Home About us Contact
|
Home About us Contact | ||
|
|
||
Faecalis
Kinds of Faecalis Terms modified by Faecalis Selected AbstractsEnterococcus faecalis with the gelatinase phenotype regulated by the fsr operon and with biofilm-forming capacity are common in the agricultural environmentENVIRONMENTAL MICROBIOLOGY, Issue 6 2009Lilia Macovei Summary The prevalence of gelatinase activity and biofilm formation among environmental enterococci was assessed. In total, 396 enterococcal isolates from swine and cattle faeces and house flies from a cattle farm were screened for gelatinase activity. The most prevalent phenotype on Todd,Hewitt agar with 1.5% skim milk was the weak protease (WP) (72.2% of isolates), followed by the strong protease (SP) 18.7%, and no protease (NP) (9.1%). The majority of WP isolates was represented by Enterococcus hirae (56.9%), followed by Enterococcus faecium (25.9%), Enterococcus casseliflavus (10.4%), Enterococcus gallinarum (5.2%) and Enterococcus saccharolyticus (1.7%). All WP isolates were negative for gelE (gelatinase) and sprE (serine protease) as well as the fsrABDC operon that regulates the two proteases, and only four isolates (7.0%) formed biofilms in vitro. All SP isolates were Enterococcus faecalis positive for the fsrABDC, gelE, sprE genes and the majority (91.2%) formed a biofilm. Diversity of NP isolates was relatively evenly distributed among E. hirae, E. faecium, E. casseliflavus, E. gallinarum, Enterococcus durans, E. saccharolyticus and Enterococcus mundtii. All NP isolates were negative for the fsr operon and only four E. hirae (11.1%) formed a biofilm. Of further interest was the loss of the gelatinase phenotype (18.9% of isolates) from SP isolates after 4 month storage at 4,8°C and several passages of subculture. Results of reverse transcription PCR analysis indicated that mRNA was produced for all the genes in the frs operon and sequencing of the gelE gene did not reveal any significant mutations. However, gelatinase was not detectable by Western blot analysis. Our study shows that E. faecalis with the complete fsr operon and the potential to form a biofilm are relatively common in the agricultural environment and may represent a source/reservoir of clinically relevant strains. In addition, many environmental enterococci, especially E. hirae, produce an unknown WP that can hydrolyse casein but does not contribute to biofilm formation. The stability of the gelatinase phenotype in E. faecalis and its regulation will require additional studies. [source] Molecular diversity and characterization of nitrite reductase gene fragments (nirK and nirS) from nitrate- and uranium-contaminated groundwaterENVIRONMENTAL MICROBIOLOGY, Issue 1 2003Tingfen Yan Summary Nitrate-contaminated groundwater samples were analysed for nirK and nirS gene diversity. The samples differed with respect to nitrate, uranium, heavy metals, organic carbon content, pH and dissolved oxygen levels. A total of 958 nirK and 1162 nirS clones were screened by restriction fragment length polymorphism (RFLP) analysis: 48 and 143 distinct nirK and nirS clones, respectively, were obtained. A single dominant nirK restriction pattern was observed for all six samples and was 83% identical to the Hyphomicrobium zavarzinii nirK gene. A dominant nirS pattern was observed for four of the samples, including the background sample, and was 95% identical to the nirS of Alcaligenes faecalis. Diversity indices for nirK and nirS sequences were not related to any single geochemical characteristic, but results suggested that the diversity of nirK genes was inversely proportional to the diversity of nirS. Principal component analysis (PCA) of the sites based on geochemistry grouped the samples by low, moderate and high nitrate but PCA of the unique operational taxonomic units (OTUs) distributions grouped the samples differently. Many of the sequences were not closely related to previously observed genes and some phylogenetically related sequences were obtained from similar samples. The results indicated that the contaminated groundwater contained novel nirK and nirS sequences, functional diversity of both genes changed in relation to the contaminant gradient, but the nirK and nirS functional diversity was affected differently. [source] In vivo production of catalase containing haem analoguesFEBS JOURNAL, Issue 12 2010Myriam Brugna Haem (protohaem IX) analogues are toxic compounds and have been considered for use as antibacterial agents, but the primary mechanism behind their toxicity has not been demonstrated. Using the haem protein catalase in the Gram-positive bacterium Enterococcus faecalis as an experimental system, we show that a variety of haem analogues can be taken up by bacterial cells and incorporated into haem-dependent enzymes. The resulting cofactor-substituted proteins are dysfunctional, generally resulting in arrested cell growth or death. This largely explains the cell toxicity of haem analogues. In contrast to many other organisms, E. faecalis does not depend on haem for growth, and therefore resists the toxicity of many haem analogues. We have exploited this feature to establish a bacterial in vivo system for the production of cofactor-substituted haem protein variants. As a pilot study, we produced, isolated and analysed novel catalase variants in which the iron atom of the haem prosthetic group is replaced by other metals, i.e. cobalt, gallium, tin, and zinc, and also variants containing meso-protoheme IX, ruthenium meso-protoporphyrin IX and (metal-free) protoporphyrin IX. Engineered haem proteins of this type are of potential use within basic research and the biotechnical industry. Structured digital abstract ,,MINT-7722358, MINT-7722368: katA (uniprotkb:Q834P5) and katA (uniprotkb:Q834P5) physically interact (MI:0915) by copurification (MI:0025) [source] Three-dimensional structure of the histidine-containing phosphocarrier protein (HPr) from Enterococcus faecalis in solutionFEBS JOURNAL, Issue 3 2001Till Maurer The histidine-containing phosphocarrier protein (HPr) transfers a phosphate group between components of the prokaryotic phosphoenolpyruvate-dependent phosphotransferase system (PTS), which is finally used to phosphorylate the carbohydrate transported by the PTS through the cell membrane. Recently it has also been found to act as an intermediate in the signaling cascade that regulates transcription of genes related to the carbohydrate-response system. Both functions involve phosphorylation/dephosphorylation reactions, but at different sites. Using multidimensional 1H-NMR spectroscopy and angular space simulated annealing calculations, we determined the structure of HPr from Enterococcus faecalis in aqueous solution using 1469 distance and 44 angle constraints derived from homonuclear NMR data. It has a similar overall fold to that found