Pseudomonas fragi and Pseudomonas lundensis have been reported as key spoilage bacteria in aerobicallystored chilled meat.However,the co-spoilage effect of these bacteria has not been effectively evaluated.This study ...Pseudomonas fragi and Pseudomonas lundensis have been reported as key spoilage bacteria in aerobicallystored chilled meat.However,the co-spoilage effect of these bacteria has not been effectively evaluated.This study evaluated the spoilage potential of P.fragi,P.lundensis and P.fragi+P.lundensis in vitro and in situ at 4℃.The results showed that P.fragi+P.lundensis performed the highest growth rate and displayed larger decomposition zone diameters on raw-pork juice agar(RJA)plates.P.fragi+P.lundensis inoculants exhibited the strongest proteolytic activity,which resulted in the highest values of trichloroacetic acid(TCA)-soluble peptides concentration,total volatile basic nitrogen(TVB-N)content and myofibril fragmentation index(MFI)in chilled pork.Moreover,the inoculated samples showed different pH and sensory changes.Notably,increased amounts of volatile organic compounds(VOCs),such as octanal,nonanal,2-nonanone,1-propanol,1-octanol,isopropyl acetate,and 2,6-dimethylpyazine,were observed in inoculated P.fragi+P.lundensis samples,hinting their potential use as spoilage markers for spoilage monitoring of co-cultures.This study would provide a deeper understanding of meat spoilage and serve as a reference for future studies to inhibit meat spoilage.展开更多
We assessed the quorum sensing(QS)inhibitory impact of sesamol against the foodborne bacterium Pseudomonas aeruginosa.At concentrations ranging from 50 to 200μg/mL,sesamol significantly inhibited the production of vi...We assessed the quorum sensing(QS)inhibitory impact of sesamol against the foodborne bacterium Pseudomonas aeruginosa.At concentrations ranging from 50 to 200μg/mL,sesamol significantly inhibited the production of virulence factors such as protease,elastase,pyocyanin,rhamnolipid,and chemotaxis,and improved the susceptibility of bacterial and biofilm cells to colistin.Integrated transcriptomics,metabolomics,and docking analyses indicated that exposure to sesamol destroyed the QS system and down-regulated the expressions of genes encoding virulence and antioxidant enzymes.The down-regulation of genes encoding antioxidant enzymes intensified oxidative stress,as demonstrated by the enhancement of reactive oxygen species and H_(2)O_(2).The enhanced oxidative stress changed the components of the cell membrane,improved its permeability,and ultimately enhanced the susceptibility of bacterial and biofilm cells to colistin.Moreover,exposure to sesamol also led to the disorder of amino acid metabolism and energy metabolism,eventually attenuating the pathogenicity of P.aeruginosa.These findings indicated that sesamol can function as a potent anti-virulence agent to defend against food spoilage caused by P.aeruginosa.展开更多
Small RNAs(sRNAs)are a class of molecules capable of perceiving environmental changes and exerting posttranscriptional regulation over target gene expression,thereby influencing bacterial virulence and host immune res...Small RNAs(sRNAs)are a class of molecules capable of perceiving environmental changes and exerting posttranscriptional regulation over target gene expression,thereby influencing bacterial virulence and host immune responses.Pseudomonas plecoglossicida is a pathogenic bacterium that poses a significant threat to aquatic animal health.However,the regulatory mechanisms of sRNAs in P.plecoglossicida remain unclear.This study focused on sRNA113,previously identified as a potential regulator of the fliP gene,a key component of the lateral flagellar type III secretion system.To investigate the effects of sRNA113on P.plecoglossicida virulence,as well as its role in regulating pathogenic processes and host immune responses,mutant strains lacking this sRNA were generated and analyzed.Deletion of sRNA113 resulted in the up-regulation of lateral flagellar type III secretion system-related genes in P.plecoglossicida,which enhanced bacterial swarming motility,biofilm formation,and chemotaxis ability in vitro.In vivo infection experiments with pearl gentian grouper revealed that sRNA113 deletion enhanced the pathogenicity of P.plecoglossicida.This heightened virulence was attributed to the up-regulation of genes associated with the lateral flagellar type III secretion system,resulting in higher bacterial loads within host tissues.This amplification of pathogenic activity intensified tissue damage,disrupted immune responses,and impaired the ability of the host to clear infection,ultimately leading to mortality.These findings underscore the critical role of sRNA113 in regulating the virulence of P.plecoglossicida and its interaction with host immune defenses.This study provides a foundation for further exploration of sRNAmediated mechanisms in bacterial pathogenesis and hostpathogen interactions,contributing to a deeper understanding of virulence regulation and immune evasion in aquatic pathogens.展开更多
