BACKGROUND The upsurge of antibiotic resistance is a significant challenge to public health,and the dry pipeline of new antibiotics has prompted the discovery of alternative treatment approaches.Enterococcus faecalis(...BACKGROUND The upsurge of antibiotic resistance is a significant challenge to public health,and the dry pipeline of new antibiotics has prompted the discovery of alternative treatment approaches.Enterococcus faecalis(E.faecalis)isolates are often multidrugresistant,posing challenges to antibiotic therapy.Bacteriophage therapy is being explored as an alternative method to treat the growing population of antibioticresistant infections.Nevertheless,many inherent limitations of phages diminish their therapeutic utility,notably the restricted host range and quick development of mutants.The specific types and quantities of bacteriophages and antibiotics may be crucial in generating the optimal phage-antibiotic synergy.AIM To optimize the doses,order,and timing to optimize the synergy of phages and vancomycin on different bacteria states.METHODS A volume of 180μL of E.faecalis bacteria in the logarithmic growth phase,with a concentration of approximately 1×10^(8)colony forming units(CFUs)/mL,was introduced onto a microtitre plate.Subsequently,20μL of phage suspension(1×10^(6)PFUs/mL),vancomycin(16μg/mL),or a combination of both was introduced into the designated wells in the specified sequence and incubated at 37°C for 48 hours.The number of live bacteria was counted at different time points using standardized CFU counting protocols.RESULTS The biofilm model demonstrated that combining phages with vancomycin can eradicate the biofilm.Sequential therapy,involving phage application 8 hours before the antibiotic at a concentration of 108 PFUs/mL,proved the most efficient in eliminating the biofilms and killing the planktonic form of E.faecalis.CONCLUSION The combination of phageɸEFP01 at a higher concentration with a subinhibitory concentration of vancomycin yields a synergistic antibacterial outcome on E.faecalis strain resistant to vancomycin.展开更多
This study provides different opinion for exploring the mechanism of catechin(CAT)relieving nonalcoholic steatohepatitis(NASH),it is more innovative to explore from the perspective of intestinal microorganism.Through ...This study provides different opinion for exploring the mechanism of catechin(CAT)relieving nonalcoholic steatohepatitis(NASH),it is more innovative to explore from the perspective of intestinal microorganism.Through in vitro fermentation experiments,CAT could improve the abundance of Enterococcus,and Enterococcus faecalis(EF)accounts for the vast majority of Enterococcus in human gut.The experimental results in vivo showed that EF group and CAT+EF group could reduce the body weight,liver index and epididymal fat index of NASH mice,and improve the changes of serum and liver indexes.Hematoxylin-eosin staining observation showed that these two groups have greatly improved the fatty degeneration,balloon degeneration and necrotic focus caused by NASH.The alleviation of CAT+EF group was more obvious.Results of targeted metabonomics showed that CAT could promote EF to produce more methyl palmitate(C_(16:0)),which plays a great role in relieving NASH.Our results indicated that EF could alleviate NASH and CAT+EF group had better alleviation may due to more production of methyl palmitate(C_(16:0))by EF.This study provides a new idea for CAT to alleviate NASH.展开更多
The rough crystal of exopolysaccharide produced by Enterococcus durans, a strain of lactic acid bacteria screened from the intestine of a cock in our laboratory, was purified by CM-cellulose column chromatography, DEA...The rough crystal of exopolysaccharide produced by Enterococcus durans, a strain of lactic acid bacteria screened from the intestine of a cock in our laboratory, was purified by CM-cellulose column chromatography, DEAE-Sephadex A-25 ionexchange and Sephadex G-100 gel chromatography to give EPS-Ⅰ. The EPS-Ⅰ was eluted as a single peak in HPLC analysis, indicating the homogeneity of EPS-Ⅰ and free from low-molecular-weight polysaccharides. The molecular weight of the EPS-Ⅰ was determined as 42 000 by the light scattering method. The result of its elemental analysis was C 41.08% and H 7.23% without the elements of N, P and S. Monosaccharide analysis showed that it was composed of Glc and Man in a molar ratio of 4∶1. Sugar composition analysis, methylation analysis and 1H and 13C NMR spectroscopy revealed that the EPS-Ⅰ was composed of pentasaccharide repeating units. The sequence of sugar residues was determined by using two-dimensional NMR, including heteronuclear multiple-bond correlation(HMBC) and nuclear overhauser effect spectroscopy(NOESY). The structure of the pentasaccharide repeating unit of EPS-Ⅰ was given, a new excellular polysaccharide from lactic acid bacterium compared with other EPSs was reported.展开更多
