Metformin has been demonstrated to attenuate hyperglycaemia by modulating the gut microbiota. However, the mechanisms through which the microbiome mediates metformin monotherapy failure (MMF) are unclear. Herein, in a prospective clinical cohort study of newly diagnosed type 2 diabetes mellitus (T2DM) patients treated with metformin monotherapy, metagenomic sequencing of faecal samples revealed that Phocaeicola vulgatus abundance was approximately 12 times higher in nonresponders than in responders. P. vulgatus rapidly hydrolysed taurine-conjugated bile acids, leading to ceramide accumulation and reversing the improvements in glucose intolerance conferred by metformin in high-fat diet-fed mice. Interestingly, C22:0 ceramide bound to mitochondrial fission factor to induce mitochondrial fragmentation and impair hepatic oxidative phosphorylation in P. vulgatus-colonized hyperglycaemic mice, which could be exacerbated by metformin. This work suggests that metformin may be unsuitable for P. vulgatus-rich T2DM patients and that clinicians should be aware of metformin toxicity to mitochondria. Suppressing P. vulgatus growth with cefaclor or improving mitochondrial function using adenosylcobalamin may represent simple, safe, effective therapeutic strategies for addressing MMF.

Objective To explore the influence of miR-155-5p on renal fibrosis in diabetic kidney disease(DKD)rats by targeting silent information regulator 1(SIRT1)/transforming growth factor-beta/Sma-and Mad-related protein(TGF-β/Smad)signaling pathway.Methods Forty-eight rats were randomly divided into normal control(NC)group,model(Mod)group,inhibitor negative control(anti-NC)group,miR-155-5p inhibitor(anti-miR-155-5p)group,miR-155-5p inhibitor+small interfering RNA negative control(anti-miR-155-5p+si-NC)group,and miR-155-5p inhibitor+SIRT1 small interfering RNA(anti-miR-155-5p+si-SIRT1)group,with 8 rats in each group.FPG,24 h UAlb,BUN and serum creatinine(Scr)were detected in each group.HE and Masson staining were used to compare the pathological changes of renal tissue in each group,and the collagen volume fraction(CVF)was calculated.The mRNA expressions of miR-155-5p and SIRT1 were detected by real-time fluorescence quantitative PCR(RT-qRCR),and the protein expressions of SIRT1,TGF-β1,Smad3,Smad7,connective tissue growth factor(CTGF)and collagen type Ⅰ(COLⅠ)were detected by Western blot.Results Compared with NC group,the expressions of FPG,24 hUAlb,BUN,Scr,CVF,miR-155-5p,TGF-β1,Smad3,CTGF and COLⅠincreased(P<0.05),while the expressions of SIRT1 mRNA and protein and Smad7 protein decreased in Mod and anti-NC groups(P<0.05).Compared with the anti-NC group,in the anti-miR-155-5p,anti-miR-155-5p+si-NC groups,the expression of SIRT1 mRNA and protein,Smad7 protein increased(P<0.05),and FPG,24 hUAlb,BUN,Scr,CVF,miR-155-5p,TGF-β1,Smad3,CTGF and COLⅠprotein were expressed(P<0.05).Compared with the anti-miR-155-5p and anti-miR-155-5p+si-NC groups,the anti-miR-155-5p+si-SIRT1 group showed the expression of FPG,24 hUAlb,BUN,Scr,CVF,miR-155-5p,TGF-β1,Smad3、CTGF、and COLⅠprotein increased(P<0.05),the expression of SIRT1 mRNA and protein,Smad7 protein decreased(P<0.05).The 3'UTR of SIRT1 mRNA contains the conserved base of miR-155-5p sequence.Conclusions Elevated miR-155-5p in DKD rats can target and regulate SIRT1 to alleviate the process of renal fibrosis.

