Growth Of Enterococcus Faecalis Research Articles

Uji Daya Hambat Ekstrak Kulit Langsat (Lansium parasiticum) Terhadap Pertumbuhan Bakteri Enterococcus faecalis Secara In Vitro

Enterococcus faecalis is a bacteria that commonly found in secondary root canal infections. Enterococcus faecalis is a gram-positive, facultative anaerobic bacteria. Langsat (Lansium parasiticum) is a natural ingredient that contains secondary metabolites and has antibacterial ativity. The aim of this study was to examine the inhibition effect of langsat fruit peel extract (Lansium parasiticum) to the growth of Enterococcus faecalis. This was a laboratory experimental study with post-only control group design. Langsat fruit peel extract with 25%, 50%, 75%, and 100% concentration was using disc diffusion method on Mueller-Hinton Agar (MHA) and the inhibition zone was measured with a sliding caliper. The data were analyzed with Kruskal-Wallis test and Mann-Whithney test. The result of this study was langsat fruit peel extract with 25%, 50%, 75% concentration showed a inhibition zone, while at 100% showed no inhibition zone. The Kruskal-Wallis test showed that there are significant differences (p <0.05) between all groups. The conclusion was langsat fruit peel extract (Lansium parasiticum) have weak inhibition effect of the growth of Enterococcus faecalis bacteria. The inhibition zone of concentrations 25% : 2,20 mm; 50%: 0,94 mm; 75%: 0,36 mm and 100% : 0,00 mm.

Uji Daya Hambat Ekstrak Kulit Langsat (Lansium parasiticum) Terhadap Pertumbuhan Bakteri Enterococcus faecalis Secara In Vitro

Enterococcus faecalis is a bacteria that commonly found in secondary root canal infections. Enterococcus faecalis is a gram-positive, facultative anaerobic bacteria. Langsat (Lansium parasiticum) is a natural ingredient that contains secondary metabolites and has antibacterial ativity. The aim of this study was to examine the inhibition effect of langsat fruit peel extract (Lansium parasiticum) to the growth of Enterococcus faecalis. This was a laboratory experimental study with post-only control group design. Langsat fruit peel extract with 25%, 50%, 75%, and 100% concentration was using disc diffusion method on Mueller-Hinton Agar (MHA) and the inhibition zone was measured with a sliding caliper. The data were analyzed with Kruskal-Wallis test and Mann-Whithney test. The result of this study was langsat fruit peel extract with 25%, 50%, 75% concentration showed a inhibition zone, while at 100% showed no inhibition zone. The Kruskal-Wallis test showed that there are significant differences (p <0.05) between all groups. The conclusion was langsat fruit peel extract (Lansium parasiticum) have weak inhibition effect of the growth of Enterococcus faecalis bacteria. The inhibition zone of concentrations 25% : 2,20 mm; 50%: 0,94 mm; 75%: 0,36 mm and 100% : 0,00 mm.

Synthesis of silver nanoparticles with remediative potential using discarded yerba mate: An eco-friendly approach

Silver nanoparticles (Ag-NPs) applications are strongly dependent on their stability against aggregation. In the present work, environmentally-friendly Ag-NPs were synthesized by a simple and efficient procedure, using discarded yerba mate extract (DYME) as a reducing and capping agent. The Ag-NPs thus obtained (DYME-Ag-NPs) were spectroscopically characterized by ultraviolet-visible (UV-Vis) spectrophotometry, dynamic light scattering (DLS), X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). These NPs were also evaluated for their adsorbent capacity through the adsorption isotherms using three organic substances, as well as for their antimicrobial properties on two bacterial strains. DYME-Ag-NPs were mostly spherical, monodispersed, with an average size of 24.07 ± 3.00 nm (DLS), and proved to be stable for 70 days without any noticeable aggregation or change in size under room temperature (20-25 °C). The adsorption efficiency for crystal violet, methylene blue, and safranin was calculated. The adsorption data derived from the isotherm analysis fitted a Langmuir isotherm model, revealing the presence of homogeneous adsorption sites, probably coming from the DYME. Using the diffusion method, we obtained a 99.99 % growth inhibition for Escherichia coli by using 10 μg/mL of Ag-NPs. However, no inhibition of Enterococcus faecalis growth was observed. We conclude that yerba mate waste may be used to obtain improved Ag-NPs highly stable and with a high surface area, which results in an enhanced adsorption capacity for organic compounds.