Background:Corneal scarring following bacterial keratitis,particularly from Pseudomonas infections,poses significant challenges in ophthalmic care.Current treatments often fall short in effectively reducing corneal ha...Background:Corneal scarring following bacterial keratitis,particularly from Pseudomonas infections,poses significant challenges in ophthalmic care.Current treatments often fall short in effectively reducing corneal haze and restoring vision.To our knowledge,this is the first report documenting the use of topical losartan,an angiotensin II receptor antagonist known to inhibit the transforming growth factor-β(TGF-β)pathway,for treating corneal haze resulting from bacterial keratitis.Case Description:A 30-year-old male presented with a persistent corneal scar in his right eye,178 days post-Pseudomonas keratitis.Despite a prolonged course of topical corticosteroids,his best-corrected visual acuity(BCVA)stabilized at 20/40 with a hybrid contact lens over a 2-month period.Given the lack of improvement,we initiated treatment with topical losartan at a concentration of 0.8 mg/mL,administered six times daily.After 4 months of therapy,the patient’s BCVA improved to 20/25.Slit-lamp examination and corneal tomography revealed a significant reduction in corneal haze,indicating a positive response to the treatment.Conclusions:This case suggests that topical losartan may be a promising therapeutic option for reducing corneal opacity following bacterial keratitis by inhibiting the TGF-βpathway.However,further clinical studies are necessary to confirm its efficacy and safety in broader patient populations.展开更多
Purpose: The genus Pseudomonas is a ubiquitous microorganism frequently detected from immunocompromised patients. The inherent resistance to numerous antimicrobial agents contributes to the opportunistic character of ...Purpose: The genus Pseudomonas is a ubiquitous microorganism frequently detected from immunocompromised patients. The inherent resistance to numerous antimicrobial agents contributes to the opportunistic character of this pathogen exhaustive monitoring of this pathogen is considered of critical importance to public health organizations. The reliable identification method able to distinguish genetic close Pseudomonas species is needed, because these organisms are difficult to differentiate by phenotypic or biochemical methods. The purpose of the present study was to design species-specific primers in order to identify and detect four Pseudomonas species which are frequently detected from the human oral cavities, and to investigate the distribution of these organisms in the living environment using a multiplex PCR. Methods: Polymerase chain reaction (PCR) primers were designed based on partial sequences of the rpoD gene of four Pseudomonas species. Swab samples were collected from fifty washstands, and the distribution of Pseudomonas species was investigated using a conventional PCR at genus level and a multiplex PCR at species level. Results: Multiplex PCR method developed in this study was able to distinguish four Pseudomonas species clearly. The genus Pseudomonas was detected from all samples (100%), whereas P. putida, P, aeruginosa, P. stutzeri and P. fluorescens were detected at 44%, 8%, 4% and 2% in fifty swab samples, respectively. Conclusion: Our developed one-step multiplex PCR method is accurate, specific, cost-effective, time-saving, and works without requiring DNA extraction. It was indicated that washstands were the uninhabitable environment for P. putida, P, aeruginosa, P. stutzeri and P. fluorescens.展开更多
The widespread use of pesticides has caused serious harm to ecosystems,necessitating effective and environmentally friendly treatment methods.Bioremediation stands out as a promising approach for pollutant treatment,w...The widespread use of pesticides has caused serious harm to ecosystems,necessitating effective and environmentally friendly treatment methods.Bioremediation stands out as a promising approach for pollutant treatment,wherein the metabolic activities of microorganisms can transform toxic pesticides into compounds with lower or no toxicity.In this study,we obtained eight pesticide-degrading strains from pesticide-contaminated sites through continuous enrichment and screening.Four highly efficient pesticide-degrading strains(degradation ratios exceeding 80%)were identified.Among them,Pseudomonas sp.BL5 exhibited the strongest growth(exceeding 10^(9) CFU·ml^(-1))and outstanding degradation of benzene derivatives and chlorinated hydrocarbons at both laboratory and pilot scales,with degradation ratios exceeding 98%and 99.6%,respectively.This research provides new tools and insights for the bioremediation of pesticide-related pollutants.展开更多
To enhance the microbiologically influenced corrosion(MIC)resistance of FeCoNiCrMn high entropy alloy(HEAs),a series of Fe_(x)Cu_((1−x))CoNiCrMn(x=1,0.75,0.5,and 0.25)HEAs were prepared.Microstructural characteristics...To enhance the microbiologically influenced corrosion(MIC)resistance of FeCoNiCrMn high entropy alloy(HEAs),a series of Fe_(x)Cu_((1−x))CoNiCrMn(x=1,0.75,0.5,and 0.25)HEAs were prepared.Microstructural characteristics,corrosion behavior(morphology observation and electrochemical properties),and antimicrobial performance of Fe_(x)Cu_((1−x))CoNiCrMn HEAs were evaluated in a medium inoculated with typical corrosive microorganism Pseudomonas aeruginosa.The aim was to identify copper-containing FeCoNiCrMn HEAs that balance corrosion resistance and antimicrobial properties.Results revealed that all Fe_(x)Cu_((1−x))CoNiCrMn(x=1,0.75,0.5,and 0.25)HEAs exhibited an FCC(face centered cubic)phase,with significant grain refinement observed in Fe_(0.75)Cu_(0.25)CoNiCrMn HEA.Electrochemical tests indicated that Fe_(0.75)Cu_(0.25)CoNiCrMn HEA demonstrated lower corrosion current density(i_(corr))and pitting potential(E_(pit))compared to other Fe_(x)Cu_((1−x))CoNiCrMn HEAs in P.aeruginosa-inoculated medium,exhibiting superior resistance to MIC.Anti-microbial tests showed that after 14 d of immersion,Fe_(0.75)Cu_(0.25)CoNiCrMn achieved an antibacterial rate of 89.5%,effectively inhibiting the adhesion and biofilm formation of P.aeruginosa,thereby achieving resistance to MIC.展开更多
