BACKGROUND:Osteonecrosis is an orthopedic disease that severely limits joint function,with complex pathogenesis involving multiple risk factors.Cathepsins,as a class of enzymes that play a key role in bone metabolism,are closely related to the proliferation,differentiation of bone cells,and remodeling of the bone matrix.However,previous studies have mostly focused on descriptive analyses,lacking direct evidence of causal relationships.OBJECTIVE:To clarify the potential causal relationship between cathepsins and osteonecrosis and to explore their possible mechanisms by analyzing large-scale sample data from the FinnGen database.METHODS:We obtained osteonecrosis-related data from the FinnGen database,including R9(a total of 359 399 samples:1 385 cases and 358 014 controls)and R10 versions(a total of 392 580 samples:1 543 cases and 391 037 controls).Single nucleotide polymorphisms associated with nine cathepsins(cathepsin B,E,F,G,H,O,S,L2,and Z)were acquired from a previous study(3 301 individuals).Univariate Mendelian randomization,reverse univariate Mendelian randomization,and multivariate Mendelian randomization analyses were conducted using the inverse variance weighted method,MR-Egger method,weighted median method,simple mode method,and weighted mode method.Initially,Mendelian randomization analysis was performed using osteonecrosis data from R9.Additionally,sensitivity analyses were conducted using Cochran's Q test,MR-Egger intercept,MR-PRESSO global test,and leave-one-out analysis to check for horizontal pleiotropy and heterogeneity.Subsequently,a validation analysis study was carried out on the R10 dataset,and a meta-analysis was conducted to combine the two datasets to explore the joint effect.RESULTS AND CONCLUSION:Univariate Mendelian randomization analysis results showed that higher levels of cathepsin B were significantly associated with a reduced risk of osteonecrosis(inverse variance weighted:odds ratio(OR)=0.865,95％confidence interval(CI):0.762-0.982,P=0.025),and no reverse causal relationship was found between the nine cathepsins and osteonecrosis(P＞0.05).These associations were validated by meta-analysis.Multivariate analysis,using the nine cathepsins as covariates,revealed a reverse causal relationship between the levels of cathepsin Band the risk of osteonecrosis(inverse variance weighted:OR=0.8710,95％CI:0.761-0.997,P=0.045),consistent with the results before adjustment.Sensitivity analyses based on heterogeneity and horizontal pleiotropy suggested that the results were relatively robust.This study suggests that there is a causal relationship between high levels of cathepsin B and the reduced risk of osteonecrosis,and it may serve as a biomarker for osteonecrosis,providing new directions and insights for the diagnosis and treatment of osteonecrosis.Although this study is based on data analysis of European populations,these findings have important implications for Chinese biomedical research,especially in understanding disease mechanisms,developing biomarkers,and formulating treatment strategies.They also encourage similar studies conducted on Chinese populations to explore the impact of racial and genetic background differences on the occurrence of osteonecrosis.

