This study aimed at conducting retrospective analysis of the clinical symptoms and genetic mutations in 20 children with Gitelman syndrome treated at the Affiliated Children′s Hospital of Nanjing Medical University from August 2015 to November 2022 and also explored the molecular mechanism of the pathogenic high-frequency mutation D486N in the Chinese population.

Objective To investigate the distribution and antimicrobial resistance profiles of the common pathogens isolated from urine from 2015 to 2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods The bacterial strains were isolated from urine and identified routinely in 51 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Antimicrobial susceptibility was determined by Kirby-Bauer method,automatic microbiological analysis system and E-test according to the unified protocol.Results A total of 261 893 nonduplicate strains were isolated from urine specimen from 2015 to 2021,of which gram-positive bacteria accounted for 23.8％(62 219/261 893),and gram-negative bacteria 76.2％(199 674/261 893).The most common species were E.coli(46.7％),E.faecium(10.4％),K.pneumoniae(9.8％),E.faecalis(8.7％),P.mirabilis(3.5％),P.aeruginosa(3.4％),SS.agalactiae(2.6％),and E.cloacae(2.1％).The strains were more frequently isolated from inpatients versus outpatients and emergency patients,from females versus males,and from adults versus children.The prevalence of ESBLs-producing strains in E.coli,K.pneumoniae and P.mirabilis was 53.2％,52.8％and 37.0％,respectively.The prevalence of carbapenem-resistant strains in E.coli,K.pneumoniae,P.aeruginosa and A.baumannii was 1.7％,18.5％,16.4％,and 40.3％,respectively.Lower than 10％of the E.faecalis isolates were resistant to ampicillin,nitrofurantoin,linezolid,vancomycin,teicoplanin and fosfomycin.More than 90％of the E.faecium isolates were ressitant to ampicillin,levofloxacin and erythromycin.The percentage of strains resistant to vancomycin,linezolid or teicoplanin was＜2％.The E.coli,K.pneumoniae,P.aeruginosa and A.baumannii strains isolated from ICU inpatients showed significantly higher resistance rates than the corresponding strains isolated from outpatients and non-ICU inpatients.Conclusions E.coli,Enterococcus and K.pneumoniae are the most common pathogens in urinary tract infection.The bacterial species and antimicrobial resistance of urinary isolates vary with different populations.More attention should be paid to antimicrobial resistance surveillance and reduce the irrational use of antimicrobial agents.

Objective To understand the distribution and changing resistance profiles of clinical isolates of Enterococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Enterococcus according to the unified protocol of CHINET program by automated systems,Kirby-Bauer method,or E-test strip.The results were interpreted according to the Clinical & Laboratory Standards Institute(CLSI)breakpoints in 2021.WHONET 5.6 software was used for statistical analysis.Results A total of 124 565 strains of Enterococcus were isolated during the 7-year period,mainly including Enterococcus faecalis(50.7％)and Enterococcus faecalis(41.5％).The strains were mainly isolated from urinary tract specimens(46.9％±2.6％),and primarily from the patients in the department of internal medicine,surgery and ICU.E.faecium and E.faecalis strains showed low level resistance rate to vancomycin,teicoplanin and linezolid(≤3.6％).The prevalence of vancomycin-resistant E.faecalis and E.faecium was 0.1％and 1.3％,respectively.The prevalence of linezolid-resistant E.faecalis increased from 0.7％in 2015 to 3.4％in 2021,while the prevalence of linezolid-resistant E.faecium was 0.3％.Conclusions The clinical isolates of Enterococcus were still highly susceptible to vancomycin,teicoplanin,and linezolid,evidenced by a low resistance rate.However,the prevalence of linezolid-resistant E.faecalis was increasing during the 7-year period.It is necessary to strengthen antimicrobial resistance surveillance to effectively identify the emergence of antibiotic-resistant bacteria and curb the spread of resistant pathogens.

