Multidrug-resistant (MDR) bacterial infections have emerged as a serious challenge of global public health crisis. The overuse and misuse of conventional antibiotics have dramatically accelerated the emergence, evolution and worldwide spread of drug-resistant bacterial strains, necessitating urgent exploration of novel antibacterial strategies. Bacteriophages serve as natural bacterial predators offering distinct advantages including high host specificity, autonomous self-replication capabilities and cost-effective large-scale production. However, wild-type phages present significant clinical limitations due to their narrow host ranges, susceptibility to rapid immune clearance and poor penetration of bacterial biofilms, which severely restrict their therapeutic applications. The convergence of synthetic biology, nanotechnology and advanced gene editing technologies has accelerated the development of engineered bacteriophage platforms, providing programmable, scalable and clinically translatable pathways to overcome these inherent biological constraints. Here, we systematically delineate four fundamental strategies for engineered bacteriophage development. Chemical modification utilizes reactive functional groups such as amino, carboxyl and thiol moieties on capsid proteins through esterification, amidation or click chemistry reactions to achieve precise drug conjugation and surface functionalization. In vivo editing encompasses ultraviolet or chemical mutagenesis for random mutation induction, homologous recombination for targeted genetic alterations, recombineering methodologies including electroporation-mediated bacteriophage recombination engineering, and CRISPR-Cas systems for precise genome editing to enable exact genetic reconstruction and host range reprogramming. In vitro synthesis leverages genome engineering platforms where intact phage genomes are transferred into yeast or host bacteria to facilitate highly efficient homologous recombination, enabling large DNA fragment assembly and cross-gene host range expansion without bacterial toxicity constraints. Directed evolution combines artificial selection through mutation library screening with rational design approaches involving chimeric receptor binding protein construction or site-specific mutagenesis, effectively balancing the discovery of unknown adaptive pathways with targeted host specificity modification. Moreover, we comprehensively discuss therapeutic applications across diverse clinical scenarios. Engineered bacteriophage effectively disrupt bacterial biofilms through sophisticated functionalized delivery platforms including nanozyme-conjugated phages, phage-liposome nanoconjugates and bio-responsive hydrogels, demonstrating significantly enhanced bactericidal efficiency compared to unmodified free phages. These bioengineered vectors attenuate bacterial virulence and resensitize pathogens to antibiotics by delivering CRISPR-Cas systems or base editors to disrupt critical virulence factors such as pili, capsule synthesis machineries and quorum sensing systems, or by inactivating antibiotic resistance determinants including beta-lactamase genes. As an intelligent nanomedicine delivery platform, engineered bacteriophage enable precise pathogen elimination an through photocatalytic reactive oxygen species generation, immunomodulatory interventions, or controlled release of antibacterial drugs. Furthermore, oral administration of engineered bacteriophage facilitates microbiota modulation, which selectively eliminate intestinal pathogens while preserve beneficial commensal microbiota, thereby restoring microbial community balance and preventing complications associated with dysbiosis. Finally, we critically analyze persistent challenges including host strain matching complexity, evolution of bacterial resistance mechanisms, pharmacokinetic optimization requirements, optimal administration route selection, large-scale production quality control standards and clinical dosing determination protocols. Through multidisciplinary integration of synthetic biology, infectious disease medicine and immunology, future translational medicine studies of bacteriophage should establish comprehensive technical platforms encompassing rapid phage screening, intelligent rational design, rigorous in vivo evaluation and standardized clinical validation processes, ultimately advancing engineered bacteriophage from laboratory innovations to clinically approved therapeutics for effectively combating MDR bacterial infections.

