Lipopolysaccharides (LPS) are major outer membrane components of Gram-negative bacteria. Unlike most Gram-negative bacteria, Acinetobacter baumannii can still survive and acquire polymyxin resistance after complete loss of LPS. Previous studies of LPS-deficient Acinetobacter baumannii mostly focused on LPS-deficient strains induced by polymyxin, whose background was complex and unstable. To investigate LPS loss-mediated polymyxin resistant-Acinetobacter baumannii, this study constructed a stable and clear background LPS-deficient strain by knocking out lpxC gene in Acinetobacter baumannii ATCC 19606 with CIRSPR/Cas9, and then studied the phenotypic changes of the lpxC-deficient strain including morphology, growth rate, antibiotic susceptibility, virulence, membrane permeability, and membrane potential. Animal experiments were approved by the Animal Care and Welfare Committee Institute of Medicinal Biotechnology, CAMS and PUMC (approval number: IMB-20240119D₉). The results indicated that the lpxC gene of Acinetobacter baumannii ATCC 19606 was successfully knocked out. After losing the lpxC, the strain underwent the morphological change from rod-shaped to spherical. Furthermore, it leads to reduced growth rate, enhanced membrane permeability, decreased membrane potential, lower virulence, and increased antibiotic susceptibility to β-lactams, quinolones, aminoglycosides, macrolides, glycopeptides. The lpxC deletion results in significant changes in membrane homeostasis and adaptability of Acinetobacter baumannii. Understanding the phenotypic changes of colistin-resistant Acinetobacter baumannii mediated by LPS loss is useful for exploring the resistance mechanism of Acinetobacter baumannii and developing new therapeutic strategies.

ObjectiveTo investigate the status of liver function abnormalities in patients with severe mental disorder (SMD) in Shanghai community, to explore the related factors to abnormal liver function in patients with SMD, and to analyze the effects of the types of mental disorders and medication status on liver function abnormalities. MethodsThe patients with SMD in Jinshan District, Minhang District, Hongkou District and Xuhui District of Shanghai were selected as the research subjects. Questionnaire survey, physical examination and laboratory tests were conducted to obtain their demographic characteristics and liver function indicators such as alanine aminotransferase (ALT) and total bilirubin (TBil). The types of mental disorders and medication status of patients in Jinshan District were also investigated. Abnormalities in liver function were determined by abnormalities in either ALT or TBil. Binary logistic regression analysis was used for multivariate analysis of the status of abnormal liver function, and the effects of mental disorder types and medication status on liver function were analyzed, simultaneously. ResultsA total of 7 251 patients with SMD were finally included into this study, and the rate of liver function abnormality was 22.7%, of which 694 cases (9.6%) had ALT abnormality and 1 084 cases (14.9%) had TBil abnormality. Univariate analysis showed that the rate of liver function abnormalities was higher in males than that in females (χ²=45.026, P<0.001), higher in suburbs than that in urban areas (χ²=25.317, P<0.001), higher in those with higher BMI than in those with lower BMI (χ²=63.748, P<0.001), higher in those with elevated blood pressure (BP) than in those without elevated BP (χ²=24.774, P<0.001), higher in those with elevated blood glucose than in those without elevated blood glucose (χ²=43.345, P<0.001), higher in those with abnormal triglyceride (TG) than in those with normal TG (χ²=15.551,P<0.001), and higher in those with abnormal total cholesterol (TC) than in those with normal TC (χ²=10.962, P=0.001). Multivariate analysis showed that the rate of abnormal liver function was higher in males than that in females (OR=1.53, 95%CI: 1.36‒1.73), higher in suburbs than that in urban areas (OR=1.43, 95%CI: 1.21‒1.70), higher in those with overweight than in those with normal BMI (OR=1.16, 95%CI: 1.01‒1.33), higher in those with obesity than in those with those with normal BMI (OR=1.61, 95%CI: 1.36‒1.91), higher in those with elevated blood glucose than in those without elevated blood glucose (OR=1.39, 95%CI: 1.23‒1.58), and higher in those with abnormal TC than in those with normal TC (OR=1.36, 95%CI: 1.13‒1.65).The difference in the rate of ALT abnormalities among the SMD patients in Jinshan District with different medication status was statistically significant (χ²=21.928, P<0.001). Whereas, the differences in the effects of the types of mental disorders and medication status on the status of liver function abnormalities were not statistically significant(P>0.05). ConclusionThe detection rate of liver function abnormalities in community-based SMD patients in Shanghai is high, and male, suburban, and accompanied by elevated BMI, BP, blood glucose, and TC are risk factors for liver function abnormalities in patients with SMD. Primary healthcare providers should pay more attention to the liver function of patients with SMD and initiate targeted and tailored prevention, detection and treatment measures.

