ObjectiveOur recent study has demonstrated that extracellular acidification promotes lipid accumulation in macrophages via the activation of acid sensing ion channel 1 (ASIC1), but the underlying mechanism remains unclear. This study aims to explore the effect of extracellular acidification on macrophage lipophagy and the underlying mechanism. MethodsRAW264.7 macrophages were incubated with 25 mg/Lox-LDL in a pH 6.5 culture medium for 24 h to build macrophage-derived foam cell models induced by extracellular acidification. Then, RAW264.7 macrophages were cultured in the acidic medium of pH 6.5 with or without PcTx-1 (ASIC1 specific blocker, 10 μg/L) or Nec-1 (RIP1 specific inhibitor, 20 μmol/L) for 24 h, intracellular lipid accumulation was observed by oil red O staining. The expressions of total ASIC1, plasma membrane ASIC1, RIP1, p-RIP1 Ser166, TFEB, p-TFEB Ser142, LC3 and p62 were measured by Western blot. The co-localization of lipids (indicated by Bodipy) with LC3II (autophagosomes) and LAMP1 (lysosomes) was analyzed by a confocal laser scanning microscopy, respectively. Morphological changes of lipophagy in the cells were observed by using transmission electron microscopy. ABCA1-mediated cholesterol efflux was determined by cholesterol fluorescence kits. ResultsCompared with pH 7.4+ox-LDL group, the intracellular lipid accumulation in the pH 6.5+ox-LDL group was significantly increased. Meanwhile, the expressions of plasma membrane ASIC1, p-RIP1 Ser166, p-TFEB Ser142, and p62 proteins were elevated significantly, while LC3II protein level and LC3II/LC3I ratio were decreased. Accordingly, compared with pH 7.4+ox-LDL group, the macrophage lipophagy of the pH 6.5+ox-LDL group was inhibited as indicated by the decreased localization of lipid droplets with LC3 and LAMP1, a decrease in the number of lipophagosomes as well as an increase in lipid droplets. Furthermore, ATP binding cassette transporter A1 (ABCA1)-dependent cholesterol efflux from the macrophages of pH 6.5+ox-LDL group reduced dramatically. However, these above effects of extracellular acidification on RAW264.7 macrophages were abolished by PcTx-1 and Nec-1, respectively. ConclusionThese findings suggest extracellular acidification promotes the phosphorylation of TFEB at Ser142 via activating ASIC1/RIP1 pathway, thereby impeding lipophagy in RAW 264.7 macrophages, and that ASIC1 may be a new potential target for preventing aberrant lipid accumulation diseases including atherosclerosis.

BACKGROUND:Mesenchymal stem cell-derived exosomes may play a crucial role in tissue damage repair,and miRNA is an important component of exosomes for therapeutic effects.Among them,miR-29b-3p has the effect of reducing cell apoptosis,promoting axonal regeneration,and angiogenesis. OBJECTIVE:To study the protective effect of adipose-derived mesenchymal stem cell-derived exosome via miR-29b-3p on a neural cell injury model simulated by H2O2-treated PC12 cells,and explore the relevant mechanisms. METHODS:(1)First,the collagenase digestion method was used to extract rat adipose-derived mesenchymal stem cells.Adipose-derived mesenchymal stem cells were transfected with miR-29b-3p mimics and inhibitors.Exosomes were extracted from the culture supernatant by ultracentrifugation and identified so as to construct adipose-derived mesenchymal stem cell-derived exosomes with high expression and knockdown miR-29b-3p.(2)By constructing a neural cell injury model simulated by PC12 cells treated with H2O2,the relevant mechanisms of the protective effect of adipose-derived mesenchymal stem cell-derived exosome via miR-29b-3p on the simulated neuronal cell injury model were studied. RESULTS AND CONCLUSION:(1)Adipose-derived mesenchymal stem cell-derived exosome had a typical cup-shaped shape and a diameter distribution in the range of 50-140 nm,expressed membrane proteins Alix,CD63,and TSG101,which were specific markers on the surface of exosomes,and could be successfully ingested by PC12 cells.(2)Adipose-derived mesenchymal stem cell-derived exosome pretreatment could reduce cell apoptosis induced by H2O2 treatment in PC12 cells,and this protective effect was enhanced with the increase of miR-29b-3p expression in the exosomes and weakened with the decrease of miR-29b-3p expression in the exosomes.The mechanism of its effect was related to adipose-derived mesenchymal stem cell-derived exosome via miR-29b-3p promoting the expression of anti-apoptotic protein Bcl-2 and inhibiting the expression of apoptotic protein Bax.

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.