BACKGROUND Bacillus subtilis(B.subtilis),Enterococcus faecium(E.faecium),and Enterococcus faecalis(E.faecalis)are probiotics that are widely used in the clinical treatment of irritable bowel syndrome(IBS).Whether the ...BACKGROUND Bacillus subtilis(B.subtilis),Enterococcus faecium(E.faecium),and Enterococcus faecalis(E.faecalis)are probiotics that are widely used in the clinical treatment of irritable bowel syndrome(IBS).Whether the supernatants of these three probiotics can improve gastrointestinal sensation and movement by regulating the serotonin transporter(SERT)expression needs to be clarified.AIM To investigate whether B.subtilis,E.faecium,and E.faecalis supernatants can upregulate SERT expression in vitro and in vivo.METHODS Caco-2 and HT-29 cells were stimulated with probiotic culture supernatants for 12 and 24 h,respectively.A male Sprague-Dawley rat model of post-infectious irritable bowel syndrome(PI-IBS)was established and the rats were treated with phosphate-buffered saline(group A)and three probiotics culture supernatants(groups B,C,and D)for 4 wk.The levels of SERT were detected by quantitative PCR and western blotting.RESULTS The levels of SERT at post-treatment 12 and 24 h were significantly elevated in Caco-2 cells treated with B.subtilis supernatant compared with those in the control group(aP<0.05).Those levels were markedly upregulated in Caco-2 cells stimulated with E.faecium and E.faecalis supernatants at 24 h(aP<0.05).In addition,SERT expression in groups B,C,and D was significantly higher than that in group A in the 2nd wk(aP<0.05).Increased SERT expression was only found in group D in the 3rd wk(aP<0.05).However,there was no significant difference in SERT expression between the groups in the last week(P>0.05).CONCLUSION The supernatants of B.subtilis,E.faecium,and E.faecalis can upregulate SERT expression in intestinal epithelial cells and the intestinal tissues in the rat model of PI-IBS.展开更多
Enterococcus faecalis and Enterococcus faecium rank among the leading causes of nosocomial bacteremia and urinary tract infections. They often persist on hospital surfaces due to their ability to withstand adverse env...Enterococcus faecalis and Enterococcus faecium rank among the leading causes of nosocomial bacteremia and urinary tract infections. They often persist on hospital surfaces due to their ability to withstand adverse environmental conditions (low or high temperatures, high pH, and high salinity). The global Enterococcus faecalis-Enterococcus faecium ratio is currently shifting towards Enterococcus faecium. Enterococci present variable levels of resistance to certain families of antibiotics. This is the case for aminoglycosides, beta-lactams and cephalosporins. In 2017, WHO ranked Enterococci among priority pathogens for research and development of new antibiotics. The objective of our study was to determine the antibiotic resistance profile of Enterococcus faecalis and Enterococcus faecium isolates from urine and pleural fluid in two hospitals in Cameroon. This cross-sectional and analytic study was carried out between June to August 2023 on hospitalized and day patients in which a cytobacteriological test of urine and pleural fluid was done. The samples were inoculated on CLED Agar for urine and on Chocolate + polyvitex and blood agar (prepared from Columbia agar) for pleural fluid samples and incubated at 37℃ for 18 to 24 hours. Identification of isolates was carried out using the API 20 STREP micro gallery (Biomerieux, France) and tested for antimicrobial susceptibility. The data on socio-demographical and potential risk factors were recorded using self-administered questionnaires and data from laboratory analyses of the specimen were collected in a data capture sheet. Potential risk factors associated with the presence of Enterococci, were evaluated using the logistic regression in univariate and multivariate analysis. P value < 0.05 was considered as significant. A total of 511 patients were recruited who were predominantly females. Enterococcus spp were isolated in 27.79% of our samples with Enterococcus faecalis mostly encountered. Enterococcus spp showed a high level of resistance to penicilline (99.3% to Ampicilline), macrolides (66.2% to Erythromycin) and cyclines (85.2% to Doxycycline). Hospitalisation, access to health facilities, contact with urine specimen and hand hygiene practices were risk factors related to infection with Enterococcus spp while hospitalisation, health facility and hand hygiene were related to glycopeptide resistant Enterococcus. Strict compliance with hygiene rules and appropriate antibiotic consumption could help in the fight against these infections.展开更多
AIM: To determine the features of Enterococcus that contribute to the development and maintenance of the inflammatory process in patients with inflammatory bowel disease (IBD). METHODS: Multiplex polymerase chain reac...AIM: To determine the features of Enterococcus that contribute to the development and maintenance of the inflammatory process in patients with inflammatory bowel disease (IBD). METHODS: Multiplex polymerase chain reaction (PCR) was applied to assess the presence of genes that encode virulence factors [surface aggregating protein (asa1), gelatinase (gelE), cytolysin (cylA), extracellular surface protein (esp) and hyaluronidase (hyl)] in the genomic DNA of 28 strains of Enterococcus isolated from the intestinal tissues of children with IBD (n =16) and of children without IBD (controls; n = 12). Additionally, strains with confirmed presence of the gelE gene were tested by PCR for the presence of quorum sensing genes (fsrA, fsrB, fsrC) that control the gelatinase production. Gelatinase activity was tested on agar plates containing 1.6% gelatin. We also analysed the ability of Enterococcus strains to release and decompose hydrogen peroxide (using Analytical Merckoquant peroxide test strips) and tested their ability to adhere to Caco-2 human gut epithelium cells and form biofilms in vitro. RESULTS: A comparison of the genomes of Enterococcus strains isolated from the inflamed mucosa of patients with IBD with those of the control group showed statistically significant differences in the frequency of theasa1 gene and thegelE gene. Furthermore, the cumulative occurrence of different virulence genes in the genome of a single strain ofEnterococcus isolated from the IBD patient group is greater than in a strain from the control group, although no significant difference was found. Statistically significant differences in the decomposition of hydrogen peroxide and adherence to the Caco-2 epithelial cell line between the strains from the patient group and control group were demonstrated. The results also showed that profuse biofilm production was more frequent amongEnterococcus strains isolated from children with IBD than in control strains. CONCLUSION: Enterococcus strains that adhere strongly to the intestinal epithelium, form biofilms and possess antioxidant defence mechanisms seem to have the greatest influence on the inflammatory process.展开更多
