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.

BACKGROUND:Microplastics are a common environmental pollutant that can cause damage to the gastrointestinal tract,liver and kidney,and reproductive system.However,little is known about the effects of microplastics on the prostate.OBJECTIVE:To investigate the effects of different charge-modified polystyrene microplastics on prostate tissues of male mice and its mechanism.METHODS:A total of 48 male BALB/c mice were randomly divided into a control group,an unmodified microplastic group,a negatively charged microplastic group,and a positively charged microplastic group using a random number table,with 12 mice in each group.The mice in the control group were given ddH2O by gavage;the mice in the unmodified microplastic group were given unmodified polystyrene microplastics by gavage,and the mice in the negatively charged microplastic group and the positively charged microplastic group were given negatively charged polystyrene microplastics and positively charged polystyrene microplastics by gavage,respectively,once a day for 4 consecutive weeks.The body weight,drinking water,and food intake of the mice were detected every week.After gavage,the prostate mass,prostate coefficient,prostate histopathological morphology,inflammatory factor expression,microplastic accumulation in the prostate tissue of the mice,and the mRNA and protein expressions of hypoxia-inducible factor 1α and vascular endothelial growth factor were compared among the groups of mice.RESULTS AND CONCLUSION:(1)With the prolongation of microplastic exposure time,the body weight of mice in the unmodified microplastics group and the positively charged microplastics exposure group was significantly suppressed.(2)After exposure to microplastics,they could enter the urinary system of mice,including prostate and bladder tissue.Among the mice in the positively charged microplastic group,the prostate mass and prostate coefficient increased most significantly.(3)Compared with the control group,the mass concentration and mRNA expression of interleukin 6,interleukin 1β,and tumor necrosis factorα were increased in the prostate tissue of the other three groups of mice(P＜0.05).Among them,the positively charged microplastic group exhibited most obvious increase.(4)Hematoxylin-eosin staining showed that the prostate tissue of mice in the unmodified microplastic group,negatively charged microplastic group,and positively charged microplastic group showed obvious proliferation of prostate epithelial cells and matrix,a significant increase in acini,and infiltration of a large number of inflammatory cells.Masson and Sirius red staining showed that compared with the control group,the prostate tissue of mice in the other three groups had obvious fibrosis.Immunohistochemical staining showed that compared with the control group,angiogenesis in the prostate tissue of mice increased in the other three groups(P＜0.05).(5)Compared with the control group,the mRNA and protein expressions of hypoxia-inducible factor 1αand vascular endothelial growth factor were increased in the prostate tissue of the other three groups of mice(P＜0.05),among which the negatively charged microplastic group and the positively charged microplastic group exhibited more significant increase.(6)The results show that polystyrene microplastics can enhance the release of inflammatory factors in mouse prostate tissue,promote angiogenesis in prostate tissue by activating the hypoxia-inducible factor 1α/vascular endothelial growth factor signaling pathway,and provide nutrition support for prostate hyperplasia and fibrosis.

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.

