Microorganisms are crucial for the breakdown of proteins and lipids in dry-fermented sausages and are intimately associated with the flavor profile of sausages.In this study,we used a mixed starter culture to ferment ...Microorganisms are crucial for the breakdown of proteins and lipids in dry-fermented sausages and are intimately associated with the flavor profile of sausages.In this study,we used a mixed starter culture to ferment sausages and investigated the flavor turnover.During the fermentation of salami,the data from free amino acids(FAAs),free fatty acids(FFAs)and volatile flavor substances were used to assess the quality of salami.At the end of fermentation,the total FAAs increased from 1171.32 to 4582.48 mg/kg in the control group and 5053.25 mg/kg in the experimental group.Additionally,following inoculation with the mixed starter culture,the levels of glutamic acid,lysine,methionine,valine and leucine were significantly higher(P<0.05)than those in the control group.Oleic acid(C_(18:1))and chondritic acid(C_(16:0))were the two most abundant FFAs in both salami samples with 45.86%and 26.07%on the 23^(th)day in mixed culture inoculated salami.The mixed starter inoculated group had significantly lower saturated fatty acids and higher percentage levels of monounsaturated fatty acids than the control group(P<0.05).In the volatile flavor substance analysis,a total of 61 volatile compounds were found.Ester compounds were progressively enriched with drying time,significantly increasing the flavor substances,like ethyl diphosgene,1-octen-3-ol,and 2,3-butanediol at P<0.05.The correlation analysis between the core flora and volatile flavor compounds during fermentation and maturation of salami indicates Lactobacillus sakei and Lactobacillus rhamnosus were significantly higher and positively correlated with the major volatile organic compounds,which are the key core microorganisms affecting the flavor quality of fermented sausages.展开更多
The mechanisms leading to neurological and neurodegenerative diseases are not completely known,and new,more effective,therapeutic treatments are necessary for most neurological pathologies.The treatment of neurologica...The mechanisms leading to neurological and neurodegenerative diseases are not completely known,and new,more effective,therapeutic treatments are necessary for most neurological pathologies.The treatment of neurological and neurodegenerative diseases is complicated due to the blood-brain barrier,which makes it difficult for drugs to access the brain areas in which they must act to improve the pathology.A tool that can help to overcome this difficulty is the use of extracellular vesicles,which can easily cross the blood-brain barrier.The extracellular vesicles are considered a main way of communication between the brain and the rest of the body,with important implications for the physiopathology and therapy of neurological diseases.In recent years,the involvement of microbiota in many neurological pathologies,as well as its possible therapeutic role,has also become evident.A key mediator in the pathologic and beneficial effects of microbiota seems to be the bacterial extracellular vesicles.There is an important communication between the brain and the intestinal microbiota(the gut-brain axis),by which the microbiota influences brain function,impacts on mental health,and plays a role in different neurological and neurodegenerative diseases.The identification of the mechanisms involved in this gut-brain axis is essential to understanding the mechanisms of neurological pathologies and to developing more effective treatments for these diseases.Bacterial extracellular vesicles would play a relevant role in these processes.This review compiles the recent information and evidence on the role of bacterial extracellular vesicles in brain pathologies and on the therapeutic utility of bacterial extracellular vesicles in neurological and neurodegenerative diseases.One advantage of bacterial extracellular vesicles compared to extracellular vesicles derived from other cell types,such as stem cells,is that bacterial extracellular vesicles are generally easier to produce and modify.Bacterial extracellular vesicles may be easily modified to target a specific pathology and/or to enhance its therapeutic efficacy.Although the studies are still scarce,they open a wide field of possibilities for future studies,which will lead to a deeper understanding of the role of microbiota and bacterial extracellular vesicles in neurological pathologies and the underlying mechanisms,as well as to the development of new treatments based on the use of bacterial extracellular vesicles in neurological diseases.展开更多
Natural product(NPT)derived from traditional Chinese medicine has a rich history as an integral part of Chinese healthcare for thousands of years.Recently,the application of NPT in sonodynamic antibacterial therapy(SD...Natural product(NPT)derived from traditional Chinese medicine has a rich history as an integral part of Chinese healthcare for thousands of years.Recently,the application of NPT in sonodynamic antibacterial therapy(SDAT)has emerged as a promising area of research.This perspective summarizes the recent NPT-based sonosensitizers in SDAT.Currently,common NPT-based sonosensitizers include curcumin,chlorophyll derivatives,hypericin,and berberine.Compared with other sonosensitizers,natural sources of NPT-based sonosensitizers with reactive oxide species production performance under ultrasound conditions,low biotoxicity,and other additional biological activity make them have application prospects in bacterial removal.Finally,the potential benefits and challenges of NPT-based nanosonosensitizers were also discussed.展开更多
Stroke induces profound neuroinflammation and systemic immune dysregulation,including disturbances in gut homeostasis.Experimental evidence suggests that intestinal barrier permeability(IBP)and bacterial translocation...Stroke induces profound neuroinflammation and systemic immune dysregulation,including disturbances in gut homeostasis.Experimental evidence suggests that intestinal barrier permeability(IBP)and bacterial translocation(BT)critically influence stroke outcomes.However,biological variability among commonly used rodent substrains has received limited attention.In this pilot study,we compared poststroke immune responses in two Wistar rat substrains obtained from different suppliers:RccHan(Envigo)and RjHan(Janvier).Naive animals(n=4)and rats subjected to permanent cerebral ischemia(n=8 per substrain)were evaluated 72 h after middle cerebral artery occlusion and stratified according to the presence or absence of BT.Immune cell populations in blood and bone marrow were analyzed using flow cytometry,and leukocyte infiltration into ischemic brain tissue was quantified using immunohisto-chemistry.Differences were considered statistically significant when p<0.05.Both substrains developed significant infarcts and neurological deficits.RccHan rats exhibited larger infarct volumes and more extensive BT across multiple organs.In contrast,RjHan rats exhibited BT mainly confined to mesenteric lymph nodes but exhibited greater IBP.Although dissemination was broader in RccHan rats,overall bacterial burden was slightly lower compared with RjHan,and extraintestinal bacterial composition differed between groups.Particularly,RjHan rats exhibited stronger systemic and central immune activation,with significant alterations in lymphocyte and monocyte populations and enhanced granulocyte and T-cell infiltration within ischemic lesions.These findings demonstrate that substrain origin profoundly influences poststroke intestinal barrier integrity,bacterial dissemination,and immune responses considering substrain-related variability is essential to improve reproducibility and translational relevance in preclinical stroke research.展开更多
BACKGROUND Edwardsiella tarda(E.tarda)belongs to the family Enterobacteriaceae and is generally seen to cause infections mainly in fish,but is also capable of infecting humans.Extraintestinal infections occur in patie...BACKGROUND Edwardsiella tarda(E.tarda)belongs to the family Enterobacteriaceae and is generally seen to cause infections mainly in fish,but is also capable of infecting humans.Extraintestinal infections occur in patients with certain risk factors,including immunocompromised status.We recently diagnosed a case of spontaneous bacterial peritonitis(SBP)due to E.tarda in an immuno-compromised dialysis patient.CASE SUMMARY Patient was a 55-year-old male,with a history of diabetic nephropathy being treated with hemodialysis three times a week.He was referred to our hospital due to an increased volume of ascites,and blood examination revealed increased inflammatory reaction.At our emergency department,he developed fever,disturbance of consciousness,abdominal distension,and abdomen-wide pain.In addition,a dialysis shunt was confirmed in his right forearm,and the shunt site showed no signs of inflammation.No wounds were confirmed on or in his body.A blood examination revealed increased values of white blood cells,C-reactive protein,and creatinine.Plain chest and abdominal computed tomography scanning revealed increased ascites volume.Abdominal paracentesis was performed and a Gram stain revealed Gramnegative bacillus.These findings prompted diagnosis of SBP.The patient was admitted and treated with cefmetazole,causing fever resolution and symptom improvements.Later,E.tarda was identified in ascites culture.The patient improved with decreased inflammatory response and was discharged on the 12th day of hospitalization.The antibiotic was terminated after 14 days of treatment.SBP in this case may have developed from chronic renal failure and diabetes mellitus.CONCLUSION We report the first known case of SBP due to E.tarda in an immuno-compromised dialysis patient.展开更多
