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.

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 compare oxytocin combined with ergometrine with oxytocin alone in terms of primary prophylaxis for postpartum hemorrhage (PPH) at the time of cesarean section (CS).Methods:This was a multicenter double-blind randomized controlled interventional study comparing ergometrine combined with oxytocin and oxytocin alone administered at CS. From December 2018 to November 2019, a total of 298 parturients were enrolled in 16 hospitals nationwide. They were randomly divided into experimental group (ergometrine intra-myometrial injection following oxytocin intravenously; 148 cases) and control group (oxytocin intra-myometrial injection following oxytocin intravenously; 150 cases) according to 1∶1 random allocation. The following indexes were compared between the two groups: (1) main index: blood loss 2 hours (h) after delivery; (2) secondary indicators: postpartum blood loss at 6 h and 24 h, placental retention time, incidence of PPH, the proportion of additional use of uterine contraction drugs, hemostatic drugs or other hemostatic measures at 2 h and 24 h after delivery, the proportion requiring blood transfusion, and the proportion of prolonged hospital stay due to poor uterine involution; (3) safety indicators: nausea, vomiting, dizziness and other adverse reactions, and blood pressure at each time point of administration.Results:(1) The blood loss at 2 h after delivery in the experimental group [(402±18) ml] was less than that in the control group [(505±18) ml], and the difference was statistically significant ( P<0.05). (2) The blood loss at 6 h and 24 h after delivery in the experimental group were less than those in the control group, and the differences were statistically significant (all P<0.05). There were no significant differences between the two groups in the incidence of PPH, the proportion of additional use of uterine contraction drugs, hemostatic drugs or other hemostatic measures at 2 h and 24 h after delivery, the proportion requiring blood transfusion, and the proportion of prolonged hospital stay due to poor uterine involution (all P>0.05). (3) Adverse reactions occurred in 2 cases (1.4%, 2/148) in the experimental group and 1 case (0.7%, 1/150) in the control group. There was no significant difference between the two groups ( P>0.05). The systolic blood pressure within 2.0 h and diastolic blood pressure within 1.5 h of drug administration in the experimental group were higher than those in the control group, and the differences were statistically significant ( P<0.05), but the blood pressure of the two groups were in the normal range. Conclusion:The use of ergometrine injection in CS could reduce the amount of PPH, which is safe and feasible.

Objective:To investigate the bacterial composition and antimicrobial resistance profile of clinical isolates from bloodstream infections in China.Methods:The clinical bacterial strains isolated from blood culture were collected during January 2020 to December 2020 in member hospitals of Blood Bacterial Resistant Investigation Collaborative System (BRICS). Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical Laboratory Standards Institute(CLSI, USA). WHONET 5.6 was used to analyze data.Results:During the study period, 10 043 bacterial strains were collected from 54 hospitals, of which 2 664 (26.5%) were Gram-positive bacteria and 7 379 (73.5%) were Gram-negative bacteria. The top 10 bacterial species were Escherichia coli (38.6%), Klebsiella pneumoniae (18.4%), Staphylococcus aureus (9.9%), coagulase-negative Staphylococci (7.5%), Pseudomonas aeruginosa (3.9%), Enterococcus faecium (3.3%), Enterobacter cloacae (2.8%), Enterococcus faecalis (2.6%), Acinetobacter baumannii (2.4%) and Klebsiella spp (1.8%). The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus aureus were 27.6% and 74.4%, respectively. No glycopeptide- and daptomycin-resistant Staphylococci were detected. More than 95% of Staphylococcus aureus were sensitive to rifampicin and SMZco. No vancomycin-resistant Enterococci strains were detected. Extended spectrum β-lactamase (ESBL) producing Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis were 48.4%, 23.6% and 36.1%, respectively. The prevalence rates of carbapenem-resistance in Escherichia coli and Klebsiella pneumoniae were 2.3% and 16.1%, respectively; 9.6% of carbapenem-resistant Klebsiella pneumoniae strains were resistant to ceftazidime/avibactam combination. The prevalence rate of carbapenem-resistance in Acinetobacter baumannii was 60.0%, while polymyxin and tigecycline showed good activity against Acinetobacter baumannii. The prevalence rate of carbapenem-resistance of Pseudomonas aeruginosa was 23.2%. Conclusions:The surveillance results in 2020 showed that the main pathogens of bloodstream infection in China were gram-negative bacteria, while Escherichia coli was the most common pathogen, and ESBL-producing strains declined while carbapenem-resistant Klebsiella pneumoniae kept on high level. The proportion and the prevalence of carbapenem-resistant Pseudomonas aeruginosa were on the rise slowly. On the other side, the MRSA incidence got lower in China, while the overall prevalence of vancomycin-resistant Enterococci was low.