Objective:To report the nationwide surveillance results of pathogenic profiles and antimicrobial resistance patterns of Gram-positive bloodstream infections in China in 2023.Methods:The clinical isolates of Gram-posttive bacteria from blood cultures were collected in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System（BRICS）during January to December 2023. Antimicrobial susceptibility testing was performed using the dilution method recommended by the Clinical and Laboratory Standards Institute（CLSI）. Statistical analyses were conducted using WHONET 5.6 and SPSS 25.0 software.Results:A total of 4 385 Gram-positive bacterial isolates were obtained from 60 participating center. The top five pathogens were Staphylococcus aureus（ n=1 544，35.2%），coagulase-negative Staphylococci（ n=1 441，32.9%）， Enterococcus faecium（ n=574，13.1%）， Enterococcus faecalis（ n=385，8.8%），and α-hemolytic Streptococci（ n=187，4.3%）. The prevalence of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）was 26.2%（405/1 544）and 69.8%（1 006/1 441），respectively. Notably，all Staphylococci remained susceptible to glycopeptide or daptomycin. Staphylococcus aureus demonstrated excellent susceptibility（>97.0%）to cephalobiol，rifampicin，trimethoprim-sulfamethoxazole，linezolid，minocycline，tigecycline，and eravacycline. No Enterococcus exhibiting resistance to linezolid were detected. Glycopeptide resistance was uncommon but more frequent in Enterococcus faecium（resistance to vancomycin and teicoplanin：both 1.7%）compared to Enterococcus faecalis（both 0.3%）. The detection rates of MRSA and MRCNS exhibited significant regional variations across the country（ χ2=17.674 and 148.650，respectively，both P<0.001）. No vancomycin-resistant Enterococci were detected in central China. Institutional comparison demonstrated higher prevalence of MRSA（ χ2=14.111， P<0.001）and MRCNS（ χ2=4.828， P=0.028）in provincial hospitals than that in municipal hospitals. Socioeconomic analysis identified elevated detection rates of both MRSA（ χ2=18.986， P<0.001）and MRCNS（ χ2=4.477， P=0.034）in less developed regions（per capita GDP

Objective:To report the results of bacterial resistant investigation collaborative system（BRICS）on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2023，and provide reference for clinical tretment of bloodstream infections and prevention and control of bacterial resistance.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of BRICS were collected during January 2023 to December 2023. 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 were used to analyze the data.Results:During the study period，11 492 strains of Gram-negative bacteria were collected from 60 hospitals，of which 10 098（87.9%）were Enterobacterales and 1 394（12.1%）were non-fermentative bacteria. The top 5 bacterial species were Escherichia coli（50.0%）， Klebsiella pneumoniae（26.1%）， Pseudomonas aeruginosa（5.1%）， Acinetobacter baumannii complex（5.0%）and Enterobacter cloacae complex（4.1%）. The ESBL-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus mirablilis were 46.8%（2 685/5 741），18.3%（549/2 999）and 44.0%（77/175），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（76/5 741）and 15.0%（450/2 999）；32.9%（25/76）and 78.0%（351/450）of CREC and CRKP were sensitive to ceftazidime/avibactam combination，respectively. 94.7%（72/76）and 90.2%（406/450）of CREC and CRKP were sensitive to aztreonam/avibactam combination. Furthermore，57.9%（44/76）and 79.1%（356/450）were sensitive to imipenem/relebactam combination. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 64.6%（370/573），while more than 80.0% of CRAB complex was sensitive to tigecycline，eravacycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 17.0%（99/581）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of important Gram-negative bacteria resistance among different regions in China，with statistically significant differences in the prevalence of CREC，CRKP，CRPA and CRAB complex（ χ2=10.6，28.6，10.8 and 19.3， P<0.05）. The prevalence of ESBL-producing Escherichia coli， CREC，CRAB complex and CRKP were higher in provincial hospitals than those in municipal hospitals（ χ2=12.5，9.8，12.7 and 57.8，all P<0.01）. Conclusions:Gram-negative bacteria are the main pathogens causing bloodstream infections in China，and Escherichia coli is ranked in the top，while the trend of Klebsiella pneumoniae increases continuously with time. CRKP infection shows a slow upward trend，CREC infecton maintains a low prevalence level，and CRAB complex infection continues to exhibit a high prevalence rate. The composition and resistance patterns of pathogens causing bloodstream infections vary to some extent across different regions and levels of hospitals in China.

Salmonella has demonstrated considerable potential as a vaccine vector,exhibiting robust immunogenicity,ease of oral administration,and cost-effective production.Live attenuated Salmo-nella carrying heterologous antigens can induce both localized mucosal immunity and systemic a-daptive immune responses in hosts after successfully reaching the intestinal tract via oral delivery.Recent advances such as permanent deletion of virulence genes,regulated-delayed attenuation and lysis systems,have initially achieved a balance between the safety and immunogenicity of these vaccine platforms.Nevertheless,practical applications of such vaccine vectors remain constrained by challenges related to gastrointestinal barrier obstruction,inefficient antigen delivery,and im-mune tolerance.With the rapid advancement of multidisciplinary technologies,these limitations are anticipated to be progressively addressed.This review presented a comprehensive summary and dis-cussion of the immune mechanisms,development strategies,current applications,advantages,and challenges associated with oral live attenuated Salmonella vaccine vectors.It also delineated the fu-ture direction of research and development,with a view to providing theoretical references for re-lated research.