In the current study, we sought to investigate whether lysed Enterococcus faecalis FK-23 （LFK）, a heat-killed probiotic preparation, attenuated eosinophil influx into the upper airway and had immunomodulatory activi...In the current study, we sought to investigate whether lysed Enterococcus faecalis FK-23 （LFK）, a heat-killed probiotic preparation, attenuated eosinophil influx into the upper airway and had immunomodulatory activity in a murine allergic rhinitis model. Eighteen BALB/c mice were divided into three groups; the ovalbumin （OVA）-sen- sitized/challenged group, which received saline orally for 6 weeks （OVA group）, the OVA-sensitized/challenged group, which received LFK orally for 6 weeks （LFK-fed group）, and the non-sensitized group, which received saline for 6 weeks （saline control group）. Nasal rubbing and sneezing were monitored during the study. After the final challenge, interleukin （IL）-4, interferon （IFN）-y, and OVA-specific IgE levels in the sera and splenocyte culture supernatants were determined, eosinophilic infiltrate into the upper airway was quantified, and splenic CD4~CD25＋ regulatory T cells （Tregs） were examined by flow cytometry. We found that nasal rubbing was sig- nificantly reduced in LFK-fed mice compared to the OVA group on d 27 and 35, and sneezing was significantly inhibited by LFK administration for 35 d. LFK-fed mice had significantly less eosinophil influx into the nasal mucosa than the OVA group. There were no significant differences between the LFK-fed group and OVA group in the serum and splenocyte culture supernatant levels of IL-4, IFN-y, and OVA-specific IgE. Interestingly, the LFK-fed mice had a significantly greater percentage of splenic CD4＋CD25＋ Tregs than OVA group. Our results indicate that oral administration of LFK may alleviate nasal symptoms, reduce nasal eosinophilia, and increase the percentage of CD4＋CD25＋ Tregs in experimental allergic rhinitis.展开更多
Background:This study aimed to investigate the effects of oral administration of Enterococcus faecium NCIMB10415(E.faecium)on intestinal development,immunological parameters and gut microbiota of neonatal piglets chal...Background:This study aimed to investigate the effects of oral administration of Enterococcus faecium NCIMB10415(E.faecium)on intestinal development,immunological parameters and gut microbiota of neonatal piglets challenged with enterotoxigenic Escherichia coli K88(ETEC).A total of 961-day-old sow-reared piglets were randomly assigned to 2 groups,with 48 piglets in each group.The piglets were from 16 litters(6 piglets each litter),and 3 piglets each litter were allocated to the E.faecium-supplemented(PRO)group,while the other 3 piglets were allocated to the control(CON)group.After colostrum intake,piglets in the PRO group were orally administrated with 3×10~9 CFU E.faecium per day for a period of one week.On day 8,one piglet per litter from each group was challenged(CON+ETEC,PRO+ETEC)or not(CON-ETEC,PRO-ETEC)with ETEC in a 2×2 factorial arrangement of treatments.On day 10(2 days after challenge),blood and tissue samples were obtained from piglets.Results:Before ETEC challenge,there were no significant differences for the average daily gain(ADG)and fecal score between the two groups of piglets.After ETEC challenge,the challenged piglets had greater fecal score compared to the non-challenged piglets,whereas E.faecium administration was able to decrease the fecal score.Piglets challenged with ETEC had shorter villous height,deeper crypt depth,and reduced number of goblet cells in the jejunum and decreased m RNA abundance of claudin-1 in the ileum,whereas increased the percentage of lymphocytes,concentrations of IL-1βin the plasma and TNF-αin the ileal mucosa,as well as increased the m RNA abundances of innate immunity-related genes in the ileum tissue.These deleterious effects caused by ETEC were partly alleviated by feeding E.faecium.In addition,piglets in PRO-ETEC group had decreased the percentage of CD8^+T cells of the peripheral blood when compared to those in CON-ETEC group.Moreover,E.faecium administration increased Verrucomicrobia at phylum level and decreased Bilophila at genus level.Conclusions:These results suggest that oral administration of E.faecium alleviated the intestinal injury and diarrhea severity of neonatal piglets challenged by ETEC,partly through improving the intestinal microbiota and immune response.This offers a potential strategy of dietary intervention against intestinal impairment by ETEC in neonatal piglets.展开更多
FabB和FabF是大肠杆菌(Escherichia.coli)脂肪酸合成的关键酶.生物信息学分析显示,粪肠球菌基因组中有2个与大肠杆菌fabF同源的基因:fabF1和fabF2,缺少与fabB同源的基因.用粪肠球菌(Enterococcus faecalis)V583总DNA为模板,PCR扩增fabF1...FabB和FabF是大肠杆菌(Escherichia.coli)脂肪酸合成的关键酶.生物信息学分析显示,粪肠球菌基因组中有2个与大肠杆菌fabF同源的基因:fabF1和fabF2,缺少与fabB同源的基因.用粪肠球菌(Enterococcus faecalis)V583总DNA为模板,PCR扩增fabF1和fabF2基因,以pBAD24为载体,构建了重组质粒pHW13(fabF1)和pHW14(fabF2).体内体外研究显示:fabF1基因能互补大肠杆菌fabB突变,FabF1具有β酮脂酰ACP合成酶Ⅰ(FabB)活性;fabF2能互补大肠杆菌fabF突变,FabF2具有β酮脂酰ACP合成酶Ⅱ(FabF)活性.同时发现粪肠球菌FabF2不同于大肠杆菌FabF,它还拥有微弱β酮脂酰ACP合成酶Ⅰ(FabB)活性,可使大肠杆菌fabB突变株产生少量的不饱和脂肪酸.上述结果表明,FabF类酶(FabF like enzyme)同样可以具有β酮脂酰ACP合成酶Ⅰ(FabB)活性.展开更多
