Bacterial biofilms are associated with at least 80% of human bacterial infections. The clinical treatment of biofilm infection is still arduous, and therefore many new treatment options are under study, such as probiotics and their derivatives, quorum sensing inhibitors, antimicrobial peptides, phage therapy, organic acids, light therapy, and plant extracts. However, most of these schemes are not mature, and it is important to develop new research directions of anti-biofilms.
Objective To study the influence of brominated furanones on the biofilm formation of Escherichia coli on the polyvinyl chloride (PVC) material, and to provide new ideas for the research of surface modification of materials and cl inicaltreatment of biomaterial centered infection. Methods Three brominated furanones with representative chemical structurewere chosen and coated on the surface modification of PVC materials, respectively [furanone 1: 3, 4-dibromo-5-hydroxy-furanone; furanone 2: 4-bromo-5-(4-methoxyphenyl)-3-(methylamino)-furanone; furanone 3: 3, 4-dibromo-5, 5-bis (4-methylphenyl)- 2 (5H)-furanone]. All the modificated PVC materials and Escherichia coli were co-cultivated. The PVC material soaked with 75% ethanol for 5 minutes and Escherichia coli were co-cultivated together as the control group. The thickness of bacterial community and bacterial community quantity in the unit area on PVC materials were measured by confocal laser scanning microscope (CLSM), and the surface structure of biofilm formation was observed by scanning electron microscope (SEM). Results The CLSM showed that the thickness of bacterial community and the bacterial community quantity in the unit area of PVC materials was significantly less (P lt; 0.05) in furanone 3 group than in control group, but no significant difference (P gt; 0.05) was found between furanone 1, furanone 2 groups and control group. SEM showed that the quantity of bacterial community in the unit area of PVC materials surface in furanone 3 group was fewer than that in control group at 6 hours; the biofilm structure on PVC materials surface formed at 18 hours in control group, furanone 1 group, and furanone 2 group, but there was no mature biofilm structure on PVC materials surface in furanone 3 group at 18 hours. Conclusion The impact of different brominated furanones on Escherichia coli biofilm formation on the surface of PVC materials is different, 3, 4-dibromo-5, 5-bis (4-methylphenyl)-2 (5H)- furanone can inhibit Escherichia coli biofilm formation on the surface of PVC material.
ObjectiveTo investigate the effect of the estradiol hormones on biofilm formati on and structure of Staphylococcus epidermidis after breast implant surgery.
MethodsThe concentration of Staphylococcus epidermidis strains ATCC35984 was adjusted to 1×107 CFU/mL or 1×108 CFU/mL, and the type strains were incubated on the surface of silica gel in 125 pmol/L estradiol suspensions to prepare bacterial biofilms model in vitro. After cultured in vitro for 4, 6, 12, 24, 48, and 72 hours, bacteria growth and biofilm formation ability were assessed by means of the XTT and crystal violet staining respectively. According to the above results, the bacterial suspension concentration was selected for experiments. The experimental concentration of Staphylococcus epidermidis ATCC35984 suspension and the concentrations of 50, 125, 250, 500 pmol/L estradiol suspensions were mixed with silica gel respectively to prepare biofilm model in vitro, no estradiol suspension served as control group. The experimental concentration of Staphylococcus epidermidis ATCC12228 suspension was used to prepare the same model in the negative control. After cultured in vitro for 4, 6, 12, 24, 48, and 72 hours, the same methods were used to assess the bacteria growth dynamics and biofilm forming ability, and the scanning electron microscope (SEM) was used to observe bacterial biofilm structure cultured on the surface of silica gel; the laser scanning confocal microscope (CLSM) was used to measure bacterial biofilm thickness on the surface of silica gel after 6, 12, and 24 hours.
