Diameter Of Growth Inhibition Zone Research Articles

Novel lipid-based dermal microgels of Neobacin

This study investigates the potential of novel microgles based on solid lipid microparticles (SLMs) as a sustained delivery system for neobacin®, a topical antibiotic drug powder. Matrices generated from sunseed oil and goat fat (1:9, 2:8 and 3:7) was surface-modified with Phospholipon® 90G and employed to formulate SLM-based microgels. The microgels were characterized in terms of in vivo wound healing in rats, in vitro permeation, membrane drug retention studies and antimicrobial activity against various microorganisms using standard cup-plate agar diffusion method. The 3:7 microgels exhibited sustained release property, achieving 34% drug permeation over 12 h, 64% membrane drug retention and largest growth inhibition zone diameters (IZD) on all organisms, whereas commercial neobacin® gel achieved 35% drug permeation at 4 h and 72% membrane drug retention. In vivo wound healing followed this order 3:7>1:9>2:8 better than neobacin® powder. Neobacin® microgel formulation despite rapid degradation possessed greater wound healing and antimicrobial property than the conventional powder form of neobacin®. Key words: Microgels, surface-modified solid lipid microparticles, sustained release, neobacin®.

Extraction, characterization and antimicrobial activity of sulfated polysaccharides from fish skins

Sulfated polysaccharides were extracted from gray triggerfish (GTSP) and smooth hound (SHSP) skins. Their chemical and physical characteristics were determined using X-ray diffraction and Infrared spectroscopic analysis. The antibacterial activities of GTSP and SHSP against Listeria monocytogenes (ATCC 43251), Staphylococcus aureus (ATCC 25923), Enterococcus faecalis (ATCC 29212), Escherichia coli (ATCC 25922), Salmonella enterica (ATCC 43972) and Enterobacter sp were evaluated by determining clear growth inhibition zone diameters and the minimum inhibitory concentration (MIC) values and by essays in liquid media. GTSP and SHSP were fractionated by a Diethylaminoethyl-cellulose chromatography. Fraction FGII, from GTSP, and fraction FSII, from SHSP, showed the most important inhibitory effects against the tested bacterial species. The sulfated polysaccharides from fish skins did not show hemolytic activity towards bovine erythrocytes. Overall, the results suggested that those polysaccharides could offer promising sources of polysaccharides for future application as dietary ingredients in the nutraceutical industry.

Antimicrobial Activity of 1,3 Dihydroxy-2-Methylimidazolium Bis (Trifluoromethylsulfonyl) Imde and Selected Antibiotics Against <i>Streptococcus</i> Species Isolated from Groundwater in the Northwest Province, South Africa

In developing countries, access to unsafe water and inadequate sanitation continue to be a danger to human health and untreated groundwater constitutes one of the main sources of drinking water supply. The consumption of untreated contaminated groundwater has frequently been identified as a potential source for the transfer and spread of both antibiotic resistant bacteria strains and waterborne infections among humans. Antibiotics are used for the treatment of bacterial infections and therefore the emergence of drug resistant bacterial strains has huge clinical implications. Faced with the rapid growth of bacterial resistance to a number of commonly used antibiotics, ionic liquids are attracting increasing attention as agents that could serve as antimicrobial agents. The aim of this study was to isolate, identify and determine the antimicrobial activity of an ionic liquid and selected antibiotics against <i>Streptococcus</i> species isolated from groundwater samples. A total of 22 samples were collected from borehole taps in some villages in the Northwest Province and analysed for the presence of streptococci. Gram-staining, catalase test, oxidase test and Prolex Streptococcal Grouping Latex assays were used for bacteria identification. The growth inhibitory effect of the ionic liquid 1,3 dihydroxy-2-methylimidazolium bis (trifluoromethylsulfonyl) imide and selected antibiotics was determined. One hundred and seventy six presumptive isolates were obtained and screened for characters of streptococci and 165 isolates were obtained. All the isolates were Gram positive cocci; a large proportion (92.7%) was oxidase negative and only 51.5% were catalase negative. Based on serotyping, 86.7% of the isolates were positively identified as streptococci. All the isolates from Motlhabeng, Stella and Taung were resistant to penicillin G. Moreover, large proportions (75.0% to 95.8%) of these isolates were resistant to vancomycin. All the isolates except a large proportion of those from Stella (88%) and Taung (83%) were found to be more susceptible (22.5% to 50%) to chloramphenicol. Generally, the growth inhibition zone diameter for 1,3 dihydroxy-2-methylimidazolium bis (trifluoromethylsulfonyl) imide against the isolates ranged from 6 to 9 mm and 9 to 22mm for 1% and 10% solutions respectively. In conclusion multi-drug resistant streptococci were isolated from groundwater intended for human consumption. Isolates were however susceptible to the IL tested and the antimicrobial effect increased with increase in concentration of the IL.

