A study was performed to estimate the prevalence of the external bacterial flora of two domestic cockroaches （Blattella germanica and Blatta orientalis） collected from households in Tebessa （northeast AIgeria）.Thr...A study was performed to estimate the prevalence of the external bacterial flora of two domestic cockroaches （Blattella germanica and Blatta orientalis） collected from households in Tebessa （northeast AIgeria）.Three major bacterial groups were cultured （total aerobic, enterobacteria, and staphylococci） from 14 specimens of cockroaches, and antibiotic susceptibility was tested for both Staphylococcus and Pseudomonas isolates. Culturing showed that the total bacterial load of cockroaches from different households were comparable （P〈0.001） and enterobacteria were the predominant colonizers of the insect surface, with a bacterial load of （2.1×10^5 CFU/insect）, whereas the staphylococci group was the minority. Twenty-eight bacterial species were isolated, and susceptibility patterns showed that most of the staphylococci isolates were highly susceptible to chloramphenicol, gentamycin, pristinamycin, ofloxacin, clindamycin, and vancomycin; however, Pseudomonas strains exhibited resistance to amoxicillin/clavulanic acid, imipenem, and the second-generation antibiotic cephalosporin cefuroxime.展开更多
[Objectives]This study aimed to evaluate the detection sensitivity of Staphylococcus aureus in dairy products utilizing the chip digital PCR(cdPCR)technique.[Methods]Specific primers and probes were designed and synth...[Objectives]This study aimed to evaluate the detection sensitivity of Staphylococcus aureus in dairy products utilizing the chip digital PCR(cdPCR)technique.[Methods]Specific primers and probes were designed and synthesized based on the conserved sequence of the heat-resistant nuclease gene nuc of S.aureus.cdPCR was employed to detect S.aureus,and the sensitivity of this technique was systematically assessed in samples exhibiting low levels of contamination.[Results]cdPCR demonstrated precise quantification when the initial concentration of the sample enrichment solution was equal to or greater than 50 CFU/mL.The detection dynamic range extended across at least five orders of magnitude,with a minimum DNA detection limit of 0.2304 pg/μL.In artificially contaminated cheese samples,the method s lower limit of quantification for detecting S.aureus was 8×10^(2) CFU/g.Regression analysis demonstrated that the gene copy number concentration measured by cdPCR exhibited a strong linear correlation with bacterial contamination concentration across a broad range.[Conclusions]The cdPCR method developed in this study demonstrates high sensitivity and robust quantitative capabilities,offering a reliable technical approach for the precise detection of low-level S.aureus contamination in dairy products.展开更多
Achillea species are known for their healing properties since ancient times.There is extensive literature on their pharmacological action due to their bioactive compounds.The present study aimed to investigate the ant...Achillea species are known for their healing properties since ancient times.There is extensive literature on their pharmacological action due to their bioactive compounds.The present study aimed to investigate the antioxidant and antimicrobial effects of hydroalcoholic extracts from the inflorescences and leaves of the species Achillea crithmifolia Waldst.and Kit.,A.grandifolia Friv.and A.millefolium L.The phytochemical profiles of all extracts were evaluated both by NMR spectroscopy and LC-MS analysis,and the results were consistent with the spectrophotometrically determined total phenolic(TP:125.42-191.98 mg/g)and total flavonoid(TF:47.34-180.02 mg/g)contents.All the extracts were tested for their antioxidant activity using DPPH and ABTS•+radical scavenging assay,as well as ferrous ion chelating ability and reducing power tests.All the extracts showed moderate antioxidant activity,compared to the reference substance BHT.Additionally,the antibacterial activity of the extracts was evaluated against major food-borne pathogens,showing moderate antimicrobial effects.展开更多
Recently,Prevotella spp.,a major genus of gram-negative commensal bacteria in humans,have emerged as a key microbial contributor to host metabolism due to its ability to ferment dietary fibers,produce beneficial short...Recently,Prevotella spp.,a major genus of gram-negative commensal bacteria in humans,have emerged as a key microbial contributor to host metabolism due to its ability to ferment dietary fibers,produce beneficial short-chain fatty acids,and influence immune responses.However,their diversity and functional differences have created challenges for their development and therapeutic use.Recent studies have shown that specific Prevotella species,such as P.copri,P.intestinalis,and P.histicola,can strengthen gut barrier integrity and reduce metabolic imbalances.Notably,Prevotella populations can be increased through high-fiber or herbal-based treatments.Traditional herbal medicines,including fiber-rich decoctions,also demonstrate the potential to boost endogenous Prevotella communities,enhance microbial fermentation,and improve glucose and lipid balance.This perspective examines the context-dependent roles of Prevotella spp.,with emphasis on the functional heterogeneity of key species such as P.copri,suggests a framework for combining herbal modulation with species-level microbiota profiling,and outlines a research plan to explore microbe-herb synergy in treating obesity,type 2 diabetes,and related metabolic disorders.This strategy offers a new,ecology-based approach to complement standard metabolic interventions.展开更多