Objective To examine the changing antimicrobial resistance profile of Enterobacter spp.isolates in 53 hospitals across China from 2015 t0 2021.Methods The clinical isolates of Enterobacter spp.were collected from 53 hospitals across China during 2015-2021 and tested for antimicrobial susceptibility using Kirby-Bauer method or automated testing systems according to the CHINET unified protocol.The results were interpreted according to the breakpoints issued by the Clinical & Laboratory Standards Institute(CLSI)in 2021(M100 31st edition)and analyzed with WHONET 5.6 software.Results A total of 37 966 Enterobacter strains were isolated from 2015 to 2021.The proportion of Enterobacter isolates among all clinical isolates showed a fluctuating trend over the 7-year period,overall 2.5％in all clinical isolates amd 5.7％in Enterobacterale strains.The most frequently isolated Enterobacter species was Enterobacter cloacae,accounting for 93.7％(35 571/37 966).The strains were mainly isolated from respiratory specimens(44.4±4.6)％,followed by secretions/pus(16.4±2.3)％and urine(16.0±0.9)％.The strains from respiratory samples decreased slightly,while those from sterile body fluids increased over the 7-year period.The Enterobacter strains were mainly isolated from inpatients(92.9％),and only(7.1±0.8)％of the strains were isolated from outpatients and emergency patients.The patients in surgical wards contributed the highest number of isolates(24.4±2.9)％compared to the inpatients in any other departement.Overall,≤ 7.9％of the E.cloacae strains were resistant to amikacin,tigecycline,polymyxin B,imipenem or meropenem,while ≤5.6％of the Enterobacter asburiae strains were resistant to these antimicrobial agents.E.asburiae showed higher resistance rate to polymyxin B than E.cloacae(19.7％vs 3.9％).Overall,≤8.1％of the Enterobacter gergoviae strains were resistant to tigecycline,amikacin,meropenem,or imipenem,while 10.5％of these strains were resistant to polycolistin B.The overall prevalence of carbapenem-resistant Enterobacter was 10.0％over the 7-year period,but showing an upward trend.The resistance profiles of Enterobacter isolates varied with the department from which they were isolated and whether the patient is an adult or a child.The prevalence of carbapenem-resistant E.cloacae was the highest in the E.cloacae isolates from ICU patients.Conclusions The results of the CHINET Antimicrobial Resistance Surveillance Program indicate that the proportion of Enterobacter strains in all clinical isolates fluctuates slightly over the 7-year period from 2015 to 2021.The Enterobacter strains showed increasing resistance to multiple antimicrobial drugs,especially carbapenems over the 7-year period.

Objective To understand the changing distribution and antimicrobial resistance profiles of Proteus,Morganella and Providencia in hospitals across China from January 1,2015 to December 31,2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods Antimicrobial susceptibility testing was carried out following the unified CHINET protocol.The results were interpreted in accordance with the breakpoints in the 2021 Clinical & Laboratory Standards Institute(CLSI)M100(31 st Edition).Results A total of 32 433 Enterobacterales strains were isolated during the 7-year period,including 24 160 strains of Proteus,6 704 strains of Morganella,and 1 569 strains of Providencia.The overall number of these Enterobacterales isolates increased significantly over the 7-year period.The top 3 specimen source of these strains were urine,lower respiratory tract specimens,and wound secretions.Proteus,Morganella,and Providencia isolates showed lower resistance rates to amikacin,meropenem,cefoxitin,cefepime,cefoperazone-sulbactam,and piperacillin-tazobactam.For most of the antibiotics tested,less than 10％of the Proteus and Morganella strains were resistant,while less than 20％of the Providencia strains were resistant.The prevalence of carbapenem-resistant Enterobacterales(CRE)was 1.4％in Proteus isolates,1.9％in Morganella isolates,and 15.6％in Providencia isolates.Conclusions The overall number of clinical isolates of Proteus,Morganella and Providencia increased significantly in the 7-year period from 2015 to 2021.The prevalence of CRE strains also increased.More attention should be paid to antimicrobial resistance surveillance and rational antibiotic use so as to prevent the emergence and increase of antimicrobial resistance.

