Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of national bloodstream infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:During the study period，9 035 strains of Gram-negative bacteria were collected from 51 hospitals，of which 7 895（87.4%）were Enterobacteriaceae and 1 140（12.6%）were non-fermenting bacteria. The top 5 bacterial species were Escherichia coli（ n=4 510，49.9%）， Klebsiella pneumoniae（ n=2 340，25.9%）， Pseudomonas aeruginosa（ n=534，5.9%）， Acinetobacter baumannii complex（ n=405，4.5%）and Enterobacter cloacae（ n=327，3.6%）. The ESBLs-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus spp. were 47.1%（2 095/4 452），21.0%（427/2 033）and 41.1%（58/141），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（58/4 510）and 13.1%（307/2 340）；62.1%（36/58）and 9.8%（30/307）of CREC and CRKP were resistant to ceftazidime/avibactam combination，respectively. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 59.5%（241/405），while less than 5% of Acinetobacter baumannii complex was resistant to tigecycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 18.4%（98/534）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of main Gram-negative bacteria resistance among different regions，with statistically significant differences in the prevalence of CRKP and CRPA（ χ2=20.489 and 20.252， P<0.001）. The prevalence of CREC，CRKP，CRPA，CRAB，ESBLs-producing Escherichia coli and Klebsiella pneumoniae were higher in provinicial hospitals than those in municipal hospitals（ χ2=11.953，81.183，10.404，5.915，12.415 and 6.459， P<0.01 or <0.05），while the prevalence of CRPA was higher in economically developed regions（per capita GDP ≥ 92 059 Yuan）than that in economically less-developed regions（per capita GDP <92 059 Yuan）（ χ2=6.240， P=0.012）. Conclusions:The proportion of Gram-negative bacteria in bloodstream infections shows an increasing trend，and Escherichia coli is ranked in the top，while the trend of CRKP decreases continuously with time. Decreasing trends are noted in ESBLs-producing Escherichia coli and Klebsiella pneumoniae. Low prevalence of carbapenem resistance in Escherichia coli and high prevalence in CRAB complex have been observed. The composition ratio and antibacterial spectrum of bloodstream infections in different regions of China are slightly different，and the proportion of main drug resistant bacteria in provincial hospitals is higher than those in municipal hospitals.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-positive bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-positive bacteria from blood cultures in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:A total of 3 163 strains of Gram-positive pathogens were collected from 51 member units，and the top five bacteria were Staphylococcus aureus（ n=1 147，36.3%），coagulase-negative Staphylococci（ n=928，29.3%）， Enterococcus faecalis（ n=369，11.7%）， Enterococcus faecium（ n=296，9.4%）and alpha-hemolyticus Streptococci（ n=192，6.1%）. The detection rates of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）were 26.4%（303/1 147）and 66.7%（619/928），respectively. No glycopeptide and daptomycin-resistant Staphylococci were detected. The sensitivity rates of Staphylococcus aureus to cefpirome，rifampin，compound sulfamethoxazole，linezolid，minocycline and tigecycline were all >95.0%. Enterococcus faecium was more prevalent than Enterococcus faecalis. The resistance rates of Enterococcus faecium to vancomycin and teicoplanin were both 0.5%（2/369），and no vancomycin-resistant Enterococcus faecium was detected. The detection rate of MRSA in southern China was significantly lower than that in other regions（ χ2=14.578， P=0.002），while the detection rate of MRCNS in northern China was significantly higher than that in other regions（ χ2=15.195， P=0.002）. The detection rates of MRSA and MRCNS in provincial hospitals were higher than those in municipal hospitals（ χ2=13.519 and 12.136， P<0.001）. The detection rates of MRSA and MRCNS in economically more advanced regions（per capita GDP≥92 059 Yuan in 2022）were higher than those in economically less advanced regions（per capita GDP<92 059 Yuan）（ χ2=9.969 and 7.606， P=0.002和0.006）. Conclusions:Among the Gram-positive pathogens causing bloodstream infections in China， Staphylococci is the most common while the MRSA incidence decreases continuously with time；the detection rate of Enterococcus faecium exceeds that of Enterococcus faecalis. The overall prevalence of vancomycin-resistant Enterococci is still at a low level. The composition ratio of Gram-positive pathogens and resistant profiles varies slightly across regions of China，with the prevalence of MRSA and MRCNS being more pronounced in provincial hospitals and areas with a per capita GDP≥92 059 yuan.