Objective:To investigate the quantitative assessment efficacy of chest CT combined with serum Vanin-1 and SPP1 in determining the progression stage of chronic obstructive pulmonary disease(COPD).Methods:A total of 100...Objective:To investigate the quantitative assessment efficacy of chest CT combined with serum Vanin-1 and SPP1 in determining the progression stage of chronic obstructive pulmonary disease(COPD).Methods:A total of 100 COPD subjects from our hospital from January 2020 to December 2023 were included and randomly divided into a healthy control group and an experimental group(50 cases each).The healthy control group underwent slow vital capacity measurement using a spirometer,while the experimental group underwent high-resolution thin-slice CT scans and serum Vanin-1 and SPP1 concentration measurements.Pulmonary function parameters,symptom burden,biomarker concentrations,and imaging characteristics were compared between the two groups.Results:The FEV1/FVC ratio in the experimental group(58.3±7.2)was lower than that in the healthy control group(92.1±4.8);the total CAT score(22.4±3.5)was higher than that in the healthy control group(3.1±1.2);both Vanin-1(18.7±2.3μg/L)and SPP1(25.6±4.1μg/L)levels were higher than those in the healthy control group;LAA%-950(38.7±6.2%)and WA%(68.5±5.3%)were significantly higher than those in the healthy control group(all p<0.001).Conclusion:Chest CT combined with serum Vanin-1 and SPP1 can accurately quantify the pathological progression of COPD,providing a dual basis for clinical staging and individualized intervention.展开更多
Staphylococcus aureus(S.aureus)is the third most common pathogen causing 10.6%of bacterial foodborne illnesses in China in 2021[1].Heat-stable Staphylococcal Enterotoxins(SEs)produced by S.aureus are the main contribu...Staphylococcus aureus(S.aureus)is the third most common pathogen causing 10.6%of bacterial foodborne illnesses in China in 2021[1].Heat-stable Staphylococcal Enterotoxins(SEs)produced by S.aureus are the main contributors to staphylococcal food poisoning(SFP),causing vomiting,diarrhea,abdominal pain,headache,muscle cramps,and other acute gastroenteritis symptoms.More than 25 SEs and staphylococcal enterotoxin-like toxins(SE/s)have been described and which together comprise a superfamily of pyrogenic toxin superantigens(SAgs)[2].展开更多
The present study aimed to evaluate <i>Syzygium aromaticum</i> (clove) plant extract, clove oil and eugenol for their antibacterial activity and their potential to eradicate bacterial biofilms alone and in...The present study aimed to evaluate <i>Syzygium aromaticum</i> (clove) plant extract, clove oil and eugenol for their antibacterial activity and their potential to eradicate bacterial biofilms alone and in combination with antibiotics. Anti-bacterial efficacy of <i>S. aromaticum</i> extract, clove oil and eugenol was evaluated as minimum inhibitory concentration (MIC) and subsequently sub-MICs was selected for inhibition of virulence factors against test bacterial strains. Biofilm cultivation and eradication was assayed using XTT reduction in 96-well microtiter plate. Checkerboard method was used to study the interaction between essential oils and antibiotics. <i>Staphylococcus aureus</i> MTCC3160, <i>Staphylococcus epidermidis</i> MTCC435, <i>Staphylococcus sciuri</i> (SC-01), <i>Staphylococcus auricularis</i> (SU-01) <i>and</i> <i>Streptococcus mutans</i> MTCC497 were found strong biofilm former among all the test bacterial strains. The potency of test agents was found in the order of eugenol > clove oil > <i>S. aromaticum</i> methanolic extract. Sub-MIC (0.5 × MIC) of clove oil and eugenol showed a significant reduction in cell surface hydrophobicity (<i>p </i>< 0.05) and hemolysin production in the test bacterial strains. Eugenol showed no increase in sessile MIC (SMIC) against <i>S. auricularis</i> (SU-01), <i>S. epidermidis</i> MTCC435 and <i>S. mutans</i> MTCC497 compared to planktonic MIC (PMIC). Antibiotics (vancomycin and azithromycin) exhibited upto 1000-folds increased in SMIC compared to PMIC against all the test bacterial strains. Synergy was observed between eugenol and antibiotics (vancomycin/azithromycin) against all the test bacterial strains in both planktonic and sessile mode. Highest synergy was exhibited between eugenol and azithromycin in planktonic mode (FICI value 0.141). Further, microscopy also confirmed the spectacular effect of combination treatment on pre-formed <i>S. aureus</i> MTCC3160 and <i>S. mutans</i> MTCC497 biofilms. These findings highlighted the promising role of clove oil and eugenol alone and in combination on pathogenic bacterial biofilms.展开更多