Objective To understand the changing distribution and antimicrobial resistance profiles of Klebsiella strains in 52 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Antimicrobial susceptibility testing was carried out according to the unified CHINET protocol.The susceptibility results were interpreted according to the breakpoints in the Clinical & Laboratory Standards Institute(CLSI)M100 document.Results A total of 241,549 nonduplicate Klebsiella strains were isolated from 2015 to 2021,including Klebsiella pneumoniae(88.0％),Klebsiella aerogenes(5.8％),Klebsiella oxytoca(5.7％),and other Klebsiella species(0.6％).Klebsiella strains were mainly isolated from respiratory tract(48.49±5.32)％.Internal medicine(22.79±3.28)％,surgery(17.98±3.10)％,and ICU(14.03±1.39)％were the top 3 departments where Klebsiella strains were most frequently isolated.K.pneumoniae isolates showed higher resistance rate to most antimicrobial agents compared to other Klebsiella species.Klebsiella isolates maintained low resistance rates to tigecycline and polymyxin B.ESBLs-producing K.pneumoniae and K.oxytoca strains showed higher resistance rates to all the antimicrobial agents tested compared to the corresponding ESBLs-nonproducing strains.The K.pneumoniae and carbapenem-resistant K.pneumoniae(CRKP)strains isolated from ICU patients demonstrated higher resistance rates to majority of the antimicrobial agents tested than the strains isolated from non-ICU patients.The CRKP strains isolated from adult patients had higher resistance rates to most of the antimicrobial agents tested than the corresponding CRKP strains isolated from paediatric patients.Conclusions The prevalence of carbapenem-resistant strains in Klebsiella isolates increased greatly from 2015 to 2021.However,the Klebsiella isolates remained highly susceptible to tigecycline and polymyxin B.Antimicrobial resistance surveillance should still be strengthened for Klebsiella strains.

Objective To investigate the changing distribution and antibiotic resistance profiles of clinical isolates of Staphylococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Staphylococcus according to the unified protocol of CHINET(China Antimicrobial Surveillance Network)using disk diffusion method and commercial automated systems.The CHINET antimicrobial resistance surveillance data from 2015 to 2021 were interpreted according to the 2021 CLSI breakpoints and analyzed using WHONET 5.6.Results During the period from 2015 to 2021,a total of 204,771 nonduplicate strains of Staphylococcus were isolated,including 136,731(66.8％)strains of Staphylococcus aureus and 68,040(33.2％)strains of coagulase-negative Staphylococcus(CNS).The proportions of S.aureus isolates and CNS isolates did not show significant change.S.aureus strains were mainly isolated from respiratory specimens(38.9±5.1)％,wound,pus and secretions(33.6±4.2)％,and blood(11.9±1.5)％.The CNS strains were predominantly isolated from blood(73.6±4.2)％,cerebrospinal fluid(12.1±2.5)％,and pleural effusion and ascites(8.4±2.1)％.S.aureus strains were mainly isolated from the patients in ICU(17.0±7.3)％,outpatient and emergency(11.6±1.7)％,and department of surgery(11.2±0.9)％,whereas CNS strains were primarily isolated from the patients in ICU(32.2±9.7)％,outpatient and emergency(12.8±4.7)％,and department of internal medicine(11.2±1.9)％.The prevalence of methicillin-resistant strains was 32.9％in S.aureus(MRSA)and 74.1％in CNS(MRCNS).Over the 7-year period,the prevalence of MRSA decreased from 42.1％to 29.2％,and the prevalence of MRCNS decreased from 82.1％to 68.2％.MRSA showed higher resistance rates to all the antimicrobial agents tested except trimethoprim-sulfamethoxazole than methicillin-susceptible S.aureus(MSSA).Over the 7-year period,MRSA strains showed decreasing resistance rates to gentamicin,rifampicin,and levofloxacin,MRCNS showed decreasing resistance rates to gentamicin,erythromycin,rifampicin,and trimethoprim-sulfamethoxazole,but increasing resistance rate to levofloxacin.No vancomycin-resistant strains were detected.The prevalence of linezolid-resistant MRCNS increased from 0.2％to 2.3％over the 7-year period.Conclusions Staphylococcus remains the major pathogen among gram-positive bacteria.MRSA and MRCNS were still the principal antibiotic-resistant gram-positive bacteria.No S.aureus isolates were found resistant to vancomycin or linezolid,but linezolid-resistant strains have been detected in MRCNS isolates,which is an issue of concern.