Background:The bacterial biofilm poses a significant challenge to traditional antibiotic therapy.There is a great need to develop novel antibiofilm agents combined with biofilm disrupting and bacteria-killing without ...Background:The bacterial biofilm poses a significant challenge to traditional antibiotic therapy.There is a great need to develop novel antibiofilm agents combined with biofilm disrupting and bacteria-killing without the dependence of antibiotic.Methods:Herein,we prepared ultrasound/magnetic field-responsive ferroferric oxide nanoparticles(Fe_(3)O_(4))/glucose oxidase microbubbles(FGMB)to form a cascade catalytic system for effective removing methicillin-resistant Staphylococcus aureus biofilms.FGMB were prepared through interfacial self-assembly of Fe_(3)O_(4) nanoparticles(NPs)and glucose oxidase(GOx)at the gas-liquid interface stabilized by surfactants.Under ultrasound/magnetic field stimulation,FGMB disrupted biofilm architecture through microbubble collapse-induced microjets and magnetically driven displacement.Simultaneously,ultrasound-triggered rupture of FGMB released GOx and Fe_(3)O_(4) NPs.Glucose can be oxidized by GOx to generate gluconic acid and hydrogen peroxide which was subsequently catalyzed into hydroxyl radicals by Fe_(3)O_(4) NPs,enabling chemical eradication of biofilm-embedded bacteria.Results:Optical microscopy images demonstrated that FGMB have spherical structure with average size of approximately 17μm.FGMB showed a 65.4%decrease in methicillin-resistant Staphylococcus aureus biofilm biomass and 1.1 log bacterial inactivation efficiency(91.2%),suggesting effective biofilm elimination.In vitro experimental results also indicate that FGMB have good biocompatibility.Conclusion:This antibiofilm strategy integrated dual modes of physical biofilm disruption with chemical bacteria-killing shows great potential as a versatile,non-resistant strategy for bacterial biofilm elimination.展开更多
The development of highly efficient and multifunctional nanozymes holds promise for addressing the challenges posed by drugresistant bacteria.Here,copper single-atom-loaded MoS_(2) nanozymes(CuSAs/MoS_(2))were develop...The development of highly efficient and multifunctional nanozymes holds promise for addressing the challenges posed by drugresistant bacteria.Here,copper single-atom-loaded MoS_(2) nanozymes(CuSAs/MoS_(2))were developed to effectively combat drug-resistant bacteria by synergistically integrating the triple strategies of oxidative damage,cuproptosis-like death and disruption of cell wall synthesis.Density functional theory revealed that each Cu center coordinated with three sulfur ligands,enhancing the adsorption of H_(2)O_(2),which reduced the activation energy of the key step by 17%,thereby improving peroxidase-like(PODlike)activity.The generation of reactive oxygen species in combination with CuSAs/MoS_(2) glutathione peroxidase-like(GSH-Px-like)for glutathione scavenging resulted in an imbalance in redox homeostasis within bacteria.CuSAs/MoS_(2),which act as nanopioneers,drive oxidative stress to initiate the process of cuproptosis-like death,leading to abnormal aggregation of lipoylated proteins and inactivation of iron-sulfur cluster proteins.Moreover,CuSAs/MoS_(2) inhibited the biosynthesis of the peptidoglycan synthesis precursors D-glutamate and m-diaminopimelic acid and disrupted the peptidoglycan cross-linking process mediated by penicillin-binding proteins,effectively blocking the compensatory cell wall remodeling pathway ofβ-lactam-resistant bacteria.Overall,CuSAs/MoS_(2) with multiple functions can not only efficiently kill bacteria but also decelerate the development of bacterial resistance to combat drug-resistant bacterial infections.展开更多
Microscopy imaging is fundamental in analyzing bacterial morphology and dynamics,offering critical insights into bacterial physiology and pathogenicity.Image segmentation techniques enable quantitative analysis of bac...Microscopy imaging is fundamental in analyzing bacterial morphology and dynamics,offering critical insights into bacterial physiology and pathogenicity.Image segmentation techniques enable quantitative analysis of bacterial structures,facilitating precise measurement of morphological variations and population behaviors at single-cell resolution.This paper reviews advancements in bacterial image segmentation,emphasizing the shift from traditional thresholding and watershed methods to deep learning-driven approaches.Convolutional neural networks(CNNs),U-Net architectures,and three-dimensional(3D)frameworks excel at segmenting dense biofilms and resolving antibiotic-induced morphological changes.These methods combine automated feature extraction with physics-informed postprocessing.Despite progress,challenges persist in computational efficiency,cross-species generalizability,and integration with multimodal experimental workflows.Future progress will depend on improving model robustness across species and imaging modalities,integrating multimodal data for phenotype-function mapping,and developing standard pipelines that link computational tools with clinical diagnostics.These innovations will expand microbial phenotyping beyond structural analysis,enabling deeper insights into bacterial physiology and ecological interactions.展开更多
Bacterial cells are widely accepted as nucleation sites for calcium carbonate precipitation in biomineralization based on the Microbially Induced Carbonate Precipitation(MICP)process.For MICP-based insitu biotreatment...Bacterial cells are widely accepted as nucleation sites for calcium carbonate precipitation in biomineralization based on the Microbially Induced Carbonate Precipitation(MICP)process.For MICP-based insitu biotreatment,the firstproblem to be solved is how to introduce and retain the bacterial cells in the soil,which involves the migration and retention of bacterial cells during the biogrouting process.Soil particle size,a key factor in determining pore throat size,can have a significanteffect on the migration and retention of bacterial cells in the soil and therefore on biomineralization.To investigate the effect of particle size on the migration and retention of bacterial cells in sand and its biomineralization,two sets of tests were carried out in this study,including percolation tests and sand column treatment tests.Soil urease activity(definedas urease activity per unit mass of soil)and calcium carbonate content of the biomineralized sand were measured to comprehensively assess the migration and retention of bacterial cells in the sand.The results indicate that sands with a particle size smaller than 0.25 mmwould inhibit the migration of bacteria in the sand,resulting in a nonuniform distribution of precipitated calcium carbonate and a low strength enhancement of biomineralization.On the other hand,sands with a particle size larger than 1.18 mm are unfavorable for retaining bacterial cells in the sand,resulting in low calcium conversion efficiency.Meanwhile,particle size would also affect the formation of effective calcium carbonate through interparticle contact number and interparticle pore size,and thus biomineralization.展开更多
The global burden of bacterial infections,exacerbated by antimicrobial resistance(AMR),necessitates innovative strategies.Bacterial protein vaccines offer promise by eliciting targeted immunity while circumventing AMR...The global burden of bacterial infections,exacerbated by antimicrobial resistance(AMR),necessitates innovative strategies.Bacterial protein vaccines offer promise by eliciting targeted immunity while circumventing AMR.However,their clinical translation is hindered by their inherently low immunogenicity,often requiring potent adjuvants and advanced delivery systems.Biomembrane nanostructures(e.g.,liposomes,exosomes,and cell membrane-derived nanostructures),characterized by superior biocompatibility,intrinsic targeting ability,and immune-modulating properties,could serve as versatile platforms that potentiate vaccine efficacy by increasing antigen stability,enabling codelivery of immunostimulants,and facilitating targeted delivery to lymphoid tissues/antigen-presenting cells.This intrinsic immunomodulation promotes robust humoral and cellular immune responses to combat bacteria.This review critically reviews(1)key biomembrane nanostructure classes for bacterial protein antigens,(2)design strategies leveraging biomembrane nanostructures to enhance humoral and cellular immune responses,(3)preclinical efficacy against diverse pathogens,and(4)translational challenges and prospects.Biomembrane nanostructure-driven approaches represent a paradigm shift in the development of next-generation bacterial protein vaccines against resistant infections.展开更多
