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 investigate the feasibility of constructing the risk index of Echinococcus infection based on the classification of echinococcosis lesions, so as to provide insights into the management of echinococcosis. Methods The imaging data of echinococcosis cases were collected from epidemiological surveys of echinococcosis in China from 2012 to 2016, and the detection of incident echinococcosis cases was captured from the annual echinococcosis prevention and control reports across provinces (autonomous regions) and Xinjiang Production and Construction Corps in China from 2017 to 2022. After echinococcosis lesions were classified, a risk index of Echinococcus infection was constructed based on the principle of discrete distribution marginal probability and multi-group classification data tests. The correlation between the risk index of Echinococcus infection and the detection of incident echinococcosis cases was evaluated in the provinces (autonomous regions and corps) from 2017 to 2022, and the correlations between the short and medium-term risk indices and between the medium and long-term risk indices of Echinococcus infection were examined using a univariate linear regression model. Results A total of 4 014 echinococcosis cases in China from 2012 to 2016 were included in this study. The short-, medium- and long-term risk indices of E. granulosus infection varied in echinococcosis-endemic provinces (autonomous regions and corps) of China (χ² = 4.12 to 708.65, all P values < 0.05), with high short- (0.058), medium- (0.137) and long-term risk indices (0.104) in Tibet Autonomous Region, and the short-, medium- and long-term risk indices of E. multilocularis infection varied in echinococcosis-endemic provinces (autonomous regions and corps) of China (χ² = 6.74 to 122.60, all P values < 0.05), with a high short-term risk index in Sichuan Province (0.016) and high medium- (0.009) and long-term risk indices in Qinghai Province (0.018). There were no significant correlations between the risk index of E. granulosus infection and the detection of incident cystic echinococcosis cases during the study period (t = −0.518 to 2.265, all P values > 0.05), and strong correlations were found between the risk indices of E. multilocularis infection and the detection of incident alveolar echinococcosis cases (including mixed type) in 2018, 2020, 2021, 2022, during the period from 2017 through 2020, from 2017 through 2021, from 2017 through 2022 (all r values > 0.7, t = 2.521 to 3.692, all P values < 0.05). Linear regression models were established between the risk index of E. multilocular infection and the detection of alveolar echinococcosis cases (including mixed type), and the models were all statistically significant (b = 0.214 to 2.168, t = 2.458 to 3.692, F = 6.044 to 13.629, all P values < 0.05). The regression coefficients for the correlations between the medium- and short-term, and between the long- and medium-term risk indices of E. granulosus infection were 2.339 and 0.765, and the regression coefficients for the correlations between the medium- and short-term, and between the long- and medium-term risk indices of E. multilocular infection were 0.280 and 1.842, with statistical significance seen in both the regression coefficients and regression models (t = 16.479 to 197.304, F = 271.570 to 38 928.860, all P values < 0.05). Conclusions The risk index of Echinococcus infection has been successfully established based on the classification of echinococcosis lesions, which may provide insights into the prevention and control, prediction, diagnosis and treatment, and classified management of echinococcosis.

Objective To establish and validate a Nomogram model for predicting the overall survival(OS)of the patients with intrahepatic cholangiocarcinoma(ICC)based on domestic multicenter data,and screen the beneficiaries of adjuvant chemotherapy based on the prediction model.Methods From December 2011 to December 2017,the data of 278 patients with postoperative pathological diagnosis of ICC from 4 medical centers in our country were collected retrospectively COX regression model was used to screen the independent risk factors of OS and constructed a Nomogram model.This model was used to stratify the risk of OS for all patients and to screen the beneficiaries of adjuvant chemotherapy.Results A total of 278 patients were enrolled,and 23 cases(8.3%)received adjuvant chemotherapy.COX multivariate analysis showed that drinking history,ECOG score,method of hepatectomy,lymph node status,number of tumors,and tumor differentiation were independent risk factors for postoperative OS.The Nomogram model had a C-index of 0.690(95%CI:0.646-0.734)in the training cohort and 0.740(95%CI:0.863-0.617)in the validation cohort.According to risk stratification by Nomogram model,in the high-risk group there was a statistically significant difference in survival between adjuvant chemotherapy and non-adjuvant chemotherapy(P=0.033),whereas in the low-risk group,there was no significant difference in survival(P=0.59).Conclusions Nomogram model based on independent risk factors of OS demonstrated excellent predictive capability for survival and could be used to screen,and identify the patients with ICC who benefit from adjuvant chemotherapy.