Objective To explore the influencing factors of different types of small intestinal bacterial overgrowth(SIBO).Methods A total of 539 patients who were hospitalized in the Department of Gastroenterology,the Sixth Medical Center of PLA General Hospital from June 2021 to December 2021 and who underwent methane-hydrogen breath test were retrospectively selected.Based on breath test results,patients were divided into SIBO-negative group(n=300)and SIBO-positive group(n=239).The clinical data were compared between two groups.According to the specific values of breath test results,SIBO-positive patients were further divided into hydrogen-producing bacterial overgrowth(hydrogen-positive,n=103),intestinal methanogen overgrowth(methanogen-positive,n=80),and simultaneous methanogen and hydrogen-producing bacterial overgrowth(double positive,n=56)groups.Multivariate logistic regression analysis was employed to identify influencing factors of different SIBO types.Additionally,SIBO-positive patients were categorized by age into<45 years(n=23),45-60 years(n=82),60-75 years(n=124),and≥75 years(n=10)to compare SIBO positivity rates across age groups.Results The patients in SIBO-positive and double positive groups were older and had a lower body mass index(BMI)than those in SIBO-negative group,with statistically significant differences(P<0.05).Compared with the patients in SIBO-negative group,those in hydrogen-positive group showed a higher proportion of history of coronary heart disease,those in methanogen-positive group were older,and higher proportion of statin use,with statistically significant differences(P<0.05).Multivariate logistic regression analysis revealed that,among different SIBO types,a history of coronary heart disease served as an independent risk factor for hydrogen-producing bacterial overgrowth(OR=2.728,95%CI 1.271-5.857,P=0.010).For methanogen overgrowth,increasing age was identified as an independent risk factor(OR=1.040,95%CI 1.009-1.063,P=0.010),while the application of statin played the role of an independent protective factor(OR=0.420,95%CI 0.236-0.754,P=0.003).As for the simultaneous overgrowth of methane-producing and hydrogen-producing bacteria,increased BMI was found to be an independent protective factor(OR=0.870,95%CI 0.786-0.964,P=0.008).In SIBO-positive group,it was found that for patients aged<45 years,both the methane-positive rate and the double-positive rate were significantly lower than the hydrogen positivity rate(P<0.05).Moreover,among patients aged 45-60 years,the double-positive rate was significantly lower than the hydrogen positivity rate(P<0.01).When it comes to the hydrogen-positive rate,it was significantly lower for patients aged 45-60 and 60-75 years compared with that of patients aged<45 years(P<0.05).In contrast,the methane-positive rate and the double-positive rate were significantly higher for patients aged 45-60 and 60-75 years than those of patients aged<45 years(P<0.01).Conclusion A history of coronary heart disease and increasing age are independent risk factors for intestinal hydrogen-producing bacterial overgrowth and methanogen overgrowth,respectively.The application of statins and increased BMI are independent protective factors for intestinal methanogen simultaneous overgrowth of methanogen and hydrogen-producing bacteria,respectively.

The inflammatory status in patients with chronic kidney disease(CKD)is closely associated with cardiovascular events,infections,and other complications,and is a powerful indicator for prognosis assessment.The core view of the"gut-kidney axis"theory reveals the relationship among inflammatory state,microbiota dysbiosis,and deterioration of renal function.The microbiota alters the microenvironment through structural changes and metabolites with different properties,subsequently leading to microbiota translocation,inducing inflammatory lesions,and damaging the kidneys.Recent studies have proposed that targeted microbiota intervention strategies such as probiotics,prebiotics,and synbiotics can modulate the microbiota structure,regulate the microenvironment,relieve renal inflammation,and affect the progression of renal disease,representing a potentially promising research direction in the future.This review discusses the characteristics of how intestinal microbiota influence the inflammatory status in CKD,focusing on the research progress of targeted microbiota intervention,aiming to discuss the effectiveness and scientific basis of these strategies,providing a foundation for the treatment of CKD and the expansion of targeted microbiota research,as well as offering references for the clinical application of probiotics,prebiotics,and synbiotics.

Objective To summarize the changing prevalence of carbapenem resistance in Enterobacterales based on the data of CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021 for improving antimicrobial treatment in clinical practice.Methods Antimicrobial susceptibility testing was performed using a commercial automated susceptibility testing system according to the unified CHINET protocol.The results were interpreted according to the breakpoints of the Clinical & Laboratory Standards Institute(CLSI)M100 31st ed in 2021.Results Over the seven-year period(2015-2021),the overall prevalence of carbapenem-resistant Enterobacterales(CRE)was 9.43％(62 342/661 235).The prevalence of CRE strains in Klebsiella pneumoniae,Citrobacter freundii,and Enterobacter cloacae was 22.38％,9.73％,and 8.47％,respectively.The prevalence of CRE strains in Escherichia coli was 1.99％.A few CRE strains were also identified in Salmonella and Shigella.The CRE strains were mainly isolated from respiratory specimens(44.23±2.80)％,followed by blood(20.88±3.40)％and urine(18.40±3.45)％.Intensive care units(ICUs)were the major source of the CRE strains(27.43±5.20)％.CRE strains were resistant to all the β-lactam antibiotics tested and most non-β-lactam antimicrobial agents.The CRE strains were relatively susceptible to tigecycline and polymyxins with low resistance rates.Conclusions The prevalence of CRE strains was increasing from 2015 to 2021.CRE strains were highly resistant to most of the antibacterial drugs used in clinical practice.Clinicians should prescribe antimicrobial agents rationally.Hospitals should strengthen antibiotic stewardship in key clinical settings such as ICUs,and take effective infection control measures to curb CRE outbreak and epidemic in hospitals.

