The national food safety standards for physical and chemical testing methods serve as a fundamental tool for food safety risk assessment and management in China. Since the enactment of the Food Safety Law in 2009, these standards have undergone rigorous consolidation and follow-up evaluation. This study systematically analyzed the development, validation, and refinement processes of these standards over the past decade. The findings demonstrate that the standardization model has yielded a scientifically rigorous and highly operable standard system, supported by a feedback-driven continuous improvement mechanism. This systematic approach, with its emphasis on analytical performance validation and practical operability, offers a valuable reference for establishing or refining similar testing standards in other regions, particularly in terms of method standardization and routine laboratory application. Furthermore, prospective insights into the future development and emerging trends of these testing method standards are discussed, offering a theoretical reference for their continuous optimization and technological advancement.

AbstractThe worldwide expansion of carbapenemase-producing hypervirulent K. pneumoniae (CP-hvKP) raises serious concerns about potentially untreatable invasive infections. ST23, an archetypal hvKP clone, has been highlighted due to the rising prevalence of carbapenem resistance largely driven by horizontal plasmid transfer. However, the factors facilitating carbapenemase acquisition in this lineage remained unclear. We characterized 1159 ST23 isolates across 49 countries, including nine clinical carbapenemase-producing strains from China's national bloodstream infection surveillance network. Global phylogenetic analysis revealed two distinct sublineages, namely the globally distributed, hypervirulent ST23-I and the geographically restricted, multidrug-resistant ST23-II. Temporal analysis showed that ST23-I concurrently accumulated virulence and antimicrobial resistance traits. Among ST23-I isolates, carbapenemase plasmids exhibited notable genetic diversity and clear geographic segregation, with IncL-blaOXA-48 dominated in Europe and IncFII-blaKPC-2 in Asia. Conjugation assays revealed that IncFIIK34-blaKPC-2 and IncL-blaOXA-48 plasmids transferred more efficiently than IncX3-blaNDM-1 and IncFIIK2-blaNDM-1 plasmids, contributing to their high prevalence. Non-synonymous mutations in the capsular polysaccharide synthesis locus, particularly in wzc, were accumulated in ST23-KL1 CP-hvKP. Isogenic mutants carrying two identified wzc mutations (either wzc2042A > G or wzc1738T > A) exhibited partially reduced capsule production and enhanced conjugation efficiency of carbapenemase plasmids, confirming the functional impact of these mutations. Collectively, these findings demonstrate that an elevated wzc mutation frequency represents an adaptive evolutionary pathway that facilitates carbapenemase acquisition in hvKP ST23. The interplay between capsule-associated chromosomal mutations and plasmid-mediated horizontal gene transfer may shape the evolutionary adaptation of resistance in this clinically important pathogen.

To the Editor: Emphysematous liver abscess(ELA)is an uncommon but severe form of liver infection,typically caused by gas-producing microor-ganisms such as Escherichia coli,Klebsiella pneumoniae,anaerobes(e.g.,Clostridium species),and certain fungi[1-3].The clinical pre-sentation of ELA is similar to other types of liver abscesses but is often more severe due to the rapid progression and potential for systemic complications[4].We herein reported an extremely rare case of ELA,emphasizing that early identification,standardized di-agnostic protocols,and timely intervention were pivotal to improv-ing patient prognosis.