ObjectiveTo investigate the role of 4-week high-intensity interval training (HIIT) in modulating the metabolic homeostasis of the pyruvate-lactate axis in the hippocampus of rats with chronic unpredictable mild stress (CUMS) to improve their depressive-like behavior. MethodsForty-eight SPF-grade 8-week-old male SD rats were randomly divided into 4 groups: the normal quiet group (C), the CUMS quiet group (M), the normal exercise group (HC), and the CUMS exercise group (HM). The M and HM groups received 8 weeks of CUMS modeling, while the HC and HM groups were exposed to 4 weeks of HIIT starting from the 5th week (3 min (85%-90%) S_max+1 min (50%-55%) S_max, 3-5 cycles, S_max is the maximum movement speed). A lactate analyzer was used to detect the blood lactate concentration in the quiet state of rats in the HC and HM groups at week 4 and in the 0, 2, 4, 8, 12, and 24 h after exercise, as well as in the quiet state of rats in each group at week 8. Behavioral indexes such as sucrose preference rate, number of times of uprightness and number of traversing frames in the absenteeism experiment, and other behavioral indexes were used to assess the depressive-like behavior of the rats at week 4 and week 8. The rats were anesthetized on the next day after the behavioral test in week 8, and hippocampal tissues were taken for assay. LC-MS non-targeted metabolomics, target quantification, ELISA and Western blot were used to detect the changes in metabolite content, lactate and pyruvate concentration, the content of key metabolic enzymes in the pyruvate-lactate axis, and the protein expression levels of monocarboxylate transporters (MCTs). Results4-week HIIT intervention significantly increased the sucrose preference rate, the number of uprights and the number of traversed frames in the absent field experiment in CUMS rats; non-targeted metabolomics assay found that 21 metabolites were significantly changed in group M compared to group C, and 14 and 11 differential metabolites were significantly dialed back in the HC and HM groups, respectively, after the 4-week HIIT intervention; the quantitative results of the targeting showed that, compared to group C, lactate concentration in the hippocampal tissues of M group, compared with group C, lactate concentration in hippocampal tissue was significantly reduced and pyruvate concentration was significantly increased, and 4-week HIIT intervention significantly increased the concentration of lactate and pyruvate in hippocampal tissue of HM group; the trend of changes in blood lactate concentration was consistent with the change in lactate concentration in hippocampal tissue; compared with group C, the LDHB content of group M was significantly increased, the content of PKM2 and PDH, as well as the protein expression level of MCT2 and MCT4 were significantly reduced. The 4-week HIIT intervention upregulated the PKM2 and PDH content as well as the protein expression levels of MCT2 and MCT4 in the HM group. ConclusionThe 4-week HIIT intervention upregulated blood lactate concentration and PKM2 and PDH metabolizing enzymes in hippocampal tissues of CUMS rats, and upregulated the expression of MCT2 and MCT4 transport carrier proteins to promote central lactate uptake and utilization, which regulated metabolic homeostasis of the pyruvate-lactate axis and improved depressive-like behaviors.