AIM:To investigate autophagic status in ischemic stroke with Liver Yang Hyperactivity and the mechanism of Tianma Gouteng Decoction(TMGTD).METHODS:SD rats were divided into sham,model,TMGTD high/medium/low-dose(20.52/10.26/5.13 g·kg-1·d-1),and Nimodipine(30 mg·kg-1·d-1)groups.A Liver Yang Hyperactivity and cerebral ischemia-reperfusion model was es-tablished using Fuzi Decoction(2 g·kg-1·d-1)and thread-occlusion.After 21 days of Fuzi decoction pretreatment,rats received daily drug administra-tion for 12 days.Syndrome indicators(irritability,24-hour water intake,24-hour urine volume,facial temperature)were recorded,plasma NE,E,cAMP,and cGMP were measured by ELISA,neurological function was assessed using Zea Longa and mNSS methods,brain histopathology was evaluated by HE staining,protein expression of soluble/insoluble p62 and LC3B was detected by Western blot,au-tophagy-related genes were analyzed by PCR array,additionally,mRNA and protein levels of CXCR4 and CXCL12 were measured by qRT-PCR and Western blot.RESULTS:Compared to the sham group,the model group showed increased irritability,24-hours water intake,24-hours urine volume,facial temper-ature,and level of NE,E,cGMP(P＜0.01),neurologi-cal scores(P＜0.01),LC3B-Ⅱ,insoluble p62,CXCR4,CXCL12 expression(P＜0.01),but decreased soluble p62(P＜0.01).TMGTD groups exhibited reduced irri-tability,water intake,urine volume,facial tempera-ture,NE,E,cGMP(P＜0.05,P＜0.01),neurological scores(P＜0.05,P＜0.01),p62 expression(P＜0.01),alongside increased LC3B-Ⅱ(P＜0.01)and improved cortical pathology.TMGD also reversed dysregulat-ed autophagy-apoptosis genes(CXCR4,Lamp1,Tgfb1,APP,Rab24)and reduced CXCR4,CXCL12 ex-pression(P＜0.01).CONCLUSION:In the Liver Yang Hyperactivity and cerebral ischemia-reperfusion model,autophagy genes were activated but flux was impaired,and Tianma Gouteng Decoction may protect by restoring autophagic flux and inhibiting the CXCL12/CXCR4 axis.