ResultsAccording to the results of semi quantitative detection of crystal violet stain and XTT methods, the bacterial suspension of 1×107 CFU/mL was selected for the experiment. XTT results indicated that the growth rates of ATCC12228 strain (at 4, 6, 12, 24, and 72 hours) and ATCC35984 strain (at 4, 6, 24, and 72 hours) in 125, 250, and 500 pmol/L estradiol were significantly faster than those in 0 and 50 pmol/L (P < 0.05). The growth rate of 500 pmol/L group was significantly faster than 125 and 250 pmol/L groups at 4, 6, and 72 hours (P < 0.05), and the growth rate of 250 pmol/L group was significantly faster than that of 125 pmol/L group at 72 hours (P < 0.05), but there was no significant difference between 0 and 50 pmol/L groups (P>0.05). At the same time point and same estradiol concentration, the growth rates showed no significant difference between 2 strains (P>0.05). Semi quantitative detection of crystal violet staining showed no biofilm formed in ATCC12228 strain in all estradiol concentration groups at different time points. In ATCC35984 strain, the biofilm was found at 4 hours and gradually thickened with time, reached the peak at 24 hours. After cultured for 4 and 6 hours, the biofilm of 0 pmol/L groups were significantly thicker than that of 125, 250, and 500 pmol/L groups (P < 0.05). At 12 hours, the 125 pmol/L group had the thickest biofilm, showing significant difference when compared with other groups (P < 0.05). The CLSM showed ATCC35984 biofilm thickness of 125, 250, and 500 pmol/L was significantly less than that of 0 and 50 pmol/L groups at 6 hours (P < 0.05), but difference was not significant between other groups (P>0.05). Then the thickness of the biofilm increased gradually, and the thickness of 125 pmol/L group was significantly larger than that of other concentration groups at 12 and 24 hours (P < 0.05). The SEM observation showed that the biofilm of 125 pmol/L group was denser and thicker than that of the other concentration groups at each time point.
ConclusionHigh level estradiol can promote bacteria growth, biofilm formation, and biofilm maturity of Staphylococcus epidermidis.
ObjectiveTo explore the function of intercellular adhesion A (icaA), fibrinogen binding protein (fbe), and accumulation-associated protein (aap) genes in formation of Staphylococcus epidermidis-Candida albicans mixed species biofilms.
MethodsThe experiment was divided into 3 groups:single culture of Staphylococcus epidermidis ATCC35984 (S. epidermidis group) or Candida albicans ATCC10231 (C. albicans group), and co-culture of two strains (mixed group) to build in vitro biofilm model. Biofilm mass was detected by crystal violet semi-quantitative adherence assay at 2, 4, 6, 8, 12, 24, 48, and 72 hours after incubation. XTT assay was performed to determine the growth kinetics in the same time. Scanning electron microscopy (SEM) was used to observe the ultrastructure of the biofilms after 24 and 72 hours of incubation. The expressions of icaA, fbe, and aap genes were analyzed by real-time fluorescent quantitative PCR.
ResultsCrystal violet semi-quantitative adherence assay showed that the biofilms thickened at 12 hours in the S. epidermidis and mixed groups; after co-cultured for 72 hours the thickness of biofilm in mixed group was more than that in the S. epidermidis group, and there was significant difference between 2 groups at the other time (P<0.05) except at 72 hours (P>0.05). In C. albicans group, the biofilm started to grow at 12 hours of cultivation, but the thickness of the biofilm was significantly lower than that in the mixed group in all the time points (P<0.05). XTT assay showed that the overall growth speed in the mixed group was greater than that in the C. albicans group, and it was greater than that in the S. epidermidis group at 48 hours; there was no significant difference in the growth speed between the mixed groups and the S. epidermidis group in the other time points (P>0.05) except at 12 hours (P<0.05). The absorbance (A) value in the mixed group was lower than that in the S. epidermidis group at 2 and 4 hours, but no significant difference was shown (P>0.05); the A value of mixed group was significantly higher than that of the C. albicans group after 6 hours (P<0.05). SEM observation showed that mature biofilms with complex structure formed in all groups. The real-time fluorescent quantitative PCR showed the expressions of fbe, icaA, and aap genes in mixed group increased 1.93, 1.52, and 1.46 times respectively at 72 hours compared with the S. epidermidis group (P<0.05).
ConclusionMixed species biofilms have more complex structure and are thicker than single species biofilms of Staphylococcus epidermidis or Candida albicans, which is related to increased expressions of the icaA, fbe, and aap genes of Staphylococcus epidermidis.
This article interprets the 2025 International Wound Infection Institute consensus Therapeutic Wound and Skin Cleansing: Clinical Evidence and Recommendations, which marks a paradigm shift in viewing wound cleansing as a “core therapy” rather than an “ancillary procedure”. It systematically analyzes the definition of “therapeutic wound cleansing”, clarifies its distinction from debridement, and explains the proposed “optimal wound care” theoretical model. The core content involves an evidence-based interpretation and comparative analysis of the 14 recommendations across 5 dimensions: timing/frequency, scope, technique/operational standards, solution selection, and pain management. Finally, considering the current state of clinical practice in China, the article discusses the consensus’s implications for promoting standardized and precise wound care, and suggests directions for future research.
