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 investigate the effect and mechanism of α-lipoic acid(ALA) on the formation of hypertrophic scar(HTS) in rabbit ears. Methods: Eighteen New Zealand white rabbits were randomly divided into normal group, model group and 4%ALA group. After 28 days of treatment, the changes of scar related indexes were evaluated by hematoxylin-eosin(HE) staining, Masson pine(Masson) staining and immunohistochemical staining, the changes of oxidative stress related indexes were evaluated, and the expression of antioxidant pathway related proteins was detected by Western blotting. Results: The color, texture and volume of scar in 4%ALA group were lighter and softer than those in model group. The results of HE, Masson staining and immunohistochemical staining showed that the number of fibrous cells and the degree of fibrosis in the 4%ALA group were less than those in the model group. In the 4%ALA group, the content of malondialdehyde(MDA) was lower than that of the model group(P<0.001), the content of hydroxyproline(Hyp) was lower than that of the model group(P<0.01), the level of glutathione(GSH) was higher than that of the model group(P<0.01), the activity of T-SOD was higher than that of the model group(P<0.001). Western blotting showed that the content of NRF2 and the expression level of downstream antioxidant proteins in the 4%ALA group were higher than those in the model group. Conclusion ALA up-regulates NRF2 signal pathway to reduce the level of oxidative stress in HTS and inhibit scar proliferation in rabbit ears.

Objective:We aimed to evaluate the predictive value of pre-implantation biopsy combined with Lifeport for the short-term prognosis of kidney allograft from donation after citizen death (DCD).Methods:Data from a total of 34 patients who had undergone kidney transplantation in Jinling Hospital from December 2017 to December 2019 were retrospectively analyzed. Histopathological data from pre-implantation biopsy , Lifeport parameters and recipient kidney transplant function at 3 months post-surgery were collected. The performances of histopathological indexes , and Lifeport parameters to predict delayed graft function (DGF) and estimated glomerular filtration rate (eGFR) at 3 months post-surgery were observed evaluated.Results:13 cases of DGF occurred, accounting for 38.2%. Serum creatinine at death and resistance index (RI) at 0.5 h, 1 h, 2 h and 4 h after Lifeport hypothermic machine perfusion (HMP) in the DGF group was significantly higher than that in the non-DGF group. Histologically, the acute tubular injury (ATI) score of the DGF group was higher than that of the non-DGF group, whereas the Remuzzi score was not statistically different between the two groups. The eGFR at 3 months post-transplant was moderately correlated with the RI at 4 h HMP and the Remuzzi score (RI: r=-0.48, P<0.001; Remuzzi score: ρ=-0.42, P=0.01), but no correlated with ATI score of the donor kidney. Although Remuzzi score was not correlated with kidney allograft recovery time (ρ=-0.25, P=0.16), it was inversely correlated with eGFR at 3 months post-transplant (ρ=-0.42, P=0.01). Combined use of Lifeport HMP 4-hour RI and ATI score increased the sensitivity and specificity of predicting DGF to 100% (95% CI: 75.3%-100%) and 90.5% (95% CI: 69.6%-98.8%) respectively. Conclusions:The serum creatinine at death, Lifeport RI, and ATI score of the DGF group were significantly higher than those of the non-DGF group, and the eGFR at 3 months post-transplant was correlated with the Lifeport RI and Remuzzi score. Combined use of ATI score and RI at 4 hours of Lifeport perfusion improved the sensitivity and specificity of predicting DGF .

Objective:To report for the first time the clinicopathologic characteristics of two patients with light chain deposition disease after renal transplantation.Methods:The clinicopathologic features were analyzed for two patients with light chain deposition disease and the related literature was reviewed.Case 1 was a 49-year-old male with unknown primary disease presenting with abnormal urine test and elevated serum creatinine at 24 months after kidney transplantation. Renal allograft biopsy hinted at light chain deposition disease. Case 2 was a 38-year-old male with light chain deposition disease in native kidneys presenting with proteinuria, microscopic hematuria and elevated serum creatinine at 15 months after kidney transplantation. Renal allograft biopsy supported recurrent light chain deposition disease.Results:1 case after bortezomib and dexamethasone dosing, serum creatinine decreased during follow-ups. 1 case received bortezomib and dexamethasone. However, sepsis and pulmonary infections developed and allograft function deteriorated.Conclusions:Light chain deposition disease after renal transplantation is a rare disorder with a rapid progression and a poor prognosis. Early detection of free light chain in blood and urine through immune fixed electrophoresis is conducive to an early diagnosis. The efficacy of bortezomib is to be furthered examined.

Objective:To explore the clinicopathologic features and renal prognosis of patients with post-transplant membranous nephropathy (MN).Methods:Patients with allograft biopsy-proven MN were reviewed retrospectively and divided into unknown etiology group (A, n=12) and recurrent membranous nephropathy (rMN) group (B, n=7). Their clinicopathological data and renal prognosis were assessed and compared.Results:No differences existed in the proportion of living-related donor or post-transplant allograft function. Group B had recurrence at 16.4 months after transplantation and it was significantly shorter than group A. Allograft impairment manifested as proteinuria, nephrotic syndrome and/or renal insufficiency in both groups. The positive rate of serum anti-PLA2R antibody and renal PLA2R staining was significantly higher in group B than that in group A. Similarly, the intensity of IgG4 subtype staining was also stronger in group B than that in group A. The 5-year cumulative renal survival rates from end-stage renal disease (ESRD) were 77.8% and 66.7% in groups A and B respectively. No significant inter-group difference existed in renal prognosis.Conclusions:Anti-PLA2R antibody plays an important role in the recurrence of rMN after renal allografting. PLA2R staining is useful for detecting primary disease and its sensitivity is higher than that of serum anti-PLA2R antibody. Rituximab is an effective treatment for post-transplant MN. Follow-up studies with a larger sample size are required for further verification.