Objective To compare the function recovery of multiple injuries combined with floating knee joint injury and simple knee joint injury,and to analyze the risk factors.Methods A retrospective case control study was conducted to analyze the clinical data of 41 patients with multiple injuries combined with Blake and McBryde Ⅱ A floating knee injury admitted to Xijing Hospital of Air Force Medical University from June 2011 to June 2017.There were 26 males and 15 females,aged 18-76 years,with an average of 34.5 years.There were 25 patients with simple knee joint injury and and 16 patients with multi-joint combined injury involving knee joint and ipsilateral hip joint or ankle joint injury.Surgical fixation was performed in different parts by external fixation,intramedullary nail and plate screw fixation.According to the Kalstr(o)m and Olerud functional evaluation criteria,the excellent and good rate of postoperative functional recovery was compared between the two groups.The surgical fixation methods of the two groups were compared.Logistic regression analysis was performed on the influencing factors of functional recovery.Results The patients were followed up for 1-7 years,with an average of 3 years.The excellent and good rate of overall functional recovery in the two groups was 68％,and the rate was 84％ in simple knee injury group and 44％ in multi-joint combined injury group (P ＜ 0.01).There was no significant difference in the ratio of intramedullary nail and plate screw fixation between the two groups (P ＞ 0.05),while the proportion of the external fixation in the multi-joint combined injury group [31％ (5/16)] was significantly higher than that in the simple knee joint injury group [16％ (4/25)] (P ＜ 0.05).Logistic regression analysis showed that the rate of external fixation was an independent factor affecting the postoperative function (OR =0.15,P ＜ 0.01).Conclusions The postoperative function in multi-joint injury patients is poorer than in the single joint injury patients.The higher rate of using external fixation in multi-joint injury patients is a risk factor.For Blake and McBryde Ⅱ A floating knee injury combined with multi-joint injury,less external fixation should be used,so as to improve the postoperative function.

Objective: To understand hepatitis B virus(HBV) infection in high school students in Guangxi, and to provide scientific foundation for hepatitis B prevention and control strategies. Methods: A selfdesigned epidemiological questionnaire was used among 2 632 participants. Information regarding general demographic characteristics, lifestyle habits, HBV infection history, knowledge of viral hepatitis prevention and control, as well as hepatitis B vaccination. Univariate and multivariate logistics regression analysis was used to analyze associated factors for hepatitis B infection. Results: A total of 192 out of 2 632 participants were found HBsAg positive and 2 440 were HBsAg negative. Multivariate analysis showed that family liver disease history and hairdressing injury positively associated with hepatitis B virus infection risk (OR=3.62, 95% CI=2.28-5.73;OR=3.06, 95%CI=1.94-4.83), and hepatitis B vaccination was negatively associated with hepatitis B virus infection risk (OR=0.08, 95%CI=0.05-0.11). Conclusion Family history of liver disease, hairdressing injury experiences, as well as low rate of hepatitis B vaccination may associate with relatively high prevalence of hepatitis B virus infection among high school students in Guangxi.

