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.

Testicular histology based on testicular biopsy is an important factor for determining appropriate testicular sperm extraction surgery and predicting sperm retrieval outcomes in patients with azoospermia. Therefore, we developed a deep learning (DL) model to establish the associations between testicular grayscale ultrasound images and testicular histology. We retrospectively included two-dimensional testicular grayscale ultrasound from patients with azoospermia (353 men with 4357 images between July 2017 and December 2021 in The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China) to develop a DL model. We obtained testicular histology during conventional testicular sperm extraction. Our DL model was trained based on ultrasound images or fusion data (ultrasound images fused with the corresponding testicular volume) to distinguish spermatozoa presence in pathology (SPP) and spermatozoa absence in pathology (SAP) and to classify maturation arrest (MA) and Sertoli cell-only syndrome (SCOS) in patients with SAP. Areas under the receiver operating characteristic curve (AUCs), accuracy, sensitivity, and specificity were used to analyze model performance. DL based on images achieved an AUC of 0.922 (95% confidence interval [CI]: 0.908-0.935), a sensitivity of 80.9%, a specificity of 84.6%, and an accuracy of 83.5% in predicting SPP (including normal spermatogenesis and hypospermatogenesis) and SAP (including MA and SCOS). In the identification of SCOS and MA, DL on fusion data yielded better diagnostic performance with an AUC of 0.979 (95% CI: 0.969-0.989), a sensitivity of 89.7%, a specificity of 97.1%, and an accuracy of 92.1%. Our study provides a noninvasive method to predict testicular histology for patients with azoospermia, which would avoid unnecessary testicular biopsy.
Humans ; Male ; Azoospermia/diagnostic imaging* ; Deep Learning ; Testis/pathology* ; Retrospective Studies ; Adult ; Ultrasonography/methods* ; Sperm Retrieval ; Sertoli Cell-Only Syndrome/diagnostic imaging*

Objective： The aim of this study is to explore the predictive value of biparametric magnetic resonance imaging(bpMRI)for pelvic lymph node metastasis in prostate cancer patients with PSA≤20 μg/L and establish a nomogram. Methods： The imaging data and clinical data of 363 patients undergoing radical prostatectomy and pelvic lymph node dissection in the First Affiliated Hospital of Nanjing Medical University from July 2018 to December 2023 were retrospectively analyzed. Univariate analysis and multivariate logistic regression were used to screen independent risk factors for pelvic lymph node metastasis in prostate cancer, and a nomogram of the clinical prediction model was established. Calibration curves were drawn to evaluate the accuracy of the model. Results： Multivariate logistic regression analysis showed extrocapusular extension (OR=8.08,95%CI=2.62－24.97, P<0.01), enlargement of pelvic lymph nodes (OR=4.45,95%CI=1.16－17.11,P=0.030), and biopsy ISUP grade(OR=1.97,95%CI=1.12－3.46, P=0.018)were independent risk factors for pelvic lymph node metastasis. The C-index of the prediction model was 0.834, which indicated that the model had a good prediction ability. The actual value of the model calibration curve and the prediction probability of the model fitted well, indicating that the model had a good accuracy. Further analysis of DCA curve showed that the model had good clinical application value when the risk threshold ranged from 0.05 to 0.70.Conclusion： For prostate cancer patients with PSA≤20 μg/L, bpMRI has a good predictive value for the pelvic lymph node metastasis of prostate cancer with extrocapusular extension, enlargement of pelvic lymph nodes and ISUP grade≥4.
Humans ; Male ; Prostatic Neoplasms/diagnostic imaging* ; Lymphatic Metastasis ; Retrospective Studies ; Nomograms ; Prostate-Specific Antigen/blood* ; Lymph Nodes/pathology* ; Pelvis ; Predictive Value of Tests ; Prostatectomy ; Lymph Node Excision ; Risk Factors ; Magnetic Resonance Imaging ; Logistic Models ; Middle Aged ; Aged