BACKGROUND The clinical incidence of spinal infection is gradually increasing,and its onset is insidious,easily leading to missed diagnosis and misdiagnosis,which may lead to serious complications such as nervous syst...BACKGROUND The clinical incidence of spinal infection is gradually increasing,and its onset is insidious,easily leading to missed diagnosis and misdiagnosis,which may lead to serious complications such as nervous system dysfunction,spinal instability and/or deformity,and cause a huge burden on society and families.Early identification of the causative agent and precision medicine will greatly reduce the suffering of patients.At present,the main pathogenic bacteria that cause spinal infection are Staphylococcus aureus,Streptococcus,Pneumococcus,Escherichia coli,and Klebsiella.There are no reports of spinal infection caused by Pseudomonas fluorescens.CASE SUMMARY We report a 32-year-old female patient with spinal infection.She presented with flank pain,initially thought to be bone metastases or bone tuberculosis,and had a family background of tumors.Her clinical features and changes in imaging and laboratory tests led to the suspicion of thoracic spine infection.Histopathology of the lesion showed inflammation,tissue culture of the lesion was negative several times,and the possible pathogen-Pseudomonas fluorescens was found after gene sequencing of the lesion.The patient recovered completely after a full course of antibiotic treatment.CONCLUSION This report increases the range of pathogens involved in spinal infections,highlights the unique advantages of gene sequencing technology in difficult-todiagnose diseases,and validates conservative treatment with a full course of antibiotics for spinal infections without complications.展开更多
Objective:To investigate the frequency of exoU and exoY genes in patients with Pseudomonas aeruginosa infection.Methods:In this study,100 clinical isolates of Pseudomonas aeruginosa were collected from patients hospit...Objective:To investigate the frequency of exoU and exoY genes in patients with Pseudomonas aeruginosa infection.Methods:In this study,100 clinical isolates of Pseudomonas aeruginosa were collected from patients hospitalized in educational-therapeutic hospitals and were identified using standard microbiological tests.Then,the antibiotic resistance pattern of the isolates was determined by the disk agar diffusion method.The bacterial DNAs were extracted by the alkaline lysis method.Finally,the presence of exoU and exoY genes was evaluated by the PCR test.Results:In this study,47%,72%,29%,39%,40%,and 44%of the isolates were non-susceptible to piperacillin,aztreonam,ceftazidime,imipenem,tobramycin,and ciprofloxacin,respectively.In addition,95%and 93%of the clinical isolates carried the exoU and exoY genes.Blood and fecal isolates had both virulence genes,while only one wound isolate had neither genes.Meanwhile,all urinary isolates contained the exoY gene and only one isolate lacked the exoU gene.Also,88 isolates simultaneously had both exoU and exoY genes.Conclusions:High prevalence of exoU and exoY genes in this region indicates a significant role of typeⅢsecretion system in pathogenesis of Pseudomonas aeruginosa.The typeⅢsecretion system may be a suitable target to reduce the pathogenicity of this bacterium.展开更多
Background:Azadirachta indica(A.indica),commonly known as neem,is a widely distributed medicinal plant in Asia and Africa and is well known to have a wide spectrum of biological activity.A.indica is considered a skin ...Background:Azadirachta indica(A.indica),commonly known as neem,is a widely distributed medicinal plant in Asia and Africa and is well known to have a wide spectrum of biological activity.A.indica is considered a skin food that was traditionally used in different cultures to treat a wide range of skin disorders.A.indica was reported to possess antibacterial activity against Pseudomonas aeruginosa(P.aeruginosa)which is considered the most common biofilm model organism.This study aims to investigate the ability of A.indica cultivated in Egypt to inhibit/reduce the biofilm formation by P.aeruginosa.Methods:The microtiter plate assay was used to evaluate the anti-biofilm activity of neem,cultivated in Egypt,leaves against P.aeruginosa as well as the ability to reduce the activity of P.aeruginosa.To investigate the phytocompounds responsible for their bioactivity and to explore potential interactions between their bioactive components and one of the quorum-sensing regulatory proteins of P.aeruginosa involved in biofilm formation,liquid chromatography-mass spectrometric and molecular docking studies were done.Results:Results showed that methanol extract of leaves can reduce the formation of P.aeruginosa biofilm at lower concentrations than those reported in other regions with 1.25 mg/mL as the optimum concentration.The two-way analysis of variance revealed the significance of the extract effect and its concentration on the reduction of biofilm formation(P<0.05).Liquid chromatography-mass spectrometric study revealed the presence of fourteen compounds that belong to limonoids and flavonoids.Molecular docking analysis against LasR,the quorum-sensing regulatory protein,of P.aeruginosa supported these findings.Nimbolinin,a limonoid,has achieved the highest Libdock score of 138.769.Conclusion:It was concluded that A.indica,cultivated in Egypt,leaves can target LasR as a new mechanism of action for biofilm control by A.indica and therefore could be a good source of leads for anti-biofilm medicine.展开更多