The Growth Inhibition Effect on the Causative Bacteria of Bacterial Vaginosis by Bacterial Strains Isolated from the Vagina of a Healthy Woman

Two Gram-positive rod strains isolated from the healthy vagina of a woman were tested for the possibility as probiotics. One strain was identified as Steroidobacter denitrificans (YH1) and the other as Lactobacillus crispatus (YH2) by 16S rRNA partial sequencing. The Casman agar and Man-Rogosa-Sharpe (MRS) agar were mixed in same quantity, supplemented with 5% human rbc lysate (CMS agar). The Wilkins-Chalgren agar and MRS agar were mixed in same quantity (WCM agar). Gardnerella vaginalis was cultured in Casman broth, supplemented with 5% human rbc lysate and 1,000 x-diluted with normal saline. Bacteroides fragilis, Mobiluncus mulieris and Peptostreptococcus asaccharolyticus were cultured in Wilkins-Chalgren anaerobe broth and 2,000x-diluted. S. denitrificans YH1 and L. crispatus YH2 were cultured in MRS broth anaerobically and 100x-diluted. The diluted suspensions of B. fragilis, M mulieris and P. asaccharolyticus were inoculated on WCM agar and G. vaginalis on CMS agar by cotton swabs. Ten ㎕ aliquots of YH1 and YH2 were inoculated on the center of WCM agar and CMS agar. The growth inhibition zone diameters of B. fragilis, G. vaginalis, M. mulieris and P. asaccharolyticus by YH1 were 35 ㎜, 35 ㎜, 25 ㎜ and 60 ㎜. The inhibition diameters by YH2 were 25 ㎜, 30 ㎜, 20 ㎜ and 40 ㎜, respectively. These results implicate that S. denitrificans YH1 can be the stronger probiotics for the treatment of bacterial vaginosis than L. crispatus, compared inhibition zone diameters by YH1 and YH2.

Chemical Compositions and Antimicrobial Activity of Essential Oil of Phlomis cancellata Bunge. from Mazandaran, Iran

Phlomis cancellata Bunge. is a native plant belongs to Labiatae family which can used more in modern medicine and different industries for its essential oil particulars, in addition to Iranian folk medicine. In this study, P. cancellata were collected in full flowering stage from mountain of Gaduk area in Mazandaran province, Iran. The aerial parts of P. cancellata were subjected to hydrodistillation (HD) in a Clevenger-type apparatus (5 h). The yield of the oil was 0.85 % (w/w). The essential oil was analyzed by GC and GC-MS. After identification of the components 44 components were identified which contained 95.8 % of the oil. Hexadecanoic acid (17.3 %), germacrene D (14.6 %), eudesmol (8.5 %), octacosane (5.6 %), (E)-caryophyllene (5.4 %), heptacosane (4.9 %) and pentacosane (3.6 %) were major components in P. cancellata oil. In vitro antimicrobial activity of essential oil of P. cancellata against a panel of four strains of bacteria have shown larger growth inhibition zone diameters (21 and 25 mm) against the gram-positive tested bacterial strains compared with gram-negative bacteria (13 and 14 mm). Antimicrobial activities of essential oil was also tested by MIC and MBC method, utilizing four gram (+/-) microorganism, exhibited the same results (MIC 4 and 8 µg/ml and MBC 8 and 16 µg/ml, against gram (+) bacteria, and also MIC 16 and 32 µg/ml and MBC 32 and 32 µg/ml, against gram (-) bacteria).

Chemical composition, antioxidant and antimicrobial activity of the essential oil of the thyme and rosemary

The present study was conducted to evaluate the in vitro antimicrobial and antioxidant properties of thyme and rosemary essential oils. The chemical compositions of hydro distilled essential oils were analyzed by GC/MS system. A total of 30 constituents representing of thyme oil were identified: thymol (39.44%), P-cymene (23.6%), γterpinene (12.51%), ledol (2.24%) and Aromadenrrene (2.12%) were the main components comprising 79.91% of the oil. While 37 constituents representing of rosemary oil were identified: borneol (24.13%), α – pinene (9.72%), αcaryophyllene (8.35%), ledol (6.42%), eucalyptol (5.11%), camphor (5.01%), γ – terpinene (5.005), Dverbenone (4.17%), limonene (2.29%) and methyl jasmonate (2.24) were the main components comprising 72.445 % of the oil. Antioxidant effects of essential oils from thyme and rosemary were determined on flaxseed and sesame oils. These essential oils were added to the oils at concentrations of 0.25% and 0.5%, besides the control groups for comparison. The samples were stored 65° C in darkness for 14 days. The antioxidant activity of the essential oils was determined by measuring peroxide values (meq O2/kg oil). On the basis of peroxide value assay, the essential oils showed stronger antioxidant effect when compared to control groups. Amongst the investigated essential oils, the thyme oil was the most effective on retarding lipid oxidation of crude oils, which was followed by rosemary oil. On the other hand in the present investigation antimicrobial activity of two essential oils has been evaluated. After bioassays, most of the essential oils were found susceptible to Gram-positive bacteria such as Staphylococcus aureus, Bacillus subtilis, and didn't showed any activity against Gram-negative bacteria Pseudomonas aueginosa, Escherichia coli. For screening of antimicrobial susceptibility in each essential oil, both positive and negative controls were set to determine growth inhibition zone diameters and MIC (minimum inhibitory concentration).Among two essential oils thyme oil was found to be highly antimicrobial, as it has shown high growth inhibition zone diameter in comparison to rosemary oil except against Aspergillus niger.