Effective final irrigation regimen is an important step in order to achieve better disinfection and ensure residual antimicrobial effects after root canal preparation. The aim of this study was to compare the residual...Effective final irrigation regimen is an important step in order to achieve better disinfection and ensure residual antimicrobial effects after root canal preparation. The aim of this study was to compare the residual antimicrobial activity of 0.2% cetrimide, and 0.2% and 2% chlorhexidine in root canals infected with Enterococcus faecalis. Biofilms of E. faecalis were grown on uniradicular roots for 4 weeks. After root canal preparation, root canals were irrigated with 17% ethylenediaminetetraacetic acid （EDTA） to remove the smear layer. The roots were randomly divided into three experimental groups （n=26） according to the final irrigating solution： Group I, 5 mL 0.2% cetrimide; Group II, 5 mL 0.2% chlorhexidine; and Group III, 5 mL 2% chlorhexidine. Samples were collected for 50 days to denote the presence of bacterial growth. The proportion of ungrown specimens over 50 days was evaluated using the nonparametric Kaplan-Meier survival analysis. Differences among groups were tested using the log-rank test and the level of statistical significance was set at P〈0.05. The highest survival value was found with 2% chlorhexidine, showing statistically significant differences from the other two groups. At 50 days, E. faecalisgrowth was detected in 69.23% specimens in Groups I and II, and in 34.61% specimens of Group III. There were no significant differences between 0.2% cetrimide and 0.2% chlorhexidine. Final irrigation with 2% chlorhexidine showed greater residual activity than 0.2% chlorhexidine and 0.2% cetrimide in root canals infected with E. faecalis.展开更多
A previous study demonstrated that alexidine has greater affinity for the major virulence factors of bacteria than chlorhexidine.The aim of this study was to compare the antimicrobial activity of 1%alexidine with that...A previous study demonstrated that alexidine has greater affinity for the major virulence factors of bacteria than chlorhexidine.The aim of this study was to compare the antimicrobial activity of 1%alexidine with that of 2%chlorhexidine using Enterococcus faecalis-infected dentin blocks.Sixty bovine dentin blocks were prepared and randomly divided into six groups of 10 each.E.faecalis was inoculated on 60 dentin blocks using the Luppens apparatus for 24 h and then the dentin blocks were soaked in 2%chlorhexidine or 1%alexidine solutions for 5 and 10 min,respectively.Sterile saline was used as a control.The antimicrobial efficacy was assessed by counting the number of bacteria adhering to the dentin surface and observing the degradation of bacterial shape or membrane rupture under a scanning electron microscope.Significantly fewer bacteria were observed in the 2%chlorhexidine-or 1%alexidine-soaked groups than in the control group(P<0.05).However,there was no significant difference in the number of bacteria adhering to the dentinal surface between the two experimental groups or between the two soaking time groups(P>0.05).Ruptured or antiseptic-attached bacteria were more frequently observed in the 10-min-soaked chlorhexidine and alexidine groups than in the 5-min-soaked chlorhexidine and alexidine groups.In conclusion,10-min soaking with 1%alexidine or 2%chlorhexidine can be effective against E.faecalis infection.展开更多
The purpose of this study was to assess the efficacy of alexidine（ALX）,alone and combined with N-acetylcysteine（NAC）,in eradicating two Enterococcus faecalis strain biofilms.The biofilms of E.faecalis ATCC 29212 a...The purpose of this study was to assess the efficacy of alexidine（ALX）,alone and combined with N-acetylcysteine（NAC）,in eradicating two Enterococcus faecalis strain biofilms.The biofilms of E.faecalis ATCC 29212 and the clinical isolate E.faecalis D1 were grown in the MBEC-high-throughput device for 24 h and were exposed to five twofold dilutions of ALX（2%–0.007 8%）alone and combined with100 mg？mL21NAC,for 1 and 5 min.Eradication was defined as 100%kill of biofilm bacteria.The Student’s t-test was used to compare the efficacy of the associations of the two irrigants.After 1-min contact time,ALX eradicated the biofilms at all concentrations except for 0.007 8%and 0.015 6%–0.007 8%with E.faecalis ATCC 29212 and E.faecalis D1,respectively.Similar results for eradication and concentration were obtained when it was combined with 100 mg？mL21NAC.After 5 min of contact time,ALX alone and combined with NAC eradicated all enterococci biofilms.ALX showed antimicrobial properties against the two E.faecalis strain biofilms tested at very low concentrations,and its combined use with NAC was not seen to enhance its activity.展开更多