Background:Pudilan Xiaoyan Oral Liquid(PDL)is a Chinese patent medicine with notable pharmacological properties,including anti-inflammatory and antibacterial effects.Drug-resistant Pseudomonas aeruginosa infection is ...Background:Pudilan Xiaoyan Oral Liquid(PDL)is a Chinese patent medicine with notable pharmacological properties,including anti-inflammatory and antibacterial effects.Drug-resistant Pseudomonas aeruginosa infection is a common and refractory bacterial infection in clinical practice.Due to its high drug resistance,it brings great challenges to treatment.This study aimed to assess the therapeutic efficacy of PDL in a murine model of pneumonia induced by drug-resistant Pseudomonas aeruginosa.Methods:Three different doses of PDL(11 mL/kg/d,5.5 mL/kg/d,2.75 mL/kg/d)were used to observe lung tissue pathology and inflammatory cytokine levels in pneumonia mouse models induced by multidrug-resistant Pseudomonas aeruginosa(MDR-PA).Additionally,the protective efficacy of PDL against mortality in infected mice was evaluated using a death model caused by MDR-PA.Finally sub-MIC concentration of levofloxacin was used to induce drug-resistant mice pneumonia model to evaluate the role of PDL in reversing drug resistance.Experimental data are expressed as mean±standard deviation.Statistical significance was determined by one-way analysis of variance followed by Tukey’s multiple-comparisons test.Results:Treatment effect of PDL on MDR-PA pneumonia:the medium and small doses of PDL can significantly reduce the lung index of multi-drug resistant bacteria infected pneumonia model mice(P<0.05),the lung index inhibition rates for these groups were 55.09%and 58.43%,and improve the degree of lung tissue lesions of mice;The expression of serum cytokines keratinocyte chemoattractant,tumor necrosis factor-αand monocyte chemoattractant protein-1 could be decreased in the three dosage groups of PDL(P<0.01).PDL treatment not only lowered the mortality but also extended the survival duration in mice infected with MDR-PA.It was found after sub-MIC concentration of levofloxacin induced resistance of Pseudomonas aeruginosa to pneumonia in mice.Compared with the model group,the lung index of mice in high and medium PDL doses was significantly reduced(P<0.05),with inhibition rates of 32.16%and 37.73%,respectively.Conclusion:PDL demonstrates protective effects against MDR-PA infection pneumonia,notably decreasing serum inflammatory factor levels.It shows promise in mitigating antibiotic resistance and offers potential for treating pneumonia resulting from Pseudomonas aeruginosa resistance.展开更多
Plant growth-promoting rhizobacteria(PGPR)such as Bacillus and Pseudomonas have drawn broad attention and interest due to their agricultural benefits.One of the major benefits of PGPR lies at their biocontrol capabili...Plant growth-promoting rhizobacteria(PGPR)such as Bacillus and Pseudomonas have drawn broad attention and interest due to their agricultural benefits.One of the major benefits of PGPR lies at their biocontrol capabilities against various plant pathogens.The biocontrol capability of PGPR is closely related to its capability of producing various kinds of antimicrobial substances.Major antimicrobial secondary metabolites secreted by PGPR include non-ribosomal lipopeptides(NRLPs),polyketides,ribosomal peptides,phenazines,pyrrolnitrins,etc.This review focuses on the major antimicrobial secondary metabolites produced by Bacillus and Pseudomonas including their classifications,structures,mechanisms of action and genetic regulations.We have also discussed their applications in plant biocontrol and provided insights into future development of improved biocontrol strains using synthetic biology approaches.展开更多
Carbofuran insecticide is one of the insecticides most often used by Indonesian farmers.The United Nations Environment Program(UNEP)2011 in the decision of UNEP/FAO/RC/CRC.11/6,agreed that the active ingredient Carbof...Carbofuran insecticide is one of the insecticides most often used by Indonesian farmers.The United Nations Environment Program(UNEP)2011 in the decision of UNEP/FAO/RC/CRC.11/6,agreed that the active ingredient Carbofuran is dangerous to human health and the environment.P.fluorescens bacteria are known to be able to remediate carbofuran-contaminated soil.This study examines more deeply the biodegradation and biotransformation processes of Carbofuran in P.fluorescens bacteria.The research was carried out at the Laboratory of Plant Diseases,Faculty of Agriculture,Brawijaya University;Analytical Chemistry Laboratory,State Polytechnic of Malang;and Analytical Chemistry Laboratory,Udayana University from February to August 2020.The results showed that P.fluorescens was able to degrade the insecticide Carbofuran in liquid media up to 82%and the growth of P.fluorescens bacteria reached 2.9×10^(12) CFU/mL,bacteria P.fluorescens is able to degrade the insecticide Carbofuran in a mixture of soil and compost up to 85%and the growth of P.fluorescens bacteria reaches 7.5 x 1013 CFU/mL,resulting in Carbofuran insecticide derivatives from the biotransformation process,there are 3-hydroxy-7-phenol;2,3-dihydro-1-benzofuran-2,2,7-triol;(2Z)-2-[(2Z)-pent-2-en-1-ylidene]butane-1,4,4-trio;7-phenol;2,2,3-trihydroxy-2,3-dihydro-1-benzofuran-7-yl hydrogen carbonate;2,2-dimethyl-2,3-dihydro-1-benzofuran-7-yl acetate;7-(hydroxymethoxy)-2,3-dihydro-1-benzofuran-2,2,3,5-tetrol;3-hidroksi-2-fenilpropil Carbamat;2-(3-hydroperoxy-2-hydroxyphenyl)ethane-1,1-diol,3-keto-7-fenol;4-hydroxy-2,2-dimethyl-2,3-dihydro-1H-inden-1-one;3-hydroxy-carbofuran;and 7-methoxy-2,2-dimethyl-2,3-dihydro-1-benzofuran-3,5-diol.Carbofuran derivative compounds from the biodegradation of P.fluorescens bacteria are less toxic than the active ingredient Carbofuran.展开更多