in HPrs from other organisms. Four , strands, A, B, C, D, encompassing residues 2,7, 32,37, 40,42 and 60,66, form an antiparallel , sheet lying opposite the two antiparallel , helices, a and c (residues 16,26 and 70,83). A short , helix, b, from residues 47,53 is also observed. The pairwise root mean square displacement for the backbone heavy atoms of the mean of the 16 NMR structures to the crystal structure is 0.164 nm. In contrast with the crystalline state, in which a torsion angle strain in the active-center loop has been described [Jia, Z., Vandonselaar, M., Quail, J.W. & Delbaere, L.T.J. (1993) Nature (London) 361, 94,97], in the solution structure, the active-site His15 rests on top of helix a, and the phosphorylation site N,1 of the histidine ring is oriented towards the surface, making it easily accessible to the solvent. Back calculation of the 2D NOESY NMR spectra from both the NMR and X-ray structures shows that the active-center structure derived by X-ray crystallography is not compatible with experimental data recorded in solution. The observed torsional strain must either be a crystallization artefact or represents a conformational state that exists only to a small extent in solution. [source] Biofilms in chronic bacterial prostatitis (NIH-II) and in prostatic calcificationsFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 3 2010Sandra Mazzoli Abstract The prevalence of inflammatory conditions of the prostate gland is increasing. In Italy, there is a high incidence of prostatitis (13.3%), also accompanied by prostatic calcifications. Cat NIH-II chronic bacterial prostatitis (CBPs) are the most frequent. Their aetiology theoretically involves the whole range of bacterial species that are able to form biofilms and infect prostate cells. The aim of our study was to isolate potential biofilm-producing bacteria from CBP patients, to evaluate their ability to produce in vitro biofilms, and to characterize intraprostatic bacteria and prostatic calcifications using scanning electron microscopy. The 150 clinical bacterial strains isolated from chronic prostatitis NIH-II patients were: 50 Enterococcus faecalis; 50 Staphylococcus spp.; 30 Escherichia coli; 20 gram-negative miscellanea. Quantitative assay of biofilm production and adhesion was performed according to the classic Christensen microwell assay. Isolates were classified as nonproducers, weak, moderate or strong producers. The majority of E. coli, gram-negative bacteria, Staphylococci and Enterococci strains were strong or medium producers: 63,30%, 75,15%, 46,36%, and 58,14%, respectively. Prostatic calcifications consisted of bacteria-like forms similar to the species isolated from biological materials and calcifications of patients. Our study proves, for the first time, that bacterial strains able to produce biofilms consistently are present in CBP. Additionally, prostatic calcifications are biofilm-related. [source] Structural organization of a complex family of palindromic repeats in EnterococciFEMS MICROBIOLOGY LETTERS, Issue 1 2009Eliana De Gregorio Abstract Enterococcus faecalis/faecium repeats (EFARs) are miniature insertion sequences spread in the genome of Enterococcus faecalis and Enterococcus faecium. Unit-length repeats measure 165,170 bp and contain two modules (B and T) capable of folding independently into stem-loop sequences, connected by a short, unstructured module J. The E. faecalis elements feature only one type of B, J and T modules. In contrast, the E. faecium elements result from the assembly of different types of B, J and T modules, and may vary in length because they carry multiple B modules. Most EFARs are located close (0,20 bp) to ORF stop codons, and are thus cotranscribed with upstream flanking genes. In both E. faecalis and E. faecium cells, EFAR transcripts accumulate in a strand-dependent fashion. Data suggest that T modules function as bidirectional transcriptional terminators, which provide a 3,-end to gene transcripts spanning B modules, while blocking antisense transcripts coming in from the opposite direction. [source] Adhesion of Enterococcus faecalis 1131 grown under subinhibitory concentrations of ampicillin and vancomycin to a hydrophilic and a hydrophobic substratumFEMS MICROBIOLOGY LETTERS, Issue 1 2001Amparo M Gallardo-Moreno Abstract The effect of two subinhibitory antibiotic concentrations of ampicillin and vancomycin during growth on the adhesion of Enterococcus faecalis 1131 to glass and silicone rubber was studied in a parallel plate flow chamber. Initial deposition rates and numbers of adhering bacteria after 4 h were higher on hydrophilic glass than on hydrophobic silicone rubber, regardless of growth conditions. The presence of 1/4 minimal inhibitory concentration (MIC) of ampicillin during growth reduced enterococcal adhesion to both substrata, but growth in the presence of 1/4 MIC vancomycin did not affect the adhesion of E. faecalis. Moreover, enterococcal adhesion increased after growth in the presence of 1/8 MIC vancomycin. The increased adhesion after growth in the presence of subinhibitory concentrations of vancomycin may have strong implications for patients living with implanted biomaterials, as they may suffer adverse effects from use of this antibiotic, especially since bacteria once adhered are less sensitive to antibiotics. [source] Composition and antimicrobial activity of essential oil of Stachys plumosa Griseb.FLAVOUR AND FRAGRANCE JOURNAL, Issue 2 2006Silvana Petrovi Abstract The essential oil of Balkan endemic Stachys plumosa Griseb. obtained by steam distillation was analysed by GC and GC,MS. Essential oil yield was 0.15% (v/w) and 45 components were identified (86.9% of the total amount). Dehydroabietane was identified as the most prominent component (61.2%), while other constituents were present in much lower quantity, predominantly diterpenes kaurene and biformene (3.2% and 3.0%, respectively). The antimicrobial activity was tested on six bacterial strains and two fungal strains, using the agar diffusion method. Diameters of growth inhibition zones were measured. The most sensitive microorganisms were, in order: Pseudomonas aeruginosa > Bacillus subtilis > Enterococcus faecalis > Klebsiella pneumoniae > Candida albicans (ATCC 10259) > Candida albicans (ATCC 24433) > Escherichia coli > Staphylococcus aureus. Copyright © 2005 John Wiley & Sons, Ltd. [source] Chemical composition and antimicrobial activity of essential oils from Tunisian Pituranthos tortuosus (Coss.) MaireFLAVOUR AND FRAGRANCE JOURNAL, Issue 1 2006A. Abdelwahed Abstract The aerial parts of Pituranthos tortuosus, collected during November and April, were analysed by GC and GC,MS. In total, 56 compounds were identified by their retention indices. Antimicrobial assays showed that the November essential oil is more effective than that of