Objective To characterize the changing species distribution and antibiotic resistance profiles of respiratory isolates in hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Commercial automated antimicrobial susceptibility testing systems and disk diffusion method were used to test the susceptibility of respiratory bacterial isolates to antimicrobial agents following the standardized technical protocol established by the CHINET program.Results A total of 589 746 respiratory isolates were collected from 2015 to 2021.Overall,82.6％of the isolates were Gram-negative bacteria and 17.4％were Gram-positive bacteria.The bacterial isolates from outpatients and inpatients accounted for(6.0±0.9)％and(94.0±0.1)％,respectively.The top microorganisms were Klebsiella spp.,Acinetobacter spp.,Pseudomonas aeruginosa,Staphylococcus aureus,Haemophilus spp.,Stenotrophomonas maltophilia,Escherichia coli,and Streptococcus pneumoniae.Each microorganism was isolated from significantly more males than from females(P＜0.05).The overall prevalence of methicillin-resistant S.aureus(MRSA)was 39.9％.The prevalence of penicillin-resistant S.pneumoniae was 1.4％.The prevalence of extended-spectrum β-lactamase(ESBL)-producing E.coli and K.pneumoniae was 67.8％and 41.3％,respectively.The overall prevalence of carbapenem-resistant E.coli,K.pneumoniae,Enterobacter cloacae,Pseudomonas aeruginosa,and Acinetobacter baumannii was 3.7％,20.8％,9.4％,29.8％,and 73.3％,respectively.The prevalence of β-lactamase was 96.1％in Moraxella catarrhalis and 60.0％in Haemophilus influenzae.The H.influenzae isolates from children(＜18 years)showed significantly higher resistance rates to β-lactam antibiotics than the isolates from adults(P＜0.05).Conclusions Gram-negative bacteria are still predominant in respiratory isolates associated with serious antibiotic resistance.Antimicrobial resistance surveillance should be strengthened in clinical practice to support accurate etiological diagnosis and appropriate antimicrobial therapy based on antimicrobial susceptibility testing results.

Objective To investigate the distribution and antimicrobial resistance profiles of common pathogens isolated from cerebrospinal fluid(CSF)in CHINET program from 2015 to 2021.Methods The bacterial strains isolated from CSF were identified in accordance with clinical microbiology practice standards.Antimicrobial susceptibility test was conducted using Kirby-Bauer method and automated systems per the unified CHINET protocol.Results A total of 14 014 bacterial strains were isolated from CSF samples from 2015 to 2021,including the strains isolated from inpatients(95.3％)and from outpatient and emergency care patients(4.7％).Overall,19.6％of the isolates were from children and 80.4％were from adults.Gram-positive and Gram-negative bacteria accounted for 68.0％and 32.0％,respectively.Coagulase negative Staphylococcus accounted for 73.0％of the total Gram-positive bacterial isolates.The prevalence of MRSA was 38.2％in children and 45.6％in adults.The prevalence of MRCNS was 67.6％in adults and 69.5％in children.A small number of vancomycin-resistant Enterococcus faecium(2.2％)and linezolid-resistant Enterococcus faecalis(3.1％)were isolated from adult patients.The resistance rates of Escherichia coli and Klebsiella pneumoniae to ceftriaxone were 52.2％and 76.4％in children,70.5％and 63.5％in adults.The prevalence of carbapenem-resistant E.coli and K.pneumoniae(CRKP)was 1.3％and 47.7％in children,6.4％and 47.9％in adults.The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)and Pseudomonas aeruginosa(CRPA)was 74.0％and 37.1％in children,81.7％and 39.9％in adults.Conclusions The data derived from antimicrobial resistance surveillance are crucial for clinicians to make evidence-based decisions regarding antibiotic therapy.Attention should be paid to the Gram-negative bacteria,especially CRKP and CRAB in central nervous system(CNS)infections.Ongoing antimicrobial resistance surveillance is helpful for optimizing antibiotic use in CNS infections.