Objectives: To evaluate the in vitro susceptibility of ESBL-producing Enterobacterales isolates to ceftolozane/tazobactam (C/T), a combination of tazobactam (a ß-lactamase inhibitor) and a new antipseudomonal cephalosporin. Methods: From 2016 to 2019, susceptibilities of 10,545 Enterobacterales isolated from intra-abdominal, urinary tract, respiratory tract and bloodstream infections to C/T and 11 other antimicrobial agents were analyzed. Non-ESBL-producing isolates were included for comparative analysis to provide a comprehensive susceptibility profile. Results: Among 10,545 isolated Enterobacterales, 54.6% were ESBL producers. The ESBL-positive rates for E. coli (4984/10,545, 47.3%) and K. pneumoniae (3606/10,545, 34.2%) were 59.8% and 51.1%, respectively. The susceptibility rate to C/T for all Enterobacterales was 79.5%. For E. coli and K. pneumoniae, the C/T susceptibilities were 89.3% and 68.0%, respectively. For non-ESBL-producing Enterobacterales, susceptibility to C/T was 99.5%. The susceptibility of non-carbapenem-resistant (CR) ESBL-producing Enterobacterales to C/T was 81.0%. The isolation rates of ESBL-positive and carbapenem-resistant Enterobacterales (CRE), CR-E. coli, and CR-K. pneumoniae were 14.3%, 5.6% and 26.8%, respectively. The susceptibility of ESBL-positive CREs to C/T was <20% for most antimicrobials except amikacin (50.4%). The susceptibility of ESBL-positive CR-E. coli to C/T was 28.2. For ESBL-producing CR-K. pneumoniae, susceptibility to most antimicrobials was <10%, except for amikacin (37.4%). Conclusions: The present research underscores the viability of C/T as an alternative to carbapenems for the treatment of ESBL-producing, carbapenem susceptible Enterobacterales. However, the susceptibilities of ESBL-positive CRE to C/T and other studied antimicrobials were consistently below 20%, emphasizing for new innovative treatment strategies.

Background:Diabetic nephropathy (DN) is the leading cause of end-stage renal disease worldwide, whose pathogenesis involves immune dysregulation and inflammatory response. Glycosylation plays key roles in numerous biological processes. This study aims to interrogate the role of glycosylation-related genes in tubulointerstitial immunoinflammatory injury in DN. Methods:We utilized two tubulointerstitial transcriptome datasets from DN patients and normal individuals. Glycosylation-related hub genes were identified by integrating differential expression analysis, glycosylation-related gene sets, and machine learning. Immune cell infiltration was assessed using single-sample GSEA (ssGSEA), and functional enrichment analysis was performed via GO and KEGG. The expression levels of hub genes were validated in STZ-induced diabetic mouse model (n=5/group) followed by the evaluation of diagnostic efficiency and clinical significance. Results:Six glycosylation-related hub genes (HEXB, B4GALT5, GALNT7, GCNT3, CGA, and VCAN) were identified, all closely associated with immune cell infiltration in DN. Enrichment analysis indicated their involvement in immune and inflammatory processes. CGA was significantly downregulated, while the other genes were upregulated in DN, which was experimentally validated in diabetic mice. ROC curve analysis revealed high diagnostic accuracy for all genes: HEXB (AUC = 0.892), B4GALT5 (AUC = 0.909), GALNT7 (AUC = 0.931), GCNT3 (AUC = 0.929), CGA (AUC = 0.898), and VCAN (AUC = 0.967). Elevated VCAN, GCNT3, and GALNT7 exhibited a positive association with renal function decline or proteinuria, providing valuable prognostic insights. Conclusion:This study highlights the significant role of glycosylation-related genes in DN pathogenesis, likely mediated through immune and inflammatory mechanisms. VCAN, GCNT3, and GALNT7 show particular promise as novel biomarkers for clinical diagnosis and immunotherapeutic targets, supporting their future clinical translation for DN management.