基金funded by the National Natural Science Foundation of China(32372404)the National Key Research and Development Program of China(2021YFD2100802-02)。
文摘Pseudomonas fragi and Pseudomonas lundensis have been reported as key spoilage bacteria in aerobicallystored chilled meat.However,the co-spoilage effect of these bacteria has not been effectively evaluated.This study evaluated the spoilage potential of P.fragi,P.lundensis and P.fragi+P.lundensis in vitro and in situ at 4℃.The results showed that P.fragi+P.lundensis performed the highest growth rate and displayed larger decomposition zone diameters on raw-pork juice agar(RJA)plates.P.fragi+P.lundensis inoculants exhibited the strongest proteolytic activity,which resulted in the highest values of trichloroacetic acid(TCA)-soluble peptides concentration,total volatile basic nitrogen(TVB-N)content and myofibril fragmentation index(MFI)in chilled pork.Moreover,the inoculated samples showed different pH and sensory changes.Notably,increased amounts of volatile organic compounds(VOCs),such as octanal,nonanal,2-nonanone,1-propanol,1-octanol,isopropyl acetate,and 2,6-dimethylpyazine,were observed in inoculated P.fragi+P.lundensis samples,hinting their potential use as spoilage markers for spoilage monitoring of co-cultures.This study would provide a deeper understanding of meat spoilage and serve as a reference for future studies to inhibit meat spoilage.
基金supported by grants from the National Natural Science Foundation of China(32000091)General Projects of Natural Science Research in Universities of Jiangsu Province(20KJB180019)Jiangsu Youth Talent Promotion Project(TJ-2021-066)。
文摘We assessed the quorum sensing(QS)inhibitory impact of sesamol against the foodborne bacterium Pseudomonas aeruginosa.At concentrations ranging from 50 to 200μg/mL,sesamol significantly inhibited the production of virulence factors such as protease,elastase,pyocyanin,rhamnolipid,and chemotaxis,and improved the susceptibility of bacterial and biofilm cells to colistin.Integrated transcriptomics,metabolomics,and docking analyses indicated that exposure to sesamol destroyed the QS system and down-regulated the expressions of genes encoding virulence and antioxidant enzymes.The down-regulation of genes encoding antioxidant enzymes intensified oxidative stress,as demonstrated by the enhancement of reactive oxygen species and H_(2)O_(2).The enhanced oxidative stress changed the components of the cell membrane,improved its permeability,and ultimately enhanced the susceptibility of bacterial and biofilm cells to colistin.Moreover,exposure to sesamol also led to the disorder of amino acid metabolism and energy metabolism,eventually attenuating the pathogenicity of P.aeruginosa.These findings indicated that sesamol can function as a potent anti-virulence agent to defend against food spoilage caused by P.aeruginosa.
基金supported by the National Natural Science Foundation of China (32373181)National Key Research and Development Program (2023YFD2400700)+2 种基金Science and Technology Plan Project of Fujian Province (2022L3059)High-quality Development of Marine and Fishery Industry Special Fund Project of Fujian Province (FJHYF-L-2023-5)Open Fund of Fujian Province Key Laboratory of Special Aquatic Formula Feed (TMKJZ2302)。
文摘Small RNAs(sRNAs)are a class of molecules capable of perceiving environmental changes and exerting posttranscriptional regulation over target gene expression,thereby influencing bacterial virulence and host immune responses.Pseudomonas plecoglossicida is a pathogenic bacterium that poses a significant threat to aquatic animal health.However,the regulatory mechanisms of sRNAs in P.plecoglossicida remain unclear.This study focused on sRNA113,previously identified as a potential regulator of the fliP gene,a key component of the lateral flagellar type III secretion system.To investigate the effects of sRNA113on P.plecoglossicida virulence,as well as its role in regulating pathogenic processes and host immune responses,mutant strains lacking this sRNA were generated and analyzed.Deletion of sRNA113 resulted in the up-regulation of lateral flagellar type III secretion system-related genes in P.plecoglossicida,which enhanced bacterial swarming motility,biofilm formation,and chemotaxis ability in vitro.In vivo infection experiments with pearl gentian grouper revealed that sRNA113 deletion enhanced the pathogenicity of P.plecoglossicida.This heightened virulence was attributed to the up-regulation of genes associated with the lateral flagellar type III secretion system,resulting in higher bacterial loads within host tissues.This amplification of pathogenic activity intensified tissue damage,disrupted immune responses,and impaired the ability of the host to clear infection,ultimately leading to mortality.These findings underscore the critical role of sRNA113 in regulating the virulence of P.plecoglossicida and its interaction with host immune defenses.This study provides a foundation for further exploration of sRNAmediated mechanisms in bacterial pathogenesis and hostpathogen interactions,contributing to a deeper understanding of virulence regulation and immune evasion in aquatic pathogens.