Objective: To investigate the efficiency and safety of domestic tyrosine kinase inhibitor (TKI) dasatinib (Yinishu) as second-line treatment for patients with chronic myeloid leukemia in chronic phase (CML-CP). Methods: A retrospective analysis of clinical data of CML-CP patients who received domestic dasatinib as second-line treatment in the CML collaborative group hospitals of Hubei province from March 2016 to July 2018 was performed. The optimal response rate, the cumulative complete cytogenetic response (CCyR), the cumulative major molecular responses (MMR), progression free survival (PFS), event free survival (EFS) and adverse effects (AEs) of the patients were assessed at 3, 6 and 12 months of treatment. Results: A total of 83 CML-CP patients were enrolled in this study. The median follow-up time was 23 months. The optimal response rates at 3, 6 and 12 months in 83 CML-CP patients treated with dasatinib were 77.5% (54/71), 72.6% (61/75) and 60.7% (51/69), respectively. By the end of follow-up, the cumulative CCyR and MMR rates were 65.5% (55/80) and 57.1% (48/73), respectively. The median time to achieving CCyR and MMR was 3 months. During follow-up time, the PFS rate was 94.0% (79/83) and the EFS rate was 77.4% (65/83). The most common non-hematological AEs of dasatinib were edema (32.5%), rash itching (18.1%) and fatigue (13.3%). The common hematological AEs of dasatinib were thrombocytopenia (31.3%), leukopenia (19.3%) and anemia (6.0%). Conclusion Domestic dasatinib was effective and safe as the second-line treatment of CML-CP patients and it can be used as an option for CML-CP patients.

Objective: To compare the biomechanical performance between the single- versus double-threaded cannulated screws in the treatment of femoral neck fractures of Pauwels type Ⅲ. Methods: Models of femoral neck fracture of Pauwels type Ⅲ (70°) were made of the Sawbone synthetic composite femurs. All specimens were divided into 2 groups (n=12). Group A was fixated with single-threaded cannulated screws and group B with double-threaded cannulated screws, both in an inverted triangle configuration. The screws ranged from 90 to 95 mm in length and from 7.3 to 7.5 mm in diameter. All the specimens were subjected to axial stiffness and failure load tests with 7° valgus (simulating normal two-legged weight-bearing stance) and 25° valgus (simulating normal one-legged weight-bearing stance) and torsion test as well. The 2 groups were compared in the torques at axial stiffness angles of 1°, 2°, 3°, 5° and 7°. Results: Group B had significantly greater axial stiffness at 7° valgus and 25° valgus (89±26 N/mm and 128±37 N/mm) and failure load (1,154±368 N) than group A did (36±12 N/mm and 47±16 N/mm; 688±94 N) (P< 0.05). The torques increased with the increase in rotation angle in both groups. However, the torques in group B (3.26±0.96, 4.16±1.23, 4.64±1.13, 5.59±1.26 and 6.53±1.47 N·m) were all significantly larger than in group A (1.44±0.19, 2.03±0.41, 2.33±0.62, 2.74±0.87 and 3.05±1.07 N·m) (P<0.05). Conclusion Double-threaded cannulated screws may provide better biomechanical stability than single-threaded ones, due to their substantial improvement in anti-compression and anti-rotation performance.

Objective: To evaluate the effect of 3DBody software assisted problem-based learning (PBL) teaching in orthopedic teaching. Methods: Undergraduates of clinical medicine from grade 2013 who had internship in our hospital were divided into experimental group and control group. Undergraduates in the experimental group were taught by 3DBody software assisted PBL teaching, with designed questions and the method of using 3DBody software handing to students before class. While undergraduates in the control group were taught by traditional teaching, with the use of textbooks and multimedia courseware. Examination scores of theory and probation were compared between the two groups. Questionnaires were used to evaluate the subjective perception of different teaching method among the participants in each group. Results: Scores of theoretical examination in the experimental group (84.6±5.9) were higher than those in the control group (73.2±6.1); scores of probation examination in the experimental group (17.7±2.1) were significantly higher than those in the control group (12.7±1.9); the degree of satisfaction in the experimental group (9.2±0.8) was significantly higher than that in the control group (7.2±1.3); all differences were statistically significant (P<0.05). Conclusion 3DBody software assisted PBL teaching can significantly improve the effectiveness of orthopedic teaching and enhance students' learning initiative and interest, which is worth promoting.