OBJECTIVE:To describe the epidemiological and molecular characterization and in vitro activity of imipenem/relebactam against imipenem non-susceptible (IPMNS) Klebsiella pneumoniae isolates in China. METHODS:K. pneumoniae isolates were collected from 16 sites in 5 regions across China during 2019. Antimicrobial susceptibility testing was performed. For IPMNS K. pneumoniae isolates, whole genome sequencing was used to screen for drug-resistance and virulence genes. RESULTS:Of 1011 clinical K. pneumoniae isolates, 277 (27.3%) were IPMNS and were significantly more common in intensive care unit patients (47.5%) and hospital-acquired infections (28.9%). Production of carbapenemase was the dominant resistance mechanism, with 228 (89.8%) IPMNS isolates harbouring blaKPC-2, 8 (3.1%) blaNDM, 2 (0.8%) blaOXA-232 and 1 (0.4%) blaOXA-181. The dominant clone was sequence type (ST) 11 (78.7%) followed by ST15 (10.2%). Relebactam restored imipenem's susceptibility in 96.5% isolates harbouring a blaKPC-2 gene. CONCLUSIONS:Harbouring the blaKPC-2 gene was the dominant mechanism of IPMNS K. pneumoniae in China. Empirical imipenem/relebactam treatment could be considered when susceptibility or carbapenemase tests are not available.

In recent decades, Acinetobacter baumannii has become a major global nosocomial pathogen, with bloodstream infections (BSIs) exhibiting mortality rates exceeding 60% and imposing substantial economic burdens. However, limited large-scale genomic epidemiology has hindered understanding of its population dynamics. Here, we analyzed 1506 non-repetitive BSI-causing A. baumannii isolates from 76 Chinese hospitals over a decade (2011-2021). We identified 149 sequence types (STs) and 101 K-locus types (KLs), revealing increased population diversity. International clone (IC) 2 accounted for 81.74% of isolates, with a notable shift in prevalent STs: ST208 increased while ST191 and ST195 declined, aligning with global trends. ST208 exhibited higher virulence, greater antibiotic resistance, enhanced desiccation tolerance, and more complex transmission patterns compared to ST191 and ST195. Its genomic plasticity drives its adaptation and spread. Using the high-resolution Oxford MLST scheme, this study uncovered greater diversity and genetic factors behind ST208's rise. A. baumannii is evolving from a low-virulence, multidrug-resistant pathogen to a more virulent one, highlighting the urgent need to address its growing threat. These findings have critical implications for infection control and public health policies.

ObjectiveTo investigate the effect of SerpinA5 on the malignant biological behavior of esophageal squamous cell carcinoma (ESCC) and its molecular mechanism. MethodsThe expression levels of the SerpinA5 gene in various tumors and adjacent normal tissues were analyzed by using the TIMER2.0 database. The expression levels of SerpinA5 in the ESCC cell line and esophageal epithelial cells were detected through Western blot analysis. Stably transfected KYSE150 cell line with overexpression of SerpinA5 was constructed through lentiviral transfection, and overexpression efficiency was detected via Western blot analysis. The effects of SerpinA5 overexpression on the proliferation, apoptosis, migration, and invasion of ESCC cells were detected by employing the CCK8, plate cloning, flow cytometry, wound healing, and Transwell invasion assays. The nude mice subcutaneous xenograft model with SerpinA5 overexpression was constructed. Tumor growth was observed, and tumor volume and mass were measured. The cell proliferation level of the subcutaneous xenograft tumors in nude mice was detected via immunohistochemistry (IHC). Coimmunoprecipitation (Co-IP) was employed to determine the interaction between SerpinA5 and Fn. Western blot analysis was applied to detect the expression levels of proteins (Fn, Integrin-β1, FAK, and p-FAK) related to the Fn/Integrin-β1 signaling pathway in transplanted tumors. ResultsSerpinA5 was expressed at low levels in ESCC tissues and cell lines. In ESCC cells, SerpinA5 overexpression can considerably inhibit cell proliferation, migration, and invasion and promote cell apoptosis. In the subcutaneous xenograft experiment on nude mice, the tumor volume and weight of the SerpinA5 overexpression group were lower than those of the negative control group. IHC results demonstrated that SerpinA5 overexpression significantly inhibited the proliferation of ESCC cells in tumor tissues. Co-IP confirmed the interaction between SerpinA5 and Fn. Western blot analysis results showed that the expression levels of Fn, Integrin-β1, and p-FAK in the Fn/Integrin-β1 signaling pathway of ESCC cells in the subcutaneous xenograft tumors of nude mice significantly decreased after SerpinA5 overexpression. ConclusionSerpin A5 may inhibit proliferation, migration, and invasion and promote apoptosis of ESCC cells by regulating the Fn/Integrin-β1 signaling pathway.