文摘Background:Corneal scarring following bacterial keratitis,particularly from Pseudomonas infections,poses significant challenges in ophthalmic care.Current treatments often fall short in effectively reducing corneal haze and restoring vision.To our knowledge,this is the first report documenting the use of topical losartan,an angiotensin II receptor antagonist known to inhibit the transforming growth factor-β(TGF-β)pathway,for treating corneal haze resulting from bacterial keratitis.Case Description:A 30-year-old male presented with a persistent corneal scar in his right eye,178 days post-Pseudomonas keratitis.Despite a prolonged course of topical corticosteroids,his best-corrected visual acuity(BCVA)stabilized at 20/40 with a hybrid contact lens over a 2-month period.Given the lack of improvement,we initiated treatment with topical losartan at a concentration of 0.8 mg/mL,administered six times daily.After 4 months of therapy,the patient’s BCVA improved to 20/25.Slit-lamp examination and corneal tomography revealed a significant reduction in corneal haze,indicating a positive response to the treatment.Conclusions:This case suggests that topical losartan may be a promising therapeutic option for reducing corneal opacity following bacterial keratitis by inhibiting the TGF-βpathway.However,further clinical studies are necessary to confirm its efficacy and safety in broader patient populations.
文摘Purpose: The genus Pseudomonas is a ubiquitous microorganism frequently detected from immunocompromised patients. The inherent resistance to numerous antimicrobial agents contributes to the opportunistic character of this pathogen exhaustive monitoring of this pathogen is considered of critical importance to public health organizations. The reliable identification method able to distinguish genetic close Pseudomonas species is needed, because these organisms are difficult to differentiate by phenotypic or biochemical methods. The purpose of the present study was to design species-specific primers in order to identify and detect four Pseudomonas species which are frequently detected from the human oral cavities, and to investigate the distribution of these organisms in the living environment using a multiplex PCR. Methods: Polymerase chain reaction (PCR) primers were designed based on partial sequences of the rpoD gene of four Pseudomonas species. Swab samples were collected from fifty washstands, and the distribution of Pseudomonas species was investigated using a conventional PCR at genus level and a multiplex PCR at species level. Results: Multiplex PCR method developed in this study was able to distinguish four Pseudomonas species clearly. The genus Pseudomonas was detected from all samples (100%), whereas P. putida, P, aeruginosa, P. stutzeri and P. fluorescens were detected at 44%, 8%, 4% and 2% in fifty swab samples, respectively. Conclusion: Our developed one-step multiplex PCR method is accurate, specific, cost-effective, time-saving, and works without requiring DNA extraction. It was indicated that washstands were the uninhabitable environment for P. putida, P, aeruginosa, P. stutzeri and P. fluorescens.
基金supported by the National Key Research and Development Program of China(2018YFA0902100)the National Natural Science Foundation of China(22178262)the Tianjin Key Research and Development Program(23YFZCSN00110).
文摘The widespread use of pesticides has caused serious harm to ecosystems,necessitating effective and environmentally friendly treatment methods.Bioremediation stands out as a promising approach for pollutant treatment,wherein the metabolic activities of microorganisms can transform toxic pesticides into compounds with lower or no toxicity.In this study,we obtained eight pesticide-degrading strains from pesticide-contaminated sites through continuous enrichment and screening.Four highly efficient pesticide-degrading strains(degradation ratios exceeding 80%)were identified.Among them,Pseudomonas sp.BL5 exhibited the strongest growth(exceeding 10^(9) CFU·ml^(-1))and outstanding degradation of benzene derivatives and chlorinated hydrocarbons at both laboratory and pilot scales,with degradation ratios exceeding 98%and 99.6%,respectively.This research provides new tools and insights for the bioremediation of pesticide-related pollutants.
基金supported by the China Postdoctoral Science Foundation(No.2022M720401)the Postdoctoral Research Foundation of Shunde Innovation School,University of Science and Technology Beijing(No.2022BH007)the National Natural Science Foundation of China(No.52301074).
文摘To enhance the microbiologically influenced corrosion(MIC)resistance of FeCoNiCrMn high entropy alloy(HEAs),a series of Fe_(x)Cu_((1−x))CoNiCrMn(x=1,0.75,0.5,and 0.25)HEAs were prepared.Microstructural characteristics,corrosion behavior(morphology observation and electrochemical properties),and antimicrobial performance of Fe_(x)Cu_((1−x))CoNiCrMn HEAs were evaluated in a medium inoculated with typical corrosive microorganism Pseudomonas aeruginosa.The aim was to identify copper-containing FeCoNiCrMn HEAs that balance corrosion resistance and antimicrobial properties.Results revealed that all Fe_(x)Cu_((1−x))CoNiCrMn(x=1,0.75,0.5,and 0.25)HEAs exhibited an FCC(face centered cubic)phase,with significant grain refinement observed in Fe_(0.75)Cu_(0.25)CoNiCrMn HEA.Electrochemical tests indicated that Fe_(0.75)Cu_(0.25)CoNiCrMn HEA demonstrated lower corrosion current density(i_(corr))and pitting potential(E_(pit))compared to other Fe_(x)Cu_((1−x))CoNiCrMn HEAs in P.aeruginosa-inoculated medium,exhibiting superior resistance to MIC.Anti-microbial tests showed that after 14 d of immersion,Fe_(0.75)Cu_(0.25)CoNiCrMn achieved an antibacterial rate of 89.5%,effectively inhibiting the adhesion and biofilm formation of P.aeruginosa,thereby achieving resistance to MIC.