April against the Gram-positive bacteria Enterococcus faecalis and Staphylococcus aureus. The April essential oil displayed the highest activity against Staphylococcus aureus. Copyright © 2005 John Wiley & Sons, Ltd. [source] Dual-association of gnotobiotic Il-10,/, mice with 2 nonpathogenic commensal bacteria induces aggressive pancolitisINFLAMMATORY BOWEL DISEASES, Issue 12 2007Sandra C. Kim MD Abstract Background: Monoassociating gnotobiotic IL-10-deficient (,/,) mice with either nonpathogenic Enterococcus faecalis or a nonpathogenic Escherichia coli strain induces T-cell-mediated colitis with different kinetics and anatomical location (E. faecalis: late onset, distal colonic; E. coli: early onset, cecal). Hypothesis: E. faecalis and E. coli act in an additive manner to induce more aggressive colitis than disease induced by each bacterial species independently. Methods: Germ-free (GF) inbred 129S6/SvEv IL-10,/, and wildtype (WT) mice inoculated with nonpathogenic E. faecalis and/or E. coli were killed 3,7 weeks later. Colonic segments were scored histologically for inflammation (0 to 4) or incubated in media overnight to measure spontaneous IL-12/IL-23p40 secretion. Bacterial species were quantified by serial dilution and plated on culture media. Mesenteric lymph node (MLN) CD4+ cells were stimulated with antigen-presenting cells pulsed with bacterial lysate (E. faecalis, E. coli, Bacteroides vulgatus) or KLH (unrelated antigen control). IFN-, and IL-17 levels were measured in the supernatants. Results: Dual-associated IL-10,/, (but not WT) mice developed mild-to-moderate pancolitis by 3 weeks that progressed to severe distal colonic-predominant pancolitis with reactive atypia and duodenal inflammation by 7 weeks. NF-,B was activated in the duodenum and colon in dual-associated IL-10,/, × NF-,BEGFP mice. The aggressiveness of intestinal inflammation and the degree of antigen-specific CD4+ cell activation were greater in dual- versus monoassociated IL-10,/, mice. Conclusion: Two commensal bacteria that individually induce phenotypically distinct colitis in gnotobiotic IL-10,/, mice act additively to induce aggressive pancolitis and duodenal inflammation. (Inflamm Bowel Dis 2007) [source] Segmented filamentous bacteria in a defined bacterial cocktail induce intestinal inflammation in SCID mice reconstituted with CD45RBhigh CD4+ T cellsINFLAMMATORY BOWEL DISEASES, Issue 10 2007Renata Stepankova PhD Abstract Background: The aim was to analyze the influence of intestinal microbiota on the development of intestinal inflammation. We used the model of chronic inflammation that develops spontaneously in the colon of conventional severe combined immunodeficiency (SCID) mice restored with the CD45 RBhigh subset of CD4+T cells isolated from the spleen of normal BALB/c mice. Methods: A CD4+CD45RBhigh subpopulation of T cells was purified from the spleen of conventional BALB/c mice by magnetic separation (MACS) and transferred into immunodeficient SCID mice. Germ-free (GF) SCID mice or SCID mice monoassociated with Enterococcus faecalis, SFB (segmented filamentous bacteria), Fusobacterium mortiferum, Bacteroides distasonis, and in combination Fusobacterium mortiferum + SFB or Bacteroides distasonis + SFB were used as recipients. SCID mice were colonized by a defined cocktail of specific pathogen-free (SPF) bacteria. Mice were evaluated 8,12 weeks after the cell transfer for clinical and morphological signs of inflammatory bowel disease (IBD). Results: After the transfer of the CD4+CD45RBhigh T-cell subpopulation to SCID mice severe colitis was present in conventional animals and in mice colonized with a cocktail of SPF microflora plus SFB. Altered intestinal barrier in the terminal ileum of mice with severe colitis was documented by immunohistology using antibodies to ZO-1 (zona occludens). Conclusions: Only SFB bacteria together with a defined SPF mixture were effective in triggering intestinal inflammation in the model of IBD in reconstituted SCID mice, while no colitis was detected in GF mice or in mice colonized either with SPF microflora or monoassociated only with SFB or colonized by Bacteroides distasonis + SFB or Fusobacterium mortiferum + SFB. (Inflamm Bowel Dis 2007) [source] The effect of ultrasonically activated irrigation on reduction of Enterococcus faecalis in experimentally infected root canalsINTERNATIONAL ENDODONTIC JOURNAL, Issue 11 2010A. J. Harrison Harrison AJ, Chivatxaranukul P, Parashos P, Messer HH. The effect of ultrasonically activated irrigation on reduction of Enterococcus faecalis in experimentally infected root canals. International Endodontic Journal, 43, 968,977, 2010. Abstract Aim, To investigate the ability of an ultrasonically activated irrigating system to eliminate bacteria from the canal wall and dentinal tubules of extracted teeth. Methodology, One hundred and thirty roots of intact human teeth were inoculated with Enterococcus faecalis for 4 weeks. The straight roots were randomly allocated to a baseline group (n = 25) or subjected to routine cleaning and shaping procedures (n = 105). Two sub-groups of prepared canals were then additionally exposed either to ultrasonic irrigation with 1% sodium hypochlorite (NaOCl) for 1 min (n = 35) or to 1 week of intracanal medication with calcium hydroxide [Ca(OH)2] (n = 35). All roots were processed for light microscopy (Brown and Brenn stain) (n = 28) or scanning electron microscopy (n = 7). Triplicate histological sections from each of the apical, middle and coronal thirds were scored for bacterial presence using pre-defined criteria. Results, Baseline bacterial penetration resulted in an average depth of tubule invasion of 151 ,m. Routine canal preparation failed to eliminate bacteria consistently from either the canal wall or within tubules. Ultrasonic irrigation and medication with Ca(OH)2 consistently eliminated bacteria from the canal wall (P < 0.001) compared with baseline and routine treatment, and more frequently from dentinal tubules than routine canal preparation alone (P < 0.01). Ultrasonic irrigation was as effective in bacterial reduction as 1 week of intracanal medication with Ca(OH)2, but neither led to complete bacterial elimination in all roots. Conclusions, Ultrasonically activated irrigation for 1 min with 1% NaOCl after canal preparation in straight root canals is potentially an effective supplementary step in microbial control. [source] Antibacterial effects of MDPB against anaerobes associated with endodontic infectionsINTERNATIONAL ENDODONTIC JOURNAL, Issue 8 2010N. Izutani Izutani N, Imazato S, Noiri Y, Ebisu S. Antibacterial effects of MDPB against anaerobes associated with endodontic infections. International Endodontic Journal. Abstract Aim, To investigate the antibacterial effects of 12-methacryloyloxydodecylpyridinium bromide (MDPB), an antibacterial