Objective To investigate the characteristics of immune exhaustion in sepsis and analyze its association with gut microbiota translocation.Methods A total of 130 mice were randomly divided into a cecal ligation and puncture(CLP)group(n=100)and a Sham group(n=30)Mouse model of sepsis was established with CLP procedure.Flow cytometry was used to analyze the proportions of peripheral blood CD4+T and CD8+T cells and programmed cell death protein 1(PD-1)positive T cell subsets in mice.Bacterial colonization in organs such as the heart,liver and kidneys was quantified by plating homogenates of the organs.Pathological changes in immune organs were observed with HE staining.The expression and localization of CD4?,CD8?,and PD-1?cells in immune organs were detected with immunohistochemical staining,and Image J software was employed for subsequent quantification of the number of the positive cells.Results HE staining demonstrated that immune organs exhibited varying degrees of pathological damages with disease progression.Compared with the Sham mice,the CLP mice exhibited significantly increased bacterial colonization in parenchymal organs and peripheral blood(P<0.05),notably in the liver,which showed the most severe infection.In the CLP group,the proportion of CD4+T lymphocytes in peripheral blood at days 1,3,and 5 postoperatively was decreased by 56%,70.57%,and 87.42%,respectively,when compared with the Sham group(P<0.001).The proportion of CD8+T lymphocytes was decreased by 48.33%relative to the Sham group only at day 5(P<0.001).In contrast,the proportion of CD4+T cell subsets expressing PD-1 was increased to 673.08,423.08,and 600 times that of the Sham group,respectively,at the same postoperative time points(P<0.001).Immunohistochemical results showed that,in the CLP group,the proportion of CD4+T cells in the thymus,spleen,and mesenteric lymph nodes was increased to 7.65,2.66,and 3.7 times that of the Sham group,respectively,at the early-stage peak(P<0.001),and then these proportions were decreased by 82.8%(P<0.001),41.9%(P<0.01),and 60.15%(P<0.001),respectively,at the late-stage trough when compared with the early-stage peak in the corresponding organs.The proportion of CD8+positive cells was increased in the early stage and then decreased insignificantly,while the proportion of PD-1+positive cells was increased continuously,and reached 6.24,13.9,and 20.96 times that of the Sham group at the peak in the thymus,spleen,and mesenteric lymph nodes respectively(P<0.001),with their expression regions showing a rough overlap with those of CD4+cells.Conclusion During sepsis,the inflammatory response can cause severe damage to immune organs and persistent exhaustion of CD4?T lymphocytes,leading to declined defenses against infection,which may be the main causes for exacerbated gut microbiota translocation and then systemic infection.

Objective To quantify the volume and movement of cardiac substructures by using coronary computed tomography angiography(CCTA)to provide guidance for the design of deep inspiratory breath-holding radiation therapy for left breast cancer and the protection of organs at risk.Methods Totally 18 female patients who received conventional chest plain scan and CCTA were selected to simulate the design process of radiotherapy plan for left breast cancer patients with internal mammary lymph nodes.Retrospective reconstruction of CCTA data was performed for each patient,with 10 phase images(with an interval of 10％)within a R-R cardiac cycle(10％-100％)to simulate the true range of motion of the heart.The heart,left atrium(LA),left ventricle(LV),right atrium(RA),right ventricle(RV),left anterior descending artery(LAD),left circumflex coronary artery(LCX)and right coronary artery(RCA)were contoured at each phase.The distances from the centroid position to the average position of LAD,LCX and RCA were measured at each phase in the superior-inferior(SI),anterior-posterior(AP)and left-right(LR).The average volume and range of volume changes of LA,LV,RA,RV and heart were analyzed within a cardiac cycle.The expansion margins of planning organs at risk volume(PRV)were calculated.SPSS 19.0 software was used for statistical analysis.Results The following average absolute displacements were found in SI,AP and LR coordinates:(1.8±0.7)mm,(1.2±0.5)mm and(1.5±0.5)mm for LAD,respectively;(2.1±0.7)mm,(1.5±0.6)mm and(1.9±0.7)mm for LCX,respectively;(1.6±0.5)mm,(2.2±0.9)mm and(2.2±0.8)mm for RCA,respectively.The volume changes of LA,LV,RA,RV and heart within a cardiac cycle ranged from 34.3 to 63.9 cm3,122.1 to 154.3 cm3,29.3 to 53.6 cm3,57.2 to 94.3 cm3 and 480.1 to 515.4 cm3,respectively.The theoretical expansion margins of LAD,LCX and RCA in all the three directions were within 2 mm.Conclusion The ranges of movement and volume changes of cardiac substructure are quantitati-vely displayed,and references are provided for the planning of deep inspiratory breath-holding radiation therapy for left breast cancer and the protection of organs at risk.[Chinese Medical Equipment Journal,2025,46(3):54-58]