Soil bacteria are integral to ecosystem functioning,significantly contributing to nutrients cycling and organic matter decomposition,and enhancing soil structure.This research considered the composition and dynamics o...Soil bacteria are integral to ecosystem functioning,significantly contributing to nutrients cycling and organic matter decomposition,and enhancing soil structure.This research considered the composition and dynamics of soil bacterial communities under different vegetation types(native Quercus brantii Lindl.and Amygdalus scoparia Spach,and non-native Pinus eldarica Medw.and Cupressus arizonica Greene.)in Zagros mountain area of Iran.This study involved a comparative analysis of soil culturable heterotrophic bacterial communities in spring(wet season)and summer(dry season)to clarify the effects of seasonal changes and vegetation on the dynamics of soil microorganisms.Soil samples were randomly collected under the canopies of various tree species and a control area,yielding a total of 48 composite samples analyzed for bacterial composition.Results indicated that 11 Gram-negative(e.g.,Citrobacter freundii,Enterobacter cloacae,Escherichia coli,Klebsiella oxytoca,Klebsiella pneumoniae,etc.)and 2 Gram-positive(Staphylococcus epidermidis and Staphylococcus aureus)bacteria were identified,showing significant seasonal variation.Specifically,53.85%of bacterial species were common to both seasons,with notable shifts in community composition observed between spring and summer,highlighting a higher abundance of Gram-negative species in spring.Bacterial community structure was significantly influenced by vegetation type,with various tree species shaping distinct microbial assemblages.Moreover,Pearson's correlations revealed that soil properties,particularly pH,phosphorus,and moisture content,were critical drivers of bacterial diversity and abundance.Our findings underscore the dynamic nature of soil bacterial communities in response to seasonal and vegetation changes,emphasizing the importance of repeated temporal sampling for accurate assessments of microbial diversity.Understanding these microbial dynamics is essential for improving soil management strategies and enhancing ecosystem resilience,particularly in arid and semi-arid areas where environmental fluctuations play a pivotal role.This research not only confirms our hypotheses but also enhances our understanding of soil biogeochemical processes and informs future vegetation management practices.展开更多
Rice-fish coculture(RFC)has aroused extensive concern for its contribution to food security and resource conservation,but whether it can improve soil phosphorus(P)availability and affect microbe-mediated P turnover re...Rice-fish coculture(RFC)has aroused extensive concern for its contribution to food security and resource conservation,but whether it can improve soil phosphorus(P)availability and affect microbe-mediated P turnover remains elusive.Herein,we conducted a microcosm experiment to assess the impacts of RFC combined with(50 mg P kg^(-1)as KH2PO4)and without inorganic P addition on P fractions,P availability,and phoD-harboring bacterial community composition.The results revealed that RFC without P addition significantly improved P availability and phosphatase activity in paddy soil,while soil available P(AP),pH,and microbial biomass P(MBP)contributed to regulating P fractions.Moreover,the phoD-harboring bacterial abundance was linked to phosphatase activity,AP,total carbon(TC),and total P(TP)contents,and the ratios of TC to total nitrogen(TN)and TN to TP.We also found that the keystone taxa of phoD-harboring bacteria contributed to phosphatase production as well as organic P mineralization,thereby improving P availability.Our findings suggest that RFC without P addition is beneficial for promoting the expression of phoD-harboring bacterial functions to improve the capacity of P mineralization.Overall,our study provides insights into the responses of phoD-harboring bacterial functions for P turnover to RFC combined with and without P addition,showing the potential utilization of P resources in agricultural soil and the contribution of phosphatase activity to P acquisition in agriculture ecosystem.展开更多
Aim: This study was carried out in order to evaluate the potential of bacteriophages in controlling tomato bacterial wilt disease caused by Ralstonia solanacearum. Study design: A purposive sampling technique was used...Aim: This study was carried out in order to evaluate the potential of bacteriophages in controlling tomato bacterial wilt disease caused by Ralstonia solanacearum. Study design: A purposive sampling technique was used to collect samples from bacterial wilt hot spot tomato growing areas in Kenya. Place and duration of study: The research work was done at Jomo Kenyatta University of Agriculture and Technology, between June 2020 and July 2021. Methodology: Thirty diseased plants and corresponding soil were collected from five counties, Nyeri, Kajiado, Nyandarua, Kiambu and Taita Taveta. Bacteria were isolated and characterized, and then used as hosts to propagate the phages. Tests done were gram stain, oxidation test, potassium hydroxide solubility test, H2S production test catalase test, NaCl test and sugar fermentation test. Molecular analysis and phenotyping were also done in order to identify the bacteria. The bacteriophages were then isolated through a double overlay method using R. solanacearum as the host. They were characterized and assayed in a greenhouse setting to determine their effectiveness in controlling bacterial wilt. Results: Six host bacteria were isolated and all belonged to biovar II. Four phages were observed based on morphology. Upon characterization the phages were stable at 30˚C, PH range between 6 - 7 and tolerance of more than an hour under UV light. In the greenhouse experiment, treatment of plants with bacteriophage prevented wilting after subsequent inoculation with the pathogen. A bacteriophage mix of SN1 and WT1 were used for efficacy tests due to their efficiency in plating and infection. Phage SN1 and WT1 exhibited high lytic activity and relatively high thermotolerance and acid tolerance, thereby showing great potential in the biocontrol of bacterial wilt infection across a variety of conditions. Conclusion: The results obtained in this research show that bacteriophages offer potential for the biocontrol of bacterial wilt.展开更多
BACKGROUND Bacterial contamination during colonoscopy is a significant concern,yet few studies have evaluated bacterial aerosols.This study aimed to determine whether covering the biopsy hole check valve with enzymoly...BACKGROUND Bacterial contamination during colonoscopy is a significant concern,yet few studies have evaluated bacterial aerosols.This study aimed to determine whether covering the biopsy hole check valve with enzymolysis gauze(refers to sterile gauze soaked in a multi-enzyme cleaning solution)reduces bacterial air pollution in endoscopy rooms.AIM To evaluate the efficacy of an enzymolysis gauze cover in reducing bacterial aerosols from the biopsy valve.METHODS This prospective,single-blind trial included 80 patients undergoing elective diagnostic colonoscopy.During the procedure,the biopsy hole check valve was either covered or left uncovered with enzymolysis gauze.Air samples(100 L)were collected at a distance of 30 cm from the biopsy hole check valve and approximately 140 cm above the floor using a percussive air sampling instrument.Gram-positive bacteria were cultured on standard 90 mm colimycin nalidixic agar blood plates.The primary outcome measures were bacterial load and species identification.RESULTS Covering the biopsy hole check valve with enzymolysis gauze reduced bacterial load near the check valve from 50 colony-forming unit(CFU)/m^(3)[interquartile range(IQR):30-80]to 20 CFU/m^(3)(IQR:10-20).At the end of the procedure each day,covering the valve also decreased bacterial load in the endoscopy room from 35 CFU/m^(3)(IQR:33-85)to 10 CFU/m^(3)(IQR:5-10).The predominant bacteria identified were Gram-positive cocci.CONCLUSION Applying enzymolysis gauze to cover the biopsy hole check valve significantly reduces bacterial aerosol contamination in endoscopy rooms during colonoscopy.展开更多