This work was to investigate the optimal treatments of imipenem (IPM) and meropenem (MEM) against bloodstream infections (BSIs) caused by Citrobacter spp. A total of 230 nonduplicate BSIs Citrobacter spp. were collected from 2014 to 2020 in three hospitals in Zhejiang Province in China. The minimum inhibitory concentrations (MICs) of 17 antibiotics were determined. Monte Carlo simulation (MCS) was used to investigate the cumulative fraction of response (CFR) of 8 regimens of IPM and 10 regimens of MEM. C. freundii (Cfr) was the predominant epidemic isolate (83.9

OBJECTIVES:To study the clinical relevance, mechanisms, and evolution of polymyxin B (POLB) heteroresistance (PHR) in carbapenem-resistant Klebsiella pneumoniae (CRKP), potentially leading to a significant rise in POLB full resistant (FR) CRKP.METHODS:Total of 544 CRKP isolates from 154 patients treated with POLB were categorized into PHR and POLB non-heteroresistance (NHR) groups. We performed statistical analysis to compare clinical implications and treatment responses. We employed whole-genome sequencing, bioinformatics, and PCR to study the molecular epidemiology, mechanisms behind PHR, and its evolution into FR.RESULTS:We observed a considerable proportion (118 of 154, 76.62%) of clinically undetected PHR strains before POLB exposure, with a significant subset of them (33 of 118, 27.97%) evolving into FR after POLB treatment. We investigated the clinical implications, epidemiological characteristics, mechanisms, and evolutionary patterns of PHR strains in the context of POLB treatment. About 92.86% (39 of 42) of patients had PHR isolates before FR, highlighting the clinical importance of PHR. the ST15 exhibited a notably lower PHR rate (1 of 8, 12.5% vs. 117 of 144, 81.25%; p < 0.01). The ST11 PHR strains showing significantly higher rate of mgrB mutations by endogenous insertion sequences in their resistant subpopulation (RS) compared with other STs (78 of 106, 73.58% vs. 4 of 12, 33.33%; p < 0.01). The mgrB insertional inactivation rate was lower in FR isolates than in the RS of PHR isolates (15 of 42, 35.71% vs. 84 of 112, 75%; p < 0.01), whereas the pmrAB mutation rate was higher in FR isolates than in the RS of PHR isolates (8 of 42, 19.05% vs. 2 of 112, 1.79%; p < 0.01). The evolution from PHR to FR was influenced by subpopulation dynamics and genetic adaptability because of hypermutability.DISCUSSION:We highlight significant genetic changes as the primary driver of PHR to FR in CRKP, underscoring polymyxin complexity.

ABSTRACT Klebsiella pneumoniae is a common pathogen of nosocomial infection, which can cause pneumonia, urinary tract infection, cystitis, and bloodstream infections (BSIs). Here, we genetically characterize a novel carbapenem-resistant K. pneumoniae (CRKP) strain recovered from the blood of a 44-year-old male patient with severe acute necrotizing pancreatitis and septic shock in China. The strain is a ST45 K. pneumoniae with a novel serotype of K43, named 18SHX166. The susceptibility testing results showed that 18SHX166 was resistant to cephalosporin and carbapenems but still susceptible to ceftazidime-avibactam, quinolones, colistin, and amikacin. Genomic sequencing revealed that 18SHX166 contains three plasmids, namely pSHX166-Hv, pSHX166-KPC, and pSHX166-3. pSHX166-Hv harbored the iucABCD operon, encoding the siderophore of aerobactin. pSHX166-KPC harbored bla KPC-2 gene and possessed complete conjugative regions. The conjugation experiment verified pSHX166-KPC as a self-transmissible plasmid mediating the dissemination of antibiotic resistance, with a conjugation rate of 2.21 × 10 −5 . Additionally, the growth curve showed that 18SHX166 demonstrates a higher growth rate than the control strains. The characteristics of 18SHX166 indicate a potential high risk of clinical transmission. IMPORTANCE ST45-K43 carbapenem-resistant Klebsiella pneumoniae isolate, 18SHX166, carries a carbapenem resistance plasmid and virulence plasmid. It has the characteristics of multidrug resistance, high transmissibility, and a fast growth rate, which could pose a threat to the control of antimicrobial resistance and clinical transmission, causing a severe challenge to public health.