monomer synthesized by combining quaternary ammonium with a methacryloyl group, against three anaerobes associated with endodontic infections using planktonic and biofilm cells. Methodology, The antibacterial activity of unpolymerized MDPB against Enterococcus faecalis, Fusobacterium nucleatum and Prevotella nigrescens was examined by agar-disc diffusion tests and determination of the minimum inhibitory/bactericidal concentrations (MIC/MBC). Rapid killing effects of MDPB against three bacteria in planktonic form were examined by a cell number counting method, and those against biofilm cells were assessed by a viability staining method. Results, MDPB demonstrated inhibition against all of the bacteria tested by agar-disc diffusion tests. The MIC/MBC values of MDPB for the three anaerobes were much smaller than those of other resin monomers, although greater compared with those of cetylpyridinium chloride or chlorhexidine diacetate for E. faecalis and F. nucleatum. Significant reduction in viable planktonic cells was obtained by contact with 250 ,g mL,1 of MDPB for 20 s (P < 0.05, Fisher's PLSD tests), and 40 s contact with 500 ,g mL,1 or 20 s contact with 1000 ,g mL,1 of MDPB resulted in more than 90% killing. Biofilm cells of all species were completely killed by application of 1000 ,g mL,1 of MDPB for 60 s. Conclusion, MDPB was found to have strong antibacterial effects against E. faecalis, F. nucleatum and P. nigrescens, and such effects were rapidly exhibited even against biofilm cells, suggesting the usefulness of application of MDPB to resin-based materials for root canal filling. [source] Investigation of the interactions between neutrophils and endodontic isolates of Enterococcus faecalisINTERNATIONAL ENDODONTIC JOURNAL, Issue 4 2010R. Sairafi Aim, The primary aim of this study was to investigate the effect of phagocytosis by neutrophils on the antimicrobial sensitivity of Enterococcus faecalis strains. A secondary aim was to determine whether carriage of a plasmid encoding aggregation substance (AS), which has been reported to increase the survival of some strains inside neutrophils, affected the antimicrobial susceptibility of E. faecalis after phagocytosis by neutrophils. Methodology, An assay was carried out to identify isolates of E. faecalis which demonstrated pheromone-responsive clumping caused by the production of aggregation substance (AS). Four E. faecalis strains grown to both logarithmic and stationary phases were exposed to sodium hypochlorite (NaOCl) and chlorhexidine gluconate (CHX) to determine the minimum inhibitory concentrations of these two agents. The antimicrobial susceptibility tests were repeated with E. faecalis strains which survived phagocytosis by neutrophils for 18 h. Results, As expected a laboratory strain of E. faecalis OG1RF which was AS negative became AS positive after introduction of the pheromone responsive plasmid pCF10 into the bacterium to give strain OG1RF(pCF10). These two strains and two endodontic isolates, E08-584 which demonstrated pheromone-responsive clumping and E08-398 which did not, were selected for further study All the test E. faecalis strains were inhibited by low concentrations of sodium hypochlorite (MIC range 0.02,0.3%) and chlorhexidine gluconate (MIC range 0.0004,0.004%). Bacteria recovered from inside neutrophils after 18 h following phagocytosis were susceptible to both ¼MIC and MIC of CHX and NaOCl. Conclusions, Aggregation substance did not appear to affect the antimicrobial susceptibility of any of the strains to CHX or NaOCl. All of the E. faecalis strains examined were capable of survival for 18 h inside the neutrophils following phagocytosis; regardless of their capacity to produce aggregation substance. In addition, all strains of E. faecalis had enhanced susceptibilities to the antimicrobial agents after residence inside neutrophils for 18 h. [source] Effectiveness of ozone against endodontopathogenic microorganisms in a root canal biofilm modelINTERNATIONAL ENDODONTIC JOURNAL, Issue 1 2009K. C. Huth Abstract Aim, To assess the antimicrobial efficacy of aqueous (1.25,20 ,g mL,1) and gaseous ozone (1,53 g m,3) as an alternative antiseptic against endodontic pathogens in suspension and a biofilm model. Methodology,Enterococcus faecalis, Candida albicans, Peptostreptococcus micros and Pseudomonas aeruginosa were grown in planctonic culture or in mono-species biofilms in root canals for 3 weeks. Cultures were exposed to ozone, sodium hypochlorite (NaOCl; 5.25%, 2.25%), chlorhexidine digluconate (CHX; 2%), hydrogen peroxide (H2O2; 3%) and phosphate buffered saline (control) for 1 min and the remaining colony forming units counted. Ozone gas was applied to the biofilms in two experimental settings, resembling canal areas either difficult (setting 1) or easy (setting 2) to reach. Time-course experiments up to 10 min were included. To compare the tested samples, data were analysed by one-way anova. Results, Concentrations of gaseous ozone down to 1 g m,3 almost and aqueous ozone down to 5 ,g mL,1 completely eliminated the suspended microorganisms as did NaOCl and CHX. Hydrogen peroxide and lower aqueous ozone concentrations were less effective. Aqueous and gaseous ozone were dose- and strain-dependently effective against the biofilm microorganisms. Total elimination was achieved by high-concentrated ozone gas (setting 2) and by NaOCl after 1 min or a lower gas concentration (4 g m,3) after at least 2.5 min. High-concentrated aqueous ozone (20 ,g mL,1) and CHX almost completely eliminated the biofilm cells, whilst H2O2 was less effective. Conclusion, High-concentrated gaseous and aqueous ozone was dose-, strain- and time-dependently effective against the tested microorganisms in suspension and the biofilm test model. [source] Octenidine in root canal and dentine disinfection ex vivoINTERNATIONAL ENDODONTIC JOURNAL, Issue 11 2007L. Tandjung Abstract Aim, The aim of the present study was to investigate the antimicrobial activity of octenidine on Enterococcus faecalis ATCC 29212 in a dentine block model. Methodology, Fifty-six root segments of extracted human teeth were infected with E. faecalis for 4 weeks. Octenidine-phenoxyethanol gel (1 : 1) was applied for different timing: 1 min, 10 min, 7 days and in a different formula (1 : 3) for 10 min. Three samples were chosen for the group with placebo gel and for the group without infection (negative control). Dentine samples were collected, and the total count of bacteria and colony-forming units were determined. In addition, for controls and the 10 min group with 1 : 1 gel, the proportion of viable bacteria (PVB) was assessed. Results, Octenidine was particularly effective after incubation periods of 10 min and 7 days. The mean PVB decreased significantly from 57.2% to 5.7% after 10 min application. After 7 days, only one of 10 