Antimicrobial Activity of Isoniazid in Conjugation with Surface-Modified Magnetic Nanoparticles against Mycobacterium tuberculosis and Nonmycobacterial Microorganisms

Isoniazid, the choice antitubercular agent, has only been employed against Mycobacterium tuberculosis. This study evaluated if the enzyme-mimetic activities of magnetic nanoparticles could accelerate the activation process of isoniazid against mycobacterial and, more importantly, non-mycobacterial microorganisms. First, magnetic nanoparticles were synthesized and coated by lipoamino acid; then, isoniazid was conjugated to synthesized nanoparticles. Antibacterial activities of nanoconjugated isoniazid were evaluated against Mycobacterium tuberculosis and four Gram-positive and Gram-negative nonmycobacterial strains through a microdilution broth process. Results showed that the required amount of isoniazid against Mycobacterium tuberculosis would decrease to 44.8% and 16.7% in conjugation with naked and surface-modified magnetic nanoparticles, respectively. Also, 32 μg/mL and 38 μg/mL of isoniazid in conjugation with naked and surface-modified nanoparticles, respectively, could prevent the growth of Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. Hence, the vicinity of magnetic nanoparticles with isoniazid could declare promising aspects of isoniazid antibacterial capabilities.

Phenolic compounds extracted from spruce (Picea abies) by supercritical carbon dioxide as antimicrobial agents against gram-positive bacteria assessed by isothermal calorimetry

Antimicrobial agents are substances that, when present at low concentrations, can delay microbial growth. For many years, several powerful antimicrobial substances have been synthetized. However, because of their significant side effects, there is a growing interest nowadays to find natural alternatives to the synthetic one. The present study aims to recover extracts with antimicrobial activity from Picea abies residues using two different extraction technologies, respectively, Soxhlet and supercritical carbon dioxide. Their antimicrobial activity was tested on the growth of Enterococcus faecalis and Streptococcus thermophilus. Isothermal calorimetry was used as a technique to quantify the antimicrobial effect of the extracts. The heat flow curves, obtained during the microbial growth, were fitted by a modified Gompertz function obtaining the lag time (λ) and the maximum growth rate (μmax) parameters. High-resolution mass spectrometry was used to identify the phenolic compounds responsible for the antimicrobial activity of the extracts. Regardless to the technology used, both extracts showed similar antimicrobial activity. For both microbial strains, the addition of the extract induced longer lag times (λ), while the maximum growth rate (μmax) decreased. S. thermophilus showed a higher resistance compared to E. faecalis suggesting a different capacity to metabolize the substrate in the presence of Picea abies extracts. Catechin, dihydroquercetin, astringin and isorhapontin were the identified phenolic compounds responsible for such effect. In conclusion, the results of this study provided an exciting potential for the future in light of the shift away from artificial preservatives and the trend toward natural alternative compounds coming from sustainable sources.

Deficiency of Intestinal α1-2-Fucosylation Exacerbates Ethanol-Induced Liver Disease in Mice.