BACKGROUND The oral cavity harbors more than 700 species of bacteria,which play crucial roles in the development of various oral diseases including caries,endodontic infection,periodontal infection,and diverse oral di...BACKGROUND The oral cavity harbors more than 700 species of bacteria,which play crucial roles in the development of various oral diseases including caries,endodontic infection,periodontal infection,and diverse oral diseases.AIM To investigate the antimicrobial action of Cymbopogon Schoenanthus and Pelargonium graveolens essential oils against Streptococcus mutans,Staphylococcus aureus,Candida albicans,Ca.dubliniensis,and Ca.krusei.METHODS Minimum microbicidal concentration was determined following Clinical and Laboratory Standards Institute documents.The synergistic antimicrobial activity was evaluated using the Broth microdilution checkerboard method,and the antibiofilm activity was evaluated with the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay.Data were analyzed by one-way analysis of variance followed by the Tukey post-hoc test(P≤0.05).RESULTS C.schoenanthus and P.graveolens essential oils were as effective as 0.12%chlorhexidine against S.mutans and St.aureus monotypic biofilms after 24 h.After 24 h P.graveolens essential oil at 0.25%was more effective than the nystatin group,and C.schoenanthus essential oil at 0.25%was as effective as the nystatin group.CONCLUSION C.schoenanthus and P.graveolens essential oils are effective against S.mutans,St.aureus,Ca.albicans,Ca.dubliniensis,and Ca.krusei at different concentrations after 5 min and 24 h.展开更多
Staphylococcus aureus (S. aureus) is a bacterial pathogen for humans and animals. These bacteria can resist against many antibiotics and this resistance constitute an alarming worldwide human health threat due to the ...Staphylococcus aureus (S. aureus) is a bacterial pathogen for humans and animals. These bacteria can resist against many antibiotics and this resistance constitute an alarming worldwide human health threat due to the morbidity and mortality. Phage therapy is one of the alternative treatments. The aim of this study was to isolate and characterize lytic phages of S. aureus from different wastewater sources in Bobo-Dioulasso, Burkina Faso. Eight strains of S. aureus were isolated from different clinical samples and were used to isolate phages. The isolation and host range of phages were done by the spot test. Phages were purified by the double-layer method. Similar phages after the determination of the host range were characterized using restriction enzymes. A total of 27 phages were obtained after isolation and purification. Nine of the 27 isolates reported a broad host range (≥67%). The results of enzymatic digestion allowed to consider that all phage isolates that presented the same host range and the same genetic fingerprint are the same phage strain;whereas phages that presented the same host range and different genetic fingerprints are different phage strains. Thus, a total of 15 distinct phages isolates specific to S. aureus were characterized. This study highlighted the abundance and lytic capacity of phages isolated from wastewater from Bobo-Dioulasso’s environment against clinical strains of S. aureus. The lytic capacity of these Staphyphages could be an effective alternative tool to combat bacteria multi-resistance.展开更多
Staphylococcus aureus infection is a global public health problem,searching and developing green alternatives for antibiotics are urgently required.In this study,the exopolysaccharides(EPS)produced by Lactobacillus he...Staphylococcus aureus infection is a global public health problem,searching and developing green alternatives for antibiotics are urgently required.In this study,the exopolysaccharides(EPS)produced by Lactobacillus helveticus WXD191 were extracted and purified.Structure analysis suggested that the EPS contained Ara,Man,Gal,GalN,Glc,GlcN,and GlcA,with a molecular of 84.2 kDa.Methylation combined with nuclear magnetic resonance(NMR)spectroscopy analysis revealed that the backbone of EPS (was→3)-β-D-Galp-(1→3)-β-D-GlcpNAc-(1→4)-β-D-GlcpA-(1→3-Man-1→2-Man-1→2,6-Man-1→2,6-Man-1→).Congo red analysis and circular dichroism(CD)spectrum indicated the existence ofα-helices.Crystalline characteristics,scanning electron microscopy,and thermogravimetric analysis revealed that EPS formed thermally stable amorphous with a small amount of microcrystalline structure and a rough and porous surface.Meanwhile,the S.aureus bloodstream infection model was used to evaluate the protection efficiency for systemic infection induced by S.aureus and found that the EPS could enhance survival as well as reduce bacterial burden and proinflammatory chemokines.Collectively,these results suggested that EPS isolated from L.helveticus was a competitive candidate for defense against S.aureus infection.展开更多