Honey, an apicultural product with a complex chemical composition, contains numerous bioactive compounds with potential antimicrobial effects. This study investigated the effect of Apis mellifera honey from Brazil’s ...Honey, an apicultural product with a complex chemical composition, contains numerous bioactive compounds with potential antimicrobial effects. This study investigated the effect of Apis mellifera honey from Brazil’s Central-West Region, combined with antibiotics, on bacterial membrane permeability, exploring the contributions of bioactive compounds and the botanical origin of honey. Six fresh Apis mellifera honey samples and their fractions (hexane and ethyl acetate) were analyzed, for a total of 18 samples. The bacteria Staphylococcus epidermidis, Helicobacter pylori and Enterococcus faecalis were used for antibacterial activity tests, which included minimum inhibitory concentration (MIC) determination and synergistic effect (checkerboard) assays. The total polyphenol and flavonoid contents were quantified, and the botanical origin was determined based on pollen analysis. The tested honey samples significantly affected bacterial membrane permeability when combined with rifampicin and clarithromycin. Although many honey-derived bioactive compounds, when isolated, did not exhibit significant activity against these bacteria, the additive or synergistic effect of multiple compounds acting on different targets appears to potentiate the antibacterial action. Descriptive statistical analysis, including means and 95% confidence intervals, confirmed the relevance of the findings. This study has provided an important discovery: Honey has an effect on bacterial membrane permeability, although the specific mechanisms involved in this process require further investigation.展开更多
The presence of the blood–brain barrier limits the drug concentration in the brain,while low concentrations of antibiotics make it difficult to kill infecting bacteria and tends to induce drug resistance,making the c...The presence of the blood–brain barrier limits the drug concentration in the brain,while low concentrations of antibiotics make it difficult to kill infecting bacteria and tends to induce drug resistance,making the clinical treatment of bacterial meningitis challenging.Herein,a nose-to-brain delivery strategy of small-sized nanozyme has been fabricated for combating bacterial meningitis,to overcome the low drug concentration and drug resistance.This strategy was achieved by a proteinsupported Au nanozyme(ANZ).With a particle size of less than 10 nm,it possesses both glucose oxidase-like and peroxidase-like activities and can generate large amounts of reactive oxygen species through a cascade effect without the addition of external H_(2)O_(2).Benefiting from the cascade catalytic amplification effect generated by its dual enzymelike activities,ANZ shows significant broad-spectrum antibacterial activity without inducing bacterial resistance in vitro.Notably,small-sized ANZ exhibits higher brain entry efficiency and greater accumulation after intranasal administration compared to oral or intravenous administration.In a mouse model of bacterial meningitis,the mice treated with ANZ had lower bacterial loads in the brain and higher survival and clinical behavior scores compared to the classical antibiotic ceftriaxone.Additionally,the meningitis mice exhibited undamaged cognitive and behavioral abilities,indicating the excellent biocompatibility of ANZ.The above results demonstrate that nose-to-brain delivery of ANZ exhibits high intracerebral accumulation,strong antibacterial efficacy and does not lead to bacterial resistance.It holds broad prospects for the treatment of bacterial meningitis.展开更多
The conversion of saline-alkali soils into paddy fields for long-term rice cultivation involves multiple disturbances,and as a result,soil microbial communities are altered to adapt to changing environmental condition...The conversion of saline-alkali soils into paddy fields for long-term rice cultivation involves multiple disturbances,and as a result,soil microbial communities are altered to adapt to changing environmental conditions.However,a comprehensive understanding of the succession of soil bacterial communities that occurs during this process is still lacking.In the present study,we utilized data obtained from paddy fields of different rice cultivation years(0-23 years)to investigate the compositional and functional succession of soil bacterial communities.We focused on core bacterial taxa that were specifically enriched at different successional stages.Generalized joint attribute modeling(GJAM)was used to identify core bacterial taxa.Results indicated that the bare saline-alkali soil(0 year,prior to any rice cultivation)shared few core amplicon sequence variants(ASVs)with paddy fields.In the bare saline-alkali soil,Longimicrobiaceae from the phylum Gemmatimonadetes was dominant,while the dominance was subsequently replaced by Burkholderiaceae and Pedosphaeraceae--phyla affiliated with Proteobacteria and Verrucomicrobia--after 5 and 23 years of rice cultivation,respectively.The relative abundances of nitrogen metabolism functions in the core bacterial communities of the bare saline-alkali soil were higher than those at other successional stages,while sulfur metabolism functions exhibited the opposite trend.These indicated that the role of the core bacterial taxa in mediating nutrient cycling also evolved and adapted to changing soil conditions as rice cultivation was established.Redundancy analysis(RDA)indicated that the composition of the core bacterial community in paddy fields with rice cultivation for 0,2 and 4,6,8,10,and 12,and 20 and 23 years were driven by soil nitrate nitrogen content,pH,available phosphorus content,and the ratio of total carbon to total nitrogen,respectively.In summary,the present study provides insights into the succession of soil bacterial communities and core bacterial taxa that occurs during long-term rice cultivation.展开更多
This study evaluated the antibacterial effects of 2%lidocaine and its combination with 0.9%saline solution on Escherichia coli infection in superficial surgical wounds in Wistar rats.The goal was to determine if these...This study evaluated the antibacterial effects of 2%lidocaine and its combination with 0.9%saline solution on Escherichia coli infection in superficial surgical wounds in Wistar rats.The goal was to determine if these treatments could effectively reduce E.coli Colony Forming Units(CFUs)below the critical threshold of 1×105.Seventy male Wistar rats were divided into seven groups,each undergoing different interventions to assess the antibacterial efficacy of lidocaine,with outcomes measured through bacterial cultures and CFU quantification.Results demonstrated a Log10reduction of approximately 0.44 in E.coli CFUs following infiltration with 2%lidocaine.The combined use of 2%lidocaine infiltration and 0.9%saline irrigation resulted in nearly complete suppression of bacterial growth.These findings suggest that these simple interventions could be valuable in emergency surgical settings to mitigate the risk of surgical site infections and serve as effective prophylactic measures.increase in hospital stay,which represents an additional cost in terms of expenses and directly impacts the patient's outcome.11Several lines of evidence point to 104colony forming units per gram of tissue(CFUs/g)as the threshold at which healing generally begins to slow.12Knowledge of the antibacterial activity of lidocaine has been used to prevent bacterial contamination of other lipid-based anesthetics,such as propofol,with a significant decrease in bacterial development13-15and its antifungal effect.15,16Other effects attributed to lidocaine concerning systemic inflammatory response are the inhibition of granulocyte adhesion at sites of inflammation,decreased leukocyte adhesion during endotoxemia,and decreased macromolecular filtration;it is suggested that it may play a therapeutic role in endothelial damage during sepsis.17-19On the other hand,different measures have been taken to reduce the surgical wound infection rate,such as prophylactic antibiotics and local wound care,including pressure irrigation with 0.9% saline solution,with good results.20The antibacterial effect of lidocaine has been demonstrated in an animal model21;however,no model resembles surgical wound infection and the use of lidocaine to prevent infection.This study aimed to demonstrate that using 2% lidocaine(2 mL/g of tissue)will reduce the E.coli CFUs below 1×105in an infected superficial surgical wound in an experimental model.展开更多
Corresponding author’s name was incorrectly written as“Dadang Guo”instead of“Dagang Guo”.The correct author name should be“Dagang Guo”.The authors would like to apologise for any inconvenience caused.
基金supported by the National Key Research and Development Program of China(2023YFD2100104)Henan Provincial Major Science and Technology Special Fund(231100110400).