Fucosyltransferase 2 (Fut2)-mediated intestinal α1-2-fucosylation is important in maintaining a symbiotic host-microbiota relationship and can protect against several pathogens. Intestinal dysbiosis is an important factor for the progression of experimental ethanol (EtOH)-induced liver disease, but the role of Fut2 in modulating the intestinal glycocalyx during alcohol-associated liver disease is unknown. We investigated the role of Fut2-mediated intestinal α1-2-fucosylation for the development of alcohol-associated liver disease. Immunohistochemistry staining was applied to evaluate α1-2-fucosylation in duodenal biopsies from patients with alcohol use disorder. Wild-type (WT) and Fut2-deficient littermate mice were subjected to Lieber-DeCarli models of chronic EtOH administration and the chronic-binge EtOH diet (NIAAA model). Intestinal α1-2-fucosylation was down-regulated in patients with alcohol use disorder. Lack of α1-2-fucosylation in Fut2-deficient mice exacerbates chronic EtOH-induced liver injury, steatosis, and inflammation without affecting EtOH metabolism. Dietary supplementation of the α1-2-fucosylated glycan 2'-fucosyllactose (2'-FL) ameliorates EtOH-induced liver disease in Fut2-deficient mice in the NIAAA model. Despite no direct effects on growth of Enterococcus faecalis in vitro, intestinal α1-2-fucosylation reduces colonization of cytolysin-positive E. faecalis in the intestine of EtOH-fed mice. Intestinal α1-2-fucosylation acts as a host-protective mechanism against EtOH-induced liver disease. 2'-FL is an oligosaccharide naturally present in human milk that could be considered as therapeutic agent for alcohol-associated liver disease.

Enterococcus faecalis Manganese Exporter MntE Alleviates Manganese Toxicity and Is Required for Mouse Gastrointestinal Colonization.

Bacterial pathogens encounter a variety of nutritional environments in the human host, including nutrient metal restriction and overload. Uptake of manganese (Mn) is essential for Enterococcus faecalis growth and virulence; however, it is not known how this organism prevents Mn toxicity. In this study, we examine the role of the highly conserved MntE transporter in E. faecalis Mn homeostasis and virulence. We show that inactivation of mntE results in growth restriction in the presence of excess Mn, but not other metals, demonstrating its specific role in Mn detoxification. Upon growth in the presence of excess Mn, an mntE mutant accumulates intracellular Mn, iron (Fe), and magnesium (Mg), supporting a role for MntE in Mn and Fe export and a role for Mg in offsetting Mn toxicity. Growth of the mntE mutant in excess Fe also results in increased levels of intracellular Fe, but not Mn or Mg, providing further support for MntE in Fe efflux. Inactivation of mntE in the presence of excess iron also results in the upregulation of glycerol catabolic genes and enhanced biofilm growth, and addition of glycerol is sufficient to augment biofilm growth for both the mntE mutant and its wild-type parental strain, demonstrating that glycerol availability significantly enhances biofilm formation. Finally, we show that mntE contributes to colonization of the antibiotic-treated mouse gastrointestinal (GI) tract, suggesting that E. faecalis encounters excess Mn in this niche. Collectively, these findings demonstrate that the manganese exporter MntE plays a crucial role in E. faecalis metal homeostasis and virulence.

Daptomycin in combination with rosuvastatin induced blood creatine phosphokinase elevation

We present the case of a 73-year-old male patient who was hospitalised with infective endocarditis, and report an elevation in his blood creatine phosphokinase (CPK) after receiving daptomycin and rosuvastatin...

The effectiveness of mixtures of tetracycline, acid and detergent, and mixtures of chlorhexidine and ethylenediaminetetraacetic acid in preventing the growth of Enterococcus faecalis: An Ex vivo study

Background: Sodium hypochlorite (5.25% NaOCl) is the gold standard among irrigation solutions, but it is toxic to periapical tissue, decreases the micromechanical characteristics of dentin, has no effect on smear layer removal, and may not completely eradicate biofilms. Therefore, many new irrigation solutions, such as mixtures of tetracycline, citric acid, and detergent (MTAD) and a mixture of chlorhexidine (CHX) and ethylenediaminetetraacetic acid (EDTA) have been introduced as the alternatives to NaOCl. Objectives: The objectives of this study are to analyze the differences in the effects of MTAD and mixtures of CHX and EDTA on the growth of Enterococcus faecalis ex vivo.Methods: This study used 28 lower premolars, divided into seven groups. Group I received MTAD. Group II received MTAD with CHX. Group III received a mixture of CHX and EDTA. Group IV received a 2% CHX solution. Group V received 17% EDTA. Group VI received a 5.25% NaOCl solution, which served as the positive control, and Group VII received sterile distilled water, which was the negative control. The effectiveness of various irrigation solutions in preventing the growth of E. faecalis was measured by the zone of growth inhibition and colony counts. Results: A one-way analysis of variance revealed a significant difference among the tested irrigation solutions, both in terms of zone inhibition of E. faecalis and E. faecalis colonies counting (P