Background:Atopic dermatitis is a chronic inflammatory skin disorder characterized by recurrent eczema-like rashes and severe itching.Taxi San is an external herbal formulation with the effects of clearing heat,drying...Background:Atopic dermatitis is a chronic inflammatory skin disorder characterized by recurrent eczema-like rashes and severe itching.Taxi San is an external herbal formulation with the effects of clearing heat,drying dampness,detoxifying,and relieving itching,making it suitable for treating acute and subacute dermatitis or eczema.Objectives:To evaluate the clinical efficacy of topical Taxi San in treating atopic dermatitis patients with dampness-heat syndrome and its inhibitory effect against Staphylococcus aureus(S.aureus)colonization.Methods:50 patients with atopic dermatitis were enrolled from the Dermatology Department of Shaanxi Provincial Hospital of Traditional Chinese Medicine,with bilateral symmetrical lesions selected as target sites.The control-side lesions were treated with boric acid solution wet compresses,while the treatment-side lesions received Taxi San solution wet compresses,both administered twice daily for 14 d.Clinical efficacy was evaluated using the Scoring Atopic Dermatitis(SCORAD),Investigator Global Assessment(IGA),Dermatology Life Quality Index/Children’s Dermatology Life Quality Index(DLQI/CDLQI),adverse events(AEs)and S.aureus colonization density,which were compared between the groups.The antibacterial efficacy of Taxi San was further investigated through in vitro antibacterial tests.Results:After 14 d of treatment with Taxi San,erythema and pimples were reduced on the treated sides.Additionally,the SCORAD,IGA,and DLQI/CDLQI scores showed significant decreases(P<0.05).S.aureus colonization on the treated sides declined markedly from 78%to 4.76%.Compared to the control sides,the reduction in S.aureus colonization following 14 d of Taxi San treatment was statistically significant(P<0.05).Furthermore,in vitro antibacterial assays demonstrated that the minimum inhibitory concentration of Taxi San against the seven tested S.aureus strains was 0.125 g/mL.Conclusions:Taxi San effectively reduces S.aureus colonization and ameliorates clinical symptoms in atopic dermatitis patients with dampness-heat syndrome,demonstrating high therapeutic potential and safety.展开更多
Although coagulase-negative Staphylococcus(CNS),along with technological activities,plays a key role in fermented sausage flavour and nutrient production,the molecular mechanism of these activities remains elusive.In ...Although coagulase-negative Staphylococcus(CNS),along with technological activities,plays a key role in fermented sausage flavour and nutrient production,the molecular mechanism of these activities remains elusive.In this study,18 CNS strains with high proteolytic activity were isolated from Chinese Dong fermented pork(Nanx Wudl),and their technological and transcriptomic properties were investigated.After biochemical identification and genetic analysis,their technological properties,including nitrate reductase,catalase,antioxidant,and lipolytic activities and their growth under varying temperatures,salt concentrations,and p H levels were evaluated.Their aroma-producing potential was also determined in a model medium resembling fermented sausages.Transcriptomic analysis was performed using the most promising isolates.Biochemical identification and 16S rDNA sequencing revealed that the 18 Staphylococcus strains belonged to Staphylococcus xylosus,Staphylococcus saprophyticus,Staphylococcus carnosus,Staphylococcus sciuri,and Staphylococcus equorum.In terms of technological properties,16 strains showed a nitrate-reducing ability,while 11 strains had a lipolytic activity.All strains exhibited superoxide dismutase(SOD)and catalase activities;four strains displayed an SOD activity of>50%.They also tolerated 10%NaCl and 150 mg/kg of nitrite.They showed significant differences in ketone and acid production.The transcriptomic analysis of S.xylosus strains Sx3 and Sx6,which were selected because of their excellent enzymatic activities and aroma-producing ability,revealed the remarkable effect of genes related to pyruvate catabolism and amino acid metabolism on aroma generation.Therefore,this study provided valuable insights into the metabolic mechanisms underlying the technological properties of CNS and identified promising candidates as starter cultures in fermented sausage manufacturing.展开更多