文摘Microorganisms are crucial for the breakdown of proteins and lipids in dry-fermented sausages and are intimately associated with the flavor profile of sausages.In this study,we used a mixed starter culture to ferment sausages and investigated the flavor turnover.During the fermentation of salami,the data from free amino acids(FAAs),free fatty acids(FFAs)and volatile flavor substances were used to assess the quality of salami.At the end of fermentation,the total FAAs increased from 1171.32 to 4582.48 mg/kg in the control group and 5053.25 mg/kg in the experimental group.Additionally,following inoculation with the mixed starter culture,the levels of glutamic acid,lysine,methionine,valine and leucine were significantly higher(P<0.05)than those in the control group.Oleic acid(C_(18:1))and chondritic acid(C_(16:0))were the two most abundant FFAs in both salami samples with 45.86%and 26.07%on the 23^(th)day in mixed culture inoculated salami.The mixed starter inoculated group had significantly lower saturated fatty acids and higher percentage levels of monounsaturated fatty acids than the control group(P<0.05).In the volatile flavor substance analysis,a total of 61 volatile compounds were found.Ester compounds were progressively enriched with drying time,significantly increasing the flavor substances,like ethyl diphosgene,1-octen-3-ol,and 2,3-butanediol at P<0.05.The correlation analysis between the core flora and volatile flavor compounds during fermentation and maturation of salami indicates Lactobacillus sakei and Lactobacillus rhamnosus were significantly higher and positively correlated with the major volatile organic compounds,which are the key core microorganisms affecting the flavor quality of fermented sausages.
基金funded by the Ministerio de Ciencia e Innovación Spain(PID2020-113388RB-I00,AEI/10.13039/501100011033)Consellería de Innovación,Universidades,Ciencia y Sociedad Digital,Generalitat Valenciana(CIPROM/2021/082)+2 种基金co-funded with European Regional Development Funds(ERDF)(PID2020-113388RB-I00,and CIPROM/2021/082)PID2022-136874OB-C33 from MCIN/AEI/10.13039/501100011033by the European Union NextGenerationEU/PRTR(to VF).
文摘The mechanisms leading to neurological and neurodegenerative diseases are not completely known,and new,more effective,therapeutic treatments are necessary for most neurological pathologies.The treatment of neurological and neurodegenerative diseases is complicated due to the blood-brain barrier,which makes it difficult for drugs to access the brain areas in which they must act to improve the pathology.A tool that can help to overcome this difficulty is the use of extracellular vesicles,which can easily cross the blood-brain barrier.The extracellular vesicles are considered a main way of communication between the brain and the rest of the body,with important implications for the physiopathology and therapy of neurological diseases.In recent years,the involvement of microbiota in many neurological pathologies,as well as its possible therapeutic role,has also become evident.A key mediator in the pathologic and beneficial effects of microbiota seems to be the bacterial extracellular vesicles.There is an important communication between the brain and the intestinal microbiota(the gut-brain axis),by which the microbiota influences brain function,impacts on mental health,and plays a role in different neurological and neurodegenerative diseases.The identification of the mechanisms involved in this gut-brain axis is essential to understanding the mechanisms of neurological pathologies and to developing more effective treatments for these diseases.Bacterial extracellular vesicles would play a relevant role in these processes.This review compiles the recent information and evidence on the role of bacterial extracellular vesicles in brain pathologies and on the therapeutic utility of bacterial extracellular vesicles in neurological and neurodegenerative diseases.One advantage of bacterial extracellular vesicles compared to extracellular vesicles derived from other cell types,such as stem cells,is that bacterial extracellular vesicles are generally easier to produce and modify.Bacterial extracellular vesicles may be easily modified to target a specific pathology and/or to enhance its therapeutic efficacy.Although the studies are still scarce,they open a wide field of possibilities for future studies,which will lead to a deeper understanding of the role of microbiota and bacterial extracellular vesicles in neurological pathologies and the underlying mechanisms,as well as to the development of new treatments based on the use of bacterial extracellular vesicles in neurological diseases.
基金supported by the Innovation and Entrepreneurship Training Program for College Students(X2025102911746,X2025102910483).
文摘Natural product(NPT)derived from traditional Chinese medicine has a rich history as an integral part of Chinese healthcare for thousands of years.Recently,the application of NPT in sonodynamic antibacterial therapy(SDAT)has emerged as a promising area of research.This perspective summarizes the recent NPT-based sonosensitizers in SDAT.Currently,common NPT-based sonosensitizers include curcumin,chlorophyll derivatives,hypericin,and berberine.Compared with other sonosensitizers,natural sources of NPT-based sonosensitizers with reactive oxide species production performance under ultrasound conditions,low biotoxicity,and other additional biological activity make them have application prospects in bacterial removal.Finally,the potential benefits and challenges of NPT-based nanosonosensitizers were also discussed.
基金Leducq Trans-Atlantic Network of Excellence,Grant/Award Number:TNE-21CVD04Spanish Ministry of Science and Innovation,Grant/Award Number:PID2020-117765RB-I00 and PID2022-140616OB-I00+1 种基金Instituto de Salud Carlos Ⅲ,European Development Regional Fund,RICORS-ICTUS Grant/Award Number:RD21/0006/0001the FORTALECE program. Grant/Award Number:FORT23/00023。
文摘Stroke induces profound neuroinflammation and systemic immune dysregulation,including disturbances in gut homeostasis.Experimental evidence suggests that intestinal barrier permeability(IBP)and bacterial translocation(BT)critically influence stroke outcomes.However,biological variability among commonly used rodent substrains has received limited attention.In this pilot study,we compared poststroke immune responses in two Wistar rat substrains obtained from different suppliers:RccHan(Envigo)and RjHan(Janvier).Naive animals(n=4)and rats subjected to permanent cerebral ischemia(n=8 per substrain)were evaluated 72 h after middle cerebral artery occlusion and stratified according to the presence or absence of BT.Immune cell populations in blood and bone marrow were analyzed using flow cytometry,and leukocyte infiltration into ischemic brain tissue was quantified using immunohisto-chemistry.Differences were considered statistically significant when p<0.05.Both substrains developed significant infarcts and neurological deficits.RccHan rats exhibited larger infarct volumes and more extensive BT across multiple organs.In contrast,RjHan rats exhibited BT mainly confined to mesenteric lymph nodes but exhibited greater IBP.Although dissemination was broader in RccHan rats,overall bacterial burden was slightly lower compared with RjHan,and extraintestinal bacterial composition differed between groups.Particularly,RjHan rats exhibited stronger systemic and central immune activation,with significant alterations in lymphocyte and monocyte populations and enhanced granulocyte and T-cell infiltration within ischemic lesions.These findings demonstrate that substrain origin profoundly influences poststroke intestinal barrier integrity,bacterial dissemination,and immune responses considering substrain-related variability is essential to improve reproducibility and translational relevance in preclinical stroke research.
文摘BACKGROUND Edwardsiella tarda(E.tarda)belongs to the family Enterobacteriaceae and is generally seen to cause infections mainly in fish,but is also capable of infecting humans.Extraintestinal infections occur in patients with certain risk factors,including immunocompromised status.We recently diagnosed a case of spontaneous bacterial peritonitis(SBP)due to E.tarda in an immuno-compromised dialysis patient.CASE SUMMARY Patient was a 55-year-old male,with a history of diabetic nephropathy being treated with hemodialysis three times a week.He was referred to our hospital due to an increased volume of ascites,and blood examination revealed increased inflammatory reaction.At our emergency department,he developed fever,disturbance of consciousness,abdominal distension,and abdomen-wide pain.In addition,a dialysis shunt was confirmed in his right forearm,and the shunt site showed no signs of inflammation.No wounds were confirmed on or in his body.A blood examination revealed increased values of white blood cells,C-reactive protein,and creatinine.Plain chest and abdominal computed tomography scanning revealed increased ascites volume.Abdominal paracentesis was performed and a Gram stain revealed Gramnegative bacillus.These findings prompted diagnosis of SBP.The patient was admitted and treated with cefmetazole,causing fever resolution and symptom improvements.Later,E.tarda was identified in ascites culture.The patient improved with decreased inflammatory response and was discharged on the 12th day of hospitalization.The antibiotic was terminated after 14 days of treatment.SBP in this case may have developed from chronic renal failure and diabetes mellitus.CONCLUSION We report the first known case of SBP due to E.tarda in an immuno-compromised dialysis patient.
