Objective:To predict the risk of cryptogenic stroke (CS) patients with right-to-left shunt (RLS) by machine learning, and provide potential solutions for accurate and efficient prediction of CS.Methods:A retrospective analysis of clinical data on 289 subjects with positive RLS detected by contrast-enhanced transcranial Doppler tests (c-TCD) treated in the Department of Neurology at Laoshan Campus, the Affiliated Hospital of Qingdao University, from January 2018 to September 2023, including demographic information, medical history, laboratory test indicators, diagnosis, and treatment.The dataset was randomly divided into a training set and a testing set by the machine learning function train_test_split(), with a ratio of 8∶2.Risk prediction models for CS in RLS subjects were constructed by algorithms such as Logistic regression, decision trees, random forests, extreme gradient boosting, artificial neural networks, gradient boosting, extra trees, and adaptive Boosting.The model performance was evaluated by receiver operating characteristic curves (ROC), area under curve (AUC), confusion matrix, precision, recall, accuracy, F1 score, calibration curves, and decision curve analysis.The optimal model was subjected to interpretability analysis by feature importance and SHAP values.The t-test, Mann-Whitney U test and χ2 test were used for data analysis by SPSS 25.0 software.Delong test was used to compare the differences in AUC between the two models. Results:In 289 RLS subjects, there were 166 cases of CS (57.5%) and 123 cases of non-CS (42.5%).The statistical analysis results showed that blood biochemical indicators such as D-dimer, mean platelet volume, and fibrinogen in CS patients were higher than those in non-CS patients (all P<0.01).There were no statistically significant differences in variables between the training and testing sets(all P>0.05).Random forest model achieved the highest AUC (0.885), precision (0.806), recall (0.879), accuracy (0.810), and F1 score (0.841) for CS risk prediction in the testing set.The calibration curve showed that the random forest model was closest to the reference line, and the decision curve analysis indicated that it had a greater net benefit.The interpretability analysis revealed that high-risk factors included mean platelet volume, D-dimer, international normalized ratio, body mass index, and age. Conclusion:The random forest-based prediction tool exhibits excellent performance, demonstrating high accuracy in predicting CS risk in RLS population.

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 investigate whether the fluctuation of blood pressure variability (BPV) before carotid endarterectomy (CEA) is related to postoperative cerebral perfusion changes in patients with carotid artery stenosis.Methods:A prospective observational cohort study was performed. Forty-seven patients with carotid artery stenosis accepted CEA in Department of Neurosurgery, Guangdong Provincial People's Hospital Affiliated to Southern Medical University from January 2019 to December 2022 were chosen. Patients' blood pressure was closely monitored 3 d before surgery (4 times/d) to obtain their BPV (the maximum △, based on the maximum absolute differences between systolic or diastolic blood pressures measured continuously during the observation period). At the same time, the changes of cerebral perfusion 3 d after surgery were monitored (criteria of cerebral hyperperfusion: newly-appeared delirium and hyperactivity after anesthesia resuscitation or intracranial hemorrhage found by imaging examination; criteria of cerebral hypoperfusion: newly-appeared speech and motor function deficits or aggravation of original cerebral ischemia symptoms after anesthesia resuscitation, or new-found cerebral infarction by imaging examination). Receiver operating characteristic (ROC) curve was used to evaluate the predictive efficacy of BPV before CEA in postoperative cerebral perfusion changes.Results:In these 47 patients, 9 patients (19.1%) had postoperative cerebral perfusion changes: 2 had neurological deficits due to postoperative cerebral infarction, and the other 7 had short-term postoperative delirium or focal neurological deficits (returned to normal after appropriate adjustment of blood pressure). Area under the ROC curve (AUC) of BPV before CEA in predicting postoperative cerebral perfusion changes was 0.876 ( P=0.001, 95% CI: 0.775-0.977). These 47 patients were divided into high BPV group ( n=16) and low BPV group ( n=31) according to the optimal index threshold (27.00), and the statistics showed that significant difference in incidence of cerebral perfusion changes after CEA was noted between the 2 groups ( P<0.05); incidence of postoperative cerebral perfusion changes in the high BPV group was 15.5 times higher than that in the low BPV group ( RR=15.500, P<0.001, 95% CI: 2.120-113.320). Conclusion:BPV before CEA in patients with carotid artery stenosis can well predict the occurrence of postoperative cerebral perfusion changes.

The epidemic of COVID-19 has become the topmost public health threat worldwide. The authors suggested that in addition to strengthening the organization and leadership of the abovementioned work, greater attention be paid to establishing and improving the prevention and control mechanism.Furthermore, special efforts should be given to the safety of the medical workers, by strengthening their infection monitoring and outbreak management. Medical workers in different work areas and positions should be placed under careful protection with due cleaning and disinfection measures. The protection during specimen collection, transportation and medical waste management should also be prioritized. Such special issues in the management of pediatric patients, as allocation of nurses, the screening and management of caregivers, the problem of breastfeeding, and the disinfection of children′s toys and diapers were discussed. This paper also put forward management suggestions for the outpatient department, isolation ward and other key departments, which aim to guide the prevention and control of COVID-19 nosocomial infection in the pediatric outpatient and ward.

The pneumonia caused by the novel coronavirus (2019-nCoV), which began in December 2019, has become the most serious public health problem, threatening people's health and life. This threat is posing a severe challenge on the diagnosis and treatment of 2019-nCoV infection, the prevention and control of hospital cross infection of medical staff. It is suggested that in addition to strengthening the organization and leadership of the abovementioned work, establishing and improving the prevention and control mechanism deserve greater attention. Furthermore, special attention should be given to the safety of the medical staff, strengthening their infection monitoring and outbreak management. Medical staff in different work areas and positions should be placed under careful protection, cleaning and disinfection measures. The protection during specimen collection, transportation and medical waste management should also be prioritized. This paper also put forward management suggestions for the outpatient department, isolation ward and other key departments. These measures are proposed to provide a guidance for the prevention and control of 2019-nCoV nosocomial infection in the pediatric outpatient and ward.