Objective To examine the diagnosis and treatment of disseminated infection caused by Enterocytozoon bieneusi in a child with leukemia and improve the awareness of the pathogen in clinical and laboratory practice.Methods A case of disseminated infection caused by Enterocytozoon bieneusi in a child with leukemia in Shanghai Children's Hospital was retrospectively analyzed,including diagnosis and treatment details.Similar cases were identified from PubMed,Wanfang Data,VIP,and CNKI databases since database establishment until June 30,2024,using search terms"Enterocytozoon bieneusi".The relevant literature was reviewed.Results This child had acute lymphoblastic leukemia as the underlying disease and was admitted to hospital for antimicrobial treatment due to fever and abdominal discomfort.The case was considered bacterial infection complicated with Enterocytozoon bieneusi infection,confirmed by detection of Klebsiella pneumoniae in blood and detection of Enterocytozoon bieneusi in blood and ascites by metagenomic next-generation sequencing(mNGS).The treatment was switched to tigecycline plus trimethoprim-sulfamethoxazole at a sufficient dose,which resulted in resolution of symptoms.Six months later,the patient suffered from acute lymphoblastic leukemia and bone marrow depression,Enterocytozoon bieneusi disseminated infection,septic shock.Her family gave up treatment and the child died.Literature review indicated that most patients infected with Enterocytozoon bieneusi had underlying conditions such as organ transplantation,AIDS,and leukemia associated with poor immunity.The onset symptoms are diarrhea,abdominal discomfort,and fever.Enterocytozoon bieneusi was detected by using methods such as modified Masson's trichrome stain,fluorescent calcofluor white staining,molecular detection techniques,and immunofluorescence.The patients were treated with drugs such as albendazole,nitazoxanide,fumagillin,and trimethoprim-sulfamethoxazole.Conclusions Enterocytozoon bieneusi is an opportunistic pathogenic fungus that infects immunocompromised patients and can cause abdominal discomfort,diarrhea,fever,and even disseminated infection and death.Conventional laboratory methods cannot culture Enterocytozoon bieneusi.Molecular detection techniques can be used to identify the pathogen early.

Objective To examine the changing prevalence and antimicrobial resistance profiles of Burkholderia cepacia in 52 hospitals across China from 2015 to 2021.Methods A total of 9 261 strains of B.cepacia were collected from 52 hospitals between January 1,2015 and December 31,2021.Antimicrobial susceptibility of the strains was tested using Kirby-Bauer method or automated antimicrobial susceptibility testing systems according to a unified protocol.The results were interpreted according to the breakpoints released in the Clinical & Laboratory Standards Institute(CLSI)guidelines(2023 edition).Results A total of 9 261 strains of B.cepacia were isolated from all age groups,especially elderly patients.The proportion was 11.1％(1 032 strains)in children,significantly lower than the proportion in adults.About half(46.5％,4 310/9 261)of the strains were isolated from patients at least 60 years old and 42.3％(3 919/9 261)of the strains were isolated from young adults.Most isolates(71.1％)were isolated from sputum and respiratory secretions,followed by urine(10.7％)and blood samples(8.1％).B.cepacia isolates were highly susceptible to the five antimicrobial agents recommended in the CLSI M100 document(33rd edition,2023).B.cepacia isolates showed relatively higher resistance rates to meropenem and levofloxacin.However,the resistance rates to ceftazidime,trimethoprim-sulfamethoxazole,and minocycline remained below 8.1％.The percentage of B.cepacia strains resistant to levofloxacin was the highest compared to other antibiotics in any of the three age groups(from 12.4％in the patients＜18 years old to 20.6％in the patients aged 60 years or older).Conclusions B.cepacia is one of the clinically important non-fermenting gram-negative bacteria.Accurate and timely reporting of antimicrobial susceptibility test results and ongoing antimicrobial resistance surveillance are helpful for rational prescription of antimicrobial agents and proper prevention and control of nosocomial infections.