The aim of this work was to assess dynamic cytokine profiles associated with bloodstream infection (BSI) caused by Klebsiella pneumoniae (Kpn) and investigate the clinical features associated with mortality. A total of 114 patients with positive BSI-Kpn and 12 sepsis individuals without blood positive bacteria culture were followed up. Cytokine profiles were analyzed by multiplex immunoassay on the first, third, seventh and fourteenth day after diagnosis. The test cytokines included arginase, interferon-gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), interleukin (IL)-1β, IL-4, IL-6, IL-10, IL-12 (p70), and IL-23. The minimum inhibitory concentration (MIC) of 24 antibiotics were tested for BSI-Kpn. Risk factors associated with the 30-day mortality and 120-day mortality were evaluated using logistic analyses and nomogram. There were 55 out of 114 patients with BSI-Kpn were included. All isolates showed high susceptibility rate to novel avibactam combinations. The level of arginase was the highest in carbapenem-resistant Kpn (CRKP) patients. The AUCs of arginase, TNF-α and IL-4 reached 0.726, 0.495, and 0.549, respectively, whereas the AUC for the combination of these three cytokines was 0.805. Notably, 120-day mortality in patients with CRKP was higher than carbapenem-sensitive K. pneumoniae (CSKP). Furthermore, the long-term and high levels of IL-6 and IL-10 were associated with death. High expression of arginase is correlated with CRKP. In addition, BSI-CRKP could result in indolent clinic course but poor long-term prognosis. Continuous increase of IL-6 and IL-10 were associated with mortality.

Abstract Objectives The aim of this study was to evaluate the characteristics of immunocyte associated with bloodstream infection (BSI) caused by Klebsiella pneumoniae (Kpn). Methods Patients with BSI-Kpn were included from 2015 to 2022 in our hospital. Immunocyte subpopulations of enrolled BSI-Kpn patients were tested on the same day of blood culture using multicolor flow cytometry analysis. Antibiotic susceptibility test was determined by agar dilution or broth dilution method. All included isolates were subjected to whole genome sequencing and comparative genomics analysis. Clinical and genetic data were integrated to investigate the risk factors associated with clinical outcome. Results There were 173 patients with non-duplicate BSI-Kpn, including 81 carbapenem-resistant Kpn (CRKP), 30 extended-spectrum β-lactamases producing Kpn (ESBL-Kpn), 62 none CRKP or ESBL-Kpn (S-Kpn). Among 68 ST11-CRKP isolates, ST11-O2v1:KL64 was the most common serotypes cluster (77.9%, 53/68), followed by ST11-OL101: KL47 (13.2%, 9/68). Compared with CSKP group, subpopulations of immunocyte in patients with CRKP were significantly lower (P < 0.01). In patients with ST11-O2v1:KL64 BSI-Kpn, the level of cytotoxic T lymphocytes (CD3 + CD8 +) is the highest, while the B lymphocytes (CD3-CD19 +) was the least. In addition, the level of immunocyte in patients with Kpn co-harbored clpV-ybtQ-qacE were lower than that in patients with Kpn harbored one of clpV, ybtQ or qacE and without these three genes. Furthermore, co-existence of clpV-ybtQ-qacE was independently associated with a higher risk for 30-day mortality. Conclusions The results demonstrate that patients with BSI-CRKP, especially for ST11-O2v1:KL64, exhibit lower leukomonocyte counts. In addition, BSI-Kpn co-harbored clpV-ybtQ-qacE is correlated to higher 30-day mortality.

