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.
Seventeen cases involving 18 fingers of acute rupture of flexor tendon within the Zone Ⅱ were repaired by microsurgical technique for reconstructing the digital sheath with biological membrane since 1989. The excellent/good rate based on Eaton grading was 89%. The main procedure of the operation. the early postoperative rehabilitation and active excercises were described.
Objective To summarize the effect of biofilm (BF) on the occurrence of prosthetic joint infection (PJI). Methods The domestic and abroad original l iterature in recent years about the relationship between BF and PJI was reviewed. Results Infection is a critical compl ication for prosthetic joint replacement. Basic research showes one of the reasons for PJI is BF. After adherence of the bacteria to the surface of prosthetic joint, BF forms through a series of regulation andcontrol system. And it lead to the occurrence of PJI. Recently a lot of progress have been made in the research fields of BF related PJI, which have covered aetiology, diagnosis, treatment, and prevention. Different studies show that BF has close relationship with PJI. Conclusion BF is proved to have close relationship with PJI. It is important on cl inical significances to diagnose, treat, and prevent PJI.
Objective To observe the inhibitory characteristics of silver nanoparticles (AgNP) on bacterial biofilms and investigate their inhibitory effect on biofilm formation on three common orthopedic biomaterials. Methods The minimal inhibitory concentration (MIC) and minimal biofilm inhibitory concentration (MBIC) of AgNP were determined by microplate dilution assay. Biofilms of Staphylococcus aureus (ATCC 25923) were cultured on three orthopedic biomaterials (titanium alloy, titanium oxide, and stainless steel) and intervened with AgNP at concentrations of 32, 16, 8, 4, 2 and 0 μg/mL to determine the MBICs on the three materials. The effects of AgNP on biofilm formation were analyzed by scanning electron microscopy and measuring optical density. Results The MIC and MBIC of AgNP in the microplate assay were both 16 µg/mL. The MBICs of AgNP on biofilm formation in titanium oxide, titanium alloy, and stainless steel were 16 μg/mL, 32 μg/mL, and 32 μg/mL, respectively. Among the three materials, the lowest optical density was observed on titanium oxide, while the highest was on titanium alloy. Conclusions AgNP has strong antibacterial biofilm characteristics and can prevent the formation of Staphylococcus aureus biofilm in vitro. Biofilm formation is most pronounced on titanium alloy, least on titanium oxide, and intermediate on stainless steel.
OBJECTIVE The human epidermal cells were bred on a kind of bio-membrane, the bio-brane, in engineering a kind of new epidermal substitute, the bio-membrane bred cell graft. METHODS Fresh and frozen grafts of biomembrane bred epidermal cells were transplanted into the full-thickness wounds of nude mice and those received simple Bio-brane were served as control. The wounds of the two groups were observed daily and biopsy was taken on the 3, 5, 7, 10, 21 and 35 days respectively. RESULTS Epidermal cells could be cultured in vitro on the bio-membrane reaching the sub-saturated state of 60 to 70 percents. The bio-membrane after being grafted the epidermal cells continued to proliferate and differentiate to form a layer of new epidermis. There was no difference between the fresh and the frozen bio-membranes. CONCLUSION Bio-membrane bred with epidermal cells could be a kind of ideal epidermal substitute.