Enterococcus faecalis （E. faecalis） is a microorganism that can survive extreme challenges in obturated root canals. The aim of this study was to evaluate the efficacy of a non-thermal atmospheric pressure plasma pl...Enterococcus faecalis （E. faecalis） is a microorganism that can survive extreme challenges in obturated root canals. The aim of this study was to evaluate the efficacy of a non-thermal atmospheric pressure plasma plume against E. faecalis in vitro. A non-thermal atmospheric pressure plasma jet device which could generate a cold plasma plume carrying a peak current of 300 mA was used. The antibacterial efficacy of this device against E. faecalis and its biofihn un- der different conditions was detected. The antibacterial efficacy of the plasma against E. faecalis and Staphylococcus aureus （S. aureus） was also evaluated. After plasma treatment, the average diameter of inhibition zone on S. aureus and E. faecalis was 2.62±0.26 cm and 1.06±0.30 cm, respectively （P 〈 0.05）. The diameter was increased with prolongation of the treatment dura- tion. The diameters of inhibition zone of the sealed Petri dishes were larger than those of the uncovered Petri dishes. There was significant difference in colony-forming units between plasma group and control group on E. faecalis biofilm （P 〈 0.01）. The transmission electron microscopy revealed that the ultrastructural changes eytoderm of E. faecalis were observed after treatment for 2min. It is concluded that the non-thermal atmospheric pressure plasma could serve as an effective adjunct to standard endodontie microbial treatment.展开更多
文摘BACKGROUND The upsurge of antibiotic resistance is a significant challenge to public health,and the dry pipeline of new antibiotics has prompted the discovery of alternative treatment approaches.Enterococcus faecalis(E.faecalis)isolates are often multidrugresistant,posing challenges to antibiotic therapy.Bacteriophage therapy is being explored as an alternative method to treat the growing population of antibioticresistant infections.Nevertheless,many inherent limitations of phages diminish their therapeutic utility,notably the restricted host range and quick development of mutants.The specific types and quantities of bacteriophages and antibiotics may be crucial in generating the optimal phage-antibiotic synergy.AIM To optimize the doses,order,and timing to optimize the synergy of phages and vancomycin on different bacteria states.METHODS A volume of 180μL of E.faecalis bacteria in the logarithmic growth phase,with a concentration of approximately 1×10^(8)colony forming units(CFUs)/mL,was introduced onto a microtitre plate.Subsequently,20μL of phage suspension(1×10^(6)PFUs/mL),vancomycin(16μg/mL),or a combination of both was introduced into the designated wells in the specified sequence and incubated at 37°C for 48 hours.The number of live bacteria was counted at different time points using standardized CFU counting protocols.RESULTS The biofilm model demonstrated that combining phages with vancomycin can eradicate the biofilm.Sequential therapy,involving phage application 8 hours before the antibiotic at a concentration of 108 PFUs/mL,proved the most efficient in eliminating the biofilms and killing the planktonic form of E.faecalis.CONCLUSION The combination of phageɸEFP01 at a higher concentration with a subinhibitory concentration of vancomycin yields a synergistic antibacterial outcome on E.faecalis strain resistant to vancomycin.
基金supported by the National Natural Science Foundation of China(32202200)Shanghai Excellent Academic/Technical Leaders Project(23XD1430500).
文摘This study provides different opinion for exploring the mechanism of catechin(CAT)relieving nonalcoholic steatohepatitis(NASH),it is more innovative to explore from the perspective of intestinal microorganism.Through in vitro fermentation experiments,CAT could improve the abundance of Enterococcus,and Enterococcus faecalis(EF)accounts for the vast majority of Enterococcus in human gut.The experimental results in vivo showed that EF group and CAT+EF group could reduce the body weight,liver index and epididymal fat index of NASH mice,and improve the changes of serum and liver indexes.Hematoxylin-eosin staining observation showed that these two groups have greatly improved the fatty degeneration,balloon degeneration and necrotic focus caused by NASH.The alleviation of CAT+EF group was more obvious.Results of targeted metabonomics showed that CAT could promote EF to produce more methyl palmitate(C_(16:0)),which plays a great role in relieving NASH.Our results indicated that EF could alleviate NASH and CAT+EF group had better alleviation may due to more production of methyl palmitate(C_(16:0))by EF.This study provides a new idea for CAT to alleviate NASH.
文摘The rough crystal of exopolysaccharide produced by Enterococcus durans, a strain of lactic acid bacteria screened from the intestine of a cock in our laboratory, was purified by CM-cellulose column chromatography, DEAE-Sephadex A-25 ionexchange and Sephadex G-100 gel chromatography to give EPS-Ⅰ. The EPS-Ⅰ was eluted as a single peak in HPLC analysis, indicating the homogeneity of EPS-Ⅰ and free from low-molecular-weight polysaccharides. The molecular weight of the EPS-Ⅰ was determined as 42 000 by the light scattering method. The result of its elemental analysis was C 41.08% and H 7.23% without the elements of N, P and S. Monosaccharide analysis showed that it was composed of Glc and Man in a molar ratio of 4∶1. Sugar composition analysis, methylation analysis and 1H and 13C NMR spectroscopy revealed that the EPS-Ⅰ was composed of pentasaccharide repeating units. The sequence of sugar residues was determined by using two-dimensional NMR, including heteronuclear multiple-bond correlation(HMBC) and nuclear overhauser effect spectroscopy(NOESY). The structure of the pentasaccharide repeating unit of EPS-Ⅰ was given, a new excellular polysaccharide from lactic acid bacterium compared with other EPSs was reported.
基金Supported by the National Natural Science Foundation of China,No.81570489and the Youth Project of National Natural Science Foundation of China,No.81900487.
