Augmented Production of Extracellular Superoxide by Blood Isolates of Enterococcus faecalis
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To assess the frequency of extracellular superoxide (O2−) production by enterococci, multiple species were surveyed in a whole organism assay for their ability to reduce ferricytochrome c in a superoxide dismutase-inhibitable fashion. For stool and clinical enterococcal isolates and 12 type strains, only Enterococcus faecalis (87/91 isolates and ATCC 19443), Enterococcus faecium (5/13 isolates), Enterococcus casselijlavus (ATCC 25788), and Enterococcus gallinarum (ATCC 35038) produced extracellular O2−. Among 106 strains comprising 13 species of enteric gram-negative bacilli and gram-positive cocci, only Lactococcus lactis subspecies lactis produced extracellular O2−, Mean (±SE) rates of extracellular O2− production in vitro by E. faecalis for isolates associated with bacteremia and endocarditis and for isolates from stool were 2.4 ± 0.2, 1.9 ± 0.2, and 1.5 ± 0.3 nmol of O2− min−1 109 cfu−1, respectively (P = .025, analysis of variance), suggesting an association between invasiveness and extracellular O2− production.Keywords:
Enterococcus faecalis
Abstract The Bowman-Birk protease inhibitor (BBI) is a soybean-derived protease inhibitor with anticarcinogenic and anti-inflammatory properties. BBI has previously been shown to suppress the release of superoxide anion radicals from purified polymorphonuclear leukocytes. In the present study we evaluated the effect of BBI on the production of superoxide anion radicals in differentiated HL-60 cells. HL-60 cells are human lymphocytic cells that acquire neutrophil-like characteristics when treated with dimethyl sulfoxide or tetradecanoyl phorbol acetate. Superoxide anion radical production by differentiated HL-60 cells was measured in the presence of various concentrations of BBI or BBI concentrate, a soybean extract containing high levels of BBI. BBI was observed to suppress superoxide anion radical production by differentiated HL-60 cells in a dose-dependent manner. Extracts of differentiated HL-60 cells were also observed to produce superoxide anion radicals, but this activity was not affected by the presence of BBI. These results suggest that BBI inhibits superoxide anion radical generation in HL-60 cells but does not act as a simple free radical scavenger.
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Endophthalmitis due to infection with Enterococcus spp. progresses rapidly and often results in substantial and irreversible vision loss. Given that the frequency of this condition caused by vancomycin-resistant Enterococcus faecalis has been increasing, the development of novel therapeutics is urgently required. We have demonstrated the therapeutic potential of bacteriophage ΦEF24C-P2 in a mouse model of endophthalmitis caused by vancomycin-sensitive (EF24) or vancomycin-resistant (VRE2) strains of E. faecalis Phage ΦEF24C-P2 induced rapid and pronounced bacterial lysis in turbidity reduction assays with EF24, VRE2, and clinical isolates derived from patients with E. faecalis-related postoperative endophthalmitis. Endophthalmitis was induced in mice by injection of EF24 or VRE2 (1 × 104 cells) into the vitreous. The number of viable bacteria in the eye increased to >1 × 107 CFU, and neutrophil infiltration into the eye was detected as an increase in myeloperoxidase activity at 24 h after infection. A clinical score based on loss of visibility of the fundus as well as the number of viable bacteria and the level of myeloperoxidase activity in the eye were all significantly decreased by intravitreous injection of ΦEF24C-P2 6 h after injection of EF24 or VRE2. Whereas histopathologic analysis revealed massive infiltration of inflammatory cells and retinal detachment in vehicle-treated eyes, the number of these cells was greatly reduced and retinal structural integrity was preserved in phage-treated eyes. Our results thus suggest that intravitreous phage therapy is a potential treatment for endophthalmitis caused by vancomycin-sensitive or -resistant strains of E. faecalis.
Enterococcus faecalis
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The article presents the epidemiological evaluation by the Enterococcus faecalis features, described microbiological characteristics bacterium, including pathogenicity factors, presented clinical features of the infection of the urinary system in children, caused by uropathogen, results of studies of phenotypic properties, adhesive activity and virulence factors of urinary isolates of Enterococcus faecalis.
Enterococcus faecalis
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In nine strains of Enterococcus, frequency of resistance gene transfer from MRSA caring gene acc(6')-aph(2") was investigated. Transfer was inducted in broth at 44 degrees C for 24 h. Presence of acc(6')-aph(2") gene was confirmed by PCR method. Frequency of gene transfer was the highest for strains Enterococcus faecalis isolated from humans (0.13), significant lower for Enterococcus avium (0.007) and the lowest for strains of Enterococcus faecalis isolated from animals (0.004).