Objective:To explore the effect of different HER2 expression levels and gene amplification on the efficacy of immunotherapy in metastatic urothelial carcinoma (UC).Methods:The clinical data of 77 patients with metastatic UC who received immunotherapy from June 2017 to April 2021 after failure to the previous chemotherapy were analyzed retrospectively, including 49 males and 28 females with the median age of 62 years. The primary tumors located in bladder in 28 cases (36.4%), renal pelvis in 25 cases (32.5%) and ureter in 24 cases (31.2%). The common metastatic sites included: lymph nodes (n = 45, 58.4%), lung (n = 40, 51.9%), bone (n = 20, 26.0%) and liver (n = 16, 20.8%). 27 patients with bladder UC received surgery on the primary tumors including radical cystectomy (n = 18), partial cystectomy (n = 4) and transurethral resection (n = 5). 43 patients with renal pelvis or ureteral UC received surgery on the primary tumors including radical nephroureterectomy (n = 38), local resection (n = 3) and palliative resection (n = 2). Postoperative intravesical chemotherapy was performed in 15 cases, adjuvant radiotherapy was performed in 6 cases. 3 patients who emerged postoperative bladder recurrence received local radiotherapy. 7 patients received radiotherapy and 1 case received microwave ablation to their metastatic sites. All patients had received first-line chemotherapy and 30 patients (40.0%) had received at least second-line treatment including 70 cases (90.9%) with platinum containing chemotherapy. All 77 patients received anti-PD-1 treatment. 38 patients received sequential regimen after failed to the anti-PD-1 therapy, including antibody-drug conjugate (n = 17), chemotherapy (n = 18) and chemotherapy combined with anti-angiogenesis drugs (n = 12). Immunohistochemical (IHC) staining was used to detect the expression level of HER2 protein in the tumor tissues (74 cases from primary tumors and 3 cases from metastatic tumors) obtained from the initial diagnosis. For patients with HER2 IHC (+ + ), the copy number (CN) of HER2 gene was detected by next-generation sequencing (NGS). HER2 copy number amplification [CN (+ )] was defined as CN ≥ 4, and HER2 copy number non-amplification [CN(-)] was defined as CN < 4. HER2 IHC (0) was defined as HER2 negative, IHC (+ ) or IHC (+ + ) / CN (-)was defined as HER2 low expression, while IHC (+ + ) / CN(+ ) and IHC (+ + + ) were defined as HER2 high expression. Chi-square test or Fisher exact test were used to evaluate the correlation between HER2 expression and objective response rate (ORR) after anti-PD-1 treatment. Kaplan-Meier method and log-rank test were used to compare the differences of median progression free survival (PFS) and overall survival (OS) under different HER2 expression status.Results:All the 77 patients received a median of 11 (range: 2 - 45) doses of anti-PD-1 treatment with a median duration of treatment of 6.4 (range: 1.5 - 47.8) months and the ORR was 33.8% (26/77). The median follow-up time was 30.9 months. The overall median PFS time was 5.8 (95% CI: 3.0 - 8.6) months and the median OS time was 23.6 (95% CI: 8.5 - 38.7) months. HER2 IHC tests were performed in 77 patients. HER2 IHC levels of (0), (+ ), (+ + ) and (+ + + ) were found in 33 (42.9%), 19 (24.7%), 20 (26.0%) and 5 (6.5%) patients, respectively. HER2 copy number was detected in 20 patients with IHC (+ + ), while 1 CN(+ ) and 19 CN(-) were found. The ORR of HER2 negative, low expression and high expression patients were 42.4% (14/33) vs. 31.6% (12/38) vs. 0 (0/6) ( P = 0.08), respectively. The median PFS of the three groups were 11.0 months, 3.7 months and 1.8 months, respectively, with significant differences in overall and pairwise comparison( P=0.001). The median OS of patients with HER2 negative and low expression after anti-PD-1 treatment were 23.6 months and 22.7 months, respectively, while the median OS of patients with HER2 high expression had not been reached, with no significant difference in the overall comparison ( P=0.623). Conclusions:For patients with metastatic UC received anti-PD-1 treatment, the PFS of patients with high HER2 expression was significantly worse than that of patients with low or negative HER2 expression. HER2 expression may have potential value in predicting the efficacy of immunotherapy for metastatic UC who failed the previous chemotherapy, which needs further research.