文摘BACKGROUND Bacillus subtilis(B.subtilis),Enterococcus faecium(E.faecium),and Enterococcus faecalis(E.faecalis)are probiotics that are widely used in the clinical treatment of irritable bowel syndrome(IBS).Whether the supernatants of these three probiotics can improve gastrointestinal sensation and movement by regulating the serotonin transporter(SERT)expression needs to be clarified.AIM To investigate whether B.subtilis,E.faecium,and E.faecalis supernatants can upregulate SERT expression in vitro and in vivo.METHODS Caco-2 and HT-29 cells were stimulated with probiotic culture supernatants for 12 and 24 h,respectively.A male Sprague-Dawley rat model of post-infectious irritable bowel syndrome(PI-IBS)was established and the rats were treated with phosphate-buffered saline(group A)and three probiotics culture supernatants(groups B,C,and D)for 4 wk.The levels of SERT were detected by quantitative PCR and western blotting.RESULTS The levels of SERT at post-treatment 12 and 24 h were significantly elevated in Caco-2 cells treated with B.subtilis supernatant compared with those in the control group(aP<0.05).Those levels were markedly upregulated in Caco-2 cells stimulated with E.faecium and E.faecalis supernatants at 24 h(aP<0.05).In addition,SERT expression in groups B,C,and D was significantly higher than that in group A in the 2nd wk(aP<0.05).Increased SERT expression was only found in group D in the 3rd wk(aP<0.05).However,there was no significant difference in SERT expression between the groups in the last week(P>0.05).CONCLUSION The supernatants of B.subtilis,E.faecium,and E.faecalis can upregulate SERT expression in intestinal epithelial cells and the intestinal tissues in the rat model of PI-IBS.
文摘Enterococcus faecalis and Enterococcus faecium rank among the leading causes of nosocomial bacteremia and urinary tract infections. They often persist on hospital surfaces due to their ability to withstand adverse environmental conditions (low or high temperatures, high pH, and high salinity). The global Enterococcus faecalis-Enterococcus faecium ratio is currently shifting towards Enterococcus faecium. Enterococci present variable levels of resistance to certain families of antibiotics. This is the case for aminoglycosides, beta-lactams and cephalosporins. In 2017, WHO ranked Enterococci among priority pathogens for research and development of new antibiotics. The objective of our study was to determine the antibiotic resistance profile of Enterococcus faecalis and Enterococcus faecium isolates from urine and pleural fluid in two hospitals in Cameroon. This cross-sectional and analytic study was carried out between June to August 2023 on hospitalized and day patients in which a cytobacteriological test of urine and pleural fluid was done. The samples were inoculated on CLED Agar for urine and on Chocolate + polyvitex and blood agar (prepared from Columbia agar) for pleural fluid samples and incubated at 37℃ for 18 to 24 hours. Identification of isolates was carried out using the API 20 STREP micro gallery (Biomerieux, France) and tested for antimicrobial susceptibility. The data on socio-demographical and potential risk factors were recorded using self-administered questionnaires and data from laboratory analyses of the specimen were collected in a data capture sheet. Potential risk factors associated with the presence of Enterococci, were evaluated using the logistic regression in univariate and multivariate analysis. P value < 0.05 was considered as significant. A total of 511 patients were recruited who were predominantly females. Enterococcus spp were isolated in 27.79% of our samples with Enterococcus faecalis mostly encountered. Enterococcus spp showed a high level of resistance to penicilline (99.3% to Ampicilline), macrolides (66.2% to Erythromycin) and cyclines (85.2% to Doxycycline). Hospitalisation, access to health facilities, contact with urine specimen and hand hygiene practices were risk factors related to infection with Enterococcus spp while hospitalisation, health facility and hand hygiene were related to glycopeptide resistant Enterococcus. Strict compliance with hygiene rules and appropriate antibiotic consumption could help in the fight against these infections.
基金Supported by The Polish Ministry of Science and Higher Education Grants No. 2 PO5A 094 29, 3 P05E 091 25, N N402 0861 and N N401 144638
文摘AIM: To determine the features of Enterococcus that contribute to the development and maintenance of the inflammatory process in patients with inflammatory bowel disease (IBD). METHODS: Multiplex polymerase chain reaction (PCR) was applied to assess the presence of genes that encode virulence factors [surface aggregating protein (asa1), gelatinase (gelE), cytolysin (cylA), extracellular surface protein (esp) and hyaluronidase (hyl)] in the genomic DNA of 28 strains of Enterococcus isolated from the intestinal tissues of children with IBD (n =16) and of children without IBD (controls; n = 12). Additionally, strains with confirmed presence of the gelE gene were tested by PCR for the presence of quorum sensing genes (fsrA, fsrB, fsrC) that control the gelatinase production. Gelatinase activity was tested on agar plates containing 1.6% gelatin. We also analysed the ability of Enterococcus strains to release and decompose hydrogen peroxide (using Analytical Merckoquant peroxide test strips) and tested their ability to adhere to Caco-2 human gut epithelium cells and form biofilms in vitro. RESULTS: A comparison of the genomes of Enterococcus strains isolated from the inflamed mucosa of patients with IBD with those of the control group showed statistically significant differences in the frequency of theasa1 gene and thegelE gene. Furthermore, the cumulative occurrence of different virulence genes in the genome of a single strain ofEnterococcus isolated from the IBD patient group is greater than in a strain from the control group, although no significant difference was found. Statistically significant differences in the decomposition of hydrogen peroxide and adherence to the Caco-2 epithelial cell line between the strains from the patient group and control group were demonstrated. The results also showed that profuse biofilm production was more frequent amongEnterococcus strains isolated from children with IBD than in control strains. CONCLUSION: Enterococcus strains that adhere strongly to the intestinal epithelium, form biofilms and possess antioxidant defence mechanisms seem to have the greatest influence on the inflammatory process.