Antibacterial Diterpenoid Against Pathogenic Oral Bacteria of Streptococcus Mutans ATCC 25175 Isolated From Sarang Semut (Myrmecodia Pendans)

Discovery of new antibacterial agent to treat oral disease caused by pathogenic oral bacteria is an attracted focus to more pay attention of researcher. The tropical natural product is the promising sources of new bioactive as antibacterial compounds. The epiphyte plant of Sarang Semut (M. pendans) empirically has been used as a drug to treat various diseases. Our previous research found that ethyl acetate extract of Sarang Semut inhibited the bacteria growth of Enterococcus faecalis. This study aims to isolate, structure determination and antibacterial activity evaluation of active compound against Streptococcus mutans ATCC 25175. The isolation by combination chromatography on normal and reverse phase resulted an antibacterial compound 1. Based on the analysis of the spectroscopic data including IR, FTIR, 1H-NMR, 13C-NMR, 2D-NMR as well as by mass spectroscopic (MS) and compare to reported data, structure of compound 1 was suggested as terpenoid type diterpene derivative. Antibacterial activity evaluation by Kirby-Bauer method of compound 1 against S. mutans ATCC 25175 showed inhibition zone values were 17.8, 14.5 and 11.1 mm at 10000, 5000 and 1000 ppm, respectively, while the MIC and MBC values were 18.125 ppm with MBC of 2500 ppm, respectively.

Pertumbuhan Curah Enterococcus faecalis Id 6017 dan Kemampuan Dekolorisasi Reactive Red-2 pada Medium yang Mengandung Gliserol

Enterococcus faecalis ID 6017 can utilize glycerol as the source of carbon and energy for its growth. The present of glycerol in the medium containing Reactive Red-2 not only influenced its growth but also its ability to decolorize Reactive Red-2. The aim of this study was to investigate the growth of Enterococcus faecalis (E. faecalis) and its ability to decolorize Reactive Red-2. The microbe was grown in batch system with three different growth medium, i.e. medium which contained (i) 1.643 g/l glycerol and 0.08 g/l reactive red-2, (ii) 1.643 g/l glycerol, and (iii) 0.08 g/l Reactive Red 2. The result of this study showed that the growth of E. faecalis and its ability to decolorize Reactive Red-2 on medium contained glycerol was better than without glycerol. E. faecalis could not growth and decolorized Reactive Red-2 on medium without glycerol.

Pertumbuhan Enterococcus faecalis ID 6017 dan Kemampuan Dekolorisasi Beberapa Konsentrasi Orange II dalam Sistem Sinambung

Orange II is the most used colorant in industries which involve coloring process. So far, Orange II decolorization process by Enterococcus faecalis ID 6017 under batch system has been proven to be able to decolorize orange to colourless. In the presence of intermediates accumulation in batch system, claimed bioprocess development with continues system. An hypothesis was carried out that continues system could reduce intermediates generated by Orange II degradation. This research aimed to know the growth of Enterococcus faecalis and its Orange II decolorization ability in the medium supplemented with Orange II with different concentration under continues system. The research was set on continues system with single cultures Enterococcus faecalis, grown in medium with 80, 120, or 160 mg/L Orange II concentration. Measured parameters were Orange II concentration, biomass, glucose concentration, intermediates compound (sulphanilic acid). It could be concluded that under continues system (D = 0.06 hour-1), Enterococcus faecalis could decolorize Orange II until 160 mg/l.