Objective To study the influence of brominated furanones on the biofilm (BF) formation of Staphylococcus epidermidis (SE) on polyvinyl chloride(PVC) materials, and provide new ideas for the research of surface modification of materials and clinical treatment of biomaterial centered infection. Methods We chose three kinds of brominated furanone with representative chemical structure for our research which were respectively 3,4dibromo-5-hydroxy2 (5H) -furanone (Mucobromic acid) in the first furanone group, 4-bromo-5(4-methoxyphenyl)3(methylamino)2(5H)furanone in the second furanone group, and 3,4dibromo-5,5-bis(4-methylphenyl)2(5H)-furanone in the third furanone group. The PVC material soaked with 75% ethanol for 5minutes was classified as the control group. The surface coating of the PVC materials in the four groups all underwent modification respectively and then they were cocultivated with staphylococcus epidermidis together. Confocal laser scanning microscope(CLSM) was adopted to detect the thickness of bacterium BF and bacterium community quantity unit area on PVC materials and scanning electron microscope(SEM) was used to observe surface structure of SE, BF formation at 6 h, 12 h, 18 h and 24 h respectively. Results The results of CLSM showed that, compared with the control group, SE bacterium community quantity unit area and the thickness of bacterium BF on the PVC material surface in the second furanone group were obviously smaller (Plt;0.05). SE bacterium community quantity unit area and thickness of bacterium BF on PVC material surface in the first and the third furanone groups had no significant difference (Pgt;0.05). The result of SEM showed that, the quantity of SE bacterium community unit area on PVC material surface in the second furanone group were smaller than that of the control group at 6 hours. The biofilm structure on PVC material surface in the control group was formed at 18 hours, but there were no mature biofilm structure on PVC material surface in the second furanone group at 18 hours. Conclusion The impact of different brominated furanone on SE biofilm formation on the surface of PVC materials is different. The second kind of furanone can inhibit the quantity of SE bacterium community unit area and SE biofilm formation on the surface of PVC materials.
Objective The intercellular adhesion (ica) gene of Staphylococcus epidermidis (SE) is a key factor to bacterial aggregation, to analysis the genotype of iatrogenic SE and to explore the effect of iatrogenic SE ica operon on theformation of bacterial biofilm on the surface of polyvinyl chloride (PVC). Methods Fifty-six cl inical isolates of iatrogenic SEwere selected, and PCR and gene sequencing were used to detect the genes related with bacterial biofilm formation. The genes contained 16S rRNA, autolysin (atlE), fibrinogen binding protein (fbe), and icaADB. The bacteria suspension of 1 × 105 cfu/mL iatrogenic SE was prepared; according to the test results of target genes, the PVC material and the genotype of icaADB+, atlE+, fbe+ strains were co-cultivated as the ica positive group; the PVC material and the genotype of icaADB-, atlE+, fbe+ strains were co-cultivated as the ica negative group. The thickness of biofilm and bacterial community quantity unit area on PVC materials were measured by confocal laser scanning microscope, and the surface structure of biofilm formation was observed by scanning electron microscope (SEM) at 6, 12, 18, 24, and 30 hours. Results The positive rate of 16S rRNA of iatrogenic SE strains was 100% (56/56). The genotype of icaADB+, atlE+, and fbe+ strains accounted for 57.1% (32/56). The genotype of icaADB-, atlE+, and fbe+ strains accounted for 37.5% (21/56). The sequencing results showed that the product sequences of 16S rRNA, atlE, fbe, and icaADB were consistent with those in GenBank. With time, no significant bacterial biofilm formed on the surface of PVC in ica operon negative group. But in ica operon positive group, the number of bacterial community was gradually increased, and the volume of bacterial biofilms was gradually increased on the surface of PVC. At 24 hours, mature bacterial biofilm structure formed, and at 30 hours, the volume of bacterial biofilms was tending towards stabil ity. The thickness of biofilm (F=6 714.395, P=0.000) and the bacterial community quantity unit area on PVC materials (F=435.985, P=0.000) in ica operon positive groupwere significantly higher than those in ica operon negative group. Conclusion Iatrogenic SE can be divided into 2 types ofica operon negative and ica operon positive bacteria. The iatrogenic SE ica operon can strengthen bacterium biofilm formation capabil ity on PVC materials, bacterium community quantity, and thickness of biofilm, it plays an important role in bacterium biofilm formation on PVC materials.
ObjectiveTo evaluate the effectiveness of liquid wound dressing in the treatment of chronic ulcer wounds.