Enterococcus faecalis
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Objective To explore the sensitivity of Enterococcus faeciumand Enterococcus faecalis isolated from 2011 to 2013and provide reference for anti-infection therapy.Methods The identification and drug sensitivity test of clinical isolates were carried out by using VITEK2 Compact system.Results The ratio of Enterococcus faeciumto Enterococcus faecalis isolates was 1.93 and it was increasing year by year.No vancomycin,linezolid and tigecycline resistant Enterococcus faeciumand Enterococcus faecalis isolates was detected.The rates of Enterococcus faeciumsensitive to quinupristin-dalfopristin and tetracycline were higher than Enterococcus faecalis(P0.05),and the rates of Enterococcus faeciumsensitive to nitrofurantoin,ampicillin,penicillin G,moxifloxacin,levofloxacin and ciprofloxacin were lower than that of Enterococcus faecalis(P0.05).Conclusion The detection rates of Enterococcus was shifting to Enterococcus faecium,and the trends became obvious year after year.The drug sensitivity of Enterococcus faeciumand Enterococcus faecalis is different,and doctors should choose the proper therapy according to their specific drug resistance.At present,vancomycin,linezolid and tigecycline are preffered for the treatment against infection caused by Enterococcus faeciumand Enterococcus faecalis.
Enterococcus faecalis
Tigecycline
Linezolid
Enterococcus faecium
Dalfopristin
Quinupristin
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The abuse of antibiotics usage in bird industry has resulted in the emerging antibiotic resistant Enterococci worldwide which has posed a threat clinically to human health. The present study was to screen and identify the potential virulence agents in antibiotic resistance E. faecalis in bird industry in Borneo. Enterococcus bacteria collected from the birds’ faeces and indoor air inside ten birdhouses were identified to species level and their antibiotic resistance was checked using antibiotic susceptibility discs. Specific primers using PCR assay were intended for the detection of four potential virulence genes (ace, AS, efaA, gelE). Out of the thirty-seven Enterococci faecal bacteria, the prevailing bacteria found were Enterococcus qallinacum (51%), Enterococcus faecalis (35%) and Enterococcus harae (8%). The airborne bacteria were reported as Enterococcus faecalis (5%) and Enterococcus qallinacum (1%). Twenty-seven percent of isolates were reported to have Multiple Antibiotic Resistance (MAR) index ≥ 0.2 with 9 distinct resistance patterns formed. E. faecalis showed higher resistance to vancomycin. Virulence genes were successfully reported in the 15 E. faecalis isolates. Sixty-seven percent of isolates were detected positive for four virulence genes, 27% possessed three (AS, efaA, gelE) genes and 6% possessed two (ace, AS) genes. Antibiotic resistance and virulence genes detection were significantly correlated. These virulence genes or antibiotic resistance genes were important in the pathogenesis of E. faecalis infections.
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The capacity of a preexisting coating of Escherichia coli 83972 to reduce catheter colonization by Enterococcus faecalis 210 was investigated. Enterococcus was chosen for these trials since it is a common urinary pathogen in patients with an indwelling urinary catheter.Each experiment tested 3 growth conditions. Group 1 or E. coli plus Enterococcus catheters were exposed to E. coli 83972 for 24 hours and then to Enterococcus for 30 minutes. Group 2 or E. coli alone catheters were incubated in E. coli for 24 hours and then in sterile broth for 30 minutes. Group 3 or Enterococcus alone catheters did not undergo the initial incubation with E. coli before the 30-minute incubation with Enterococcus: All catheters were then incubated in sterile human urine for 24 hours. Catheters were washed with saline and cut into 5, 1 cm. segments. Each segment was sonicated and the sonication fluid was diluted and plated. The results of each of the 5 segments were averaged and the set of experiments was repeated 7 times.A preexisting coating of E. coli 83972 reduced catheter colonization by E. faecalis 210 more than 10-fold. Enterococcus alone catheters had a median of 9.7 x 10(5) enterococci per cm., whereas E. coli plus Enterococcus catheters had a median of 0.38 x 10(5) enterococci per cm. (p = 0.016).Pre-inoculating urinary catheters with E. coli 83972 significantly impedes catheter colonization by Enterococcus: These promising in vitro results prompt the clinical investigation of this particular application of bacterial interference.
Enterococcus faecalis
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Monocyte extravasation into the vessel wall has been shown to be a critical step in the development of atherosclerosis. Upon activation, monocytes produce a burst of superoxide anion due to activation of the NADPH oxidase enzyme complex. Monocyte-derived superoxide anion contributes to oxidant stress in inflammatory sites, is required for monocyte-mediated LDL oxidation, and alters basic cell functions such as adhesion and proliferation. We hypothesize that monocyte-derived superoxide anion production contributes to atherosclerotic lesion formation. In this brief review, we summarize our current understanding of the signal transduction pathways regulating NADPH oxidase activation and related superoxide anion production in activated human monocytes. Novel pathways are identified that may serve as future targets for therapeutic intervention in this pathogenic process. The contributions of superoxide anion and NADPH oxidase to atherogenesis are discussed. Future experiments are needed to clarify the exact role of NADPH oxidase-derived superoxide anion in atherogenesis, particularly that derived from monocytes.
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Respiratory burst
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Enterococcus faecalis
Blood Culture
Peptide nucleic acid
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Enterococcus faecalis commensals of the intestinal tract of human and animals and is an important opportunistic pathogen.Enterococcus have emerged as a major cause of nosocomial infections because of antibiotcswidely used and animal feed added in.Control and therapy of an Enterococcus faecalis clinic become more and more difficult because it has special mechanisms of acquired drug resistance and some virulence factors.This study progress focuses on the biological characteristics of Enterococcus faecalis,pathogenic mechanisms,antibiotic resistance,laboratory diagnosis and treatment.
Enterococcus faecalis
Digestive tract
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