Objective:To investigate the diagnostic consistency of extrauterine growth restriction (EUGR) assessed by the Fenton 2013 preterm growth charts (Fenton 2013) and the growth charts by International Fetal and Newborn Growth Consortium for the 21st Century (IG-21).Methods:This multicenter retrospective cohort study included 5 591 preterm infants with a gestational age (GA) at birth of less than 32 weeks admitted to 19 member hospitals of the Neonatal Perinatal Collaborative Network of Suxinyun from January 1 st, 2019, to December 31 st, 2024. Clinical data including baseline characteristics, complications, feeding practices and anthropometrics were processed and analyzed. EUGR was assessed using both the Fenton 2013 and the IG-21. A decrease in weight Z-score at discharge compared to admission by more than 1 was defined as longitudinal EUGR, and discharge weight below the P10 for the corresponding corrected GA was defined as cross-sectional EUGR. Diagnostic consistency was assessed using the Kappa coefficient between the 2 standards, and diagnostic performance of the 2 standards was compared using the McNemar test. Risk factors for EUGR under different definitions were analyzed using univariate analysis and multivariate Logistic regression analysis. Results:A total of 5 591 preterm infants were included, with a GA at birth of (29.7±1.6) weeks and a birth weight of (1 360±315) g and at discharge with a corrected GA of (36.3±2.0) weeks and weight of (2 246±370) g. Detection rates of cross-sectional and longitudinal EUGR diagnosed by Fenton 2013 were both higher than those by IG-21 (37.0% (2 214/5 991) vs. 23.7% (1 324/5 591), 61.1% (3 662/5 991) vs. 30.7% (1 714/5 591), χ2=326.77 and 1 358.05, both P<0.001). Using Fenton 2013 as a reference, IG-21 demonstrated superior diagnostic value and consistency in identifying cross-sectional EUGR compared with longitudinal EUGR (sensitivity of 100.0% (3 377/3 377) vs. 99.6% (1 922/1 929), specificity of 59.8% (1 324/2 214) vs. 46.6% (1 707/3 662), positive predictive value of 79.1% (3 377/4 267) vs. 49.6% (1 922/3 877), negative predictive value of 100.0% (1 324/1 324) vs. 99.6% (1 707/1 714), accuracy of 84.1% (4 701/5 591) vs. 64.9% (3 629/5 591), and Kappa 0.64 vs. 0.37, all P<0.001). In multivariate Logistic regression models, risk factors common to EUGR across both standards included smaller GA at birth, lower birth weight, boy, early-onset sepsis, late-onset sepsis and the elder age at full enteral feeding (all P<0.05). Hemodynamically significant patent ductus arteriosus remained an independent risk factor for longitudinal EUGR regardless of whether by the Fenton 2013 or IG-21 standard (adjust odds ratio ( aOR) =1.25 and 1.27, 95% CI 1.09-1.42 and 1.11-1.45). In addition, under the IG-21 standard, severe bronchopulmonary dysplasia was an independent risk factor for cross-sectional EUGR ( aOR=1.54, 95% CI 1.00-2.38), while severe necrotizing enterocolitis was an independent risk factor for longitudinal EUGR ( aOR=2.18, 95% CI 1.01-4.73). Conclusions:IG-21 showed lower detection rates of both cross-sectional and longitudinal EUGR than Fenton 2013, suggesting greater clinical applicability of IG-21 by reducing overdiagnosis while maintaining sensitivity for predicting complications. Across both standards, cross-sectional EUGR facilitates early identification of growth restriction, whereas longitudinal EUGR better tracks dynamic growth patterns and complications of preterm infants.