Objective: To evaluate the characteristics of immunocytes and cytokines associated with bloodstream infections (BSIs) caused by Klebsiella pneumoniae (CRKP). Methods: Patients with BSIs K. pneumoniae (BSIs-Kpn) were enrolled in our hospital between 2015 and 2022. Whole blood and serum samples were collected on the first day after diagnosis. Immunocytes and cytokines profiles were assessed using multicolor flow cytometry and multiplex immunoassays, respectively. The test cytokines included interferon-gamma (IFN-gamma), tumor necrosis factoralpha (TNF-alpha), interleukin (IL)-2, IL-4, IL-6, IL-10, and IL-17A. Results: A total of 313 patients had BSIs-Kpn, including 145 with CRKP, 43 with extended-spectrum beta-lactamases (ESBL) producing Kpn (ESBL-Kpn) and 125 with non-CRKP or non-ESBL-Kpn (susceptible Kpn, S-Kpn). Absolute number of leukomonocyte (CD45 +) in CRKP, ESBL-Kpn and S-Kpn were 280.0 (138.0-523.0) cells/mu L, 354.5 (150.3-737.3) cells/mu L, and 637.0 (245.0-996.5) cells/ mu L, respectively. Compared with S-Kpn group, the absolute numbers of leukomonocyte (including T lymphocytes, B lymphocytes and natural killer cells) in patients with CRKP were significantly lower than that in patients with S-Kpn (P < 0.01). The levels of cytokines IL-2 and IL-17A were significantly higher in patients with S-Kpn than in those patients with CRKP (P<0.05). The area under receiver operating curve (AUC) of IL-2, IL-4, and IL-17A for S-Kpn was 0.576, 0.513, and 0.561, respectively, whereas that for the combination of these three cytokines with immunocytes was 0.804. Conclusion: Patients with BSIs-CRKP had lower leukomonocyte counts. High levels of IL-2 and IL-17A combined with immunocyte subpopulations showed relatively high diagnostic value for BSIs-S-Kpn from BSIs-CRKP.

OBJECTIVES:The aim of this study was to evaluate the efficacy and safety of inhaled antibiotics for adults with pneumonia by meta-analysis. METHODS:Literature retrieval was completed through five databases (PubMed, Embase, Cochrane Library, Web of Science and Scopus) by the deadline of May 31, 2024. The process of study selection and data extraction were performed independently by two reviewers. The quality of observational studies and randomized controlled trial (RCT) studies were evaluated by Newcastle Ottawa scale and Jadad scale, respectively. The primary outcomes included mortality, clinical cure, and microbiological cure. Secondary outcomes were recurrence and renal impairment. RESULTS:There were 30 studies were analyzed, including 12 RCT studies and 18 observational studies. Inhaled antibiotics did not significantly reduce mortality in RCT studies (odds ratio (OR) = 1.06, 95 % confidence interval (CI): 0.80-1.41). Inhaled antibiotics were associated with higher rates of clinical cure (OR = 1.47 95%CI: 0.82-2.66 in RCT studies and OR = 2.09, 95%CI: 1.36-3.21 in observational studies) and microbiological cure (OR = 7.00 in RCT studies and OR = 2.20 in observational studies). Subgroup analysis showed patients received inhaled antibiotics combined with intravenous administration and inhaled amikacin had better improvements of mortality, clinical cure and microbiological cure. Inhaled antibiotics were not associated with recurrence. The pooled OR of renal impairment were 0.65 (95%CI: 0.27-1.13; I-squared = 43.5 %, P = 0.124) and 0.63(95%CI: 0.26-1.11; I-squared = 69.0 %, P = 0.110) in RCT studies and observational studies, respectively. CONCLUSIONS:Inhaled antibiotics decreased risk of renal impairment and achieved significant improvements of clinical and microbiological cure in patients with pneumoniae.