Salmonella has demonstrated considerable potential as a vaccine vector,exhibiting robust immunogenicity,ease of oral administration,and cost-effective production.Live attenuated Salmo-nella carrying heterologous antigens can induce both localized mucosal immunity and systemic a-daptive immune responses in hosts after successfully reaching the intestinal tract via oral delivery.Recent advances such as permanent deletion of virulence genes,regulated-delayed attenuation and lysis systems,have initially achieved a balance between the safety and immunogenicity of these vaccine platforms.Nevertheless,practical applications of such vaccine vectors remain constrained by challenges related to gastrointestinal barrier obstruction,inefficient antigen delivery,and im-mune tolerance.With the rapid advancement of multidisciplinary technologies,these limitations are anticipated to be progressively addressed.This review presented a comprehensive summary and dis-cussion of the immune mechanisms,development strategies,current applications,advantages,and challenges associated with oral live attenuated Salmonella vaccine vectors.It also delineated the fu-ture direction of research and development,with a view to providing theoretical references for re-lated research.

OBJECTIVE To investigate the current status and existing issues of hospital-associated infection manage-ment in non-public medical institutions,so as to provide data for the formulation of hospital-associated infec-tion management policies and the construction of a quality evaluation system for hospital-associated infection man-agement in non-public medical institutions.METHODS A qualitative research method was employed.In Dec.2023,semi-structured interviews were conducted with 38 directors of hospital-associated infection management depart-ments in primary,secondary and tertiary non-public medical institutions.The interview data were coded and ana-lyzed by Nvivo 12.0 software to refine themes.RESULTS Three themes were refined:the organizational system for hospital-associated infection management in non-public medical institutions had been basically established,but the division of functions and responsibilities was not yet fully clear,hospital-associated infection management had achieved certain results,including collaborating with other departments to standardize and implement infection control measures,enhancing staff awareness of infection control,and promoting the establishment of organization-al systems.There were issues in infection control works such as insufficient funding,personnel allocation not meeting requirements,and difficulties in implementing infection control measures.The most urgent assis-tance needed was to address the training and professional title promotion for full-time and part-time infection con-trol personnel.CONCLUSION Non-public medical institutions should strengthen staffing and training,enhance the pro-fessional capabilities of infection control personnel,and establish hospital-associated infection management standards that are tailored to the characteristics of non-public medical institutions at all levels.

OBJECTIVE To investigate the current status and existing issues of hospital-associated infection manage-ment in non-public medical institutions,so as to provide data for the formulation of hospital-associated infec-tion management policies and the construction of a quality evaluation system for hospital-associated infection man-agement in non-public medical institutions.METHODS A qualitative research method was employed.In Dec.2023,semi-structured interviews were conducted with 38 directors of hospital-associated infection management depart-ments in primary,secondary and tertiary non-public medical institutions.The interview data were coded and ana-lyzed by Nvivo 12.0 software to refine themes.RESULTS Three themes were refined:the organizational system for hospital-associated infection management in non-public medical institutions had been basically established,but the division of functions and responsibilities was not yet fully clear,hospital-associated infection management had achieved certain results,including collaborating with other departments to standardize and implement infection control measures,enhancing staff awareness of infection control,and promoting the establishment of organization-al systems.There were issues in infection control works such as insufficient funding,personnel allocation not meeting requirements,and difficulties in implementing infection control measures.The most urgent assis-tance needed was to address the training and professional title promotion for full-time and part-time infection con-trol personnel.CONCLUSION Non-public medical institutions should strengthen staffing and training,enhance the pro-fessional capabilities of infection control personnel,and establish hospital-associated infection management standards that are tailored to the characteristics of non-public medical institutions at all levels.