Objective:To investigate the diagnostic consistency of extrauterine growth restriction (EUGR) assessed by the Fenton 2013 preterm growth charts (Fenton 2013) and the growth charts by International Fetal and Newborn Growth Consortium for the 21st Century (IG-21).Methods:This multicenter retrospective cohort study included 5 591 preterm infants with a gestational age (GA) at birth of less than 32 weeks admitted to 19 member hospitals of the Neonatal Perinatal Collaborative Network of Suxinyun from January 1 st, 2019, to December 31 st, 2024. Clinical data including baseline characteristics, complications, feeding practices and anthropometrics were processed and analyzed. EUGR was assessed using both the Fenton 2013 and the IG-21. A decrease in weight Z-score at discharge compared to admission by more than 1 was defined as longitudinal EUGR, and discharge weight below the P10 for the corresponding corrected GA was defined as cross-sectional EUGR. Diagnostic consistency was assessed using the Kappa coefficient between the 2 standards, and diagnostic performance of the 2 standards was compared using the McNemar test. Risk factors for EUGR under different definitions were analyzed using univariate analysis and multivariate Logistic regression analysis. Results:A total of 5 591 preterm infants were included, with a GA at birth of (29.7±1.6) weeks and a birth weight of (1 360±315) g and at discharge with a corrected GA of (36.3±2.0) weeks and weight of (2 246±370) g. Detection rates of cross-sectional and longitudinal EUGR diagnosed by Fenton 2013 were both higher than those by IG-21 (37.0% (2 214/5 991) vs. 23.7% (1 324/5 591), 61.1% (3 662/5 991) vs. 30.7% (1 714/5 591), χ2=326.77 and 1 358.05, both P<0.001). Using Fenton 2013 as a reference, IG-21 demonstrated superior diagnostic value and consistency in identifying cross-sectional EUGR compared with longitudinal EUGR (sensitivity of 100.0% (3 377/3 377) vs. 99.6% (1 922/1 929), specificity of 59.8% (1 324/2 214) vs. 46.6% (1 707/3 662), positive predictive value of 79.1% (3 377/4 267) vs. 49.6% (1 922/3 877), negative predictive value of 100.0% (1 324/1 324) vs. 99.6% (1 707/1 714), accuracy of 84.1% (4 701/5 591) vs. 64.9% (3 629/5 591), and Kappa 0.64 vs. 0.37, all P<0.001). In multivariate Logistic regression models, risk factors common to EUGR across both standards included smaller GA at birth, lower birth weight, boy, early-onset sepsis, late-onset sepsis and the elder age at full enteral feeding (all P<0.05). Hemodynamically significant patent ductus arteriosus remained an independent risk factor for longitudinal EUGR regardless of whether by the Fenton 2013 or IG-21 standard (adjust odds ratio ( aOR) =1.25 and 1.27, 95% CI 1.09-1.42 and 1.11-1.45). In addition, under the IG-21 standard, severe bronchopulmonary dysplasia was an independent risk factor for cross-sectional EUGR ( aOR=1.54, 95% CI 1.00-2.38), while severe necrotizing enterocolitis was an independent risk factor for longitudinal EUGR ( aOR=2.18, 95% CI 1.01-4.73). Conclusions:IG-21 showed lower detection rates of both cross-sectional and longitudinal EUGR than Fenton 2013, suggesting greater clinical applicability of IG-21 by reducing overdiagnosis while maintaining sensitivity for predicting complications. Across both standards, cross-sectional EUGR facilitates early identification of growth restriction, whereas longitudinal EUGR better tracks dynamic growth patterns and complications of preterm infants.

Objective To summarize the changing prevalence of carbapenem resistance in Enterobacterales based on the data of CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021 for improving antimicrobial treatment in clinical practice.Methods Antimicrobial susceptibility testing was performed using a commercial automated susceptibility testing system according to the unified CHINET protocol.The results were interpreted according to the breakpoints of the Clinical & Laboratory Standards Institute(CLSI)M100 31st ed in 2021.Results Over the seven-year period(2015-2021),the overall prevalence of carbapenem-resistant Enterobacterales(CRE)was 9.43％(62 342/661 235).The prevalence of CRE strains in Klebsiella pneumoniae,Citrobacter freundii,and Enterobacter cloacae was 22.38％,9.73％,and 8.47％,respectively.The prevalence of CRE strains in Escherichia coli was 1.99％.A few CRE strains were also identified in Salmonella and Shigella.The CRE strains were mainly isolated from respiratory specimens(44.23±2.80)％,followed by blood(20.88±3.40)％and urine(18.40±3.45)％.Intensive care units(ICUs)were the major source of the CRE strains(27.43±5.20)％.CRE strains were resistant to all the β-lactam antibiotics tested and most non-β-lactam antimicrobial agents.The CRE strains were relatively susceptible to tigecycline and polymyxins with low resistance rates.Conclusions The prevalence of CRE strains was increasing from 2015 to 2021.CRE strains were highly resistant to most of the antibacterial drugs used in clinical practice.Clinicians should prescribe antimicrobial agents rationally.Hospitals should strengthen antibiotic stewardship in key clinical settings such as ICUs,and take effective infection control measures to curb CRE outbreak and epidemic in hospitals.