This study was aimed at identifying the pathogenic bacteria responsible for the death of a young tiger at the Fujian Meihua Mountain South China Tiger Breeding Research Institute.Tissue samples from the lungs,liver,and intestines of the deceased tiger were collected,and the bacteria were cultured inasterile environment.The bacterial strains were characterized according to their morphological and molecular biological properties,including assessment of virulence genes and antibiotic resistance genes,mouse lethality tests,and antibiotic susceptibility evaluations.A predominant bacterial strain isolated from the liver of the deceased tiger was identified as enterotoxigenic Escherichia coli(ETEC)strain Tiger22513F.Phylogenetic analysis of the 16S rRNA gene revealed that the Tiger22513F strain exhibited close genetic similarity to the reference strain ETEC(MF919609.1),with 99.9%nucleotide similarity,and resided on the same evolutionary branch.The Tiger22513F strain contained 11 antibiotic resistance genes(tetA,sul1,sul3,cmlA,floR,blaTEM,blaSHV,blaCMY-2,qnrA,qnrS,and qnrD)along with five virulence genes(VT1,fyuA,tsh,iucD,and ST).Mouse lethality tests indicated significant pathogenicity toward mice,affecting primarily the lungs,liver,and intestines.Antibiotic susceptibility testing demonstrated that this strain exhibited resistance to various classes of beta-lactam antibiotics,as well as quinolones and aminoglycosides.This investigation successfully isolated a multi-drug resistant enterotoxigenic Escherichia coli strain with pronounced pathogenicity from the liver of a deceased tiger;thus providing valuable scientific insights for clinical diagnosis,as well as prevention and control measures,against ETEC infections in South China tigers.

This research investigated the contamination level,distribution of drug-resistant strains,and molecular epidemiologi-cal characteristics of Campylobacter,and further explored transmission pathways and prevention strategies.Cecum,chicken carcass,chicken product,and environmental samples,as well as swabs from workers'hands,were collected from a slaughterhouse in a large broiler group in the Jiaodong area between August 2023 and July 2024.Quantitative contamination assessment of Campylobacter in chicken carcasses and chicken products was performed.After microbial mass spectrometry identification,the representative strains of different links were selected for drug resistance testing and whole genome sequencing(WGS).On the basis of the sequencing results,the resistance genes,virulence genes,multilocus sequence typing(MLST),and phylogenetic characteristics of representative strains were analyzed.Homology comparisons were performed between isolates and strains from patients with diarrhea in the NCBI database.A total of 297 Campylobacter strains were isolated from 806 samples,and the overall detection rate was 36.85%.The detection rate of Campylobacter was highest in the evisceration process(47.33%),followed by the cutting process(35.64%).Overall,the Campylo-bacter detection rate first increased,then decreased,and subsequently increased.Drug sensitivity testing revealed that 90 isolates were resistant to nalidixic acid and ciprofloxacin,and 94.97%of isolates were resistant to tetracycline.WGS showed that both Campylo-bacter jejuni(C.jejuni)and Campylobacter coli(C.coli)carried many drug resistance and virulence genes.ST-14176 of C.jejuni was isolated for the first time herein.The predominant ST-8261 strain of C.jejuni and ST-860,ST-829,and ST-1586 strains of C.coli are known to cause human diarrhea.LOS expression genes associated with Guillain-Barré syndrome(GBS)were detected in both C.jejuni isolates from the slaughter chain and patients with GBS.Some strains exhibited close genetic relatedness to human-derived Campylo-bacter strains from the NCBI database.The detection rate of Campylobacter in the slaughterhouse first increased,then decreased,and subsequently increased,and the quantitative contamination level of each link was similar to the detection rate.Quantitative analysis of chicken carcasses/products revealed that the average bacterial load was highest in eviscerated carcasses(102.80 cfu/g),and the high-est amount of Campylobacter in chicken products reached 451.80 cfu/g.Abundant drug resistance genes and virulence genes were iden-tified,and the drug resistance genes were highly correlated with the drug resistance rate.Therefore,surveillance intensity and control measures for Campylobacter in slaughter processes should be strengthened.