samples showed positive culture. Conclusion, The present study showed the effectiveness of octenidine against E. faecalis in dentine disinfection. Further laboratory and clinical studies are required. [source] Response to alkaline stress by root canal bacteria in biofilmsINTERNATIONAL ENDODONTIC JOURNAL, Issue 5 2007L. E. Chávez de Paz Abstract Aim, To determine whether bacteria isolated from infected root canals survive alkaline shifts better in biofilms than in planktonic cultures. Methodology, Clinical isolates of Enterococcus faecalis, Lactobacillus paracasei, Olsenella uli, Streptococcus anginosus, S. gordonii, S. oralis and Fusobacterium nucleatum in biofilm and planktonic cultures were stressed at pH 10.5 for 4 h, and cell viability determined using the fluorescent staining LIVE/DEAD BacLight bacterial viability kit. In addition, proteins released into extracellular culture fluids were identified by Western blotting. Results,Enterococcus faecalis, L. paracasei, O. uli and S. gordonii survived in high numbers in both planktonic cultures and in biofilms after alkaline challenge. S. anginosus, S. oralis and F. nucleatum showed increased viability in biofilms compared with planktonic cultures. Alkaline exposure caused all planktonic cultures to aggregate into clusters and resulted in a greater extrusion of cellular proteins compared with cells in biofilms. Increased levels of DnaK, HPr and fructose-1,6-bisphosphate aldolase were observed in culture fluids, especially amongst streptococci. Conclusions, In general, bacteria isolated from infected roots canals resisted alkaline stress better in biofilms than in planktonic cultures, however, planktonic cells appeared to use aggregation and the extracellular transport of specific proteins as survival mechanisms. [source] Efficacy of various concentrations of NaOCl and instrumentation techniques in reducing Enterococcus faecalis within root canals and dentinal tubulesINTERNATIONAL ENDODONTIC JOURNAL, Issue 1 2006V. B. Berber Abstract Aim, To evaluate the efficacy of 0.5%, 2.5% and 5.25% sodium hypochlorite (NaOCl) as intracanal irrigants associated with hand and rotary instrumentation techniques against Enterococcus faecalis within root canals and dentinal tubules. Methodology, A total of 180 extracted human premolar teeth were infected for 21 days with E. faecalis. The specimens were divided into 12 groups, as follows: group 1: 5.25% NaOCl + Hybrid technique (Valdrighi et al. 1998); group 2: 5.25% NaOCl + nickel,titanium (NiTi) rotary technique 4 mm shorter than the apex (by FOP-UNICAMP); group 3: 5, 25% NaOCl + NiTi rotary technique (Hero 642); group 4: 2.5% NaOCl +Hybrid technique; group 5: 2.5% NaOCl + NiTi rotary technique 4 mm shorter than the apex; group 6: 2.5% NaOCl + NiTi rotary technique (Hero 642); group 7: 0.5% NaOCl + Hybrid technique; group 8: 0.5% NaOCl + NiTi rotary technique 4 mm shorter than the apex; group 9: 0.5% NaOCl + NiTi rotary technique (Hero 642); group 10: sterile saline solution + Hybrid technique; group 11: sterile saline solution + NiTi rotary technique 4 mm shorter than the apex; group 12: sterile saline solution + NiTi rotary technique (Hero 642). Canals were sampled before and after preparation. After serial dilution, samples were plated onto brain heart infusion (BHI) agar, and the colony forming units (CFU) that were grown were counted. The teeth were sectioned into three thirds and dentine chips were removed from the canals with conical burs. The samples obtained with each bur were immediately collected into test tubes containing BHI broth, and were incubated at 37 °C and plated onto BHI agar. The CFU were counted and analysed. Results, At all depths and thirds of the root canals and for all techniques used, 5.25% NaOCl was shown to be the most effective irrigant solution tested when dentinal tubules were analysed, followed by 2.5% NaOCl. No differences among concentrations in cleaning the canals were found. Conclusions, Especially at higher concentrations, NaOCl, was able to disinfect the dentinal tubules, independent of the canal preparation technique used. [source] Recovery of Enterococcus faecalis after single- or multiple-visit root canal treatments carried out in infected teeth ex vivoINTERNATIONAL ENDODONTIC JOURNAL, Issue 10 2005N. Vivacqua-Gomes Abstract Aim, To assess the presence of Enterococcus faecalis after root canal treatment in single or multiple visits in an ex vivo model. Methodology, Forty-five premolar teeth were infected ex vivo with E. faecalis for 60 days. The canals were then prepared using a crowndown technique with System GT and Gates,Glidden burs and irrigated with 2% chlorhexidine gel. The specimens were divided into five groups (G1, G2, G3, G4 and G5) according to the time elapsed between chemical,mechanical preparation and root canal filling, the irrigant solution used and the use or nonuse of a calcium hydroxide intra-canal medicament. The teeth were then root-filled and incubated for 60 days at 37 °C. Dentine chips were removed from the canal walls with sequential sterile round burs at low speed. The samples obtained with each bur were immediately collected in separate test tubes containing Brain,Heart Infusion broth. These samples were placed onto agar plates and colony forming units were counted after 24 h at 37 °C. Data were ranked and analysed using the Kruskal,Wallis statistical test. Results,Enterococcus faecalis was recovered from 20% (three of 15 specimens) of G1 (chlorhexidine irrigation and immediate root filling in a single visit), 25% (four of 15 specimens) of G2 (chlorhexidine irrigation and filling after 14 days use of a calcium hydroxide dressing in multiple visits), 40% (two of five specimens) of G3 (chlorhexidine irrigation and filling after 7 days), 60% (three of five specimens) of G4 (saline irrigation and filling after 7 days) and from 100% (five of five specimens) of G5 (saline irrigation and immediate filling without sealer). Conclusions, Neither single- nor multiple-visit root canal treatment ex vivo, eliminated E. faecalis completely from dentinal tubules. Up to 60 days after root filling, E. faecalis remained viable inside dentinal tubules. When no sealer was used, E. faecalis presented a higher growth rate. [source] An in-vitro investigation of the antibacterial effect of nisin in root canals and canal wall radicular dentineINTERNATIONAL ENDODONTIC JOURNAL, Issue 10 2004S. R. Turner Abstract Aim, To determine whether nisin, a bacteriocin, would be effective at killing Enterococcus faecalis and Streptococcus gordonii cells in solution and within the root canal system. Methodology, Bacterial isolates of E. faecalis and S. gordonii were grown from glycerol stocks in closed tubes containing BHY broth at 37 °C. The minimum bactericidal concentration (MBC) of nisin for both bacterial species was determined