The aim of this study was to identify the synergistic effect and mechanisms of fosfomycin (FM) combined with colistin (COL) against KPC-producing Klebsiella pneumoniae (KPC-Kp). The bactericidal effects, induced drug resistance and cytotoxicity of FM combined with COL were evaluated by time-kill assays and mutation rate test. Time-kill assays and transcriptomics analysis were used to further clarify the mechanism of FM combined with COL. The bacteria were taken from different points in time-kill assays, reactive oxygen species (ROS), nitric oxide and redox related enzymes were detected. The mechanism of synergistic bactericidal action was analyzed by transcriptome. The bactericidal effect of FM combined with COL was better than that of monotherapy. The mutation frequency of FM alone at low dose (8 mg/L) was higher than that at high dose (64 mg/L). COL induced resistant isolates resulted in FM and COL resistance, while FM alone or combined with COL only resulted in FM resistance. The survival rate of Thp-1 cells in FM combined with COL against K. pneumoniae was higher than that of monotherapy. The intracellular nitric oxide, activities of total superoxide dismutase and catalase were increased along with the increase of FM concentration against KPC-Kp. FM combined with COL induced ROS accumulation and antioxidant capacity increase. Transcriptome analysis showed FM combined with COL could regulate the levels of soxRS and oxidative phosphorylation, in order to clear ROS and repair damage. In addition, FM combined with COL could result in synergetic bactericidal efficacy by inhibiting ribosomal transcription. FM combined with COL mediated synergistic bactericidal effect by regulating ROS accumulation and inhibiting ribosomal protein transcription, resulting in lower resistance and cytotoxicity.

Abstract Objectives: The aim of this study was to summarize available dataon monotherapy or combination therapy for bloodstream infection (BSI) caused by carbapenem-resistant Klebsiella pneumoniae (CRKP). Methods: A systematic review and meta-analysis was conducted to compare monotherapy with combination therapy in patients with BSI-CRKP. Mortality was the primary outcome. Results: A total of 1675 patients in 13 studies were included. The pooled risk ratio (RR) of mortality were 0.79 (95%CI: 0.60-1.05) between combination therapy and monotherapy. However, no significant difference in mortality was observed. The RR of polymyxins-based and tigecycline-based combination therapy were 0.72 (95%CI: 0.47-1.12) and 0.67 (95%CI: 0.42-1.09), respectively. Similarly, the difference is statistically insignificant. Further analysis showed the lower mortality associated with polymyxins+tigecycline-based combination therapies than that with tigecycline combined with other antibiotics (RR=0.66, 95%CI: 0.52-0.83, P=0.00). Conclusions: Combination therapy against BSI-CRKP has survival benefit, especially for polymyxins+tigecycline-containing therapies.

Abstract The rise of Klebsiella pneumoniae resistant to last‐resort antimicrobials poses an urgent threat to global health. The ramR‐ramA regulatory system critically influences drug resistance by regulating the AcrAB‐TolC efflux pump, which also plays a crucial role in the pathogenicity of K. pneumoniae. However, the mechanism of the ramR‐ramA system on bacteria‐host interaction remains unclear. To determine how specific mutations in ramR influence eravacycline (ERV) resistance and their impact on the immune activation capabilities of K. pneumoniae, thereby highlighting potential targets for therapeutic intervention, we performed genetic sequencing to identify mutations in ramR. Then, the CRISPR‐Cas9 technology was employed to construct specific ramR mutations into K. pneumoniae, which were then subjected to phenotypic and functional assays in both in vitro and in vivo (mouse models, macrophage, and blood‐killing experiment) settings. ramR L58P and F165L genetic alterations disrupt the binding affinity of RamR to the ramA promoter, thereby upregulating the efflux pump expression and increasing ERV minimum inhibitory concentration values up to 64‐fold compared to the wild‐type. Concurrently, these mutations modulate lipid A structure by increasing 2‐hydroxy fatty acid chain abundance. In mouse models, ramR L58P and F165L mutants showed lower bacterial burden in organs (spleen, lung, and kidney) 6 h post‐infection, and are fast cleared in 48 h. Furthermore, despite lower intracellular bacterial loads, ramR L58P and F165L mutants induce heightened pro‐inflammatory cytokine responses in macrophages and elevate systemic cytokine levels (interleukin [IL]2, IL4, IL6, IL12, interferon‐α, and interferon‐γ) in human blood co‐culture experiments. This study illuminates the critical role of ramR mutations in conferring ERV resistance and enhancing immune responses in K. pneumoniae. The dual impact of these mutations on both antimicrobial resistance and immune activation not only underscores the challenges in treating infections but also advocates for heightened surveillance and innovative strategies to counteract the emerging threat of antimicrobial‐resistant K. pneumoniae.