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 examine the changing prevalence and antimicrobial resistance profiles of Burkholderia cepacia in 52 hospitals across China from 2015 to 2021.Methods A total of 9 261 strains of B.cepacia were collected from 52 hospitals between January 1,2015 and December 31,2021.Antimicrobial susceptibility of the strains was tested using Kirby-Bauer method or automated antimicrobial susceptibility testing systems according to a unified protocol.The results were interpreted according to the breakpoints released in the Clinical & Laboratory Standards Institute(CLSI)guidelines(2023 edition).Results A total of 9 261 strains of B.cepacia were isolated from all age groups,especially elderly patients.The proportion was 11.1％(1 032 strains)in children,significantly lower than the proportion in adults.About half(46.5％,4 310/9 261)of the strains were isolated from patients at least 60 years old and 42.3％(3 919/9 261)of the strains were isolated from young adults.Most isolates(71.1％)were isolated from sputum and respiratory secretions,followed by urine(10.7％)and blood samples(8.1％).B.cepacia isolates were highly susceptible to the five antimicrobial agents recommended in the CLSI M100 document(33rd edition,2023).B.cepacia isolates showed relatively higher resistance rates to meropenem and levofloxacin.However,the resistance rates to ceftazidime,trimethoprim-sulfamethoxazole,and minocycline remained below 8.1％.The percentage of B.cepacia strains resistant to levofloxacin was the highest compared to other antibiotics in any of the three age groups(from 12.4％in the patients＜18 years old to 20.6％in the patients aged 60 years or older).Conclusions B.cepacia is one of the clinically important non-fermenting gram-negative bacteria.Accurate and timely reporting of antimicrobial susceptibility test results and ongoing antimicrobial resistance surveillance are helpful for rational prescription of antimicrobial agents and proper prevention and control of nosocomial infections.

BACKGROUND:Microplastics are a common environmental pollutant that can cause damage to the gastrointestinal tract,liver and kidney,and reproductive system.However,little is known about the effects of microplastics on the prostate.OBJECTIVE:To investigate the effects of different charge-modified polystyrene microplastics on prostate tissues of male mice and its mechanism.METHODS:A total of 48 male BALB/c mice were randomly divided into a control group,an unmodified microplastic group,a negatively charged microplastic group,and a positively charged microplastic group using a random number table,with 12 mice in each group.The mice in the control group were given ddH2O by gavage;the mice in the unmodified microplastic group were given unmodified polystyrene microplastics by gavage,and the mice in the negatively charged microplastic group and the positively charged microplastic group were given negatively charged polystyrene microplastics and positively charged polystyrene microplastics by gavage,respectively,once a day for 4 consecutive weeks.The body weight,drinking water,and food intake of the mice were detected every week.After gavage,the prostate mass,prostate coefficient,prostate histopathological morphology,inflammatory factor expression,microplastic accumulation in the prostate tissue of the mice,and the mRNA and protein expressions of hypoxia-inducible factor 1α and vascular endothelial growth factor were compared among the groups of mice.RESULTS AND CONCLUSION:(1)With the prolongation of microplastic exposure time,the body weight of mice in the unmodified microplastics group and the positively charged microplastics exposure group was significantly suppressed.(2)After exposure to microplastics,they could enter the urinary system of mice,including prostate and bladder tissue.Among the mice in the positively charged microplastic group,the prostate mass and prostate coefficient increased most significantly.(3)Compared with the control group,the mass concentration and mRNA expression of interleukin 6,interleukin 1β,and tumor necrosis factorα were increased in the prostate tissue of the other three groups of mice(P＜0.05).Among them,the positively charged microplastic group exhibited most obvious increase.(4)Hematoxylin-eosin staining showed that the prostate tissue of mice in the unmodified microplastic group,negatively charged microplastic group,and positively charged microplastic group showed obvious proliferation of prostate epithelial cells and matrix,a significant increase in acini,and infiltration of a large number of inflammatory cells.Masson and Sirius red staining showed that compared with the control group,the prostate tissue of mice in the other three groups had obvious fibrosis.Immunohistochemical staining showed that compared with the control group,angiogenesis in the prostate tissue of mice increased in the other three groups(P＜0.05).(5)Compared with the control group,the mRNA and protein expressions of hypoxia-inducible factor 1αand vascular endothelial growth factor were increased in the prostate tissue of the other three groups of mice(P＜0.05),among which the negatively charged microplastic group and the positively charged microplastic group exhibited more significant increase.(6)The results show that polystyrene microplastics can enhance the release of inflammatory factors in mouse prostate tissue,promote angiogenesis in prostate tissue by activating the hypoxia-inducible factor 1α/vascular endothelial growth factor signaling pathway,and provide nutrition support for prostate hyperplasia and fibrosis.

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.