Daya bunuh dan daya hambat antimikrobial chlorhexidine 2% dan povidone iodine 1% sebagai medikamen saluran akar terhadap Enterococcus faecalis The ability of chlorhexidine 2% and povidone iodine 1% as root canal medicaments to kill and inhibit Enterococcus faecalis

Background. Enterococcus faecalis is one of the pathogenic organisms associated with root canal treatment failure and apical periodontitis. Root canal medicament is needed to prevent re-infection in the root canal and increase the success of treatment. Chlorhexidine and povidone iodine is a broad spectrum root canal medicaments that can kill gram-positive bacteria. Purpose. The purpose of this study was to discover the ability to kill and inhibit of antimicrobial chlorhexidine 2% and 1% povidone iodine asvroot canal medicaments against bacteria Enterococcus faecalis. Methode. This research was done by measuring the inhibition zone and count the number of colonies. Determination of the inhibition of root canal medicaments against Enterococcus faecalis by diffusion method. 10 microliter root canal medicaments dropped on paperdisk and placed on nutrient agar media with enterococcus faecalis, then inhibition zone was calculated. Determination ability to kill enterococcus faecalis is done by inserting 1 ml medicaments root canal into 5 ml BHIB media, then 0.05 ml inoculum of Enterococcus faecalis inserted into each tube, except the negative control. 0.1 ml of each tube implanted in the media nutrient agar. Media incubated for 24 hours, then Enterococcus faecalis bacterial colonies that grow in media calculated using the CFU. Results. There no colony growth of enterococcus faecalis in both root canal medicaments. There are significant differences in inhibition zone of 2% chlorhexidine and 1% povidone iodine (p<0.05). Conclusion. Both of root canal medicaments can kill enterococcus faecalis, but chlorhexidine 2% was more capable inhibit Enterococcus faecalis.

Development of a carboxymethyl xylan film containing licorice essential oil with antioxidant properties to inhibit the growth of foodborne pathogens

Antioxidant and antibacterial edible films based on carboxymethyl xylan with licorice essential oil incorporated were successfully developed. The films were prepared by the casting method and characterized using FTIR. The grammage, thickness, contact angle, mechanical and optical properties of the films were measured, together with the evaluation of their antioxidant, antibacterial and anti-biofilm properties against common foodborne pathogens. The FTIR spectra of the films clearly show the successful incorporation of the essential oil. The antioxidant properties of the films linked to scavenging free radicals and lipid peroxidation inhibition were maintained even after a storage period at room temperature (20 days, 25 °C). Moreover, the capacity of these films to inhibit the growth of Enterococcus faecalis and Listeria monocytogenes was demonstrated. The results also suggest the anti-biofilm potential of films incorporated with licorice essential oil. Therefore, these biodegradable films can be used in active packages for food, improving the overall shelf life.

The Bidirectional Interactions between Resveratrol and Gut Microbiota: An Insight into Oxidative Stress and Inflammatory Bowel Disease Therapy.

Dysbiosis and oxidative stress in the gut have contributed to the progression of intestinal inflammatory bowel disease (IBD). The current study has reported that enteric bacteria mediate redox homeostasis through the regulation of reactive oxygen species (ROS) production. Resveratrol, one of the most abundant polyphenols, with poor oral bioavailability, is considered as a scavenger of ROS and other free radicals. Recent studies have shown that resveratrol effectively enhances the growth of Lactococcus lactis and inhibits the growth of Enterococcus faecalis. (1) In terms of the two-way relationship between gut microbiota and resveratrol, resveratrol modulates gut microbiota; (2) in terms of resveratrol biotransformation by gut microbiota, we speculate that gut microbiota could be a target of resveratrol to maintain gut homeostasis. Here, we reviewed the current researches about the cellular signaling pathways in intestinal epithelial cells triggered by gut microbiota in response to oxidative stress. These results suggest that the modulation of the gut microbiota through resveratrol supplementation appears as a promising potential approach for the therapy of inflammatory bowel disease.