Objective To characterize the changing species distribution and antibiotic resistance profiles of respiratory isolates in hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Commercial automated antimicrobial susceptibility testing systems and disk diffusion method were used to test the susceptibility of respiratory bacterial isolates to antimicrobial agents following the standardized technical protocol established by the CHINET program.Results A total of 589 746 respiratory isolates were collected from 2015 to 2021.Overall,82.6％of the isolates were Gram-negative bacteria and 17.4％were Gram-positive bacteria.The bacterial isolates from outpatients and inpatients accounted for(6.0±0.9)％and(94.0±0.1)％,respectively.The top microorganisms were Klebsiella spp.,Acinetobacter spp.,Pseudomonas aeruginosa,Staphylococcus aureus,Haemophilus spp.,Stenotrophomonas maltophilia,Escherichia coli,and Streptococcus pneumoniae.Each microorganism was isolated from significantly more males than from females(P＜0.05).The overall prevalence of methicillin-resistant S.aureus(MRSA)was 39.9％.The prevalence of penicillin-resistant S.pneumoniae was 1.4％.The prevalence of extended-spectrum β-lactamase(ESBL)-producing E.coli and K.pneumoniae was 67.8％and 41.3％,respectively.The overall prevalence of carbapenem-resistant E.coli,K.pneumoniae,Enterobacter cloacae,Pseudomonas aeruginosa,and Acinetobacter baumannii was 3.7％,20.8％,9.4％,29.8％,and 73.3％,respectively.The prevalence of β-lactamase was 96.1％in Moraxella catarrhalis and 60.0％in Haemophilus influenzae.The H.influenzae isolates from children(＜18 years)showed significantly higher resistance rates to β-lactam antibiotics than the isolates from adults(P＜0.05).Conclusions Gram-negative bacteria are still predominant in respiratory isolates associated with serious antibiotic resistance.Antimicrobial resistance surveillance should be strengthened in clinical practice to support accurate etiological diagnosis and appropriate antimicrobial therapy based on antimicrobial susceptibility testing results.

The amino acid sequences of the OmpA protein isolated from Escherichia coli QML2206-1(E.coli QML2206-1)in our laboratory were analyzed for homology with different strains of OmpA proteins using bioinformatics software,and the OmpA protein was analyzed for its physicochemical properties,transmembrane structure and signal peptide prediction,B-cell anti-genic epitope prediction,secondary and tertiary structure prediction.The OmpA gene fragment was ligated with pET-32a vector to construct a prokaryotic expression vector,which was purified by a nickel column affinity purification system after prokaryotic expression and optimization of ex-pression conditions in BL21(DE3).The purified recombinant protein was fully mixed with Freund's adjuvant to immunize mice,and the levels of mouse-specific IgG antibody and the expression levels of cytokines CD4,CD8 and IL-4 in mouse serum were detected by ELISA,and the immuno-protective effect was evaluated by mouse attack protection test.OmpA protein is a hydrophilic protein with no transmembrane structural domains and a secondary structure consisting mainly of irregular coils(47.98％)and α-helices(29.77％),with 12 antigenic epitopes that can bind to anti-bodies produced by B cells.The recombinant protein OmpA with a relative molecular mass of a-bout 55 kDa was successfully obtained by prokaryotic expression,and the highest expression was induced by IPTG concentration of 0.000 4 mmol/L for 6 h at 37 ℃.The serum-specific IgG anti-body potency of recombinant protein immunized mice was up to 1∶32 000;the expression levels of CD4,CD8 and IL-4 in the serum of immunized mice were elevated compared with those of the con-trol group.The survival rate of mice was 80％and 40％after attack with minimum lethal dose(MLD)and 2 times minimum lethal dose(2MLD),respectively.OmpA recombinant protein has good antigenicity and certain immunoprotective effects,and this study provides a technical basis for the next step in the development of a genetically engineered subunit vaccine against yak-appli-cable E.coli based on OmpA protein.

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.

Necrotizing enterocolitis（NEC）is a gastrointestinal emergency commonly seen in premature infants，and its etiology and high-risk factors have not been fully elucidated.Premature infants who receive blood component transfusions are at significantly increased risk of developing NEC，with a higher incidence and mortality rate.This review focuses on a comprehensive analysis of the association between multiple blood component transfusions and NEC，the pathogenesis，prevention measures，and the threshold of blood component transfusions，aiming to provide a reference for the safe and rational use of blood component transfusions in clinical practice，and to guide fulture research directions.

