Antimicrobial resistance and species composition of Enterococcus spp. isolated from waters and sands of marine recreational beaches in Southeastern Brazil

Density, species composition and antimicrobial resistance in bacteria of the Enterococcus genus were evaluated in seawater and sands from 2 marine recreational beaches with different levels of pollution. The 2 beaches showed predominance of Enterococcus faecalis and Enterococcus faecium, in the water and the sand. Dry sand presented higher densities of Enterococcus sp. and higher frequency of resistant strains than wet sand and seawater. The beach with a higher degree of pollution presented higher percentages of resistant strains (66.7% and 61.5%, in sand and in water, respectively) and resistance to a larger number of antimicrobials compared with the less polluted beach, Ilha Porchat (35.7% and 31.25% of resistant strains in sand and water, respectively). in water samples, the highest frequencies of resistance were obtained against streptomycin (38.5%) and erythromycin (25%), whilst in sand, the highest frequencies were observed in relation to erythromycin and tetracycline (38.1% and 14.3%, respectively). These results show that water and sands from beaches with high indexes of faecal contamination of human origin may be potential sources of contamination by pathogens and contribute to the dissemination of bacterial resistance. (C) 2007 Elsevier Ltd. All rights reserved.

Intake of isoflavone-supplemented soy yogurt fermented with Enterococcus faecium lowers serum total cholesterol and non-HDL cholesterol of hypercholesterolemic rats

The aim of this study was to obtain an isoflavone-supplemented soy yogurt, fermented with Enterococcus faecium CRL 183 and Lactobacillus helveticus ssp jugurti, with suitable sensory properties and to assess the effects of the final product on blood lipids in hypercholesterolemic rats. Four isoflavone supplementation procedures were tested, in which the isoflavone was added at these stages: (1) before heat-treatment; (2) after heating and before fermentation; (3) after fermentation and (4) in the okara (by-product of soy milk) flour stirred into the fermented product when consumed. The products were subjected to a test of sensory acceptability. To assess their potential hypocholesterolemic properties in vivo, four groups of rats were used: control (C), hypercholesterolemic (H), hypercholesterolemic plus fermented product (HF) and hypercholesterolemic plus isoflavone-supplemented fermented product (HFI). Hypercholesterolemia was induced in rats of groups H, HF and HFI by feeding them on a commercial rat chow to which cholesterol and cholic acid had been added. Total, HDL and non-HDL cholesterol and triglycerides were measured in the blood of the rats. No significant sensorial differences were detected among the samples of soy yogurt supplemented with isoflavones at various processing stages. Rats fed a fermented soy product enriched with isoflavones (HFI group) had significantly (P < 0.05) less serum total cholesterol (15.5%) compared with rats fed a hypercholesterolemic diet (H group). Non-HDL cholesterol was less (P < 0.05) in rats fed a fermented soy product enriched or not with isoflavones (27.4 and 23.2%) compared to H group. The HDL-C and triglyceride concentrations did not differ significantly among the groups. It was possible to obtain an isoflavone-supplemented soy yogurt with satisfactory sensory characteristics. The resulting supplemented soy yogurt was capable of producing a lipid-lowering effect in hypercholesterolemic rats, relative to the animals that did not consume this product.

A soy-based product fermented by Enterococcus faecium and Lactobacillus helveticus inhibits the development of murine breast adenocarcinoma

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Probiotic Enterococcus faecium CRL 183 inhibit chemically induced colon cancer in male Wistar rats

Several animal studies have shown that supplementation with specific strains of lactic acid bacteria could prevent the establishment, growth, and metastasis of transplantable and chemically induced tumors. The goal of this study was to determine the effect of Enterococcus faecium CRL 183 on the incidence of colorectal tumors induced experimentally by dimethylhydrazine (DMH). We used thirty 4-week old male Wistar rat. The animals belonging to the DMH groups were injected s.c 20 mg/kg body weight of 1,2 dimethylhydrazine and 1 mM EDTA (pH 6.5), in a weekly dose, for 14 weeks. Three groups were used: (1) Control (not initiated); (2) Initiated with DMH; (3) Initiated with DMH + intake of E. faecium CRL 183. At the end of the 42nd week, all the animals were euthanized; the colons were removed and analyzed histologically. All the groups were compared histologically and IL-4, IFN-gamma and TNF-alpha cytokines. The control group did not develop pre-neoplastic lesions. The E. faecium CRL 183-DMH group showed a 50% inhibition in incidence in average number of tumors (P < 0.001), reduced the formation of ACF (P < 0.001), the lowest number of adenocarcinoma being found in this group (P < 0.001) and enhanced the immune response by increasing IL-4, IFN-gamma and TNF-alpha (P < 0.001) when compared with the DMH group.