Addressing the uncontrolled spread and increase in antibiotic resistance in methicillin-resistant Staphylococcus aureus(MRSA)will require new control strategies,particularly to improve the safety of food.Our results r...Addressing the uncontrolled spread and increase in antibiotic resistance in methicillin-resistant Staphylococcus aureus(MRSA)will require new control strategies,particularly to improve the safety of food.Our results revealed the efficacy of theaflavin-3,3′-digallate(TFBG),which is a novel polyphenol derived from tea,in targeting the key regulatory protein multiple gene regulator A(MgrA)in S.aureus.Through fluorescence anisotropy,we showed that the half maximal inhibitory concentration(IC50)of TFBG was 26.76μg/mL.TFBG uniquely counters S.aureus by regulating its virulence factors and adhesion processes rather than by killing the bacteria directly.This compound alters the expression of key virulence factors and modulates the transcription levels of genes related to adhesion in S.aureus,ultimately reducing the bacteria’s ability to adhere to fibrinogen and its hemolytic activity.Our assays confirmed that TFBG directly interacts with the MgrA protein in MRSA,and we identified critical binding sites.Our in vivo studies highlighted the potent efficacy of TFBG.TFBG administration is an innovative approach to improve food safety by diminishing MRSA virulence and reducing its pathogenicity.展开更多
文摘A study was performed to estimate the prevalence of the external bacterial flora of two domestic cockroaches （Blattella germanica and Blatta orientalis） collected from households in Tebessa （northeast AIgeria）.Three major bacterial groups were cultured （total aerobic, enterobacteria, and staphylococci） from 14 specimens of cockroaches, and antibiotic susceptibility was tested for both Staphylococcus and Pseudomonas isolates. Culturing showed that the total bacterial load of cockroaches from different households were comparable （P〈0.001） and enterobacteria were the predominant colonizers of the insect surface, with a bacterial load of （2.1×10^5 CFU/insect）, whereas the staphylococci group was the minority. Twenty-eight bacterial species were isolated, and susceptibility patterns showed that most of the staphylococci isolates were highly susceptible to chloramphenicol, gentamycin, pristinamycin, ofloxacin, clindamycin, and vancomycin; however, Pseudomonas strains exhibited resistance to amoxicillin/clavulanic acid, imipenem, and the second-generation antibiotic cephalosporin cefuroxime.
基金Supported by Science and Technology Program of Inner Mongolia Autonomous Region"Research and Demonstration of Novel Molecular Biological Identification Technology for Multiple Source Components in Milk and Dairy Products"(2025YFSH0029).
文摘[Objectives]This study aimed to evaluate the detection sensitivity of Staphylococcus aureus in dairy products utilizing the chip digital PCR(cdPCR)technique.[Methods]Specific primers and probes were designed and synthesized based on the conserved sequence of the heat-resistant nuclease gene nuc of S.aureus.cdPCR was employed to detect S.aureus,and the sensitivity of this technique was systematically assessed in samples exhibiting low levels of contamination.[Results]cdPCR demonstrated precise quantification when the initial concentration of the sample enrichment solution was equal to or greater than 50 CFU/mL.The detection dynamic range extended across at least five orders of magnitude,with a minimum DNA detection limit of 0.2304 pg/μL.In artificially contaminated cheese samples,the method s lower limit of quantification for detecting S.aureus was 8×10^(2) CFU/g.Regression analysis demonstrated that the gene copy number concentration measured by cdPCR exhibited a strong linear correlation with bacterial contamination concentration across a broad range.[Conclusions]The cdPCR method developed in this study demonstrates high sensitivity and robust quantitative capabilities,offering a reliable technical approach for the precise detection of low-level S.aureus contamination in dairy products.
基金supported by the Serbian Ministry of Education,Science and Technological Development(Agreements No.451-03-136/2025-03/200122 and 451-03-136/2025-03/200378).
文摘Achillea species are known for their healing properties since ancient times.There is extensive literature on their pharmacological action due to their bioactive compounds.The present study aimed to investigate the antioxidant and antimicrobial effects of hydroalcoholic extracts from the inflorescences and leaves of the species Achillea crithmifolia Waldst.and Kit.,A.grandifolia Friv.and A.millefolium L.The phytochemical profiles of all extracts were evaluated both by NMR spectroscopy and LC-MS analysis,and the results were consistent with the spectrophotometrically determined total phenolic(TP:125.42-191.98 mg/g)and total flavonoid(TF:47.34-180.02 mg/g)contents.All the extracts were tested for their antioxidant activity using DPPH and ABTS•+radical scavenging assay,as well as ferrous ion chelating ability and reducing power tests.All the extracts showed moderate antioxidant activity,compared to the reference substance BHT.Additionally,the antibacterial activity of the extracts was evaluated against major food-borne pathogens,showing moderate antimicrobial effects.
基金supported by the National Research Foundation of Korea(2020R1F1A1074155).