Objective It is difficult to treat chronic osteomyel itis due to the formation of the Staphylococcus aureus biofilms. Liposomal gentamicin-impregnated allogeneic cortical bone can inhibit the formation of the Staphylococcus aureusbiofilms. To explore the treatment of chronic osteomyel itis of rabbit by l iposomal gentamicin-impregnated allogeneic cortical bone. Methods The l iposomal gentamicin, l iposomal gentamicin-impregnated allogeneic cortical bone and gentamicinimpregnated allogeneic cortical bone were produced. Then the chronic Staphylococcus aureus osteomyel itis models of rabbit were made in left lower l imbs of 40 6-month-old rabbits and the right lower l imbs were used as controls. After 2 weeks, the observations of gross and X-ray were done. Four rabbits died within 10 days after the models were made and other 36 rabbits were devided into 6 groups: group A (no antibiotics), group B (intravenous injection of gentamicin), group C (intravenous injection of l i posomal gentamicin), group D (implantation of gentamicin-impregnated allogeneic cortical bone), group E (implantation of l i posomal gentamicin-impregnated allogeneic cortical bone), and group F (implantation of allogeneic cortical bone). After 2 weeks of treatment, the bacterial culture, X-ray and HE staining were done. Results The chronic Staphylococcus aureus osteomyel itis model of rabbit was made successfully. The X-ray showed dissolution of bone and periosteal reaction in groups A, B, C, and F, and no obvious dissolution of bone and periosteal reaction in groups D and E. The Norden scores were (2.5 ± 0.3), (2.1 ± 0.2), (1.5 ± 0.3), (1.5 ± 0.2), (0.9 ± 0.3), and (2.7 ± 0.3) points in groups A-F, respectively; showing significant differences between group A and groups B-E (P lt; 0.05), between groups B, E, F and other groups (P lt; 0.05). The results of blood and marrow cultures for Staphylococcus aureus were positive in groups A and F, and negative in other 4 groups; the results of bone marrow culture for Staphylococcus aureus were positive in 6 rabbits of group B, 4 rabbits of group C and 3 rabitts of group D; and the results were negative in group E. HE staining showed: in groups A and F, abscess and dead bone formed, and no new bone formation were observed; in groups B and C, different degrees of neutrophil accumulation was seen; in group D, some neutrophil accumulation occurred, and osteoprogenitor cells and osteoclasts were seen around implanted bone; and in group E, no neutrophil accumulation was observed, a lot of granulation tissues formed, and osteoprogenitor cells and osteoclasts were seen around implanted bone. Conclusion Implantation of l iposomal gentamicin-impregnated allogeneic cortical bone has remarkly better effect in treating chronic osteomyel itis than intravenous injection of l iposomal gentamicin and implantation of gentamicin-impregnated allogeneic cortical bone.
ObjectiveTo investigate biofilm formation on the surface of silica gel by breast surgery clinical specimens of Staphylococcus epidermidis and to analyze the relationship between biofilm formation and icaA, icaD, and accumulation-associated protein (aap) gene. MethodsBetween December 2011 and January 2013, 44 strains of Staphylococcus epidermidis were isolated from the clinical specimens of the female patients who had no symptom of infection. The icaA, icaD, and aap genes were detected by PCR and 4 genotypic groups were divided:icaA+icaD+/aap+ group (group A), icaA+icaD+/aap- group (group B), icaA-icaD-/aap+ group (group C), and icaA-icaD-/aap- group (group D). Biofilms mass was semi-quantified by semi-quantitative adherence assay after 8, 12, 24, 30, and 36 hours of incubation. The thickness of biofilms was measured by confocal laser scanning microscope (CLSM) at 12 and 24 hours after incubation. The ultrastructure of biofilms was observed by scanning electron microscope (SEM) at 24 hours after incubation. ResultsPCR test showed that 13 strains were icaA+icaD+/aap+(group A), 12 strains were icaA+icaD+/aap-(group B), 16 strains were icaA-icaD-/aap+(group C), and 3 strains were icaA-icaD-/aap-(group D). In 29 strains which had bacterial biofilm formation (65.9%), there were 13 strains in group A, 7 strains in group B, 9 strains in group C, and 0 in group D. The result of semi-quantitative adherence assay showed no significant difference in the absorbance (A) values among 4 groups at 8 hours (P>0.05). The A values of groups A, B, and C were significantly higher than that of group D at 12-36 hours, and group A was significantly higher than groups B and C (P<0.05), but there was no significant difference between groups B and C (P>0.05). The results of CLSM showed that the thickness of biofilm in groups A, B, and C was significantly larger than that in group D at 12 and 24 hours after incubation (P<0.05), and the thickness of biofilm in group A was significantly larger than that in groups B and C (P<0.05), but there was no significant difference between groups B and C (P>0.05). The result of SEM showed that the mature biofilm could be observed on the surface of silica gel in groups A, B, and C, and the ultrastructure of biofilms in group A were the most abundant and extensive among 3 groups. The ultrastructure of biofilm in group B was similar to that in group C. No obvious biofilms formed in group D. ConclusionicaA, icaD, and aap genes all play key roles in the process for biofilm formation of Staphylococcus epidermidis. Futhermore, aap gene enhance the ability of biofilm-forming when aap and ica genes coexist, so the biofilm-forming ability of icaA+icaD+/aap+ is strongest.
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.
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.