基金supported by the National Natural Science Foundation of China(22375101)the Natural Science of Colleges and Universities in Jiangsu Province(24KJB430027).
文摘Background:The bacterial biofilm poses a significant challenge to traditional antibiotic therapy.There is a great need to develop novel antibiofilm agents combined with biofilm disrupting and bacteria-killing without the dependence of antibiotic.Methods:Herein,we prepared ultrasound/magnetic field-responsive ferroferric oxide nanoparticles(Fe_(3)O_(4))/glucose oxidase microbubbles(FGMB)to form a cascade catalytic system for effective removing methicillin-resistant Staphylococcus aureus biofilms.FGMB were prepared through interfacial self-assembly of Fe_(3)O_(4) nanoparticles(NPs)and glucose oxidase(GOx)at the gas-liquid interface stabilized by surfactants.Under ultrasound/magnetic field stimulation,FGMB disrupted biofilm architecture through microbubble collapse-induced microjets and magnetically driven displacement.Simultaneously,ultrasound-triggered rupture of FGMB released GOx and Fe_(3)O_(4) NPs.Glucose can be oxidized by GOx to generate gluconic acid and hydrogen peroxide which was subsequently catalyzed into hydroxyl radicals by Fe_(3)O_(4) NPs,enabling chemical eradication of biofilm-embedded bacteria.Results:Optical microscopy images demonstrated that FGMB have spherical structure with average size of approximately 17μm.FGMB showed a 65.4%decrease in methicillin-resistant Staphylococcus aureus biofilm biomass and 1.1 log bacterial inactivation efficiency(91.2%),suggesting effective biofilm elimination.In vitro experimental results also indicate that FGMB have good biocompatibility.Conclusion:This antibiofilm strategy integrated dual modes of physical biofilm disruption with chemical bacteria-killing shows great potential as a versatile,non-resistant strategy for bacterial biofilm elimination.
基金supported by the National Natural Science Foundation of China(82372552)the Excellent Youth of Natural Science Research Projects in Anhui Province Universities(2023AH030060)+1 种基金Anhui Provincial Natural Science Foundation(2408085Y016)Anhui Province Excellent Research and Innovation Team Project(2024AH010013)。
文摘The development of highly efficient and multifunctional nanozymes holds promise for addressing the challenges posed by drugresistant bacteria.Here,copper single-atom-loaded MoS_(2) nanozymes(CuSAs/MoS_(2))were developed to effectively combat drug-resistant bacteria by synergistically integrating the triple strategies of oxidative damage,cuproptosis-like death and disruption of cell wall synthesis.Density functional theory revealed that each Cu center coordinated with three sulfur ligands,enhancing the adsorption of H_(2)O_(2),which reduced the activation energy of the key step by 17%,thereby improving peroxidase-like(PODlike)activity.The generation of reactive oxygen species in combination with CuSAs/MoS_(2) glutathione peroxidase-like(GSH-Px-like)for glutathione scavenging resulted in an imbalance in redox homeostasis within bacteria.CuSAs/MoS_(2),which act as nanopioneers,drive oxidative stress to initiate the process of cuproptosis-like death,leading to abnormal aggregation of lipoylated proteins and inactivation of iron-sulfur cluster proteins.Moreover,CuSAs/MoS_(2) inhibited the biosynthesis of the peptidoglycan synthesis precursors D-glutamate and m-diaminopimelic acid and disrupted the peptidoglycan cross-linking process mediated by penicillin-binding proteins,effectively blocking the compensatory cell wall remodeling pathway ofβ-lactam-resistant bacteria.Overall,CuSAs/MoS_(2) with multiple functions can not only efficiently kill bacteria but also decelerate the development of bacterial resistance to combat drug-resistant bacterial infections.
基金financially supported by the Open Project Program of Wuhan National Laboratory for Optoelectronics(No.2022WNLOKF009)the National Natural Science Foundation of China(No.62475216)+2 种基金the Key Research and Development Program of Shaanxi(No.2024GH-ZDXM-37)the Fujian Provincial Natural Science Foundation of China(No.2024J01060)the Startup Program of XMU,and the Fundamental Research Funds for the Central Universities.
文摘Microscopy imaging is fundamental in analyzing bacterial morphology and dynamics,offering critical insights into bacterial physiology and pathogenicity.Image segmentation techniques enable quantitative analysis of bacterial structures,facilitating precise measurement of morphological variations and population behaviors at single-cell resolution.This paper reviews advancements in bacterial image segmentation,emphasizing the shift from traditional thresholding and watershed methods to deep learning-driven approaches.Convolutional neural networks(CNNs),U-Net architectures,and three-dimensional(3D)frameworks excel at segmenting dense biofilms and resolving antibiotic-induced morphological changes.These methods combine automated feature extraction with physics-informed postprocessing.Despite progress,challenges persist in computational efficiency,cross-species generalizability,and integration with multimodal experimental workflows.Future progress will depend on improving model robustness across species and imaging modalities,integrating multimodal data for phenotype-function mapping,and developing standard pipelines that link computational tools with clinical diagnostics.These innovations will expand microbial phenotyping beyond structural analysis,enabling deeper insights into bacterial physiology and ecological interactions.
基金support by the National Natural Science Foundation of China(NSFC)(Grant Nos.52178319,42477160,52338007).
文摘Bacterial cells are widely accepted as nucleation sites for calcium carbonate precipitation in biomineralization based on the Microbially Induced Carbonate Precipitation(MICP)process.For MICP-based insitu biotreatment,the firstproblem to be solved is how to introduce and retain the bacterial cells in the soil,which involves the migration and retention of bacterial cells during the biogrouting process.Soil particle size,a key factor in determining pore throat size,can have a significanteffect on the migration and retention of bacterial cells in the soil and therefore on biomineralization.To investigate the effect of particle size on the migration and retention of bacterial cells in sand and its biomineralization,two sets of tests were carried out in this study,including percolation tests and sand column treatment tests.Soil urease activity(definedas urease activity per unit mass of soil)and calcium carbonate content of the biomineralized sand were measured to comprehensively assess the migration and retention of bacterial cells in the sand.The results indicate that sands with a particle size smaller than 0.25 mmwould inhibit the migration of bacteria in the sand,resulting in a nonuniform distribution of precipitated calcium carbonate and a low strength enhancement of biomineralization.On the other hand,sands with a particle size larger than 1.18 mm are unfavorable for retaining bacterial cells in the sand,resulting in low calcium conversion efficiency.Meanwhile,particle size would also affect the formation of effective calcium carbonate through interparticle contact number and interparticle pore size,and thus biomineralization.
基金the National Natural Science Foundation of China(82573571)the Shanghai 2025 Basic Research Plan Natural Science Foundation(25ZR1401393)the First Batch of Open Topics of the Shanghai Key Laboratory of Nautical Medicine and Translation of Drugs and Medical Devices(2025QN13)。
文摘The global burden of bacterial infections,exacerbated by antimicrobial resistance(AMR),necessitates innovative strategies.Bacterial protein vaccines offer promise by eliciting targeted immunity while circumventing AMR.However,their clinical translation is hindered by their inherently low immunogenicity,often requiring potent adjuvants and advanced delivery systems.Biomembrane nanostructures(e.g.,liposomes,exosomes,and cell membrane-derived nanostructures),characterized by superior biocompatibility,intrinsic targeting ability,and immune-modulating properties,could serve as versatile platforms that potentiate vaccine efficacy by increasing antigen stability,enabling codelivery of immunostimulants,and facilitating targeted delivery to lymphoid tissues/antigen-presenting cells.This intrinsic immunomodulation promotes robust humoral and cellular immune responses to combat bacteria.This review critically reviews(1)key biomembrane nanostructure classes for bacterial protein antigens,(2)design strategies leveraging biomembrane nanostructures to enhance humoral and cellular immune responses,(3)preclinical efficacy against diverse pathogens,and(4)translational challenges and prospects.Biomembrane nanostructure-driven approaches represent a paradigm shift in the development of next-generation bacterial protein vaccines against resistant infections.