The correlation between hearing loss (HL) and physical performance in patients receiving maintenance hemodialysis (MHD) remains poorly investigated. This study explored the association between HL and physical performance in patients on MHD. Methods: This multicenter cross-sectional study was conducted between July 2020 and April 2021 in seven hemodialysis centers in Shanghai and Suzhou, China. The hearing assessment was performed using pure-tone average (PTA). Physical performance was assessed using the Timed Up and Go Test (TUGT), handgrip strength, and gait speed. Results: Finally, 838 adult patients (male, 516 [61.6%]; 61.2 ± 2.6 years) were enrolled. Among them, 423 (50.5%) had mild to profound HL (male, 48.6% and female, 53.4%). Patients with HL had poorer physical performance than patients without HL (p < 0.001). TUGT was positively correlated with PTA (r = 0.265, p < 0.001), while handgrip strength and gait speed were negatively correlated with PTA (r = –0.356, p < 0.001 and r = –0.342, p < 0.001, respectively). Physical performance in patients aged <60 years showed significant dose-response relationships with HL. After adjusting for confounders, the odds ratios (95% confidence intervals) for HL across the TUGT quartiles (lowest to highest) were 1.00 (reference), 1.15 (0.73–1.81), 1.69 (1.07–2.70), and 2.87 (1.69–4.88) (p for trend = 0.005). Conclusion: Lower prevalence of HL was associated with a faster TUGT and a stronger handgrip strength in patients on MHD.

Objective: To investigate the epidemiology and hospitalization costs of pediatric community-acquired pneumonia (CAP) in Shanghai. Methods: A retrospective case summary was conducted on 63 614 hospitalized children with CAP in 59 public hospitals in Shanghai from January 2018 to December 2020. These children's medical records, including their basic information, diagnosis, procedures, and costs, were extracted. According to the medical institutions they were admitted, the patients were divided into the children's hospital group, the tertiary general hospital group and the secondary hospital group; according to the age, they were divided into <1 year old group, 1-<3 years old group, 3-<6 years old group, 6-<12 years old group and 12-18 years old group; according to the CAP severity, they were divided into severe pneumonia group and non-severe pneumonia group; according to whether an operation was conducted, the patients were divided into the operation group and the non-operation group. The epidemiological characteristics and hospitalization costs were compared among the groups. The χ² test or Wilcoxon rank sum test was used for the comparisons between two groups as appropriate, and the Kruskal-Wallis H test was conducted for comparisons among multiple groups. Results: A total of 63 614 hospitalized children with CAP were enrolled, including 34 243 males and 29 371 females. Their visiting age was 4 (2, 6) years. The length of stay was 6 (5, 8) days. There were 17 974 cases(28.3%) in the secondary hospital group, 35 331 cases (55.5%) in the tertiary general hospital group and 10 309 cases (16.2%) in the children's hospital group. Compared with the hospitalizations cases in 2018 (27 943), the cases in 2019 (29 009) increased by 3.8% (1 066/27 943), while sharply declined by 76.2% (21 281/27 943) in 2020 (6 662). There were significant differences in the proportion of patients from other provinces and severe pneumonia cases, and the hospitalization costs among the children's hospital, secondary hospital and tertiary general hospital (7 146 cases(69.3%) vs. 2 202 cases (12.3%) vs. 9 598 cases (27.2%), 6 929 cases (67.2%) vs. 2 270 cases (12.6%) vs. 9 397 cases (26.6%), 8 304 (6 261, 11 219) vs. 1 882 (1 304, 2 796) vs. 3 195 (2 364, 4 352) CNY, χ²=10 462.50, 9 702.26, 28 037.23, all P<0.001). The annual total hospitalization costs of pediatric CAP from 2018 to 2020 were 110 million CNY, 130 million CNY and 40 million CNY, respectively. And the cost for each hospitalization increased year by year, which was 2 940 (1 939, 4 438), 3 215 (2 126, 5 011) and 3 673 (2 274, 6 975) CNY, respectively. There were also significant differences in the hospitalization expenses in the different age groups of <1 year old, 1-<3 years old, 3-<6 years old, 6-<12 years old and 12-18 years old (5 941 (2 787, 9 247) vs. 2 793 (1 803, 4 336) vs. 3 013 (2 070, 4 329) vs. 3 473 (2 400, 5 097) vs. 4 290 (2 837, 7 314) CNY, χ²=3 462.39, P<0.001). The hospitalization cost of severe pneumonia was significantly higher than that of non-severe cases (5 076 (3 250, 8 364) vs. 2 685 (1 780, 3 843) CNY, Z=109.77, P<0.001). The cost of patients who received operation was significantly higher than that of whom did not (10 040 (4 583, 14 308) vs. 3 083 (2 025, 4 747) CNY, Z=44.46, P<0.001). Conclusions: The number of children hospitalized with CAP in Shanghai decreased significantly in 2020 was significantly lower than that in 2018 and 2019.The proportion of patients from other provinces and with severe pneumonia are mainly admitted in children's hospitals. Hospitalization costs are higher in children's hospitals, and also for children younger than 1 year old, severe cases and patients undergoing operations.
Infant ; Female ; Male ; Humans ; Child ; Retrospective Studies ; China/epidemiology* ; Hospitalization ; Community-Acquired Infections/therapy* ; Hospitals, Pediatric ; Pneumonia/therapy*