Objective To establish a stable,reliable,and clinically relevant porcine model of endotoxin-induced acute respiratory distress syndrome(ARDS).Methods Ten 8-month-old male Bama minipigs were deeply sedated,followed by invasive mechanical ventilation and electrocardiographic monitoring.Lipopolysaccharide(LPS)was intravenously pumped at 600 μg/(kg·h)for 3 hours,then maintained at 15 μg/(kg·h)thereafter.Dynamic monitoring was performed at five time points after LPS injection(LPS 0,1,3,5,and 8 h),including arterial blood gas analysis and chest computed tomography(CT)scans.Pathological examination of lung tissues obtained via bronchoscopic biopsy(HE staining and transmission electron microscopy)was conducted.These indicators were comprehensively used to evaluate the success of the animal model.Results At 5 hours after LPS administration,8 minipigs developed symptoms such as skin cyanosis,elevated body temperature,and respiratory distress.The oxygenation index decreased to<300 mmHg.Chest CT scans showed diffuse pulmonary infiltrates.Histopathology revealed alveolar edema and hyaline membrane formation.Transmission electron microscopy demonstrated disruption of pulmonary blood-air barrier,depletion of lamellar bodies in type Ⅱ pneumocytes,inflammatory cell infiltration,and exudation of plasma proteins and fibrin.Compared with LPS 0 h,at LPS 8 h,the oxygenation index and arterial blood pH were significantly decreased(P<0.001),while blood lactic acid and serum potassium were significantly increased(P<0.05);serum calcium and base excess were significantly decreased(P<0.05),and the lung injury score based on HE-stained lung sections was significantly increased(P<0.01).Conclusion The porcine ARDS model established by continuous LPS injection can dynamically simulate the pathophysiological characteristics and typical pathological manifestations of clinical septic ARDS,making it an effective tool to study the pathogenesis,prevention,and treatment strategies of septic ARDS.

The aim of this study was to establish a rapid,highly sensitive,and specific nucleic acid detection method for the H5N6 and H9N2 avian influenza virus(AIV)subtypes by using reverse transcription-recombinase polymerase amplification(RT-RPA)combined with clustered regularly interspaced short palindromic repeats(CRISPR)-Cas13a proteins.The conserved regions were selected to design specific RT-RPA primers and crRNA sequences of H5,H6,H9,and N2 genes.RT-RPA tech-nology combined with CRISPR-Cas13a detection was used to evaluate the sensitivity and specificity of AIV nucleic acid detec-tion.The detection was performed on avian influenza environmental samples and compared with the results of fluorescence quantitative RT-PCR,to evaluate the effectiveness of the RT-RPA technology combined with CRISPR-Cas13a.AIV H5,H9,and N2 subtypes were detected with a sensitivity as high as 1 copy/μL,and AIV N6 subtypes were detected with a sensitivity of 10 copies/μL.Plasmid samples with differing copy numbers showed fluorescence under blue LED transillumination.The four AIV subtypes showed high specificity and did not cross-react with the other AIV subtypes.The detection of avian influenza ex-ternal environmental samples containing AIV H5,N6,and H9 subtypes was consistent with the results of fluorescence quanti-tative RT-PCR,with 100％accuracy.For AIV N2 subtypes,one additional negative sample was detected with 97.9％accuracy.The established RT-RPA technology combined with CRISPR-Cas13a detection enabled sensitive,specific visual detection of AIV H5N6 and H9N2 subtypes.This study provides a new nucleic acid detection method for AIV surveillance and subtype clas-sification.