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 explore the risk factors and treatments of portal vein thrombosis (PVT) in children after pediatric living donor liver transplantation (pLDLT) .Method:From January 2014 to December 2021, the relevant clinical data were retrospectively reviewed for 975 LDLT children at Department of Pediatric Organ Transplantation of Tianjin First Central Hospital. Based upon the postoperative occurrence of PVT, they were assigned into two groups of PVT (19 cases) and non-PVT (956 cases). Univariate and multivariate analyses were performed for screening the risk factors of PVT post-LDLT and discussing the managements and prognoses of PVT.Result:Among them, overall incidence of PVT post-LDLT was 1.9% (19/975), and median time for an initial occurrence of PVT 8 (1-495) day. Single-factor analysis indicated that donor height ( P=0.014), operative duration ( P=0.002) and vascular interposition ( P=0.001) were correlated with the occurrence of postoperative PVT post-pLDLT. Multifactorial analysis revealed that operative duration ( P=0.008) and vascular interposition ( P<0.01) were independent risk factors for PVT post-pLDLT. For 19 cases of postoperative PVT, the measures included surgical thrombectomy (8 cases), urokinase thrombolysis plus warfarin anticoagulation (3 cases), interventional treatment (3 cases), warfarin anticoagulation (4 cases) and retransplantation (1 cases). After treatment, the outcomes were a disappearance of PVT (15 cases), symptomatic improvement (2 cases) and unrelated mortality (2 cases) . Conclusion:During pLDLT, intraoperative placement of blood vessels and operative duration are independent risk factors for the occurrence of PVT. Timely standardized treatment may achieve satisfactory therapeutic outcomes.

Objective:To explore the reconstruction strategy and technical selection of S3 hepatic vein with middle hepatic vein confluence in pediatric liver transplantation(LT)using living donor left lateral segment to lower the risk of vascular complications caused by variant grafts.Methods:From January 2015 to June 2021, retrospective analysis is performed for 840 consecutive cases of pediatric living donor LT using left lateral segment(LLS).There are 32 cases of S3 hepatic vein with middle hepatic vein confluence with an overall incidence of 3.81%.Individualized reconstruction strategies are implemented according to the specific conditions of variation and different interposition vessels available: group I unification venoplasty technique with interposition vein graft is employed for reconstructing HV from grafts, prolonged S3 is formed into a single opening with S2 and then anastomosed with recipient(21 cases); group Ⅱ dual HV reconstructions were performed(11 cases); venoplasty of recipients'LHV, MHV and inferior vena cava(IVC)is performed for creating a large orifice for anastomosis with S2 HV from graft and S3 is anastomosed with stump of recipient right HV directly or interposed blood vessels.Clinical features and prognosis of two groups, the incidence, treatment and prognosis of HVOO and the incidence of HVOO between variant and non-variant groups were compared.Results:The median follow-up time of variant group(32 cases)is 23.8 month with an incidence of HVOO at 15.6%.During the same period, the non-variant group incidence of HVOO is 4.5%.There is inter-group statistical difference( P=0.014).The only statistical difference between groups Ⅰ and Ⅱ is ultrasonic blood flow velocity of S3 HV at 14 POD [(39.15±16.37)vs(20.05±8.52)cm/s, P=0.001].HVOO occurred in 7 cases and 6 cases respectively in groupⅠ and group Ⅱ.There is no statistical difference( P=0.310).There are no intractable vascular complications.Long-term vascular patency of allogeneic and autologous interposition vein is satisfactory and there is no graft failure or mortality related to HVOO. Conclusions:Selecting strategies and techniques for reconstructing S3 hepatic vein with middle hepatic vein confluence at our center are reasonable, safe and effective.And the overall treatment efficacy is satisfactory.Reasonable selection of multidimensional reconstruction methods and accurate application of various technologies are conducive to improving patient prognosis.

Objective:To evaluate the effect of parental liver donation on early acute cellular rejection(ACR)after liver transplantation(LT)in children aged under one year.Methods:From January 2018 to January 2021, retrospective review is conducted for clinical data of living donor LT recipients and donors aged under 1 year at Tianjin First Central Hospital.Donor livers are assigned into two groups of paternal donor liver(156 cases)and maternal donor liver(206 cases)according to the source of donor liver, Clinical characteristics and postoperative ACR occurrence of two groups are analyzed.Results:The rates of ACR during early postoperative period is 14.9%(54/362), 20.5%(32/156)in paternal liver donor group and 10.7%(22/206)in maternal liver donor group.There is statistically significant difference(λ 2=6.763, P=0.009).In analysis of gender matching of donor recipients, the rates of ACR is 22.6% in paternal donor group and 10.3% in maternal donor group.There is statistically significant difference(λ 2=5.411, P=0.020).Median time of initial postoperative ACR is 13.00(8.25~20.25)day in paternal liver donor group and 17.00(9.00~28.25)day in maternal donor group.The difference is not statistically significant( P>0.05). ACR is mostly mild-to-moderate in two groups . Conclusions:In living donor LT for children aged under 1 year, the rates of early ACR is lower for maternal donor than that for paternal donor, especially in female recipients.