文摘BACKGROUND The clinical incidence of spinal infection is gradually increasing,and its onset is insidious,easily leading to missed diagnosis and misdiagnosis,which may lead to serious complications such as nervous system dysfunction,spinal instability and/or deformity,and cause a huge burden on society and families.Early identification of the causative agent and precision medicine will greatly reduce the suffering of patients.At present,the main pathogenic bacteria that cause spinal infection are Staphylococcus aureus,Streptococcus,Pneumococcus,Escherichia coli,and Klebsiella.There are no reports of spinal infection caused by Pseudomonas fluorescens.CASE SUMMARY We report a 32-year-old female patient with spinal infection.She presented with flank pain,initially thought to be bone metastases or bone tuberculosis,and had a family background of tumors.Her clinical features and changes in imaging and laboratory tests led to the suspicion of thoracic spine infection.Histopathology of the lesion showed inflammation,tissue culture of the lesion was negative several times,and the possible pathogen-Pseudomonas fluorescens was found after gene sequencing of the lesion.The patient recovered completely after a full course of antibiotic treatment.CONCLUSION This report increases the range of pathogens involved in spinal infections,highlights the unique advantages of gene sequencing technology in difficult-todiagnose diseases,and validates conservative treatment with a full course of antibiotics for spinal infections without complications.
文摘Objective:To investigate the frequency of exoU and exoY genes in patients with Pseudomonas aeruginosa infection.Methods:In this study,100 clinical isolates of Pseudomonas aeruginosa were collected from patients hospitalized in educational-therapeutic hospitals and were identified using standard microbiological tests.Then,the antibiotic resistance pattern of the isolates was determined by the disk agar diffusion method.The bacterial DNAs were extracted by the alkaline lysis method.Finally,the presence of exoU and exoY genes was evaluated by the PCR test.Results:In this study,47%,72%,29%,39%,40%,and 44%of the isolates were non-susceptible to piperacillin,aztreonam,ceftazidime,imipenem,tobramycin,and ciprofloxacin,respectively.In addition,95%and 93%of the clinical isolates carried the exoU and exoY genes.Blood and fecal isolates had both virulence genes,while only one wound isolate had neither genes.Meanwhile,all urinary isolates contained the exoY gene and only one isolate lacked the exoU gene.Also,88 isolates simultaneously had both exoU and exoY genes.Conclusions:High prevalence of exoU and exoY genes in this region indicates a significant role of typeⅢsecretion system in pathogenesis of Pseudomonas aeruginosa.The typeⅢsecretion system may be a suitable target to reduce the pathogenicity of this bacterium.
文摘Background:Azadirachta indica(A.indica),commonly known as neem,is a widely distributed medicinal plant in Asia and Africa and is well known to have a wide spectrum of biological activity.A.indica is considered a skin food that was traditionally used in different cultures to treat a wide range of skin disorders.A.indica was reported to possess antibacterial activity against Pseudomonas aeruginosa(P.aeruginosa)which is considered the most common biofilm model organism.This study aims to investigate the ability of A.indica cultivated in Egypt to inhibit/reduce the biofilm formation by P.aeruginosa.Methods:The microtiter plate assay was used to evaluate the anti-biofilm activity of neem,cultivated in Egypt,leaves against P.aeruginosa as well as the ability to reduce the activity of P.aeruginosa.To investigate the phytocompounds responsible for their bioactivity and to explore potential interactions between their bioactive components and one of the quorum-sensing regulatory proteins of P.aeruginosa involved in biofilm formation,liquid chromatography-mass spectrometric and molecular docking studies were done.Results:Results showed that methanol extract of leaves can reduce the formation of P.aeruginosa biofilm at lower concentrations than those reported in other regions with 1.25 mg/mL as the optimum concentration.The two-way analysis of variance revealed the significance of the extract effect and its concentration on the reduction of biofilm formation(P<0.05).Liquid chromatography-mass spectrometric study revealed the presence of fourteen compounds that belong to limonoids and flavonoids.Molecular docking analysis against LasR,the quorum-sensing regulatory protein,of P.aeruginosa supported these findings.Nimbolinin,a limonoid,has achieved the highest Libdock score of 138.769.Conclusion:It was concluded that A.indica,cultivated in Egypt,leaves can target LasR as a new mechanism of action for biofilm control by A.indica and therefore could be a good source of leads for anti-biofilm medicine.
基金supported by Scientific and Technological Innovation Project of China Academy of Chinese Medical Sciences(No.CI2021B015)the Fundamental Research Funds for the Central Public Welfare Research Institutes(JJPY2022017).