Background::Pulmonary arterial hypertension (PAH) is characterized by excessive proliferation of small pulmonary arterial vascular smooth muscle cells (PASMCs), endothelial dysfunction, and extracellular matrix remodeling. G protein-coupled receptor kinase 2 (GRK2) plays an important role in the maintenance of vascular tone and blood flow. However, the role of GRK2 in the pathogenesis of PAH is unknown.Methods::GRK2 levels were detected in lung tissues from healthy people and PAH patients. C57BL/6 mice, vascular smooth muscle cell-specific Grk2-knockout mice ( Grk2?SM22), and littermate controls ( Grk2flox/flox) were grouped into control and hypoxia mice ( n = 8). Pulmonary hypertension (PH) was induced by exposure to chronic hypoxia (10%) combined with injection of the SU5416 (cHx/SU). The expression levels of GRK2 and Yes-associated protein (YAP) in pulmonary arteries and PASMCs were detected by Western blotting and immunofluorescence staining. The mRNA expression levels of Grk2 and Yes-associated protein ( YAP) in PASMCs were quantified with real-time polymerase chain reaction (RT-PCR). Wound-healing assay, 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide (MTT) assay, and 5-Ethynyl-2′-deoxyuridine (EdU) staining were performed to evaluate the proliferation and migration of PASMCs. Meanwhile, the interaction among proteins was detected by immunoprecipitation assays. Results::The expression levels of GRK2 were upregulated in the pulmonary arteries of patients with PAH and the lungs of PH mice. Moreover, cHx/SU-induced PH was attenuated in Grk2?SM22 mice compared with littermate controls. The amelioration of PH in Grk2?SM22 mice was accompanied by reduced pulmonary vascular remodeling. In vitro study further confirmed that GRK2 knock-down significantly altered hypoxia-induced PASMCs proliferation and migration, whereas this effect was severely intensified by overexpression of GRK2. We also identified that GRK2 promoted YAP expression and nuclear translocation in PASMCs, resulting in excessive PASMCs proliferation and migration. Furthermore, GRK2 is stabilized by inhibiting phosphorylating GRK2 on Tyr86 and subsequently activating ubiquitylation under hypoxic conditions. Conclusion::Our findings suggest that GRK2 plays a critical role in the pathogenesis of PAH, via regulating YAP expression and nuclear translocation. Therefore, GRK2 serves as a novel therapeutic target for PAH treatment.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical bacterial isolates from bloodstream infections in China in 2021.Methods:The clinical bacterial strains isolated from blood culture from member hospitals of Blood Bacterial Resistant Investigation Collaborative System (BRICS) were collected during January 2021 to December 2021. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical Laboratory Standards Institute (CLSI). WHONET 5.6 was used to analyze data.Results:During the study period, 11 013 bacterial strains were collected from 51 hospitals, of which 2 782 (25.3%) were Gram-positive bacteria and 8 231 (74.7%) were Gram-negative bacteria. The top 10 bacterial species were Escherichia coli (37.6%), Klebsiella pneumoniae (18.9%), Staphylococcus aureus (9.8%), coagulase-negative Staphylococci (6.3%), Pseudomonas aeruginosa (3.6%), Enterococcus faecium (3.6%), Acinetobacter baumannii (2.8%), Enterococcus faecalis (2.7%), Enterobacter cloacae (2.5%) and Klebsiella spp (2.1%). The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus aureus were 25.3% and 76.8%, respectively. No glycopeptide- and daptomycin-resistant Staphylococci was detected; more than 95.0% of Staphylococcus aureus were sensitive to ceftobiprole. No vancomycin-resistant Enterococci strains were detected. The rates of extended spectrum B-lactamase (ESBL)-producing isolated in Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis were 49.6%, 25.5% and 39.0%, respectively. The prevalence rates of carbapenem-resistance in Escherichia coli and Klebsiella pneumoniae were 2.2% and 15.8%, respectively; 7.9% of carbapenem-resistant Klebsiella pneumoniae was resistant to ceftazidime/avibactam combination. Ceftobiprole demonstrated excellent activity against non-ESBL-producing Escherichia coli and Klebsiella pneumoniae. Aztreonam/avibactam was highly active against carbapenem-resistant Escherichia coli and Klebsiella pneumoniae. The prevalence rate of carbapenem-resistance in Acinetobacter baumannii was 60.0%, while polymyxin and tigecycline showed good activity against Acinetobacter baumannii (5.5% and 4.5%). The prevalence of carbapenem-resistance in Pseudomonas aeruginosa was 18.9%. Conclusions:The BRICS surveillance results in 2021 shows that the main pathogens of blood stream infection in China are gram-negative bacteria, in which Escherichia coli is the most common. The MRSA incidence shows a further decreasing trend in China and the overall prevalence of vancomycin-resistant Enterococci is low. The prevalence of Carbapenem-resistant Klebsiella pneumoniae is still on a high level, but the trend is downwards.