基金supported by the International Cooperation Program of Jiangsu Department of Science and Technology (BZ2011045)the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD 2010-2013)the Health Promotion Project of Jiangsu Province (RC2007065 and RC2011071),China
文摘In the current study, we sought to investigate whether lysed Enterococcus faecalis FK-23 （LFK）, a heat-killed probiotic preparation, attenuated eosinophil influx into the upper airway and had immunomodulatory activity in a murine allergic rhinitis model. Eighteen BALB/c mice were divided into three groups; the ovalbumin （OVA）-sen- sitized/challenged group, which received saline orally for 6 weeks （OVA group）, the OVA-sensitized/challenged group, which received LFK orally for 6 weeks （LFK-fed group）, and the non-sensitized group, which received saline for 6 weeks （saline control group）. Nasal rubbing and sneezing were monitored during the study. After the final challenge, interleukin （IL）-4, interferon （IFN）-y, and OVA-specific IgE levels in the sera and splenocyte culture supernatants were determined, eosinophilic infiltrate into the upper airway was quantified, and splenic CD4~CD25＋ regulatory T cells （Tregs） were examined by flow cytometry. We found that nasal rubbing was sig- nificantly reduced in LFK-fed mice compared to the OVA group on d 27 and 35, and sneezing was significantly inhibited by LFK administration for 35 d. LFK-fed mice had significantly less eosinophil influx into the nasal mucosa than the OVA group. There were no significant differences between the LFK-fed group and OVA group in the serum and splenocyte culture supernatant levels of IL-4, IFN-y, and OVA-specific IgE. Interestingly, the LFK-fed mice had a significantly greater percentage of splenic CD4＋CD25＋ Tregs than OVA group. Our results indicate that oral administration of LFK may alleviate nasal symptoms, reduce nasal eosinophilia, and increase the percentage of CD4＋CD25＋ Tregs in experimental allergic rhinitis.
基金supported by the Projects of The National Key Research and Development Program of China(grant number 2016YFD0501204)Sichuan provincial project on S&T application and demonstration(grant number2016CC0070)the project on commercialization of research findings under funding of government of Sichuan province(grant number16ZHSF0385).
文摘Background:This study aimed to investigate the effects of oral administration of Enterococcus faecium NCIMB10415(E.faecium)on intestinal development,immunological parameters and gut microbiota of neonatal piglets challenged with enterotoxigenic Escherichia coli K88(ETEC).A total of 961-day-old sow-reared piglets were randomly assigned to 2 groups,with 48 piglets in each group.The piglets were from 16 litters(6 piglets each litter),and 3 piglets each litter were allocated to the E.faecium-supplemented(PRO)group,while the other 3 piglets were allocated to the control(CON)group.After colostrum intake,piglets in the PRO group were orally administrated with 3×10~9 CFU E.faecium per day for a period of one week.On day 8,one piglet per litter from each group was challenged(CON+ETEC,PRO+ETEC)or not(CON-ETEC,PRO-ETEC)with ETEC in a 2×2 factorial arrangement of treatments.On day 10(2 days after challenge),blood and tissue samples were obtained from piglets.Results:Before ETEC challenge,there were no significant differences for the average daily gain(ADG)and fecal score between the two groups of piglets.After ETEC challenge,the challenged piglets had greater fecal score compared to the non-challenged piglets,whereas E.faecium administration was able to decrease the fecal score.Piglets challenged with ETEC had shorter villous height,deeper crypt depth,and reduced number of goblet cells in the jejunum and decreased m RNA abundance of claudin-1 in the ileum,whereas increased the percentage of lymphocytes,concentrations of IL-1βin the plasma and TNF-αin the ileal mucosa,as well as increased the m RNA abundances of innate immunity-related genes in the ileum tissue.These deleterious effects caused by ETEC were partly alleviated by feeding E.faecium.In addition,piglets in PRO-ETEC group had decreased the percentage of CD8^+T cells of the peripheral blood when compared to those in CON-ETEC group.Moreover,E.faecium administration increased Verrucomicrobia at phylum level and decreased Bilophila at genus level.Conclusions:These results suggest that oral administration of E.faecium alleviated the intestinal injury and diarrhea severity of neonatal piglets challenged by ETEC,partly through improving the intestinal microbiota and immune response.This offers a potential strategy of dietary intervention against intestinal impairment by ETEC in neonatal piglets.
文摘FabB和FabF是大肠杆菌(Escherichia.coli)脂肪酸合成的关键酶.生物信息学分析显示,粪肠球菌基因组中有2个与大肠杆菌fabF同源的基因:fabF1和fabF2,缺少与fabB同源的基因.用粪肠球菌(Enterococcus faecalis)V583总DNA为模板,PCR扩增fabF1和fabF2基因,以pBAD24为载体,构建了重组质粒pHW13(fabF1)和pHW14(fabF2).体内体外研究显示:fabF1基因能互补大肠杆菌fabB突变,FabF1具有β酮脂酰ACP合成酶Ⅰ(FabB)活性;fabF2能互补大肠杆菌fabF突变,FabF2具有β酮脂酰ACP合成酶Ⅱ(FabF)活性.同时发现粪肠球菌FabF2不同于大肠杆菌FabF,它还拥有微弱β酮脂酰ACP合成酶Ⅰ(FabB)活性,可使大肠杆菌fabB突变株产生少量的不饱和脂肪酸.上述结果表明,FabF类酶(FabF like enzyme)同样可以具有β酮脂酰ACP合成酶Ⅰ(FabB)活性.