Objective To investigate the antimicrobial resistance of clinical isolates from elderly patients(≥65 years)in major medical institutions across China.Methods Bacterial strains were isolated from elderly patients in 52 hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program during the period from 2015 to 2021.Antimicrobial susceptibility test was carried out by disk diffusion method and automated systems according to the same CHINET protocol.The data were interpreted in accordance with the breakpoints recommended by the Clinical and Laboratory Standards Institute(CLSI)in 2021.Results A total of 514 715 nonduplicate clinical isolates were collected from elderly patients in 52 hospitals from January 1,2015 to December 31,2021.The number of isolates accounted for 34.3％of the total number of clinical isolates from all patients.Overall,21.8％of the 514 715 strains were gram-positive bacteria,and 78.2％were gram-negative bacteria.Majority(90.9％)of the strains were isolated from inpatients.About 42.9％of the strains were isolated from respiratory specimens,and 22.9％were isolated from urine.More than half(60.7％)of the strains were isolated from male patients,and 39.3％isolated from females.About 51.1％of the strains were isolated from patients aged 65-＜75 years.The prevalence of methicillin-resistant strains(MRSA)was 38.8％in 32 190 strains of Staphylococcus aureus.No vancomycin-or linezolid-resistant strains were found.The resistance rate of E.faecalis to most antibiotics was significantly lower than that of Enterococcus faecium,but a few vancomycin-resistant strains(0.2％,1.5％)and linezolid-resistant strains(3.4％,0.3％)were found in E.faecalis and E.faecium.The prevalence of penicillin-susceptible S.pneumoniae(PSSP),penicillin-intermediate S.pneumoniae(PISP),and penicillin-resistant S.pneumoniae(PRSP)was 94.3％,4.0％,and 1.7％in nonmeningitis S.pneumoniae isolates.The resistance rates of Klebsiella spp.(Klebsiella pneumoniae 93.2％)to imipenem and meropenem were 20.9％and 22.3％,respectively.Other Enterobacterales species were highly sensitive to carbapenem antibiotics.Only 1.7％-7.8％of other Enterobacterales strains were resistant to carbapenems.The resistance rates of Acinetobacter spp.(Acinetobacter baumannii 90.6％)to imipenem and meropenem were 68.4％and 70.6％respectively,while 28.5％and 24.3％of P.aeruginosa strains were resistant to imipenem and meropenem,respectively.Conclusions The number of clinical isolates from elderly patients is increasing year by year,especially in the 65-＜75 age group.Respiratory tract isolates were more prevalent in male elderly patients,and urinary tract isolates were more prevalent in female elderly patients.Klebsiella isolates were increasingly resistant to multiple antimicrobial agents,especially carbapenems.Antimicrobial resistance surveillance is helpful for accurate empirical antimicrobial therapy in elderly patients.

Objective To investigate the distribution and antimicrobial resistance profiles of clinically isolated Haemophilus influenzae and Moraxella catarrhalis in hospitals across China from 2015 to 2021,and provide evidence for rational use of antimicrobial agents.Methods Data of H.influenzae and M.catarrhalis strains isolated from 2015 to 2021 in CHINET program were collected for analysis,and antimicrobial susceptibility testing was performed by disc diffusion method or automated systems according to the uniform protocol of CHINET.The results were interpreted according to the CLSI breakpoints in 2022.Beta-lactamases was detected by using nitrocefin disk.Results From 2015 to 2021,a total of 43 642 strains of Haemophilus species were isolated,accounting for 2.91％of the total clinical isolates and 4.07％of Gram-negative bacteria in CHINET program.Among the 40 437 strains of H.influenzae,66.89％were isolated from children and 33.11％were isolated from adults.More than 90％of the H.influenzae strains were isolated from respiratory tract specimens.The prevalence of β-lactamase was 53.79％in H.influenzae strains.The H.influenzae strains isolated from children showed higher resistance rate than the strains isolated from adults.Overall,779 strains of H.influenzae did not produce β-lactamase but were resistant to ampicillin(BLNAR).Beta-lactamase-producing strains showed significantly higher resistance rates to these antimicrobial agents than the β-lactamase-nonproducing strains.Of the 16 191 M.catarrhalis strains,80.06％were isolated from children and 19.94％isolated from adults.M.catarrhalis strains were mostly susceptible to both amoxicillin-clavulanic acid and cefuroxime,evidenced by resistance rate lower than 2.0％.Conclusions The emergence of antibiotic-resistant H.influenzae due to β-lactamase production poses a challenge for clinical anti-infective treatment.Therefore,it is very important to implement antibiotic resistance surveillance for H.influenzae and guide rational antibiotic use.All local clinical microbiology laboratories should actively improve antibiotic susceptibility testing and strengthen antibiotic resistance surveillance for H.influenzae.