Objective: To investigate the characteristics of schizophrenic patients using long-acting antipsychotic medications, so as to provide the basis for applicable population of long-acting antipsychotic medications. Methods: Data of schizophrenic patients using long-acting antipsychotic medications in Shanghai City from June 2020 to June 2022 were collected through Shanghai Mental Health Information Management System, and demographic characteristics, illness and medication use of patients were descriptively analyzed. Results: A total of 2 684 schizophrenic patients using long-acting antipsychotic medications were included in the study, had a mean age of (46.92±12.39) years, with 1 246 males (46.42%) and 1 438 females (53.58%). There were 1 397 unemployed cases, accounting for 52.05%; 1 429 cases with an educational level in junior high school or below, accounting for 53.24%; 1 301 unmarried cases, accounting for 48.47%; 832 cases in poverty, accounting for 31.00%. The caregivers of patients were mainly their parents, with 1 507 cases accounting for 56.15%. The courses of illness were mainly ≤10 years and >10-20 years, with 860 cases each, both accounting for 32.04%; 1 963 cases with incomplete self-awareness, accounting for 73.14%; 1 570 cases hospitalized at least once, accounting for 58.49%. There were 2 486 cases with continuous medication, accounting for 92.62%. The main method of taking medication was given by others, with 1 947 cases accounting for 72.54%. The medication adherence was mainly taking medication on time and in the right amount, with 2 437 cases accounting for 90.80%. Conclusion The main characteristics of schizophrenic patients using long-acting antipsychotic medications are young, unmarried, and unemployed adults, with incomplete self-awareness, continuous medication and medication given by others.

Objective:To explore the risk factors of ultrasound-guided closed reduction failure of unstable lateral humeral condylar fractures in children.Methods:A retrospective case-control study was conducted to analyze the clinical data of 158 children with unstable lateral humeral condyle fractures admitted to Anhui Provincial Children′s Hospital from January 2022 to August 2023, including 102 males and 56 females, aged 1-14 years [5(4, 8)years]. The patients were divided into reduction success group ( n=136) and reduction failure group ( n=22) according to the results of ultrasound-guided closed reduction. The gender, age, body mass index, injury side, time from injury to surgery, direction of sagittal plane displacement of the fracture fragment, Milch classification, Song classification, concomitant subcutaneous bruising or not, nighttime surgery or not, surgeons′ lack of experience or not, and concomitant elbow dislocation or not were recorded in both groups. Univariate analysis and binary Logistic regression analysis were used to evaluate and identify the independent risk factors for ultrasound-guided closed reduction failure of unstable lateral humeral condylar fractures in children. Results:Univariate analysis showed that there were significant differences in the time from injury to surgery, direction of sagittal plane displacement of the fracture fragment, and surgeons′ lack of experience or not between the reduction success group and reduction failure group ( P<0.01), while there were no significant differences in gender, age, body mass index, injury side, Milch classification, Song classification, concomitant subcutaneous bruising or not, nighttime surgery or not, or concomitant elbow dislocation or not between the two groups ( P>0.05). Binary Logistic regression analysis showed that the time from injury to surgery≥5 days ( OR=1.47, 95% CI 1.17, 1.86, P<0.01), sagittal anterior displacement of the fracture fragment ( OR=7.07, 95% CI, 1.79, 27.98, P<0.01) and surgeons′ lack of experience ( OR=4.67, 95% CI, 1.21, 18.05, P<0.05) were significantly correlated with ultrasound-guided closed reduction failure of unstable lateral humeral condylar fractures in children. Conclusion:The time from injury to surgery ≥5 days, sagittal anterior displacement of the fracture fragment and surgeons′ lack of experience are the independent risk factors for ultrasound-guided closed reduction failure of unstable lateral humeral condylar fractures in children.

Osteoporosis is an important cause of internal fixation loosening after spinal surgery.Cement-augmented pedicle screw instru-mentation(CAPSI)technique is the most widely used technique in clinical practice to improve the stability of pedicle screw,mainly applied in osteoporosis and revision surgery,which included conventional solid pedicles crews and fenestrated/cannulated pedicle screws technique.CAPSI technique may cause cement leakage and pulmonary embolism,and there is no consensus on its indications or technical points.Therefore,this article reviews the research progress of CAPSI,in order to provide relevant reference for clinical practice.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in tertiary hospitals in major regions of China in 2022.Methods Clinical isolates from 58 hospitals in China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2022 Clinical &Laboratory Standards Institute(CLSI)breakpoints.Results A total of 318 013 clinical isolates were collected from January 1,2022 to December 31,2022,of which 29.5％were gram-positive and 70.5％were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species(excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi)was 28.3％,76.7％and 77.9％,respectively.Overall,94.0％of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 90.8％of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis showed significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 94.2％in the isolates from children and 95.7％in the isolates from adults.The resistance rate to carbapenems was lower than 13.1％in most Enterobacterales species except for Klebsiella,21.7％-23.1％of which were resistant to carbapenems.Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.1％to 13.3％.The prevalence of meropenem-resistant strains decreased from 23.5％in 2019 to 18.0％in 2022 in Pseudomonas aeruginosa,and decreased from 79.0％in 2019 to 72.5％in 2022 in Acinetobacter baumannii.Conclusions The resistance of clinical isolates to the commonly used antimicrobial agents is still increasing in tertiary hospitals.However,the prevalence of important carbapenem-resistant organisms such as carbapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a downward trend in recent years.This finding suggests that the strategy of combining antimicrobial resistance surveillance with multidisciplinary concerted action works well in curbing the spread of resistant bacteria.

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.