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 study the impact of donor left hepatic vein classification and the reconstruction methods on hepatic venous outflow obstruction (HVOO) after pediatric living-donor liver transplantation using left lateral liver segments.Methods:A retrospective study was performed on the clinical data of 653 children recipients who underwent living-donor liver transplantation with left lateral liver segments from January 2014 to December 2020 at Tianjin First Central Hospital. There were 309 males and 344 females, aged 7.0 (6.0, 10.0) months, with an age range of 3-121 months. Based on the left hepatic vein on preoperative donor enhancement CT as well as the intraoperative reconstruction methods, the recipients were divided into 3 groups: type Ⅰ group ( n=514), anastomosis using a single opening was performed directly between the donor and the recipient; type Ⅱ group ( n=118), angioplasty was performed on two adjacent recipient venous orifices before anastomosis, and type Ⅲ group ( n=21), an interposition vessel was anastomosed to two widely spaced openings or the two veins were anastomosed separately. The preoperative general status of the patient, postoperative HVOO incidences, and graft and recipient survival rates were compared among the three groups. The patients were followed up by outpatient reexamination or telephone. Results:Graft to recipient weight ratio in the type Ⅲ group was smaller than that in the type Ⅰ group and the type Ⅱ group ( P<0.05). For all the 653 patients, the incidence of postoperative HVOO was 4.59% (30/653), with the incidences of HVOO in the 3 groups of patients were 4.1% for the type Ⅰ group (21/514), 5.1% for the type Ⅱ group (6/118), and 14.3% for the type Ⅲ group (3/21), respectively. There was no significant difference among the groups ( P>0.05). The recipient cumulative survival rates at 1 and 3 years after surgery in the type I group were 97.8% and 97.0%, and the corresponding rates in the type Ⅱ group were 96.5% and 94.2%, and in the type Ⅲ group were 94.1% and 86.9%, respectively. There was a significant difference between the type Ⅰ and type Ⅲ groups ( P=0.048). The graft cumulative survival rates at 1 and 3 years in the type Ⅰ group were 97.4% and 96.9%, and the corresponding rates in the type Ⅱ group were 94.9% and 92.5%, and in the type Ⅲ group were 94.1% and 86.9%, respectively. The difference in the postoperative graft cumulative survival rates between the type Ⅰ group and type Ⅱ group was significant ( P=0.044). Conclusions:The anatomy of the left hepatic vein supplying the left lateral liver segment was highly variable, and the majority of the variations could be reconstructed. A reasonable reconstructive method could reduce the incidence of postoperative HVOO and improved the outcomes of the graft.

Objective:To explore the impact of graft recipient weight ratio(GRWR)on pediatric whole liver transplantation in infants aged under 1 year.Methods:From January 2014 to December 2019, clinical data were retrospectively reviewed for 140 children aged under 1 year with whole liver transplantation.They were divided into 3 groups of low GRWR(GRWR<2.5%, 48 cases), middle GRWR(2.5%≤GRWR<5%, 73 cases)and high GRWR(GRWR≥5%, 19 cases). Basic profiles, major postoperative complications and survival rate of graft/recipient were compared.Results:There were 62 males and 78 females with an average age of (7.34±1.81)months and an average weight of(6.81±1.09)kg.The median GRWR was 3.27%(1.33%~8.12%). The higher level of GRWR, the greater age, weight and graft weight of donor in three groups and there was statistical difference ( P<0.05); operative duration, postoperative ICU stay and hospital stay were longer in low GRWR group than those in middle GRWR group and there was statistical difference( P<0.05); The incidence of postoperative hepatic artery thrombosis was higher in low GRWR group than that in middle GRWR group(31.3%vs 8.2%)and there was statistical difference( P<0.05); 4 cases of small-for-size syndrome occurred in low GRWR group, it was significantly different from the other two groups and there was statistical difference( P<0.05); the median follow-up period was(50.7±23.4)months.The survival rates of grafts at 3-month and 1/5-year were 89.6%, 91.8%, 100%; 87.5%, 87.7%, 100%; 87.5%, 87.7%, 100%and there was no inter-group difference( P>0.05). The survival rates of recipients at 3 months, 1 year and 5 years post-operation were 93.8%, 91.8%, 100%; 91.7%, 87.7%, 100%; 91.7%, 87.7%, 100%and there was no inter-group difference( P>0.05). Conclusions:Different from pediatric living donor transplantation, GRWR≥5%does not affect the survival rate of recipient/graft during whole liver transplantation.And GRWR<2.5%may boost the postoperative incidence of hepatic artery thrombosis and small liver syndrome.