ObjectiveThis study aimed to investigate the effects of 4-week high-intensity interval training (HIIT) on synaptic plasticity in the prefrontal cortex (PFC) of rats exposed to chronic unpredictable mild stress (CUMS), and to explore its potential mechanisms. MethodsA total of 48 male Sprague-Dawley rats were randomly divided into 4 groups: control (C), model (M), control plus HIIT (HC), and model plus HIIT (HM). Rats in groups M and HM underwent 8 weeks of CUMS to establish depression-like behaviors, while groups HC and HM received HIIT intervention beginning from the 5th week for 4 consecutive weeks. The HIIT protocol consisted of repeated intervals of 3 min at high speed (85%-90% maximal training speed, S_max) alternated with one minute at low speed (50%-55% S_max), with 3 to 5 sets per session, conducted 5 d per week. Behavioral assessments and tail-vein blood lactate levels were measured at the end of the 4th and 8th weeks. After the intervention, rat PFC tissues were collected for Golgi staining to analyze synaptic morphology. Enzyme-linked immunosorbent assays (ELISA) were employed to detect brain-derived neurotrophic factor (BDNF), monocarboxylate transporter 1 (MCT1), lactate, and glutamate levels in the PFC, as well as serotonin (5-HT) levels in serum. Additionally, Western blot analysis was conducted to quantify the expression of synaptic plasticity-related proteins, including c-Fos, activity-regulated cytoskeleton-associated protein (Arc), and N-methyl-D-aspartate receptor 1 (NMDAR1). ResultsCompared to the control group (C), the CUMS-exposed rats (group M) exhibited significant reductions in sucrose preference rates, number of grid crossings, frequency of upright postures, and entries into and duration spent in open arms of the elevated plus maze, indicating marked depressive-like behaviors. Additionally, the group M showed significantly reduced dendritic spine density in the PFC, along with elevated levels of c-Fos, Arc, NMDAR1 protein expression, and increased concentrations of lactate and glutamate. Conversely, BDNF and MCT1 contents in the PFC and 5-HT levels in serum were significantly decreased. Following HIIT intervention, rats in the group HM displayed considerable improvement in behavioral indicators compared with the group M, accompanied by significant elevations in PFC MCT1 and lactate concentrations. Furthermore, HIIT notably normalized the expression levels of c-Fos, Arc, NMDAR1, as well as glutamate and BDNF contents in the PFC. Synaptic spine density also exhibited significant recovery. ConclusionFour weeks of HIIT intervention may alleviate depressive-like behaviors in CUMS rats by increasing lactate levels and reducing glutamate concentration in the PFC, thereby downregulating the overexpression of NMDAR, attenuating excitotoxicity, and enhancing synaptic plasticity.

Objective: To investigate the distribution of IgM anti-A/B titers among group O whole blood donors in Jiangsu, establish a low-titer threshold, and analyze the demographic characteristics of low-titer donors, so as to provide data for recruiting low-titer group O whole blood (LTOWB) donors. Methods: Plasma samples from 1 009 group O whole blood donors were tested for IgM anti-A and anti-B titers using the microplate technique. The distribution of antibody titers was analyzed to establish a low-titer threshold. The distribution trends of titers across different demographic groups were also analyzed. Results: The peak titer for anti-A, anti-B were 64 (31.5%), 4 (23.8%), respectively, The proportion of donors with both anti-A and anti-B titers below 64 was 97.3% (982/1 009). The mean anti-A titer was higher than anti-B titer. Anti-A titers were higher in female donors than in male donors (P<0.05). The anti-A titers differed significantly among different age groups (P<0.05). However, no significant difference in titers was observed based on the number of donations (P>0.05). Conclusion: A titer of 64 can be used as the reference threshold of LTOWB in Jiangsu. Male donors of appropriate age are more suitable than female donors for establishing an emergency panel of LTOWB mobile donors.

Objective To explore the pathogenesis of Alzheimer's disease by examining the effects of dihydroartemisinin(DHA)on cognitive behavior,hippocampal,cerebral cortex and retinal cell morphology,β-amyloid(Aβ)and autophagy-related proteins in 5×FAD mice.Methods Twenty 5×FAD mice and 5 wild type(WT)mice were selected,all of which were female.The 5×FAD mice were randomly divided into model(M)group,donepezil(D)group,low-dose DHA(DHA-L)group,and high-dose DHA(DHA-H)group.The WT and M groups were not treated,and the D group was given donepezil 0.1 mg/kg per day.DHA-L group and DHA-H group were given 10 mg/kg and 20 mg/kg DHA per day,respectively.Group D,group DHA-L and group DHA-H were given intragastric administration once a day for 3 months.The changes of in cognitive behavior were measured by Morris experiment.HE staining was used to observe the arrangement and morphology of nerve cells in cerebral cortex,hippocampus and retina.The expressions of Aβ protein in cerebral cortex,hippocampus and retina were detected by immunohistochemistry.Western blotting detected the expression of autophagy related proteins(LC3-Ⅰ,LC3-Ⅱ,Beclin-1,P62,β-actin).Results The DHA-H group and the D group exhibited more frequent adoption of both linear and trending exploration routes.Compared to the model group,significant differences in the contents of Aβ in the hippocampal CA1,cerebral cortex S1,and retinal were observed(P＜0.0001)in the other four groups.The analysis also showed significant differences in autophagy-associated proteins between the DHA-L,DHA-H,and model groups(P＜0.01).Conclusion DHA improves cognitive function and increases the number of nerve cells in mice.It also reduces Aβ content in the cerebral cortex,hippocampus,and retina,along with improving autophagy-associated protein deposition in mice.