by a microdilution method. Extracted human teeth were decoronated to produce roots of equal length with a single canal and divided into six groups of 10 roots. The canals were prepared to a master apical size 30 file using 0.04 taper Ni-Ti rotary instruments. Bacterial samples of each species were inoculated into three groups of prepared roots and incubated in closed tubes at 37 °C for 21 days. The root canals in each group were then medicated with water (control), calcium hydroxide powder mixed with sterile water [Ca(OH)2], or nisin and incubated for a further 7 days. Rotary Ni-Ti files were used to take radicular dentine samples from the walls of each canal which were then incubated in BHY broth for 24 h. Optical density (OD600) readings were taken as a measure of bacterial growth. Results, The MBC of nisin for E. faecalis and S. gordonii was 70 and 20 mg mL,1 respectively. Calcium hydroxide and nisin medication eradicated infection within the root canal while cells remained viable in the control group. Mean optical density (OD600) readings from canal wall dentine shavings infected with E. faecalis were 1.32 ± 0.98, 0.73 ± 0.27 and 0.69 ± 0.38 for the control, Ca(OH)2 and nisin samples respectively. Corresponding mean readings for S. gordonii were 1.19 ± 0.18, 0.73 ± 0.15 and 0.60 ± 0.29. The Ca(OH)2 and nisin group readings were significantly (P < 0.01) lower than the control for each species as tested by Student's t -test and Mann,Whitney U statistical analysis. Values for Ca(OH)2 and nisin were not significantly (P > 0.01) different. Conclusion, Nisin was effective at eradicating E. faecalis and S. gordonii cells in pure culture and was comparable with Ca(OH)2 in the elimination of these species from within the root canal system. [source] Antimicrobial activity of varying concentrations of sodium hypochlorite on the endodontic microorganisms Actinomyces israelii, A. naeslundii, Candida albicans and Enterococcus faecalisINTERNATIONAL ENDODONTIC JOURNAL, Issue 7 2004C. E. Radcliffe Abstract Aim, To determine the resistance of microorganisms associated with refractory endodontic infections to sodium hypochlorite used as a root canal irrigant. Methodology, Two strains each of Actinomyces naeslundii, Candida albicans and Enterococcus faecalis were tested as late logarithmic phase inocula, against sodium hypochlorite adjusted to 0.5, 1.0, 2.5 and 5.25% w/v. Contact times used were 0, 10, 20, 30, 60 and 120 s. In the case of E. faecalis, additional experiments used contact times of 1.0, 2.0, 5.0, 10.0 and 30.0 min. Anti-microbial action was halted by sodium thiosulphate addition. Survivors were measured primarily using viable counts on drop plates. Additionally, pour plates were used to count low colony-forming units (cfu) and dilutions to 10,6 were used to count high cfu. Results, All concentrations of NaOCl lowered cfu below the limit of detection after 10 s in the case of A. naeslundii and C. albicans. However, E. faecalis proved to be more resistant to NaOCl. Using 0.5% NaOCl for 30 min reduced cfu to zero for both strains tested. This compares with 10 min for 1.0%, 5 min for 2.5% and 2 min for 5.25% (P < 0.001). Regression analysis for the dependent variable loge(count + 1) with loge(time + 1) and concentration as explanatory variables gave rise to a significant interaction between time and concentration (P < 0.001). Conclusion, The published association of E. faecalis with refractory endodontic infection may result, at least partially, from high resistance of this species to NaOCl. This does not appear to be the case with A. naeslundii or C. albicans. [source] In vitro antimicrobial effect of chlorhexidine-impregnated gutta percha points on Enterococcus faecalisINTERNATIONAL ENDODONTIC JOURNAL, Issue 2 2004J. N. Lui Abstract Aim, To evaluate the in vitro antimicrobial effect of chlorhexidine-impregnated gutta percha points, Roeko activ point (Roeko, Langenau, Germany) on Enterococcus faecalis. Methodology, Human maxillary premolar roots were prepared with .04 rotary ProFile instruments to a master apical file size 40, autoclave-sterilized and then infected with E. faecalis (ATCC 29212) for 3 weeks. Baseline controls were carried out verifying negligible effects of plain gutta percha cones on E. faecalis. Subsequent to intracanal placement of calcium hydroxide, ,activ points' or saline (positive control) and the 2-week incubation in 54 root specimens, dentine sampling at depths of 100 and 250 µm was carried out using .04 rotary ProFile instruments at sizes 60 and 90 to assess the quantity of bacteria present. Inactivating agents were used prior to sampling and the colony-forming units (CFU) of E. faecalis were then plate-counted after culturing. Statistical analysis was completed using the paired t -test. Results, In comparison to the positive control, treatment with calcium hydroxide (P = 0.000 and 0.000) or activ points (P = 0.000 and 0.002) produced significantly lower colony counts of E. faecalis at dentine depths of 100 and 250 µm, respectively. Calcium hydroxide (2.10 × 102 CFU mL,1) was significantly more effective than activ points (1.58 × 103 CFU mL,1) at 100 µm (P = 0.013), but not at 250 µm (P = 0.353). Neither of these two medications was able to eliminate E. faecalis completely. Conclusions, Chlorhexidine-impregnated activ points did not possess an in vitro inhibitory activity strong enough to eliminate E. faecalis completely from infected dentinal tubules. [source] In vitro antimicrobial activity of several concentrations of sodium hypochlorite and chlorhexidine gluconate in the elimination of Enterococcus faecalisINTERNATIONAL ENDODONTIC JOURNAL, Issue 6 2001B. P. F. A. Gomes Abstract Aim The aim of this study was to assess, in vitro, the effectiveness of several concentrations of NaOCl (0.5%, 1%, 2.5%, 4% and 5.25%) and two forms of chlorhexidine gluconate (gel and liquid) in three concentrations (0.2%, 1% and 2%) in the elimination of E. faecalis. Methodology A broth dilution test using 24-well cell culture plates was performed and the time taken for the irrigants to kill bacterial cells was recorded. Isolated 24 h colonies of pure cultures of E. faecalis grown on 10% sheep blood plus Brain Heart Infusion (BHI) agar plates were suspended in sterile 0.85% NaCl solution. The cell suspension was adjusted spectrophotometrically to match the turbidity of a McFarland 0.5 scale. One mL of each tested substance was placed on the bottom of wells of 24-well cell culture plates (Corning, NY), including the control group (sterile saline). Six wells were used for each time period and irrigant concentration. Two mL of the bacterial suspension were ultrasonically mixed for 10 s with the irrigants and placed in contact with them for 10, 30, and 45 s; 1, 3, 5, 10, 20, and 30 min; and 1 and 2 h. After each period of time, 1 mL from each well