Objectives: Membranous nephropathy (MN) and minimal change disease (MCD) are two common types of nephrotic syndrome that have similar clinical presentations but require different treatment strategies. Currently, the definitive diagnosis for these conditions relies on invasive renal biopsy, which can be limited in clinical practice.Methods: In this study, we aimed to differentiate idiopathic MN (IMN) from MCD using clinical data and gut microbiota. We collected clinical data and stool samples from 115 healthy individuals, 115 IMN, and 45 MCD at the onset of disease and performed 16S rRNA sequencing. Through machine learning methods including random forest, logistic regression, and support vector machine, a classifier to differentiate IMN from MCD was constructed.Results: Baseline clinical data comparing the IMN and MCD groups showed that the MCD had higher levels of hemoglobin, uric acid, cystatin C, β2-microglobulin, α1-microglobulin, total cholesterol, and low-density lipoprotein and lower levels of albumin and CD4+ T-cell counts. The gut microbiota of the two groups differed at all levels of the phylum and genus. Differential gut microbiota may disturb the integrity of the intestinal wall and lead to the passage of inflammatory mediators through the intestinal barrier, causing kidney injury. We constructed a noninvasive classifier with a discrimination efficacy of 0.939 that combined the clinical data and gut microbiota information to identify IMN and MCD.Conclusions: The classifier of the gut microbiota combined with clinical indicators has achieved good performance in identifying IMN and MCD, which provides a new approach for the noninvasive discrimination of different pathological types of kidney disease.

Background Previous studies suggested that tumor size was an independent risk factor of prognosis for hepatocellular carcinoma (HCC). However, the general prognostic analysis did not consider the interaction between variables. The purpose of this study was to investigate whether the effect of tumor size on the prognosis of isolated HCC without vascular invasion varies according to covariates. Methods Patients were selected from the Surveillance, Epidemiology, and End Results (SEER) database to investigate whether there was an interaction between age and tumor size on the prognosis. Then the trend test and the value of per 1 SD of tumor size were calculated. In addition, the data of Zhejiang Provincial People's Hospital meeting the requirements were selected to verify the obtained conclusions. Results Multivariable Cox regression analysis of the database cohort showed that age, gender, tumor size, pathological grade and marital status were independent risk factors for prognosis. Interaction test showed that there was an interaction between age and tumor size (P for interaction < 0.05). Stratified analysis by age showed that tumor size was an independent risk factor for prognosis when age ≤65 years old (HR:1.010,95%CI1.007–1.013 P < 0.001), while tumor size was not an independent risk factor for prognosis when age >65 years old. This result was confirmed by trend analysis (P for trend < 0.001), and the prognostic risk increased by 42.1% for each standard deviation increase of tumor size among patients age ≤65 years. Consistent conclusion was obtained by multivariable cox regression analysis and interaction test on the verification cohort. In the validation cohort, for each standard deviation increase of tumor size in patients ≤65 years old, the risk of prognosis increased by 52.4%. Conclusion Tumor size is not an independent risk factor for the prognosis of isolated HCC without vascular invasion when patient's age >65 years. Therefore, when analyzing the relationship between tumor size and prognosis, stratified analysis should be performed according to age.