 907), respectively, with no statistically significant differences between them (all P>0.05). Conclusion: It is safe for adults aged 60 years and older to receive quadrivalent influenza split virion vaccine and 23-valent pneumococcal polysaccharide vaccine at the same time.

Objective: To evaluate the safety of simultaneous administration of quadrivalent influenza split virion vaccine and 23-valent pneumococcal polysaccharide vaccine in adults aged 60 years and older. Methods: From November 2021 to May 2022, eligible participants aged 60 years and older were recruited in Taizhou City, Jiangsu Province, China, and a total of 2 461 participants were ultimately enrolled in this study. Each participant simultaneously received one dose of quadrivalent influenza split virion vaccine and one dose of 23-valent pneumococcal polysaccharide vaccine. The safety was observed within 28 days after vaccination. Safety information was collected through voluntary reporting and regular follow-ups. Results: All 2 461 participants completed the simultaneous administration of both vaccines and the safety follow-ups for 28 days after vaccination. The mean age of the participants was (70.66±6.18) years, with 54.61% (1 344) being male, and all participants were Han Chinese residents. About 22.51% (554) of the participants had underlying medical conditions. The overall incidence of adverse reactions within 0-28 days after simultaneous vaccination was 2.07% (51/2 461), mainly consisting of Grade 1 adverse reactions [1.83% (45/2 461)], with no reports of Grade 4 or higher adverse reactions or vaccine-related serious adverse events. The incidence of local adverse reactions was 0.98% (24/2 461), primarily presenting as pain at the injection site [0.93% (23/2 461)]. The incidence of systemic adverse reactions was 1.42% (35/2 461), with fever [0.85% (21/2 461)] being the main symptom. In the group with underlying medical conditions and the healthy group, their overall incidence of adverse reactions was 2.53% (14/554) and 1.94% (37/1 907), respectively. The incidence of local adverse reactions in the two groups was 1.62% (9/554) and 0.79% (15/1 907), respectively, and the incidence of systemic adverse reactions was 1.44% (8/554) and 1.42% (27/1 907), respectively, with no statistically significant differences between them (all P>0.05). Conclusion: It is safe for adults aged 60 years and older to receive quadrivalent influenza split virion vaccine and 23-valent pneumococcal polysaccharide vaccine at the same time.