In-Vitro Comparison of Antibacterial Efficacy of a New Irrigation Solution Containing Nanosilver with Sodium Hypochlorite and Chlorhexidine

Objective: Antibacterial properties of silver nanoparticles have recently come into the spotlight in endodontic therapy. This study was conducted aiming at comparing the antimicrobial activity of a new irrigation solution containing nanosilver particles with that of sodium hypochlorite and chlorhexidine against Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa and Candida albicans with direct culture technique. Methods: In this in vitro experimental study, Mueller Hinton agarmedium was prepared for cultivation of E. coli, C. albicans and P. aeruginosa species and Bile-Esculin agar culture medium was used for E. faecalis. Understudy irrigation solutions were chlorhexidine 2%, chlorhexidine 0.2%, sodium hypochlorite 5.25%, sodium hypochlorite 2.5%, sodium hypochlorite 1.125% and nanosilver solutions of 25, 50, 100, 150, 200, 400 and 4000 ppm. After preparation, the bacteria were exposed to these solutions and the culture media were stored in an incubator at 37C for 24 hours.The diameter of growth inhibition zone was determined for different microbial species and data were analyzed using Kruskal-Wallis and Dunnett’s tests. Results: Significant differences were found between various irrigation solutions based on the diameter of growth inhibition zones for E. faecalis, E. coli, C. albicans and P. aeruginosa (P<0.0001). The greatest antimicrobial activity against microbial species belonged to sodium hypochlorite 5.25% and 2.5%. Silver nanoparticle solution had an acceptable antimicrobial activity in comparison to other solutions and its antimicrobial property constantly improved by increased concentration of Ag ions. The nanosilver containing irrigation solution at different concentrations up to 100 ppm did not show a significant difference with sodium hypochlorite 1.25% in terms of antimicrobial efficacy. Furthermore, the greatest antibacterial activity against P.aeruginosa was observed at different concentrations of nanosilver up to 100 ppm; whereas, chlorhexidine showed no antimicrobial activity against this microorganism. Conclusion: Based on the obtained results, nanosilver canal irrigation solution had a lower but acceptable antimicrobial activity against various bacterial species compared to conventional irrigation solutions. Therefore, once other characteristics of nanosilver are approved, further studies can be performed to improve its properties and use it as an alternative to conventional root canal

Antimicrobial Resistance in Some Gram‐Negative Bacteria Isolated from the Bovine Ejaculate

The bacterial load and degree of antibiotic resistance present in untreated and antibiotic-treated semen samples were investigated in five bulls standing at a cattle-breeding centre. Bacterial load was determined by colony counts from semen samples cultured on brain heart infusion and nutrient agar plates. Antibiotic resistance in these bacteria was assessed by measuring the diameter of bacterial growth inhibition zones around discs containing different concentrations of antibiotics. Representative antibiotic-resistant bacterial isolates were selected for identification. Untreated semen contained few culturable bacteria, and all were completely sensitive to gentamycin, spectinomycin and lincomycin: six of the isolates showed some resistance to tylosin. In semen to which antibiotics had been added as part of the routine production process, two isolates were sensitive to all of the antibiotics tested, and the remainder were resistant to all. Resistant Gram-negative isolates that were identified included Pseudomonas and Stenotrophomonas spp. both in the class Gammaproteobacteria and a Sphingomonas sp. which is in the class Alphaproteobacteria.