文摘Background:Pudilan Xiaoyan Oral Liquid(PDL)is a Chinese patent medicine with notable pharmacological properties,including anti-inflammatory and antibacterial effects.Drug-resistant Pseudomonas aeruginosa infection is a common and refractory bacterial infection in clinical practice.Due to its high drug resistance,it brings great challenges to treatment.This study aimed to assess the therapeutic efficacy of PDL in a murine model of pneumonia induced by drug-resistant Pseudomonas aeruginosa.Methods:Three different doses of PDL(11 mL/kg/d,5.5 mL/kg/d,2.75 mL/kg/d)were used to observe lung tissue pathology and inflammatory cytokine levels in pneumonia mouse models induced by multidrug-resistant Pseudomonas aeruginosa(MDR-PA).Additionally,the protective efficacy of PDL against mortality in infected mice was evaluated using a death model caused by MDR-PA.Finally sub-MIC concentration of levofloxacin was used to induce drug-resistant mice pneumonia model to evaluate the role of PDL in reversing drug resistance.Experimental data are expressed as mean±standard deviation.Statistical significance was determined by one-way analysis of variance followed by Tukey’s multiple-comparisons test.Results:Treatment effect of PDL on MDR-PA pneumonia:the medium and small doses of PDL can significantly reduce the lung index of multi-drug resistant bacteria infected pneumonia model mice(P<0.05),the lung index inhibition rates for these groups were 55.09%and 58.43%,and improve the degree of lung tissue lesions of mice;The expression of serum cytokines keratinocyte chemoattractant,tumor necrosis factor-αand monocyte chemoattractant protein-1 could be decreased in the three dosage groups of PDL(P<0.01).PDL treatment not only lowered the mortality but also extended the survival duration in mice infected with MDR-PA.It was found after sub-MIC concentration of levofloxacin induced resistance of Pseudomonas aeruginosa to pneumonia in mice.Compared with the model group,the lung index of mice in high and medium PDL doses was significantly reduced(P<0.05),with inhibition rates of 32.16%and 37.73%,respectively.Conclusion:PDL demonstrates protective effects against MDR-PA infection pneumonia,notably decreasing serum inflammatory factor levels.It shows promise in mitigating antibiotic resistance and offers potential for treating pneumonia resulting from Pseudomonas aeruginosa resistance.
基金supported by the National Key Research and Development Program of China(2022YFF1000400)National Natural Science Foundation of China(32270034,32370044)+2 种基金Changjiang Young Scholar Program of Chinese Ministry of Education,Natural Science Funds for Distinguished Young Scholar of Hubei Province(2022CFA044)Wuhan Science and Technology Major Project(2023020302020708)the Fundamental Research Funds for the Central Universities.
文摘Plant growth-promoting rhizobacteria(PGPR)such as Bacillus and Pseudomonas have drawn broad attention and interest due to their agricultural benefits.One of the major benefits of PGPR lies at their biocontrol capabilities against various plant pathogens.The biocontrol capability of PGPR is closely related to its capability of producing various kinds of antimicrobial substances.Major antimicrobial secondary metabolites secreted by PGPR include non-ribosomal lipopeptides(NRLPs),polyketides,ribosomal peptides,phenazines,pyrrolnitrins,etc.This review focuses on the major antimicrobial secondary metabolites produced by Bacillus and Pseudomonas including their classifications,structures,mechanisms of action and genetic regulations.We have also discussed their applications in plant biocontrol and provided insights into future development of improved biocontrol strains using synthetic biology approaches.
文摘Carbofuran insecticide is one of the insecticides most often used by Indonesian farmers.The United Nations Environment Program(UNEP)2011 in the decision of UNEP/FAO/RC/CRC.11/6,agreed that the active ingredient Carbofuran is dangerous to human health and the environment.P.fluorescens bacteria are known to be able to remediate carbofuran-contaminated soil.This study examines more deeply the biodegradation and biotransformation processes of Carbofuran in P.fluorescens bacteria.The research was carried out at the Laboratory of Plant Diseases,Faculty of Agriculture,Brawijaya University;Analytical Chemistry Laboratory,State Polytechnic of Malang;and Analytical Chemistry Laboratory,Udayana University from February to August 2020.The results showed that P.fluorescens was able to degrade the insecticide Carbofuran in liquid media up to 82%and the growth of P.fluorescens bacteria reached 2.9×10^(12) CFU/mL,bacteria P.fluorescens is able to degrade the insecticide Carbofuran in a mixture of soil and compost up to 85%and the growth of P.fluorescens bacteria reaches 7.5 x 1013 CFU/mL,resulting in Carbofuran insecticide derivatives from the biotransformation process,there are 3-hydroxy-7-phenol;2,3-dihydro-1-benzofuran-2,2,7-triol;(2Z)-2-[(2Z)-pent-2-en-1-ylidene]butane-1,4,4-trio;7-phenol;2,2,3-trihydroxy-2,3-dihydro-1-benzofuran-7-yl hydrogen carbonate;2,2-dimethyl-2,3-dihydro-1-benzofuran-7-yl acetate;7-(hydroxymethoxy)-2,3-dihydro-1-benzofuran-2,2,3,5-tetrol;3-hidroksi-2-fenilpropil Carbamat;2-(3-hydroperoxy-2-hydroxyphenyl)ethane-1,1-diol,3-keto-7-fenol;4-hydroxy-2,2-dimethyl-2,3-dihydro-1H-inden-1-one;3-hydroxy-carbofuran;and 7-methoxy-2,2-dimethyl-2,3-dihydro-1-benzofuran-3,5-diol.Carbofuran derivative compounds from the biodegradation of P.fluorescens bacteria are less toxic than the active ingredient Carbofuran.