Objective:To investigate the effects of hypertensive disorders during pregnancy (HDP) on preterm newborns in terms of umbilical cord blood serum ferritin (SF), hemoglobin (Hb) at birth and outcome.Methods:Among inpatients of the First Maternity and Infant Health Hospital Affiliated to Tongji University from October 1, 2015 to December 31, 2016, totally 1 419 cases of preterm newborns were prospectively collected.Preterm infants whose mothers with diagnosis of HDP were recruited as the HDP group.Meanwhile, premature newborns whose mothers without HDP were recruited as the control group.Umbilical cord blood SF levels, Hb levels at birth, outcome of preterm newborns and the basic information for maternity were compared between the two groups.The data of normal distribution between the two groups were compared by independent sample t test.The count data was tested by χ2, and the count data with frequency <5 was tested by Fisher′ s exact test. Results:SF levels of HDP group were significantly lower than the control group [(85.6±67.2) μg/L vs. (103.9±95.5) μg/L]. But Hb levels of HDP group were much higher than the control group [(206.2±33.8) g/L vs. (193.2±31.9) g/L]. The difference between two groups was statistically significant ( t=2.791, 4.825 all P<0.05). Umbilical cord blood SF levels were negatively correlated with Hb levels at birth ( r=-0.120, P<0.001). Moreover, compared to the control group, statistically significant lower incidence of neonatal respiratory distress syndrome (NRDS), pneumonia and bronchopulmonary dysplasia (BPD) in HDP group was observed (all P<0.05). Conclusions:HDP was correlated with umbilical cord blood SF levels and Hb levels at birth in premature newborns.Higher Hb levels and relatively lower incidences of NRDS, pneumonia and BPD were observed in these newborns delivered by mothers with diagnosis of HDP.

To compare the performance of self-inflating bag (SIB) with T-piece resuscitator (TPR) in neonatal resuscitation.Methods:This study involved the trainees participating in a Neonatal Resuscitation Simulation Camp (NRSC) organized by Shanghai First Maternity and Infant Hospital in December 2019. They were trained to provide positive pressure ventilation with the two devices on artificial lungs. Ventilation parameters including peak inspiratory pressure (PIP), positive end-expiratory pressure (PEEP), PIP in pulmonary alveoli (PIP alv), mean airway pressure (MAP), frequency, inspiratory time (Ti), tidal volume and minute ventilation volume were recorded and analyzed by independent sample t-test or rank sum test. Results:The PIP alv, PIP, oxygen flow rate, tidal volume and minute ventilation volume delivered by TPR were significantly lower than those by SIB [(17.18±1.61) vs (24.05±4.29) cmH 2O (1 cmH 2O=0.098 kPa), t=－6.87; (17.91±1.35) vs (29.97±4.50) cmH 2O, t=－14.06; (3.65±0.25) vs (6.88±1.59) L/min, t=－11.33; (15.90±1.81) vs (24.02±4.29) ml/min, t=－10.99; (664.71±88.94) vs (1 069.49±205.68) ml/min, t=－9.89; all P<0.001]. However, compared with SIB, the PEEP in pulmonary alveoli, Ti, duration of ventilation, inspiratory to expiratory ratio were increased when using TPR [(4.76(4.69-5.57) vs 0.19(0.12-4.10) cmH 2O, T=1 190.00; (0.59±0.15) vs (0.43±0.09) s, t=5.01; (1.46±0.23) vs (1.36±0.11) s, t=2.15; 0.71±0.22 vs 0.47±0.13, t=5.14; all P<0.05]. Conclusion:TPR could deliver more stable and safer PIP, PEEP and tidal volume than SIB and keeping MAP at a stable level during positive pressure ventilation on artificial lungs.

Team training significantly affects the performance of clinicians in neonatal resuscitation, which plays an important role in improving outcomes of asphyxiated newborns. Since 2016, team training was formally described in the Textbook of Neonatal Resuscitation, including 10 key points, which were summarized into three core elements in this review: teamwork, communication, and leadership. We review the application of these three elements in current team training and the main training approaches, aiming to offer a framework for standardized team training and to improve the success rate of neonatal resuscitation.