Effect of a calcium hydroxide/chlorhexidine paste as intracanal dressing in human primary teeth with necrotic pulp against Porphyromonas gingivalis and Enterococcus faecalis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of pH, available chlorine content, and antibacterial activity of endodontic irrigants and their combinations against Enterococcus faecalis

Objectives. The objectives of this study were to evaluate pH, available chlorine content, and antibacterial activity of endodontic irrigants and their combinations.Study design. The pH and chlorine content of sodium hypochlorite (NaOCl) were analyzed pure and in combination with 10% citric acid (CA) and apple vinegar (AV). The antibacterial effect of the following solutions was measured by direct contact test against Enterococcus faecalis: 2.5% NaOCl, 2.5% NaOCl + 10% CA (7:3), 2.5% NaOCl + AV (5:5), 10% CA, and AV. Sterile saline was used as control. The colony-forming units were determined by serial decimal dilutions.Results. The combination of 2.5% NaOCl with CA or AV lowered the pH and the chlorine content. NaOCl, alone or in combination was able to eliminate E. faecalis in 30 seconds, and CA, after 10 minutes. AV promoted reduction (32.2%) after 10 minutes.Conclusions. NaOCl with acidic solutions lowered the pH and the chlorine content, but did not alter its antibacterial effect. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011; 112:132-135)

Enterococcus faecalis leakage of root canal sealers: an ex vivo study

The aim of this ex vivo study was to evaluate bacterial penetration after filling root canals using 3 different techniques. Three experimental groups of 25 teeth each, obturated with lateral-warm-vertical condensation of gutta-percha, Microseal technique and EndoREZ (R) system, respectively, were tested in a split chamber model system using Enterococcus faecalis and monitored for 180 days to determine bacterial penetration. A statistical analysis was performed using the Kaplan-Meier method. Median survival time was 25 days for Microseal system, 41 for lateral-warm-vertical condensation and 81 for EndoREZ (R). Significant differences were demonstrated between Microseal and EndoREZ (R) (p<0.001) and between Microseal and lateral-warm-vertical condensation technique (p<0.05). No statistically significant differences were observed between EndoREZ (R) and lateral-warm-vertical condensation. After 180 days of assessment, 20% of the EndoREZ (R) samples resisted bacterial penetration and furthermore, the EndoREZ (R) system has the potential to be a filler system compatible with other currently used systems.

Effectiveness of calcium hydroxide-based intracanal medicaments against Enterococcus faecalis

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Antibacterial efficacy of endodontic irrigating solutions and their combinations in root canals contaminated with Enterococcus faecalis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effectiveness of ozonated water on Candida albicans, Enterococcus faecalis, and endotoxins in root canals

The aim of this study was to evaluate the effectiveness of ozonated water in the elimination of Candida albicans, Enterococcus faecalis, and endotoxins from root canals. Twenty-four single-rooted human teeth were inoculated with C. albicans and E. faecalis, and 24 specimens were inoculated with Escherichia coli endotoxin. Ozonated water (experimental group) or physiologic solution (control group) was used as irrigant agent. Antimicrobial effectiveness was evaluated by the reduction of microbial counts. Lipopolissacharide complex presence was assessed by limulus amebocyte lysate test and B-lymphocyte stimulation. Data were analyzed by Wilcoxon and Mann-Whitney tests (5%). Ozonated water significantly reduced the number of C. albicans and E. faecalis at the immediate sampling, but increased values were detected after 7 days. Ozonated water did not neutralize endotoxin. It could be concluded that ozonated water was effective against C. albicans and E. faecalis but showed no residual effect. No activity on endotoxin was observed.