MethodsBetween January 2014 and October 2015, 84 patients with chronic ulcer wounds were included and divided into 2 groups randomly. The chronic ulcer wounds were covered with liquid wound dressing in the treatment group (n=44) and were managed with iodophor in the control group (n=40). There was no significant difference in age, gender, causes, location, wound area, and disease duration between 2 groups (P > 0.05). The frequency of dress changing, effective rate of treatment, wound healing time, wound healing rate at 5, 10, and 20 days, positive rate of bacteria culture at 1, 5, and 10 days, and the rate of side effect were recorded and compared between 2 groups. Vancouver scar scale was used to evaluate scar formation.
ResultsThe effective rate of the treatment group (100%) was significantly higher than that of the control group (85%) (P=0.009). The frequency of dress changing in the treatment group[(11.36±3.40) times] was significantly lower than that in the control group[(16.94±4.51) times] (t=-6.231, P=0.000). The wound healing rates at 5, 10, and 20 days were significantly increased (P < 0.05) and the wound healing time was significantly decreased (t=-6.627, P=0.000) in the treatment group when compared with the control group. The positive rates of bacteria culture at 5 and 10 days in the treatment group were significantly lower than those in the control group (χ2=12.313, P=0.000; P=0.005), but no significant difference was found at 1 day (χ2=0.066, P=0.797). Side effect was observed in 4 cases of the control group. Vancouver scar scale score was 8.59±1.32 in the treatment group and was 9.85±1.65 in the control group, showing significant difference (t=-3.752, P=0.000).
ConclusionThe application of the liquid wound dressing in the treatment of chronic ulcer wound can improve the wound healing rate, shorten the healing time and decrease the frequency of dress change, which could promote the wound healing process.
Objective To explore the mechanism of antibiotic delivery system targeting bacterial biofilm with linezolid (LZD) based on ε-poly-L-lysine (ε-PLL) and cyclodextrin (CD) (ε-PLL-CD-LZD), aiming to enhance antibiotic bioavailability, effectively penetrate and disrupt biofilm structures, and thereby improve the treatment of bone and joint infections. Methods ε-PLL-CD-LZD was synthesized via chemical methods. The grafting rate of CD was characterized using nuclear magnetic resonance. In vitro biocompatibility was evaluated through live/dead cell staining after co-culturing with mouse embryonic osteoblast precursor cells (MC3T3-E1), human umbilical vein endothelial cells, and mouse embryonic fibroblast cells (3T3-L1). The biofilm-enrichment capacity of ε-PLL-CD-LZD was assessed using Staphylococcus aureus biofilms through enrichment studies. Its biofilm eradication efficacy was investigated via minimum inhibitory concentration (MIC) determination, scanning electron microscopy, and live/dead bacterial staining. A bone and joint infection model in male Sprague-Dawley rats was established to validate the antibacterial effects of ε-PLL-CD-LZD. Results In ε-PLL-CD-LZD, the average grafting rate of CD reached 9.88%. The cell viability exceeded 90% after co-culturing with three types cells. The strong biofilm enrichment capability was observed with a MIC of 2 mg/L. Scanning electron microscopy observations revealed the effective disruption of biofilm structure, indicating potent biofilm eradication capacity. In vivo rat experiments demonstrated that ε-PLL-CD-LZD significantly reduced bacterial load and infection positivity rate at the lesion site (P<0.05). ConclusionThe ε-PLL-CD antibiotic delivery system provides a treatment strategy for bone and joint infections with high clinical translational significance. By effectively enhancing antibiotic bioavailability, penetrating, and disrupting biofilms, it demonstrated significant anti-infection effects in animal models.
Objective To investigate the effect of aureolysin （Aur） on staphylococcus aureus biofilm formation of dacron biomaterial surfaces under different Aur concentration. Methods Ninety dacron biomaterials were divided into 3 groups （group A, group IA, control group） with random number table （30 piece in each group）. Dacron biomaterials were put into vials contained staphylococcus aureus （105 CFU/ml） respectively; then Aur was added to make the concentration at 400ng/ml in group A, and group B at 80ng/ml. The thickness and number of staphylococcus aureus biofilm on the surfaces of dacron biomaterials of each group were evaluated by confocal laser microscopy and scanning electron microscopy after incubating 6h, 16h, 24h, 30h, and 48h. Results The thickness and number of staphylococcus aureus biofilm on dacron biomaterials surfaces increased significantly with time dependence in control group. The thickness and number of staphylococcus aureus biofilm in group A were less than those in group B and control group at each time points （P〈0. 05）. The thickness and number in group B were significantly decreased than those in control group （P 〈 0. 05）. Conclusion The study shows that Aur can effectively inhibit the formation of staphylococcus aureus biofilm on dacron biomaterials surfaces with dose dependence.