文摘Soil bacteria are integral to ecosystem functioning,significantly contributing to nutrients cycling and organic matter decomposition,and enhancing soil structure.This research considered the composition and dynamics of soil bacterial communities under different vegetation types(native Quercus brantii Lindl.and Amygdalus scoparia Spach,and non-native Pinus eldarica Medw.and Cupressus arizonica Greene.)in Zagros mountain area of Iran.This study involved a comparative analysis of soil culturable heterotrophic bacterial communities in spring(wet season)and summer(dry season)to clarify the effects of seasonal changes and vegetation on the dynamics of soil microorganisms.Soil samples were randomly collected under the canopies of various tree species and a control area,yielding a total of 48 composite samples analyzed for bacterial composition.Results indicated that 11 Gram-negative(e.g.,Citrobacter freundii,Enterobacter cloacae,Escherichia coli,Klebsiella oxytoca,Klebsiella pneumoniae,etc.)and 2 Gram-positive(Staphylococcus epidermidis and Staphylococcus aureus)bacteria were identified,showing significant seasonal variation.Specifically,53.85%of bacterial species were common to both seasons,with notable shifts in community composition observed between spring and summer,highlighting a higher abundance of Gram-negative species in spring.Bacterial community structure was significantly influenced by vegetation type,with various tree species shaping distinct microbial assemblages.Moreover,Pearson's correlations revealed that soil properties,particularly pH,phosphorus,and moisture content,were critical drivers of bacterial diversity and abundance.Our findings underscore the dynamic nature of soil bacterial communities in response to seasonal and vegetation changes,emphasizing the importance of repeated temporal sampling for accurate assessments of microbial diversity.Understanding these microbial dynamics is essential for improving soil management strategies and enhancing ecosystem resilience,particularly in arid and semi-arid areas where environmental fluctuations play a pivotal role.This research not only confirms our hypotheses but also enhances our understanding of soil biogeochemical processes and informs future vegetation management practices.
基金supported by the Key-Area Research and Development Program of Guangdong Province,China(No.2021B0202030002)the Science and Technology Planning Project of Guangdong Province,China(No.2019B030301007)+2 种基金the Guangdong Provincial Special Project of Rural Revitalization Strategy,China(No.(2021)12)the Joint Team Project of Guangdong Laboratory for Lingnan Modern Agriculture,China(No.NT2021010)the Innovation Team Construction Project of Modern Agricultural Industry Technology Systems of Guangdong Province,China(No.2022KJ105).
文摘Rice-fish coculture(RFC)has aroused extensive concern for its contribution to food security and resource conservation,but whether it can improve soil phosphorus(P)availability and affect microbe-mediated P turnover remains elusive.Herein,we conducted a microcosm experiment to assess the impacts of RFC combined with(50 mg P kg^(-1)as KH2PO4)and without inorganic P addition on P fractions,P availability,and phoD-harboring bacterial community composition.The results revealed that RFC without P addition significantly improved P availability and phosphatase activity in paddy soil,while soil available P(AP),pH,and microbial biomass P(MBP)contributed to regulating P fractions.Moreover,the phoD-harboring bacterial abundance was linked to phosphatase activity,AP,total carbon(TC),and total P(TP)contents,and the ratios of TC to total nitrogen(TN)and TN to TP.We also found that the keystone taxa of phoD-harboring bacteria contributed to phosphatase production as well as organic P mineralization,thereby improving P availability.Our findings suggest that RFC without P addition is beneficial for promoting the expression of phoD-harboring bacterial functions to improve the capacity of P mineralization.Overall,our study provides insights into the responses of phoD-harboring bacterial functions for P turnover to RFC combined with and without P addition,showing the potential utilization of P resources in agricultural soil and the contribution of phosphatase activity to P acquisition in agriculture ecosystem.
文摘Aim: This study was carried out in order to evaluate the potential of bacteriophages in controlling tomato bacterial wilt disease caused by Ralstonia solanacearum. Study design: A purposive sampling technique was used to collect samples from bacterial wilt hot spot tomato growing areas in Kenya. Place and duration of study: The research work was done at Jomo Kenyatta University of Agriculture and Technology, between June 2020 and July 2021. Methodology: Thirty diseased plants and corresponding soil were collected from five counties, Nyeri, Kajiado, Nyandarua, Kiambu and Taita Taveta. Bacteria were isolated and characterized, and then used as hosts to propagate the phages. Tests done were gram stain, oxidation test, potassium hydroxide solubility test, H2S production test catalase test, NaCl test and sugar fermentation test. Molecular analysis and phenotyping were also done in order to identify the bacteria. The bacteriophages were then isolated through a double overlay method using R. solanacearum as the host. They were characterized and assayed in a greenhouse setting to determine their effectiveness in controlling bacterial wilt. Results: Six host bacteria were isolated and all belonged to biovar II. Four phages were observed based on morphology. Upon characterization the phages were stable at 30˚C, PH range between 6 - 7 and tolerance of more than an hour under UV light. In the greenhouse experiment, treatment of plants with bacteriophage prevented wilting after subsequent inoculation with the pathogen. A bacteriophage mix of SN1 and WT1 were used for efficacy tests due to their efficiency in plating and infection. Phage SN1 and WT1 exhibited high lytic activity and relatively high thermotolerance and acid tolerance, thereby showing great potential in the biocontrol of bacterial wilt infection across a variety of conditions. Conclusion: The results obtained in this research show that bacteriophages offer potential for the biocontrol of bacterial wilt.
基金Supported by the Construction Fund of Key Medical Disciplines of Hangzhou,No.2025HZGF05the Key R and D Program of Zhejiang Province,No.2023C03054 and No.2024C03048+1 种基金the Key Discipline of Integrated Chinese and Western Medicine(Digestive Diseases)in Zhejiang Province,No.2024-XK-61the Zhejiang Province Medical and Health Science and Technology Plan Project,No.2021KY848.
文摘BACKGROUND Bacterial contamination during colonoscopy is a significant concern,yet few studies have evaluated bacterial aerosols.This study aimed to determine whether covering the biopsy hole check valve with enzymolysis gauze(refers to sterile gauze soaked in a multi-enzyme cleaning solution)reduces bacterial air pollution in endoscopy rooms.AIM To evaluate the efficacy of an enzymolysis gauze cover in reducing bacterial aerosols from the biopsy valve.METHODS This prospective,single-blind trial included 80 patients undergoing elective diagnostic colonoscopy.During the procedure,the biopsy hole check valve was either covered or left uncovered with enzymolysis gauze.Air samples(100 L)were collected at a distance of 30 cm from the biopsy hole check valve and approximately 140 cm above the floor using a percussive air sampling instrument.Gram-positive bacteria were cultured on standard 90 mm colimycin nalidixic agar blood plates.The primary outcome measures were bacterial load and species identification.RESULTS Covering the biopsy hole check valve with enzymolysis gauze reduced bacterial load near the check valve from 50 colony-forming unit(CFU)/m^(3)[interquartile range(IQR):30-80]to 20 CFU/m^(3)(IQR:10-20).At the end of the procedure each day,covering the valve also decreased bacterial load in the endoscopy room from 35 CFU/m^(3)(IQR:33-85)to 10 CFU/m^(3)(IQR:5-10).The predominant bacteria identified were Gram-positive cocci.CONCLUSION Applying enzymolysis gauze to cover the biopsy hole check valve significantly reduces bacterial aerosol contamination in endoscopy rooms during colonoscopy.