文摘Recently,Prevotella spp.,a major genus of gram-negative commensal bacteria in humans,have emerged as a key microbial contributor to host metabolism due to its ability to ferment dietary fibers,produce beneficial short-chain fatty acids,and influence immune responses.However,their diversity and functional differences have created challenges for their development and therapeutic use.Recent studies have shown that specific Prevotella species,such as P.copri,P.intestinalis,and P.histicola,can strengthen gut barrier integrity and reduce metabolic imbalances.Notably,Prevotella populations can be increased through high-fiber or herbal-based treatments.Traditional herbal medicines,including fiber-rich decoctions,also demonstrate the potential to boost endogenous Prevotella communities,enhance microbial fermentation,and improve glucose and lipid balance.This perspective examines the context-dependent roles of Prevotella spp.,with emphasis on the functional heterogeneity of key species such as P.copri,suggests a framework for combining herbal modulation with species-level microbiota profiling,and outlines a research plan to explore microbe-herb synergy in treating obesity,type 2 diabetes,and related metabolic disorders.This strategy offers a new,ecology-based approach to complement standard metabolic interventions.
基金Baoding Science and Technology Plan Project(Project No.:2341ZF214)。
文摘Objective:To investigate the quantitative assessment efficacy of chest CT combined with serum Vanin-1 and SPP1 in determining the progression stage of chronic obstructive pulmonary disease(COPD).Methods:A total of 100 COPD subjects from our hospital from January 2020 to December 2023 were included and randomly divided into a healthy control group and an experimental group(50 cases each).The healthy control group underwent slow vital capacity measurement using a spirometer,while the experimental group underwent high-resolution thin-slice CT scans and serum Vanin-1 and SPP1 concentration measurements.Pulmonary function parameters,symptom burden,biomarker concentrations,and imaging characteristics were compared between the two groups.Results:The FEV1/FVC ratio in the experimental group(58.3±7.2)was lower than that in the healthy control group(92.1±4.8);the total CAT score(22.4±3.5)was higher than that in the healthy control group(3.1±1.2);both Vanin-1(18.7±2.3μg/L)and SPP1(25.6±4.1μg/L)levels were higher than those in the healthy control group;LAA%-950(38.7±6.2%)and WA%(68.5±5.3%)were significantly higher than those in the healthy control group(all p<0.001).Conclusion:Chest CT combined with serum Vanin-1 and SPP1 can accurately quantify the pathological progression of COPD,providing a dual basis for clinical staging and individualized intervention.
基金supported by the Ministry of Science and Technology of the People’s Republic of China(2022YFD1800400).
文摘Staphylococcus aureus(S.aureus)is the third most common pathogen causing 10.6%of bacterial foodborne illnesses in China in 2021[1].Heat-stable Staphylococcal Enterotoxins(SEs)produced by S.aureus are the main contributors to staphylococcal food poisoning(SFP),causing vomiting,diarrhea,abdominal pain,headache,muscle cramps,and other acute gastroenteritis symptoms.More than 25 SEs and staphylococcal enterotoxin-like toxins(SE/s)have been described and which together comprise a superfamily of pyrogenic toxin superantigens(SAgs)[2].
文摘The present study aimed to evaluate <i>Syzygium aromaticum</i> (clove) plant extract, clove oil and eugenol for their antibacterial activity and their potential to eradicate bacterial biofilms alone and in combination with antibiotics. Anti-bacterial efficacy of <i>S. aromaticum</i> extract, clove oil and eugenol was evaluated as minimum inhibitory concentration (MIC) and subsequently sub-MICs was selected for inhibition of virulence factors against test bacterial strains. Biofilm cultivation and eradication was assayed using XTT reduction in 96-well microtiter plate. Checkerboard method was used to study the interaction between essential oils and antibiotics. <i>Staphylococcus aureus</i> MTCC3160, <i>Staphylococcus epidermidis</i> MTCC435, <i>Staphylococcus sciuri</i> (SC-01), <i>Staphylococcus auricularis</i> (SU-01) <i>and</i> <i>Streptococcus mutans</i> MTCC497 were found strong biofilm former among all the test bacterial strains. The potency of test agents was found in the order of eugenol > clove oil > <i>S. aromaticum</i> methanolic extract. Sub-MIC (0.5 × MIC) of clove oil and eugenol showed a significant reduction in cell surface hydrophobicity (<i>p </i>< 0.05) and hemolysin production in the test bacterial strains. Eugenol showed no increase in sessile MIC (SMIC) against <i>S. auricularis</i> (SU-01), <i>S. epidermidis</i> MTCC435 and <i>S. mutans</i> MTCC497 compared to planktonic MIC (PMIC). Antibiotics (vancomycin and azithromycin) exhibited upto 1000-folds increased in SMIC compared to PMIC against all the test bacterial strains. Synergy was observed between eugenol and antibiotics (vancomycin/azithromycin) against all the test bacterial strains in both planktonic and sessile mode. Highest synergy was exhibited between eugenol and azithromycin in planktonic mode (FICI value 0.141). Further, microscopy also confirmed the spectacular effect of combination treatment on pre-formed <i>S. aureus</i> MTCC3160 and <i>S. mutans</i> MTCC497 biofilms. These findings highlighted the promising role of clove oil and eugenol alone and in combination on pathogenic bacterial biofilms.