Perbandingan Aktivitas Antibakteri Ekstrak Curcuma zedoaria dan Bahan Irigasi Natrium Hipoklorit 2.5% terhadap Enterococcus faecalis

Sodium hypochlorite (NaOCl) is a powerful disinfectant used in root canal therapy, yet it has some disadvantages. There are growing interests of using extracts of natural materials containing antibacterial secondary metabolite compounds as an alternative of irrigation solution. Aim, to compare the antibacterial activity of white turmeric extracts and 2,5% sodium hypochlorite irrigant against Enterococcus faecalis. Methods, this was a quasi experimental study. White turmeric extracts at the concentrations of 75%, 50%, 25% and 10% were used as experimental groups, while 2,5% NaOCl and distilled water were the control groups. Suspensions of Enterococcus faecalis were prepared to a 0.5 Mc Farland standard and applied onto petri plates containing Muller Hinton Agar. Six wells were created in each plate, and filled with 20 mL of the test solution. Plates were incubated at 37 ° C for 24 hours. The antibacterial activity was evaluated by measuring the clear zone around the well. Data were analyzed by Kruskall Wallis and continued by Mann U Whitney. Results, the largest growth inhibition zones were produced when the test bacteria were in contact with 2,5% NaOCl (15,0233 mm). White turmeric extract 75% concentration had weak antibacterial effect, while white turmeric extract 50%, 25%, 10% concentration, and distilled water did not has antibacterial properties against Enterococcus faecalis. Conclusion, white turmeric extract 75% concentration can inhibit the growth of Enterococcus faecalis with weak antibacterial activity.

Photodynamic inactivation of Enterococcus faecalis by conjugates of zinc(II) phthalocyanines with thymol and carvacrol loaded into lipid vesicles

Terpene-macrocycle conjugates, consisting of thymol or carvacrol and phthalocyanine were synthesized, characterized, and subjected to detailed optical and biological studies. The macrocyclization reactions of terpene-substituted o-phthalonitrile derivatives were performed in a microwave reactor to give thymol- and carvacrol-phthalocyanine conjugates, which were carefully purified by column chromatography and subsequently analyzed using HPLC and characterized using UV–Vis, NMR and MS. Both isolated phthalocyanine derivatives represent isomers of C2v symmetry, which was confirmed by NMR study. The absorption UV–Vis spectra of studied thymol- and carvacrol-phthalocyanine conjugates with the Soret and the Q band possesses the same profile. Both molecules reveal emission in the red region of the spectrum with fluorescence quantum yields about two-fold lower in DMF and significantly lower in DMSO than that observed for zinc(II) phthalocyanine. The analyzed phthalocyanine derivatives generate singlet oxygen upon excitation with light at ca. three-fold lower level then that noticed for zinc(II) phthalocyanine. In comparison to zinc(II) phthalocyanine, both molecules also reveal two-fold lower photostability in DMF and similar stability in DMSO. Thymol- and carvacrol-phthalocyanine conjugates, zinc(II) phthalocyanine, thymol, and carvacrol were loaded into modified liposomes and subjected to biological activity study. Thymol-phthalocyanine conjugate at both 100 and 10 µM revealed high, ca. 5 log photoinactivation potential on the growth of Enterococcus faecalis, similarly to reference zinc(II) phthalocyanine. For carvacrol-phthalocyanine conjugate, an increase of photoinactivation activity was observed at only 100 µM in comparison to zinc(II) phthalocyanine, whereas a decrease at the concentration of 10 µM was noticed. It is crucial that both studied phthalocyanines cross the border of 3 log photoinactivation potential, which indicates their bactericidal potential. In the Microtox® bioassay both conjugates revealed significantly decreased dark toxicity in comparison to thymol and carvacrol only. Interestingly, the carvacrol-phthalocyanine conjugate was found to be more toxic in comparison to thymol-phthalocyanine conjugate and zinc(II) phthalocyanine.