was transferred to tubes containing 2 mL of freshly prepared BHI + neutralizers in order to prevent a residual action of the irrigants. All tubes were incubated at 37°C for 7 days. The tubes considered to have positive growth were those which presented medium turbidity during the incubation period. Data were analysed statistically by the Kruskal,Wallis test, with the level of significance set at P < 0.05. Results All irrigants were effective in killing E. faecalis, but at different times. Chlorhexidine in the liquid form at all concentrations tested (0.2%, 1% and 2%) and NaOCl (5.25%) were the most effective irrigants. However, the time required by 0.2% chlorhexidine liquid and 2% chlorhexidine gel to promote negative cultures was only 30 s and 1 min, respectively. Conclusions Even though all tested irrigants possessed antibacterial activity, the time required to eliminate E. faecalis depended on the concentration and type of irrigant used. [source] Isolation of yeasts and enteric bacteria in root-filled teeth with chronic apical periodontitisINTERNATIONAL ENDODONTIC JOURNAL, Issue 6 2001V. Peciuliene Abstract Aims The aim of this study was to determine the occurrence and role of yeasts, enteric gram-negative rods and Enterococcus species in root-filled teeth with chronic apical periodontitis, and the antimicrobial effect of iodine potassium iodide (IKI) irrigation. Methodology Forty symptom-free root-filled teeth with chronic apical periodontitis were included in the study. The patients were divided into two groups. In group A the canals were filled with calcium hydroxide for 10,14 days after cleaning and shaping; in group B the canals were irrigated with IKI for 5 min after cleaning and shaping followed by a permanent root filling. Microbiological samples were taken from the canals before and after the chemomechanical preparation and after iodine irrigation (group B). Results Microbes were isolated from 33 of 40 teeth in the initial sampling. Yeasts were isolated from six teeth, three of them together with E. faecalis. Enteric rods (Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis) were present in three teeth and E. faecalis was isolated from 21 of the 33 culture positive teeth, 11 in pure culture. Growth was detected in 10 teeth of the second samples. Six of the 10 cases were E. faecalis, with five being a pure culture. All third samples (after IKI) except one were negative. The number of microbial cells per sample did not correlate with lesion size. Two flare-ups were recorded, both in teeth with a mixed infection. Conclusion The high prevalence of enteric bacteria and yeasts in root-filled teeth with chronic apical periodontitis was established. IKI improved the antimicrobial effect of the treatment. [source] Effect of conditioning films and a novel anti-adherent agent on bacterial adherence to dentineINTERNATIONAL ENDODONTIC JOURNAL, Issue 4 2001A. Maglad Aim,Adherence of bacteria to dentine is a prerequisite to infection of the root canal system, yet adherence of root canal bacteria to dentine is poorly understood. The aim of this study was to evaluate the effect of conditioning films and anti-adherent compounds on bacterial adherence to dentine. Methodology,Freshly extracted molar teeth were prepared and sectioned to give 225 discs of predetermined dimensions. The discs were allocated to two groups. Group 1 (n = 189) was divided into three subgroups (n = 63) and coated with one of three conditioning agents (artificial saliva, serum, or distilled water) prior to bacterial inoculation. Group 2 discs (n = 36) were treated with either a novel anti-adherent agent (PC1036, Biocompatibles) (n = 18) or distilled water (n = 18) prior to conditioning with artificial saliva. Monospecies bacterial biofilms were generated on the dentine discs by incubating them in brain heart infusion broth (37 gL,1) containing Streptococcus intermedius (Si), Enterococcus faecalis (Ef) or Lactobacillus fermentum (Lf) (originally isolated from infected root canals). The number of bacteria adhering to the discs in each of the groups was determined using standard serial dilution protocols. Additional discs were prepared under all conditions for scanning electron microscopy. Where appropriate, statistical analysis by one way anova, post hoc Bonferroni, and independent t -test were used. Results,Si adhered significantly better to dentine when conditioned with serum compared with artificial saliva (P = 0.005) or distilled water (P = 0.009). Conversely, Ef adhered significantly better to the control discs (distilled water) compared with serum conditioned discs (P = 0.016). The conditioning films had no effect on the adherence of Lf, which adhered to the dentine discs significantly less (P = 0.001) than either Si or Ef. The anti-adherent coating significantly reduced the number of Si adhering to the dentine compared with the control (P = 0.012). Conclusion,Given the importance of adherence in root canal infection it is conceivable that an anti-adherent compound, could be used to prevent bacterial recontamination of cavities or the root canal system. [source] Inactivation of root canal medicaments by dentine, hydroxylapatite and bovine serum albuminINTERNATIONAL ENDODONTIC JOURNAL, Issue 3 2001I. Portenier Abstract Aim This study examined and compared the inhibition of the antibacterial effect of saturated calcium hydroxide solution, chlorhexidine acetate and iodine potassium iodide by dentine, hydroxylapatite and bovine serum albumin. MethodologyEnterococcus faecalis strain A197A prepared to a suspension of 3 × 108 cells per ml in 0.5% peptone water was used. Fifty µL of saturated calcium hydroxide solution, 0.05% chlorhexidine acetate or 0.2/0.4% iodine potassium iodide were incubated at 37 °C with 28 mg dentine powder (DP), hydroxylapatite (HA) or bovine serum albumin (BSA) in 50 µL water for 1 h before adding 50 µL of the bacterial suspension. Samples for bacterial culturing were taken from the suspension 1 and 24 h after adding the bacteria. In further experiments, the amount of dentine was stepwise reduced from 28 mg 150 µL,1 to 2.8 mg 150 µL,1. Results Calcium hydroxide was totally inactivated by the presence of 28 mg of DP, HA or BSA. Chlorhexidine (0.05%) was strongly inhibited by BSA and slowed down by dentine. However, HA had little or no inhibitory effect on chlorhexidine. The antibacterial effect of 0.2/0.4% iodine potassium iodide on E. faecalis was totally inhibited by dentine (28 mg), but was practically unaffected by HA or BSA. A stepwise reduction of dentine from 28 mg 150 µL,1 to 2.8 mg 150 µL,1 was followed by a similar reduction of the inhibition of the antibacterial activity of chlorhexidine. Iodine potassium iodide was not inhibited at all with dentine amounts less than 28 mg. However, the effect of saturated calcium hydroxide solution was totally