文摘BACKGROUND The oral cavity harbors more than 700 species of bacteria,which play crucial roles in the development of various oral diseases including caries,endodontic infection,periodontal infection,and diverse oral diseases.AIM To investigate the antimicrobial action of Cymbopogon Schoenanthus and Pelargonium graveolens essential oils against Streptococcus mutans,Staphylococcus aureus,Candida albicans,Ca.dubliniensis,and Ca.krusei.METHODS Minimum microbicidal concentration was determined following Clinical and Laboratory Standards Institute documents.The synergistic antimicrobial activity was evaluated using the Broth microdilution checkerboard method,and the antibiofilm activity was evaluated with the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay.Data were analyzed by one-way analysis of variance followed by the Tukey post-hoc test(P≤0.05).RESULTS C.schoenanthus and P.graveolens essential oils were as effective as 0.12%chlorhexidine against S.mutans and St.aureus monotypic biofilms after 24 h.After 24 h P.graveolens essential oil at 0.25%was more effective than the nystatin group,and C.schoenanthus essential oil at 0.25%was as effective as the nystatin group.CONCLUSION C.schoenanthus and P.graveolens essential oils are effective against S.mutans,St.aureus,Ca.albicans,Ca.dubliniensis,and Ca.krusei at different concentrations after 5 min and 24 h.
文摘Staphylococcus aureus (S. aureus) is a bacterial pathogen for humans and animals. These bacteria can resist against many antibiotics and this resistance constitute an alarming worldwide human health threat due to the morbidity and mortality. Phage therapy is one of the alternative treatments. The aim of this study was to isolate and characterize lytic phages of S. aureus from different wastewater sources in Bobo-Dioulasso, Burkina Faso. Eight strains of S. aureus were isolated from different clinical samples and were used to isolate phages. The isolation and host range of phages were done by the spot test. Phages were purified by the double-layer method. Similar phages after the determination of the host range were characterized using restriction enzymes. A total of 27 phages were obtained after isolation and purification. Nine of the 27 isolates reported a broad host range (≥67%). The results of enzymatic digestion allowed to consider that all phage isolates that presented the same host range and the same genetic fingerprint are the same phage strain;whereas phages that presented the same host range and different genetic fingerprints are different phage strains. Thus, a total of 15 distinct phages isolates specific to S. aureus were characterized. This study highlighted the abundance and lytic capacity of phages isolated from wastewater from Bobo-Dioulasso’s environment against clinical strains of S. aureus. The lytic capacity of these Staphyphages could be an effective alternative tool to combat bacteria multi-resistance.
基金funding from multiple sources including the Science and Technology Major Project of the Inner Mongolia Autonomous Region of China(2021ZD0013)the Key Scientific and Technological Research Program of Inner Mongolia Autonomous Region(2021GG0156)+1 种基金Inner Mongolia Key Laboratory for Molecular Regulation of the Cell(2021PT0002)the National Natural Science Foundation of China(32060800).
文摘Staphylococcus aureus infection is a global public health problem,searching and developing green alternatives for antibiotics are urgently required.In this study,the exopolysaccharides(EPS)produced by Lactobacillus helveticus WXD191 were extracted and purified.Structure analysis suggested that the EPS contained Ara,Man,Gal,GalN,Glc,GlcN,and GlcA,with a molecular of 84.2 kDa.Methylation combined with nuclear magnetic resonance(NMR)spectroscopy analysis revealed that the backbone of EPS (was→3)-β-D-Galp-(1→3)-β-D-GlcpNAc-(1→4)-β-D-GlcpA-(1→3-Man-1→2-Man-1→2,6-Man-1→2,6-Man-1→).Congo red analysis and circular dichroism(CD)spectrum indicated the existence ofα-helices.Crystalline characteristics,scanning electron microscopy,and thermogravimetric analysis revealed that EPS formed thermally stable amorphous with a small amount of microcrystalline structure and a rough and porous surface.Meanwhile,the S.aureus bloodstream infection model was used to evaluate the protection efficiency for systemic infection induced by S.aureus and found that the EPS could enhance survival as well as reduce bacterial burden and proinflammatory chemokines.Collectively,these results suggested that EPS isolated from L.helveticus was a competitive candidate for defense against S.aureus infection.
基金supported by the Shaanxi Provincial Research and Innovation Team for Atopic Dermatitis of Traditional Chinese Medicine(No.TZKN-CXTD-02)the Key Industry Innovation Chain Project of Shaanxi Province(No.2021ZDLSF04-12).