Antibacterial activity of endophytic fungi isolated from Sceletium tortuosum L. (Kougoed)

Endophytic fungi have the ability to co-exist with their host plants without causing any harm and are beneficial to both the plant and the fungi. The current study determined the antimicrobial properties and identify the chemical compounds of secondary metabolites produced by endophytic fungi isolated from Sceletium tortuosum L. A total of 60 endophytic fungi produced secondary metabolites that were detected after fermentation and extraction. Antibacterial properties of the secondary metabolites were determined using the disc diffusion assay against pathogenic environmental Gram-positive and Gram-negative bacteria as well as control stains. The chemical compounds were characterized by GC-MS. Overall, 15% of fungal extracts displayed narrow spectrum of activity against the bacteria strains. Despite this, none of the fungal extracts inhibited growth of Enterococcus faecalis (ATCC S1299) and Enterococcus gallinarum (ATCC 700425) while Bacillus cereus (ATCC 10876) was the most susceptible against the fungal extracts. Fusarium oxysporum (GG 008) with accession no. KJ774041.1 displayed significant antibacterial activity that was linked to high levels of 5-hydroxymethylfurfural (HMF) and octadecanoic acid as revealed by GC-MS. This study revealed the presence of bioactive secondary metabolites with antibacterial activities from fungi isolated from Sceletium tortuosum L.

An optimised series of substituted N-phenylpyrrolamides as DNA gyrase B inhibitors

ATP competitive inhibitors of DNA gyrase and topoisomerase IV have great therapeutic potential, but none of the described synthetic compounds has so far reached the market. To optimise the activities and physicochemical properties of our previously reported N-phenylpyrrolamide inhibitors, we have synthesized an improved, chemically variegated selection of compounds and evaluated them against DNA gyrase and topoisomerase IV enzymes, and against selected Gram-positive and Gram-negative bacteria. The most potent compound displayed IC50 values of 6.9 nM against Escherichia coli DNA gyrase and 960 nM against Staphylococcus aureus topoisomerase IV. Several compounds displayed minimum inhibitory concentrations (MICs) against Gram-positive strains in the 1–50 μM range, one of which inhibited the growth of Enterococcus faecalis, Enterococcus faecium, S. aureus and Streptococcus pyogenes with MIC values of 1.56 μM, 1.56 μM, 0.78 μM and 0.72 μM, respectively. This compound has been investigated further on methicillin-resistant S. aureus (MRSA) and on ciprofloxacin non-susceptible and extremely drug resistant strain of S. aureus (MRSA VISA). It exhibited the MIC value of 2.5 μM on both strains, and MIC value of 32 μM against MRSA in the presence of inactivated human blood serum. Further studies are needed to confirm its mode of action.

A Promising Probiotic Irrigant: An In Vitro Study.

AIM:The present study aimed to investigate the inhibitory effect of Lactobacillus rhamnosus (B-445) as a probiotics irrigant on the growth of Enterococcus faecalis.METHODS:Forty-two extracted single human canal anterior teeth were prepared with rotary instrumentation and sterilised. Teeth were divided into 3 groups according to the type of irrigant, N = 14. Three experimental groups were inoculated with E. faecalis and cultured for 21 days before use; Group 1 was 2.5% NaOCl (positive control), Group 2 was saline (negative control), Group 3 was the experimental probiotic irrigant. Paper point sampling of the canals of each group was obtained before irrigation (S1), immediately after irrigation (S2) and after 24 hours (post irrigation samples) (S3) to determine remaining colony forming units for E. faecalis. Also, Colony counts for L. rhamnosus in Group 3 after immediate irrigation, as well as 24 hours post irrigation, was performed to determine the survival profile of these bacteria in infected root canal with E. faecalis.RESULTS:The NaOCl irrigant group had the lowest mean value of (log 10 CFU/mL) of E. faecalis after immediate irrigation and after 24 hrs post irrigation followed by the probiotic group, while the highest mean value was the saline group (P ≤ 0.001). The survival profile for L. rhamnosus in Group 3 after immediate irrigation and post-irrigation were slightly higher than for E. faecalis (P ≤ 0.001).CONCLUSION:Lactobacillus rhamnosus which revealed a potential inhibitory effect on the growth of Enterococcus faecalis, could be used as a new natural, safe probiotic irrigant agent.