Objective To investigate gender differences and age-related changes in body composition(BC)among Miao adults in Rongshui,Guangxi Province,and to provide the basis for assessing nutritional status and health.Methods With informed consent,630 Miao adults(218 males,412 females)were randomly selected for this study.Body composition was assessed using bioelectrical impedance analysis(BIA).Results Weight,fat-free mass,muscle mass,trunk muscle mass,limb muscle mass,waist-to-hip ratio(WHR),body water,presumtion of bone mass and protein were significantly higher in males than in females.And the fat mass,trunk fat mass,limb fat mass,visceral fat content,subcutaneous fat content and percentage of body fat were significantly higher in females than in males.According to the evaluation of body mass index(BMI)and WHR,the proportion of overweight and obesity of Miao adults was higher than the average level of Miao residents,and their obesity was characterized by central obesity.With age,weight,fat mass,muscle mass,fat-free mass,limb muscle mass,limb fat mass,subcutaneous fat content,percentage of body fat,body water,presumtion of bone mass,and protein of Rongshui Miao adults showed a gradual decreasing trend,while visceral fat content and WHR increased progressively.BMI in male Miao adults,along with BMI,fat mass,trunk fat mass,subcutaneous fat content,percentage of body fat,and body water in female Miao adults,showed a trend of increasing followed by decreasing,peaking at the age of 40-49 years.Conclusion The body composition of Miao adults in Rongshui,Guangxi,exhibits significant gender differences and age-related variation change patterns,which may increase the risk of sarcopenia and metabolic diseases with aging.

Objective To evaluate the technical feasibility and safety of video-assisted thoracoscopic surgery(VATS)without chest tube placement for infants with congenital pulmonary airway malformation(CPAM).Methods Clinical data of 145 infants with CPAM treated by VATS from May 2019 to August 2022 were retrospectively analyzed.Six cases had a chest tube placement at the end of the surgery,while 139 cases did not.Among them,there were 99 segmental lobectomies,36 lobectomies,and 4 lobectomies and segmental lobectomies.Clinical efficacy and postoperative complications were observed.Results All the 145 patients underwent resection by VATS without conversion to thoracotomy.There was no mortality during the perioperative period.In the 139 cases without chest tube placement at the end of surgery,the operation time was(42.0±16.6)min,and the intraoperative blood loss was(2.7±2.0)ml.The were 6 cases who were given indwelling drainage tube for pneumothorax or pleural effusion after surgery,the rate of re-catheterization being 4.3％.The remaining 133 cases had chest X-ray review on the third day after routine surgery.Among them,8 cases had mild pneumothorax(lung compression＜20％)on the surgical side,which did not require further treatment.Before discharge,chest X-ray re-examination showed that pneumothorax was basically absorbed.All the patients were discharged with uneventful recovery,and the hospital stay was(6.6±1.3)d.Conclusion VATS without chest tube placement is a safe and feasible surgical procedure for some selective infants with congenital pulmonary airway malformation.

