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 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 explore the value of synthetic MRI and dynamic contrast-enhanced MRI (DCE-MRI) in differentiating benign and malignant breast lesions.Methods:Totally 116 patients (female, aged 22-80 years) with suspicious breast lesions found by clinical examination in General Hospital of Ningxia Medical University from September 2020 to March 2021 were retrospectively analyzed. All patients received synthetic MRI and DCE-MRI scans, and the quantitative parameters of synthetic MRI [T 1, T 2, proton density (PD) value before enhancement of breast lesions (T 1pre, T 2pre, PD pre) and T 1, T 2, PD value after enhancement of breast lesions (T 1Gd, T 2Gd, PD Gd)] were measured. The difference before and after enhancement (?T 1, ?T 2, ?PD) and the ratio before and after enhancement(T 1ratio, T 2ratio, PD ratio) were calculated. All lesions were confirmed by biopsy or surgery. Independent sample t test was used to compare the differences of parameters between benign and malignant lesions, and parameters with statistically significant differences were analyzed by multivariate logistic regression to screen out independent predictors for the diagnosis of breast malignant lesions. The efficacy of quantitative parameters alone and in combination with DCE-MRI, was evaluated by the receiver operating characteristic (ROC) curve. Results:Of 116 patients, 27 patients were benign and 89 patients were malignant. T 2pre, PD pre, T 2Gd, PD Gd, ?T 2, T 1ratio and T 2ratio values of malignant patients were lower than those of benign lesions ( P<0.05). Multivariate logistic regression analysis showed that T 2pre (OR=0.961,95%CI 0.926-0.993, P=0.022)and PD pre(OR=0.945, 95%CI 0.908-0.979, P=0.003) were independent predictors of breast malignant lesions. The area under ROC curve (AUC) of T 2pre+PD pre in differentiating benign and malignant breast lesions was 0.77, and the accuracy, sensitivity, specificity, positive predictive value and negative predictive value were 0.84, 0.87, 0.68, 0.92 and 0.56, respectively. The AUC of T 2pre+PD pre combined with DCE-MRI in differentiating benign and malignant breast lesions was 0.95, indicating the best diagnostic efficiency, and higher than that of DCE-MRI alone (0.92)( Z=2.20, P<0.05). Conclusions:T 2pre and PD pre values of synthetic MRI can be used as reference parameters for differentiating benign and malignant breast lesions. Synthetic MRI combined with DCE-MRI can effectively improve the diagnostic efficiency of breast malignant lesions.