基金supported by the Research Group CTS-167 of the Junta de Andalucí'a, Spain
文摘Effective final irrigation regimen is an important step in order to achieve better disinfection and ensure residual antimicrobial effects after root canal preparation. The aim of this study was to compare the residual antimicrobial activity of 0.2% cetrimide, and 0.2% and 2% chlorhexidine in root canals infected with Enterococcus faecalis. Biofilms of E. faecalis were grown on uniradicular roots for 4 weeks. After root canal preparation, root canals were irrigated with 17% ethylenediaminetetraacetic acid （EDTA） to remove the smear layer. The roots were randomly divided into three experimental groups （n=26） according to the final irrigating solution： Group I, 5 mL 0.2% cetrimide; Group II, 5 mL 0.2% chlorhexidine; and Group III, 5 mL 2% chlorhexidine. Samples were collected for 50 days to denote the presence of bacterial growth. The proportion of ungrown specimens over 50 days was evaluated using the nonparametric Kaplan-Meier survival analysis. Differences among groups were tested using the log-rank test and the level of statistical significance was set at P〈0.05. The highest survival value was found with 2% chlorhexidine, showing statistically significant differences from the other two groups. At 50 days, E. faecalisgrowth was detected in 69.23% specimens in Groups I and II, and in 34.61% specimens of Group III. There were no significant differences between 0.2% cetrimide and 0.2% chlorhexidine. Final irrigation with 2% chlorhexidine showed greater residual activity than 0.2% chlorhexidine and 0.2% cetrimide in root canals infected with E. faecalis.
基金supported by the National Research Foundation(NRF) of Korea funded by the Ministry of Education,Science and Technology(MEST) (No.2009-0086835,2011-0014231,2012-0008693:Drs KY Kum,SH Han and SW Chang),South Korea
文摘A previous study demonstrated that alexidine has greater affinity for the major virulence factors of bacteria than chlorhexidine.The aim of this study was to compare the antimicrobial activity of 1%alexidine with that of 2%chlorhexidine using Enterococcus faecalis-infected dentin blocks.Sixty bovine dentin blocks were prepared and randomly divided into six groups of 10 each.E.faecalis was inoculated on 60 dentin blocks using the Luppens apparatus for 24 h and then the dentin blocks were soaked in 2%chlorhexidine or 1%alexidine solutions for 5 and 10 min,respectively.Sterile saline was used as a control.The antimicrobial efficacy was assessed by counting the number of bacteria adhering to the dentin surface and observing the degradation of bacterial shape or membrane rupture under a scanning electron microscope.Significantly fewer bacteria were observed in the 2%chlorhexidine-or 1%alexidine-soaked groups than in the control group(P<0.05).However,there was no significant difference in the number of bacteria adhering to the dentinal surface between the two experimental groups or between the two soaking time groups(P>0.05).Ruptured or antiseptic-attached bacteria were more frequently observed in the 10-min-soaked chlorhexidine and alexidine groups than in the 5-min-soaked chlorhexidine and alexidine groups.In conclusion,10-min soaking with 1%alexidine or 2%chlorhexidine can be effective against E.faecalis infection.
基金supported by the Research Group CTS-167 of the Junta de Andaluc'a,Spain
文摘The purpose of this study was to assess the efficacy of alexidine（ALX）,alone and combined with N-acetylcysteine（NAC）,in eradicating two Enterococcus faecalis strain biofilms.The biofilms of E.faecalis ATCC 29212 and the clinical isolate E.faecalis D1 were grown in the MBEC-high-throughput device for 24 h and were exposed to five twofold dilutions of ALX（2%–0.007 8%）alone and combined with100 mg？mL21NAC,for 1 and 5 min.Eradication was defined as 100%kill of biofilm bacteria.The Student’s t-test was used to compare the efficacy of the associations of the two irrigants.After 1-min contact time,ALX eradicated the biofilms at all concentrations except for 0.007 8%and 0.015 6%–0.007 8%with E.faecalis ATCC 29212 and E.faecalis D1,respectively.Similar results for eradication and concentration were obtained when it was combined with 100 mg？mL21NAC.After 5 min of contact time,ALX alone and combined with NAC eradicated all enterococci biofilms.ALX showed antimicrobial properties against the two E.faecalis strain biofilms tested at very low concentrations,and its combined use with NAC was not seen to enhance its activity.
基金supported by National Natural Science Foundation of China (No. 10875048)
文摘Enterococcus faecalis （E. faecalis） is a microorganism that can survive extreme challenges in obturated root canals. The aim of this study was to evaluate the efficacy of a non-thermal atmospheric pressure plasma plume against E. faecalis in vitro. A non-thermal atmospheric pressure plasma jet device which could generate a cold plasma plume carrying a peak current of 300 mA was used. The antibacterial efficacy of this device against E. faecalis and its biofihn un- der different conditions was detected. The antibacterial efficacy of the plasma against E. faecalis and Staphylococcus aureus （S. aureus） was also evaluated. After plasma treatment, the average diameter of inhibition zone on S. aureus and E. faecalis was 2.62±0.26 cm and 1.06±0.30 cm, respectively （P 〈 0.05）. The diameter was increased with prolongation of the treatment dura- tion. The diameters of inhibition zone of the sealed Petri dishes were larger than those of the uncovered Petri dishes. There was significant difference in colony-forming units between plasma group and control group on E. faecalis biofilm （P 〈 0.01）. The transmission electron microscopy revealed that the ultrastructural changes eytoderm of E. faecalis were observed after treatment for 2min. It is concluded that the non-thermal atmospheric pressure plasma could serve as an effective adjunct to standard endodontie microbial treatment.