Objective To study the perinatal outcomes of monochorionic diamnionic ( MCDA ) twins.Method A retrospective study had been conducted to analyze the outcomes of MCDA twins delivered in Hospital from Jan 2011 to Dec 2012.According to whether complicated with twin to twin transfusion syndrome ( TTTS, n=14 ) and/or selective intrauterine growth restriction ( sIUGR, n=41 ) , the infants enrolled in the study were assigned into complicated group (n=55) and uncomplicated group (n=90).The infants with sIUGR were further subdivided into three groups .The outcomes of the neonates were compared between the groups.Result A total of 145 pairs of MCDA twins were delivered , 285 neonates (12 of them died after birth ) and 5 cases of stillbirth. The gestational age at delivery in complicated group were significantly lower than those in uncomplicated group (33.8 ±2.8weeks vs.35.5 ±1.6weeks, P<0.001);The birth weight in complicated group ( the birth weight of the bigger baby was 2072 ±460 g vs.2520 ± 383 g, the smaller one 1620 ±477 g vs.2320 ±373 g ) were significantly lighter than those in uncomplicated group;The incidence of fetal death in complicated MCDA twin pregnancies (7.3% vs.0) was significantly higher than controls .Neonatal outcomes of fetuses complicated with sIUGRⅠ ( n=23 ) were similar to controls.Neonates complicated with TTTS, sIUGRⅡ(n =6) or sIUGRⅢ (n =12) had significantly increased incidence of respiratory distress syndrome , asphyxia, cardiac disorders, retinopathy of prematurity and neonatal death compared with controls .Conclusion Neonates of MCDA with TTTS or sIUGR had more complications compared with uncomplicated MCDA twins .The fetuses with abnormal umbilical artery Doppler blood flow are more vulnerable to stillbirth , neonatal death and other serious adverse outcomes .

Objective: To investigate the incidence and pathogen distribution of ventilator-associated pneumonia (VAP) among preterm infants admitted to level Ⅲ neonatal intensive care units (NICU) in China. Method: A prospective study was conducted in 25 level Ⅲ NICU, enrolling all preterm infants <34 weeks gestational age admitted to the participating NICU within the first 7 days of life from May 2015 to April 2016. Chi-square test, t test and Mann-Whitney U test were used for statistical analysis. Result: A total of 7 918 patients were enrolled, within whom 4 623(58.4%) were males. The birth weight was (1 639±415) g and the gestational age was (31.4±2.0) weeks; 4 654(58.8%) infants required non-invasive mechanical ventilation and 2 154(27.2%) required intubation. Of all the mechanically ventilated patients, VAP occurred in 95 patients. The overall VAP rate was 7.0 episodes per 1 000 ventilator days, varying from 0 to 34.4 episodes per 1 000 ventilator days in different centers. The incidence of VAP was 9.6 and 6.0 per 1 000 ventilator days in children′s hospitals and maternity-infant hospitals respectively, without significant differences (t=1.002, P=0.327). Gram-negative bacilli (76 strains, 91.6%) were the primary VAP microorganisms, mainly Acinetobacter baumannii (24 strains, 28.9%), Klebsiella pneumonia (23 strains, 27.7%), and Pseudomonas aeruginosa (10 strains, 12.0%). Conclusion The incidence of VAP in China is similar to that in developed counties, with substantial variability in different NICU settings. More efforts are needed to monitor and evaluate the preventable factors associated with VAP and conduct interventions that could effectively reduce the occurrence of VAP.

Objective To establish a reference range of cancellous bone ultrasonic backscatter coefficient (BSC) in term neonates,and to determine the significance of BSC in bone nutritional status in term newborns and infants.Methods Six hundred and sixty-five term newborns,who were born in Shanghai First Maternity and Infant Hospital from July 2014 to August 2014,were enrolled.On the third day and the 42nd day after birth,all infants underwent ultrasonic measurement of the calcaneum bone using a broadband-non-focus ultrasonic transducer at three frequencies (2.25,3.5 and 5 MHz).MATLAB software was used to analyze the backscatter signals.Clinical data of the infants,including gestational age,birth weight and birth age,were recorded at the same time.Statistical analyses of the data included variance analysis,Tukey's test,rank sum test,Dunn test and Pearson or Spearman correlation analysis.Results (1) Of the 665 infants,335 were male.The mean gestational age at birth was (38.0± 1.9) weeks,and the mean birth weight was (3 1524±226) g.(2) On the third day,there were significant differences in BSC values acquired at 2.25 and 3.5 MHz among the groups with different gestational ages or birth weights (2.25 MHz:H=9.842 and 17.271;3.5 MHz:H=6.275 and 21.450,respectively,all P＜0.05).At 3.5 and 2.25 MHz,BSC values were positively correlated with gestational age (r=0.047 and 0.035,respectively,both P＜0.05) and birth weight (r=0.125 and 0.186,both P＜0.05).(3) On the 42nd day,significant differences in BSC were observed at each frequency among the groups with different gestational ages or birth weights (gestational age:H=76.832,16.498 and 32.756;birth weight:H=70.014,18.095 and 34.126;all P＜0.01).Gestational age and birth weight were positively correlated with BSC value acquired at each frequency (r=0.397,0.286 and 0.272 for gestational age,0.451,0.223 and 0.196 for birth weight;all P＜0.01).Conclusions A preliminary BSC reference percentile in term-born infants is established.There are positive correlations between BSC value and newborn gestational age and birth weight at certain frequencies,which can reflect the status of the newborn's cancellous bone.Determination of BSC value should be performed during the follow-up period to assess the nutritional status of neonatal bone.