Objective To explore the influence of miR-155-5p on renal fibrosis in diabetic kidney disease(DKD)rats by targeting silent information regulator 1(SIRT1)/transforming growth factor-beta/Sma-and Mad-related protein(TGF-β/Smad)signaling pathway.Methods Forty-eight rats were randomly divided into normal control(NC)group,model(Mod)group,inhibitor negative control(anti-NC)group,miR-155-5p inhibitor(anti-miR-155-5p)group,miR-155-5p inhibitor+small interfering RNA negative control(anti-miR-155-5p+si-NC)group,and miR-155-5p inhibitor+SIRT1 small interfering RNA(anti-miR-155-5p+si-SIRT1)group,with 8 rats in each group.FPG,24 h UAlb,BUN and serum creatinine(Scr)were detected in each group.HE and Masson staining were used to compare the pathological changes of renal tissue in each group,and the collagen volume fraction(CVF)was calculated.The mRNA expressions of miR-155-5p and SIRT1 were detected by real-time fluorescence quantitative PCR(RT-qRCR),and the protein expressions of SIRT1,TGF-β1,Smad3,Smad7,connective tissue growth factor(CTGF)and collagen type Ⅰ(COLⅠ)were detected by Western blot.Results Compared with NC group,the expressions of FPG,24 hUAlb,BUN,Scr,CVF,miR-155-5p,TGF-β1,Smad3,CTGF and COLⅠincreased(P<0.05),while the expressions of SIRT1 mRNA and protein and Smad7 protein decreased in Mod and anti-NC groups(P<0.05).Compared with the anti-NC group,in the anti-miR-155-5p,anti-miR-155-5p+si-NC groups,the expression of SIRT1 mRNA and protein,Smad7 protein increased(P<0.05),and FPG,24 hUAlb,BUN,Scr,CVF,miR-155-5p,TGF-β1,Smad3,CTGF and COLⅠprotein were expressed(P<0.05).Compared with the anti-miR-155-5p and anti-miR-155-5p+si-NC groups,the anti-miR-155-5p+si-SIRT1 group showed the expression of FPG,24 hUAlb,BUN,Scr,CVF,miR-155-5p,TGF-β1,Smad3、CTGF、and COLⅠprotein increased(P<0.05),the expression of SIRT1 mRNA and protein,Smad7 protein decreased(P<0.05).The 3'UTR of SIRT1 mRNA contains the conserved base of miR-155-5p sequence.Conclusions Elevated miR-155-5p in DKD rats can target and regulate SIRT1 to alleviate the process of renal fibrosis.

Objective:To report the nationwide surveillance results of pathogenic profiles and antimicrobial resistance patterns of Gram-positive bloodstream infections in China in 2023.Methods:The clinical isolates of Gram-posttive bacteria from blood cultures were collected in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System（BRICS）during January to December 2023. Antimicrobial susceptibility testing was performed using the dilution method recommended by the Clinical and Laboratory Standards Institute（CLSI）. Statistical analyses were conducted using WHONET 5.6 and SPSS 25.0 software.Results:A total of 4 385 Gram-positive bacterial isolates were obtained from 60 participating center. The top five pathogens were Staphylococcus aureus（ n=1 544，35.2%），coagulase-negative Staphylococci（ n=1 441，32.9%）， Enterococcus faecium（ n=574，13.1%）， Enterococcus faecalis（ n=385，8.8%），and α-hemolytic Streptococci（ n=187，4.3%）. The prevalence of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）was 26.2%（405/1 544）and 69.8%（1 006/1 441），respectively. Notably，all Staphylococci remained susceptible to glycopeptide or daptomycin. Staphylococcus aureus demonstrated excellent susceptibility（>97.0%）to cephalobiol，rifampicin，trimethoprim-sulfamethoxazole，linezolid，minocycline，tigecycline，and eravacycline. No Enterococcus exhibiting resistance to linezolid were detected. Glycopeptide resistance was uncommon but more frequent in Enterococcus faecium（resistance to vancomycin and teicoplanin：both 1.7%）compared to Enterococcus faecalis（both 0.3%）. The detection rates of MRSA and MRCNS exhibited significant regional variations across the country（ χ2=17.674 and 148.650，respectively，both P<0.001）. No vancomycin-resistant Enterococci were detected in central China. Institutional comparison demonstrated higher prevalence of MRSA（ χ2=14.111， P<0.001）and MRCNS（ χ2=4.828， P=0.028）in provincial hospitals than that in municipal hospitals. Socioeconomic analysis identified elevated detection rates of both MRSA（ χ2=18.986， P<0.001）and MRCNS（ χ2=4.477， P=0.034）in less developed regions（per capita GDP