Objective:To understand the evolution and variation characteristics of the H1N1 influenza virus in Wuxi City from 2018 to 2023.Methods:Real time PCR was used to perform nucleic acid testing on throat swab samples of influenza like cases sent to sentinel hospitals for testing. The influenza A (H1N1) pdm09 positive samples were subjected to cell culture, and nucleic acid was extracted from strains with a red blood cell agglutination test (HA) ≥1∶8. The whole genome sequence was amplified, and a library was constructed. The MiSeq sequencer was used for sequencing on the machine. Using NC_026431.1 as a reference strain, we analyzed the offline data using CLC Genomics Workbench (Version 23) software. MEGA 7.0 software was used to construct a phylogenetic tree, and NetNGlyc 1.0 Server software was used to predict N-glycosylation sites.Results:The nucleotide and amino acid homology between 38 strains of A (H1N1) pdm09 influenza virus from 2018 to 2023 were 96.06%-100% and 96.12%-100%, respectively. From February to May 2023, all 12 strains of A (H1N1) pdm09 had two amino acid mutation sites occurring in the HA antigenic determinant cluster, namely the Ca region (A203T) and the Cb region (K71Q). No mutations were found in the HA receptor binding site and NA resistance site. The strains from January to June 2018 belong to the 6B. 1A evolutionary branch, the strains from December 2018 to January 2020 belong to three evolutionary branches: 6B. 1A. 1, 6B. 1A. 5a, and 6B. 1A. 7, and the strains from February to May 2023 belong to the 6B. 1A. 5a. 2a evolutionary branch. 38 strains of A (H1N1) pdm09 HA gene all have 7 potential N-glycosylation sites, while NA gene has 7-8 potential N-glycosylation sites.Conclusions:There are characteristic amino acid mutation sites of H1N1 influenza A in Wuxi City from 2018 to 2023. The emergence of these mutation sites may affect the virus′s transmission and antigenic changes.

This study explored the effects and underlying mechanism of Raf kinase inhibitory protein(RKIP)on apoptosis in mast cells sensitized by Echinococcus granulosus cyst fluid.Bone marrow-derived mast cells(BMMCs)were isolated and cultured from RKIP knockout(KO)and wild-type(WT)C57BL/6 mice.Cells were divided into control and sensitized groups.The sensitized group was incubated for 24 h in RPMI1640 medium containing 10%serum from mice infected with E.granulosus,then activated for 3 h or 6 h with E.granulosus cyst fluid.The control group was incubated for 24 h in RPMI1640 medium,and then received an equal vol-ume of PBS.Cells and supernatants were collected for analysis.Flow cytometry was used to detect the expression of CD117 and FcεRⅠα on BMMCs.The levels of β-hexosaminidase,IL-4,and TNF-α in the supernatant were quantified with ELISA.Western blot analy-sis was used to assess expression changes in RKIP,apoptosis-related proteins,and pathway proteins in BMMC before and after sensi-tization.Flow cytometry analysis revealed that after 4 weeks of induction,the CD117 and FcεRⅠα double-positivity rates on both WT and KO BMMC exceeded 90%.ELISA indicated that the E.granulosus cyst fluid resulted in significantly greater β-hexosaminidase re-lease(F=16.88,P<0.05),and levels of IL-4(F=16.51,P<0.05)and TNF-α(F=9.78,P<0.05)in the KO sensitized group than the WT sensitized group.With respect to the WT control group,the WT sensitized group showed significantly down-regulated pro-tein expression levels of RKIP(F=8.20,P<0.05)and Bcl-2(F=101.40,P<0.01)after 3 h,but significantly up-regulated levels of p-PI3K(F=8.04,P<0.05),p-Akt(F=32.52,P<0.01),p-P65(F=13.29,P<0.05),and cleaved-caspase-3(F=46.34,P<0.01).With respect to the WT sensitized group,the KO sensitized group showed significantly up-regulated protein expression of p-PI3K(F=8.45,P<0.05),p-Akt(F=8.58,P<0.05),p-P65(F=11.02,P<0.05),and Bcl-2(F=84.50,P<0.001)after 3 h,but significantly down-regulated expression of cleaved-caspase-3(F=15.66,P<0.05).In conclusion,RKIP may inhibit the PI3K/Akt/NF-κB pathway,thereby inducing apoptosis in mast cells sensitized by E.granulosus cyst fluid.This process may help ease aller-gic reactions caused by mast cells in echinococcosis,thus offering a promising new approach for preventing and treating such reactions.

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.