eliminated by dentine, in all four concentrations. Conclusion Inhibition by dentine of the antibacterial activity of calcium hydroxide, chlorhexidine and iodine potassium iodide occurs by different mechanisms. Different components of dentine may be responsible for the inhibition of these three medicaments. Calcium hydroxide was particularly sensitive to inhibition by both inorganic and organic compounds. [source] Technological characterization of the natural lactic acid bacteria of artisanal Turkish White Pickled cheeseINTERNATIONAL JOURNAL OF DAIRY TECHNOLOGY, Issue 2 2008ELIF DAGDEMIR The aim of this study was to characterize the lactic acid bacteria (LAB) isolated from White Pickled cheeses produced with traditional methods; and to improve the quality of cheesemaking with a selection of bacterial cultures from artisanal White cheeses. LAB were isolated and identified from 30 White Pickled cheese samples collected from various cities in Turkey. Also, the numbers of several microbial groups (total aerobic mesophilic bacteria, LAB, enterococci, coliforms, moulds and yeasts) of cheese samples were enumerated. Lactobacilli, lactococci and enterococci were the most abundant microbial groups. The numbers of Enterococcus and Lactobacillus isolates were higher than those of the other LAB. Enterococcus faecalis (24.43%), Enterococcus faecium (17.61%) and Lactobacillus fermentum (19.88%) isolates were the most frequently isolated species. Lactococcus strains showed the highest acidifying activity, followed by Enterococcus and Lactobacillus strains. Proteolytic activity of Enterococcus faecalis strains was higher than that of the other enterococci species, except Enterococcus avium strains. Within lactobacilli strains, the highest mean proteolytic activity was that of Lactobacillus bifermentans, Lactobacillus brevis and Lactobacillus casei strains. [source] Potential of peanut skin phenolic extract as antioxidative and antibacterial agent in cooked and raw ground beefINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 7 2010Jianmei Yu Summary This study investigated the potential of peanut skin extract (PSE) as inhibitor of lipid oxidation in cooked and raw ground beef (GB) and as antimicrobial agent in raw GB. Results show that addition of PSE to raw GB before cooking significantly inhibited the formation of peroxides and TBARS in cooked GB during the refrigerated storage. PSE at concentration ,0.06% was as effective as BHA/BHT at 0.02% in inhibiting lipid oxidation. PSE also inhibited the oxidation of meat pigments thereby preserving the fresh redness of treated meat when used at 0.02,0.10%. Microplate assay showed complete inhibition of test bacteria (Bacillus subtilis, Salmonella typhimurium, Staphylococcus aureus, Streptococcus faecalis and Escherichia coli) in the presence of PSE at 0.4% or higher. However, the antimicrobial effect of PSE in GB was less potent. Hence, PSE can primarily serve the dual purposes of preserving the colour of raw GB and preventing lipid oxidation in cooked products. [source] Assessment of survival of Listeria monocytogenes, Salmonella Infantis and Enterococcus faecalis artificially inoculated into experimental waste or compostJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2010N. Paniel Abstract Aims:, To evaluate survival of pathogenic strains, Listeria monocytogenes and Salmonella Infantis and a sanitation indicator Enterococcus faecalis in composts at different stages of the composting process and during storage. Methods and Results:, The studied pathogenic and indicator strains, originally isolated from compost, were inoculated into compost samples from the various stages of the composting process. During incubation, indigenous microflora diversity was monitored with DGGE analysis. After 90 days of incubation, strain survival was observed in compost sampled before the beginning of the cooling phase, and DGGE analysis demonstrated an increase of microbial diversity up to the cooling phase. However, inoculated strains were not detected in composts after 30, 60 or 90 days of incubation in compost sampled after the start of the cooling phase. Microbial diversity also became stable, and DGGE profiles reached a maximum number of bands at this stage. Conclusions:, Strain survival was not observed in stabilized composts. The cooling phase seems to be the turning point for pathogen survival and at this stage the indigenous microflora appeared to play a significant role in suppression. Significance and Impact of the Study:, The importance of indigenous microflora in the survival of pathogens in four different composts was demonstrated. Stabilized composts were recommended for spreading on land. [source] Characterization of enterococci populations collected from a subsurface flow constructed wetlandJOURNAL OF APPLIED MICROBIOLOGY, Issue 4 2010A.K. Graves Abstract Aims:, The aim of this study was to identify and characterize the population of Enterococcus sp. in domestic wastewater as it flows through a constructed wetland. Methods and Results:, Four hundred and eighty-four Enterococcus isolates were collected from the inlet, various sites within and from the outlet of a plastic lined constructed wetland in College Station, TX. The wetland treated septic tank effluent that passed sequentially through two 1·89 m3 septic tanks and a 1·89 m3 pump tank allowing 48 l doses at a 24 l min,1 rate. The Enterococcus isolates were identified to species using the commercial Biolog system. The 484 Enterococcus isolates were comprised of ten different species, including Enterococcus faecalis (30·6%), Enterococcus pseudoavium (24·0%), Enterococcus casseliflavus (12·8%), Enterococcus faecium (11·2%), Enterococcus mundtii (7·9%), Enterococcus gallinarum (6·2%), Enterococcus dispar (3·7%), Enterococcus hirae (2·1%), Enterococcus durans and Enterococcus flavescens both 0·8%. Of the 88 isolates collected from the inlet, only 9·1% of the isolates were identified as Ent. faecalis and Ent. pseudoavium (36·4%) was identified as the predominant species. Whereas of the 74 isolates collected from the outlet, the predominant species were identified as Ent. faecalis (29·7%). Species identification varied among sites within the wetland, but often Ent. faecalis was the predominant species. Conclusions:, Our data suggest that while Ent. faecalis is the predominant species of Enterococcus found in domestic wastewater, the populations may shift during treatment as the wastewater flows through the constructed wetland. Significance and Impact of the Study:, We found that shifts in Enterococcus species composition occurred during domestic wastewater treatment. This has implications for the identification of faecal pollution based on the presence of specific bacterial types associated with domestic wastewater. [source] | |||||||||||||||||||||||||||||||