ANTIMICROBIAL ACTIVITY of SODIUM HYPOCHLORITE ASSOCIATED WITH INTRACANAL MEDICATION FOR Candida albicans and Enterococcus faecalis INOCULATED IN ROOT CANALS

Objective: The purpose of this study was to evaluate the action of sodium hypochlorite (NaOCl) associated with an intracanal medication against Candida albicans and Enterococcus faecalis inoculated in root canals. Material and Methods: Thirty-six human single-rooted teeth with single root canals were used. The canals were contaminated with C. albicans and E. faecalis for 21 days and were then instrumented with 1% NaOCl. The roots were divided into 3 groups (n=12) according to the intracanal medication applied: calcium hydroxide paste, 2% chlorhexidine (CHX) gel, and 2% CHX gel associated with calcium hydroxide. The following collections were made from the root canals: a) initial sample (IS): 21 days after contamination (control), b) S1: after instrumentation, c) S2: 14 days after intracanal medication placement; S3: 7 days after intracanal medication removal. The results were analyzed statistically by the Kruskal-Wallis test at 5% significance level. Results and Conclusions: Both 1% NaOCl irrigation and the intracanal medications were effective in eliminating E. faecalis and C. albicans inoculated in root canals.

In vitro antibacterial efficacy of endodontic irrigants against Enterococcus faecalis

Objective. The objective of this study was to compare the in vitro antimicrobial activity of 2% chlorhexidine gel against Enterococcus faecalis with sodium hypochlorite in 2 different concentrations (1.5% and 5.25%).Study design. Eighty human lower premolars with single root canals were prepared, autoclaved, and infected for 7 days with E. faecalis monocultures. The roots were then separated into 5 experimental groups according to the irrigant solution used during the standardized preparation. To assess the antimicrobial action of the irrigant solutions, 3 microbial samples were taken: S1-initial (before the biomechanical preparation), S2-posttreatment (immediately after the biomechanical preparation), and S3-final (7 days after the biomechanical preparation). The microbiological samples were plated to count the colony-forming units (CFU).Results. The 2% chlorhexidine gel and 5.25% sodium hypochlorite significantly reduced the E. faecalis CFU in the posttreatment and final microbiological samples. The 1.5% sodium hypochlorite also reduced the E. faecalis CFU immediately after the root canal instrumentation, but the E. faecalis CFU increased in the final sample showing no statistical difference from the control group.Conclusion. The 2% chlorhexidine gluconate gel and 5.25% sodium hypochlorite were effective in eliminating E. faecalis even 7 days after the instrumentation; moreover, the higher the concentration of sodium hypochlorite the better its antimicrobial action.

Demonstration of the cellular viability and safety of Enterococcus faecium CRL 183 in long-term experiments

Enterococcus faecium CRL 183, a strain isolated from NSLAB cheese starter, has been the focus of much research on its potential probiotic capacity, although its survival through the gastrointestinal tract has not been demonstrated so far. In order to determine the capacity of E. faecium CRL 183 to survive such conditions, this strain was administered daily to rats for 30 weeks. The experimental animals were divided into Group I: those that did not receive E. faecium, Group II: those that received a pure culture of E. faecium CRL 183 and Group III: animals that received E. faecium CRL 183 in the form of a fermented soy-based product. Faecal samples were collected at the beginning and at the 50%, 75% and 100% stages of the experimental period. Isolation and counts of Enterococcus were carried out on KF selective media. To distinguish the various Enterococcus species in the faeces, biochemical (API Strep 20) and molecular (PCR) tests were performed. Initially, E. faecium was absent from the intestinal flora of the rats; however, after 15 weeks of administration, E. faecium could be recovered from the faeces of Groups II and III, demonstrating that E. faecium CRL 183 was able to survive gastrointestinal transit under the study conditions. This is further evidence of the probiotic qualities of this strain. The safety of the strain was also investigated with regard to body weight and serum biochemical analysis.

Heat-killed Enterococcus faecalis Alters Nitric Oxide and CXCL12 Production but not CXCL8 and CCL3 Production by Cultured Human Dental Pulp Fibroblasts

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)