Objective:To evaluate the pulmonary protective effect of individualized positive end-expiratory pressure (PEEP) ventilation guided by driving pressure in patients undergoing rib fracture surgery.Methods:In this prospective randomized controlled trial, 80 American Society of Anesthesiologists Physical Status classification Ⅱ or Ⅲ patients of either sex, aged 18-64 yr, with a body mass index of 19-28 kg/m 2, who underwent elective open reduction and internal fixation of unilateral rib fractures at the Third Hospital of Hebei Medical University from March to October 2024, were selected and divided into 2 groups ( n=40 each) by the random number table method: fixed PEEP ventilation group (group C) and driving pressure-guided individualized PEEP ventilation group (group DP). Group C adopted the ventilation strategy of fixed PEEP with 5 cmH 2O. Group DP adopted the ventilation strategy guided by the driving pressure: PEEP was titrated from 10 cmH 2O, being gradually decreased to 3 cmH 2O at intervals of 1 cmH 2O. Each PEEP level was maintained for 10 respiratory cycles, and the driving pressure of the last cycle was calculated, and the PEEP that could achieve the lowest driving pressure was selected and applied. Lung ultrasound examinations were performed immediately after entering the operating room (T 0) and at 30 min after entering the anesthesia recovery room (T 3), and the lung ultrasound score was recorded. The occurrence of severe postoperative pulmonary complications within 7 days was recorded. Arterial blood gas analysis was performed at T 0, 1 h after PEEP setting (T 1), at the end of suture at the surgical site (T 2) and at T 3, and the oxygenation index was calculated. The peak airway pressure, PEEP and driving pressure were recorded at T 1 and T 2. The duration of the indwelling thoracic drainage tube use and length of postoperative hospital stay were recorded. Results:The incidence of severe postoperative pulmonary complications within 7 days after surgery was 28%(11/40) in group C and 10% in group DP, and the incidence was significantly lower in DP group than in C group ( P<0.05). Compared with group C, the lung ultrasund score was significantly decreased at T 3, the oxygenation index was increased at T 1-3, the PEEP was increased and the driving pressure was decreased at T 1-2, and the length of postoperative hospital stay was shortened in group DP ( P<0.05). Conclusions:Driving pressure-guided individualized PEEP ventilation can decrease the risk of severe postoperative pulmonary complications, alleviate postoperative lung injury and provide a certain degree of lung protection in patients undergoing rib fracture surgery.

Objective:To establish 30-day of age transcutaneous bilirubin (TcB) reference curves for healthy neonates, and to investigate regional variations in bilirubin dynamics.Methods:A multicenter retrospective cohort study was conducted. A total of 220 950 healthy neonates born at a gestational age of 35-<42 weeks, with a birth weight ≥2 000 g, who did not receive phototherapy within 60 h after birth were recruited. All of them underwent remote TcB monitoring using the Bilibaby remote jaundice monitoring system between August 1 st, 2020 and December 31 st, 2024 in 426 hospitals. TcB data were collected within the period from birth to 30-day of age. The P40, P75, and P95 of TcB values were calculated, and dynamic TcB curves for 30-day of age were constructed. Patterns of bilirubin change, rates of change, and transition outcomes were described. Regional comparisons between South and North were conducted using linear mixed-effects models for TcB trajectories and Pearson′s chi-square test for outcome differences. Results:A total of 220 950 neonates were included, of whom 101 711 (46.03%) were female. Gestational age at birth was (38.75±1.12) weeks, and birth weight was (3 272±417) g. TcB levels increased rapidly within 3-day of age, peaked at 4-6-day of age, with peak values at P40, P75, and P95 of 200.6, 239.7 and 275.4 μmol/L (11.8, 14.1 and 16.2 mg/dl), respectively. TcB levels gradually declined thereafter and stabilized after 13-day of age, with values at P40, P75, and P95 fluctuating between 147.9-159.8, 190.4-200.6, and 231.2-239.7 μmol/L (8.7-9.4, 11.2-11.8, 13.6-14.1 mg/dl), respectively. Notably, among neonates categorized as low-or low-intermediate-risk within 3-day of age, 6 700 (12.76%) progressed to intermediate-high or high risk between 4 and 30 days of age. Before 13-day of age, TcB levels in the southern regions were consistently higher than those in the northern regions ( P=0.039); from 14 to 30 days of age, the overall TcB levels had no statistically difference, but the temporal changes in TcB still showed regional differences (degrees of freedom=3, all interaction P<0.05). Among neonates classified as low-or low-intermediate risk within 3-day of age, 25 326 were from southern regions, of whom 4 254 (16.80%) progressed to intermediate-high or high risk between 4 and 30 days of age. In northern regions, 27 193 neonates were classified as low-or low-intermediate risk within 3-day of age, among whom 2 446 (8.99%) progressed to intermediate-high or high risk. The risk progression between the 2 regions had statistically difference ( χ2=716.49, P<0.001). Conclusions:A TcB percentile curve for neonates within 30-day of age was established, revealing that both the overall TcB level and its temporal trend were higher in southern than in northern newborns. These findings provide baseline data to support continuous management of neonatal jaundice.