文摘Background:Atopic dermatitis is a chronic inflammatory skin disorder characterized by recurrent eczema-like rashes and severe itching.Taxi San is an external herbal formulation with the effects of clearing heat,drying dampness,detoxifying,and relieving itching,making it suitable for treating acute and subacute dermatitis or eczema.Objectives:To evaluate the clinical efficacy of topical Taxi San in treating atopic dermatitis patients with dampness-heat syndrome and its inhibitory effect against Staphylococcus aureus(S.aureus)colonization.Methods:50 patients with atopic dermatitis were enrolled from the Dermatology Department of Shaanxi Provincial Hospital of Traditional Chinese Medicine,with bilateral symmetrical lesions selected as target sites.The control-side lesions were treated with boric acid solution wet compresses,while the treatment-side lesions received Taxi San solution wet compresses,both administered twice daily for 14 d.Clinical efficacy was evaluated using the Scoring Atopic Dermatitis(SCORAD),Investigator Global Assessment(IGA),Dermatology Life Quality Index/Children’s Dermatology Life Quality Index(DLQI/CDLQI),adverse events(AEs)and S.aureus colonization density,which were compared between the groups.The antibacterial efficacy of Taxi San was further investigated through in vitro antibacterial tests.Results:After 14 d of treatment with Taxi San,erythema and pimples were reduced on the treated sides.Additionally,the SCORAD,IGA,and DLQI/CDLQI scores showed significant decreases(P<0.05).S.aureus colonization on the treated sides declined markedly from 78%to 4.76%.Compared to the control sides,the reduction in S.aureus colonization following 14 d of Taxi San treatment was statistically significant(P<0.05).Furthermore,in vitro antibacterial assays demonstrated that the minimum inhibitory concentration of Taxi San against the seven tested S.aureus strains was 0.125 g/mL.Conclusions:Taxi San effectively reduces S.aureus colonization and ameliorates clinical symptoms in atopic dermatitis patients with dampness-heat syndrome,demonstrating high therapeutic potential and safety.
基金the financial support of the National Natural Science Foundation of China(32102016)the Taishan Industrial Experts Program。
文摘Although coagulase-negative Staphylococcus(CNS),along with technological activities,plays a key role in fermented sausage flavour and nutrient production,the molecular mechanism of these activities remains elusive.In this study,18 CNS strains with high proteolytic activity were isolated from Chinese Dong fermented pork(Nanx Wudl),and their technological and transcriptomic properties were investigated.After biochemical identification and genetic analysis,their technological properties,including nitrate reductase,catalase,antioxidant,and lipolytic activities and their growth under varying temperatures,salt concentrations,and p H levels were evaluated.Their aroma-producing potential was also determined in a model medium resembling fermented sausages.Transcriptomic analysis was performed using the most promising isolates.Biochemical identification and 16S rDNA sequencing revealed that the 18 Staphylococcus strains belonged to Staphylococcus xylosus,Staphylococcus saprophyticus,Staphylococcus carnosus,Staphylococcus sciuri,and Staphylococcus equorum.In terms of technological properties,16 strains showed a nitrate-reducing ability,while 11 strains had a lipolytic activity.All strains exhibited superoxide dismutase(SOD)and catalase activities;four strains displayed an SOD activity of>50%.They also tolerated 10%NaCl and 150 mg/kg of nitrite.They showed significant differences in ketone and acid production.The transcriptomic analysis of S.xylosus strains Sx3 and Sx6,which were selected because of their excellent enzymatic activities and aroma-producing ability,revealed the remarkable effect of genes related to pyruvate catabolism and amino acid metabolism on aroma generation.Therefore,this study provided valuable insights into the metabolic mechanisms underlying the technological properties of CNS and identified promising candidates as starter cultures in fermented sausage manufacturing.
文摘Addressing the uncontrolled spread and increase in antibiotic resistance in methicillin-resistant Staphylococcus aureus(MRSA)will require new control strategies,particularly to improve the safety of food.Our results revealed the efficacy of theaflavin-3,3′-digallate(TFBG),which is a novel polyphenol derived from tea,in targeting the key regulatory protein multiple gene regulator A(MgrA)in S.aureus.Through fluorescence anisotropy,we showed that the half maximal inhibitory concentration(IC50)of TFBG was 26.76μg/mL.TFBG uniquely counters S.aureus by regulating its virulence factors and adhesion processes rather than by killing the bacteria directly.This compound alters the expression of key virulence factors and modulates the transcription levels of genes related to adhesion in S.aureus,ultimately reducing the bacteria’s ability to adhere to fibrinogen and its hemolytic activity.Our assays confirmed that TFBG directly interacts with the MgrA protein in MRSA,and we identified critical binding sites.Our in vivo studies highlighted the potent efficacy of TFBG.TFBG administration is an innovative approach to improve food safety by diminishing MRSA virulence and reducing its pathogenicity.