[Abstract] Objective: Elevated levels of soluble PD-L1 (sPD-L1) are associated with worse prognosis of renal cell carcinoma and multiple myeloma. However, the regulatory roles and functions of sPD-L1 in advanced melanoma are not fully understood. This study was designed to evaluate the association between circulating sPD-L1 concentrations and prognosis of patients with advanced acral or mucosal melanoma. Methods: A total of 102 untreated patients with advanced acral and mucosal melanoma admitted to Peking University Cancer Hospital between January 2012 and December 2015 were enrolled in this study. In the meanwhile, peripheral blood samples were obtained from 40 healthy donors. Circulating sPD-L1 concentrations were determined using an enzyme-linked immunosorbent assay. Results: The advanced melanoma cohort included 58 acral melanoma patients and 44 mucosal melanoma patients. The pre-treatment concentration of sPD-L1 (2.91±2.23 ng/ml) in plasma of patients group was elevated as compared with that in healthy donors (0.59 ng/ml). The concentration of sPD-L1 in serum was significantly upregulated in 39/102 (38.2%) patients and significantly associated with increased LDH level (P=0.021) and number of Tregs (P=0.017). The overall survival rates of patients with high or low concentrations of sPD-L1 were statistically different (8.5 months [high level] vs 11.6 months [low level], P=0.022). Conclusion: sPD-L1 concentration is elevated in patients with advanced acral or mucosal melanoma, which may play an important role in predicting prognosis.

[Abstract] Objective: To explore the expression patterns of melanoma lineage antigens and nuclear antigen Ki-67 and their correlations with survival in melanoma patients. Methods: A retrospective analysis was conducted to analyze the pathological data of melanoma patients treated at the Department of Melanoma, Peking University Cancer Hospital from February 2008 to August 2020, mainly including the expression patterns of melanoma lineage antigens (S-100, HMB-45, Melan-A) and Ki-67, demographics, clinical features and survival. The correlation between expression patterns of melanoma lineage antigens, Ki-67 and melanoma-specific survival (MSS) was analyzed. Results: In total, 603 patients were included in this study. The median follow-up time was 47.4 months. The positive rates of S-100, HMB, and Melan-A were 92.8%, 92.1% and 90.0%, respectively. The percentages of patients with melanoma lineage antigen scores (S-100, HMB-45 and Melan-A was scored each, as 1 when positive and 0 when negative) of 0, 1, 2, and 3 were 0.5%, 5.0%, 15.6%, and 78.8%, respectively. The percentages of patients with Ki-67 scores of 0, 1, 2, and 3 were 43.0%, 36.3%, 16.3%, and 4.5%, respectively. Ki-67 was highly expressed in mucosal and progressive melanomas. In a multivariate analysis, Ki-67 expression was an independent prognostic factor for poorer MSS (HR=1.506, 95%CI: 1.248-1.818, P<0.001) as the incidence of MSS event increased by 50% per 25% increase in Ki-67 expression, whereas there was no statistical correlation between melanoma lineage antigen expression and MSS (HR=0.991, 95%CI: 0.759-1.293, P=0.94). Conclusion: High expressions melanoma lineage antigens are ubiquitous in melanoma tissues, and Ki-67 is an independent prognostic factor for MSS.