文摘Honey, an apicultural product with a complex chemical composition, contains numerous bioactive compounds with potential antimicrobial effects. This study investigated the effect of Apis mellifera honey from Brazil’s Central-West Region, combined with antibiotics, on bacterial membrane permeability, exploring the contributions of bioactive compounds and the botanical origin of honey. Six fresh Apis mellifera honey samples and their fractions (hexane and ethyl acetate) were analyzed, for a total of 18 samples. The bacteria Staphylococcus epidermidis, Helicobacter pylori and Enterococcus faecalis were used for antibacterial activity tests, which included minimum inhibitory concentration (MIC) determination and synergistic effect (checkerboard) assays. The total polyphenol and flavonoid contents were quantified, and the botanical origin was determined based on pollen analysis. The tested honey samples significantly affected bacterial membrane permeability when combined with rifampicin and clarithromycin. Although many honey-derived bioactive compounds, when isolated, did not exhibit significant activity against these bacteria, the additive or synergistic effect of multiple compounds acting on different targets appears to potentiate the antibacterial action. Descriptive statistical analysis, including means and 95% confidence intervals, confirmed the relevance of the findings. This study has provided an important discovery: Honey has an effect on bacterial membrane permeability, although the specific mechanisms involved in this process require further investigation.
基金financially supported by the National Natural Science Foundation of China(No.32172855)Fundamental Research Funds for the Central Universities(Nos.2632024ZD07,2632024TD02)the Open Project of Jiangsu Provincial Science and Technology Resources(Clinical Resources)Coordination Service Platform(No.TC2023B001)。
文摘The presence of the blood–brain barrier limits the drug concentration in the brain,while low concentrations of antibiotics make it difficult to kill infecting bacteria and tends to induce drug resistance,making the clinical treatment of bacterial meningitis challenging.Herein,a nose-to-brain delivery strategy of small-sized nanozyme has been fabricated for combating bacterial meningitis,to overcome the low drug concentration and drug resistance.This strategy was achieved by a proteinsupported Au nanozyme(ANZ).With a particle size of less than 10 nm,it possesses both glucose oxidase-like and peroxidase-like activities and can generate large amounts of reactive oxygen species through a cascade effect without the addition of external H_(2)O_(2).Benefiting from the cascade catalytic amplification effect generated by its dual enzymelike activities,ANZ shows significant broad-spectrum antibacterial activity without inducing bacterial resistance in vitro.Notably,small-sized ANZ exhibits higher brain entry efficiency and greater accumulation after intranasal administration compared to oral or intravenous administration.In a mouse model of bacterial meningitis,the mice treated with ANZ had lower bacterial loads in the brain and higher survival and clinical behavior scores compared to the classical antibiotic ceftriaxone.Additionally,the meningitis mice exhibited undamaged cognitive and behavioral abilities,indicating the excellent biocompatibility of ANZ.The above results demonstrate that nose-to-brain delivery of ANZ exhibits high intracerebral accumulation,strong antibacterial efficacy and does not lead to bacterial resistance.It holds broad prospects for the treatment of bacterial meningitis.
基金supported by the National Natural Science Foundation of China(Nos.32371734,42007034,41920104008,and U22A20593)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA28020400)+2 种基金the Youth Innovation Promotion Association of Chinese Academy of Sciences(No.2023205)the Young Scientist Group Project of Northeast Institute of Geography and Agroecology of China(No.2022QNXZ04)the Science and Technology Development Project of Jilin Province of China(No.YDZJ202101ZYTS006).
文摘The conversion of saline-alkali soils into paddy fields for long-term rice cultivation involves multiple disturbances,and as a result,soil microbial communities are altered to adapt to changing environmental conditions.However,a comprehensive understanding of the succession of soil bacterial communities that occurs during this process is still lacking.In the present study,we utilized data obtained from paddy fields of different rice cultivation years(0-23 years)to investigate the compositional and functional succession of soil bacterial communities.We focused on core bacterial taxa that were specifically enriched at different successional stages.Generalized joint attribute modeling(GJAM)was used to identify core bacterial taxa.Results indicated that the bare saline-alkali soil(0 year,prior to any rice cultivation)shared few core amplicon sequence variants(ASVs)with paddy fields.In the bare saline-alkali soil,Longimicrobiaceae from the phylum Gemmatimonadetes was dominant,while the dominance was subsequently replaced by Burkholderiaceae and Pedosphaeraceae--phyla affiliated with Proteobacteria and Verrucomicrobia--after 5 and 23 years of rice cultivation,respectively.The relative abundances of nitrogen metabolism functions in the core bacterial communities of the bare saline-alkali soil were higher than those at other successional stages,while sulfur metabolism functions exhibited the opposite trend.These indicated that the role of the core bacterial taxa in mediating nutrient cycling also evolved and adapted to changing soil conditions as rice cultivation was established.Redundancy analysis(RDA)indicated that the composition of the core bacterial community in paddy fields with rice cultivation for 0,2 and 4,6,8,10,and 12,and 20 and 23 years were driven by soil nitrate nitrogen content,pH,available phosphorus content,and the ratio of total carbon to total nitrogen,respectively.In summary,the present study provides insights into the succession of soil bacterial communities and core bacterial taxa that occurs during long-term rice cultivation.
文摘This study evaluated the antibacterial effects of 2%lidocaine and its combination with 0.9%saline solution on Escherichia coli infection in superficial surgical wounds in Wistar rats.The goal was to determine if these treatments could effectively reduce E.coli Colony Forming Units(CFUs)below the critical threshold of 1×105.Seventy male Wistar rats were divided into seven groups,each undergoing different interventions to assess the antibacterial efficacy of lidocaine,with outcomes measured through bacterial cultures and CFU quantification.Results demonstrated a Log10reduction of approximately 0.44 in E.coli CFUs following infiltration with 2%lidocaine.The combined use of 2%lidocaine infiltration and 0.9%saline irrigation resulted in nearly complete suppression of bacterial growth.These findings suggest that these simple interventions could be valuable in emergency surgical settings to mitigate the risk of surgical site infections and serve as effective prophylactic measures.increase in hospital stay,which represents an additional cost in terms of expenses and directly impacts the patient's outcome.11Several lines of evidence point to 104colony forming units per gram of tissue(CFUs/g)as the threshold at which healing generally begins to slow.12Knowledge of the antibacterial activity of lidocaine has been used to prevent bacterial contamination of other lipid-based anesthetics,such as propofol,with a significant decrease in bacterial development13-15and its antifungal effect.15,16Other effects attributed to lidocaine concerning systemic inflammatory response are the inhibition of granulocyte adhesion at sites of inflammation,decreased leukocyte adhesion during endotoxemia,and decreased macromolecular filtration;it is suggested that it may play a therapeutic role in endothelial damage during sepsis.17-19On the other hand,different measures have been taken to reduce the surgical wound infection rate,such as prophylactic antibiotics and local wound care,including pressure irrigation with 0.9% saline solution,with good results.20The antibacterial effect of lidocaine has been demonstrated in an animal model21;however,no model resembles surgical wound infection and the use of lidocaine to prevent infection.This study aimed to demonstrate that using 2% lidocaine(2 mL/g of tissue)will reduce the E.coli CFUs below 1×105in an infected superficial surgical wound in an experimental model.
文摘Corresponding author’s name was incorrectly written as“Dadang Guo”instead of“Dagang Guo”.The correct author name should be“Dagang Guo”.The authors would like to apologise for any inconvenience caused.