Comparative Antimicrobial Activity and Durability of Different Glass Ionomer Restorative Materials with and without Chlorohexidine

Objectives : To evaluate the in vitro antibacterial effect of three different restorative materials (Glass Ionomer Cements (GIC)) containing chlorohexidine on Streptococcus mutans , and lactobacillus acidophilus. Materials and Methods : Three commercially available glass ionomer cements, i.e., Fuji 1X (GIC1), Ketac molar (GIC2) and Riva (GIC3) were evaluated each alone and in combination with chlorohexidine diacetate or chlorohexidine digluconate. GICs were manipulated in accordance with manufacturer’s guidelines and embedded in wells made-up in plates of trypticase soy agar seeded with Streptococcus mutans and Lactobacillus MRS agar seeded with Lactobacillus acidophilus . The antibacterial activity was evaluated by using a caliper to measure the diameter of growth inhibition zones. The study was performed in triplicate and Duncan post-Hoc Multiple comparisons at p≤ 0.05 is used for means comparison. Results : the three Glass ionomers with chlorohexidine diacetate powder (1%) showed the highest activity and prolonged effect on the tested strains compared to glass ionomers free from chlorohexidine and the other glass ionomers with chlorohexidine digluconate liquid. Also, it was found that Fuji IX glass ionomer showed higher and prolonged effect in comparison to Ketac-Molar and Riva glass ionomers. Glass ionomers in combination with chlorohexidine diacetate showed higher efficacy against streptococcus mutans than for lactobacillus acidophilus. Conclusion : All three GIC’s under evaluation, promoted growth inhibition of the cariogenic bacteria assayed. Fuji IX glass ionomer with chlorohexidine diacetate showed the highest efficacy and durability against the tested strains.

Anti–bacterial activity and brine shrimp lethality bioassay of methanolic extracts of fourteen different edible vegetables from Bangladesh

ObjectiveTo investigate the antibacterial and cytotoxic activity of fourteen different edible vegetables methanolic extract from Bangladesh. MethodsThe antibacterial activity was evaluated using disc diffusion assay method against 12 bacteria (both gram positive and gram negative). The plant extracts were also screened for cytotoxic activity using the brine shrimp lethality bioassay method and the lethal concentrations (LC50) were determined at 95% confidence intervals by analyzing the data on a computer loaded with “Finney Programme”. ResultsAll the vegetable extracts showed low to elevated levels of antibacterial activity against most of the tested strains (zone of inhibition=5-28 mm). The most active extract against all bacterial strains was from Xanthium indicum which showed remarkable antibacterial activity having the diameter of growth inhibition zone ranging from 12 to 28 mm followed by Alternanthera sessilis (zone of inhibition=6-21 mm). All extracts exhibited considerable general toxicity towards brine shrimps. The LC50 value of the tested extracts was within the range of 8.447 to 60.323 μg/mL with respect to the positive control (vincristine sulphate) which was 0.91 μg/mL. Among all studied extracts, Xanthium indicum displayed the highest cytotoxic effect with LC50 value of 8.447 μg/mL. ConclusionsThe results of the present investigation suggest that most of the studied plants are potentially good source of antibacterial and anticancer agents.

The influence of plant extracts on growth of Erwinia amylovora - the causal agent of fire blight

Ethanol and water extracts obtained on Soxhlet apparatus from various organs and parts (leaves, flowers, shoots, onion, bark, fruit) of 30 herbal and woody plants species were tested for growth inhibition of &lt;i&gt;Erwinia amylovora&lt;/i&gt; using agar diffusion method. Active extracts were found in 23 plant species but in 13 ofthem it was found for the first time. The highest diameter of growth inhibition zone of this bacterium was caused by extracts from &lt;i&gt;Aloe arborescens, Juglans regia, Rhus typhina, Salvia offici nalis&lt;/i&gt; and &lt;i&gt;Satureja hortensis&lt;/i&gt;. In almost all cases ethanol appeared to be a better solvent of active plant substances against &lt;i&gt;E.amylovora&lt;/i&gt; than water.

Evaluation of cefoxitin disk diffusion breakpoint for detection of methicillin resistance in Staphylococcus pseudintermedius isolates from dogs

Cefoxitin disk diffusion susceptibility testing is a recommended screening method for the detection of methicillin resistance in human isolates of Staphylococcus aureus and coagulase-negative staphylococci. A retrospective analysis of 1,146 clinical isolates of Staphylococcus pseudintermedius from dogs was conducted to determine if screening by the cefoxitin disk method can be similarly useful with S. pseudintermedius. The distribution of cefoxitin growth inhibition zone diameters within this collection was bimodal and correlated well with the results of methicillin resistance gene (mecA) detection by polymerase chain reaction. Of the isolates, 5% had discordant results and, when retested, 84% of these were in agreement. While a greater diversity of isolates and interlaboratory comparisons must be tested, the current study suggests that an epidemiological breakpoint (of approximately ≤ 30 mm = resistant; ≥ 31 = susceptible) can be established to predict methicillin resistance in S. pseudintermedius.

Monitoring Of Antimicrobial Effect of GC-MS Standardized Melaleuca alternifolia Oil (Tea Tree Oil) On Multidrug Resistant Uropathogens

The aim of this work was to investigate antimicrobial action of tea tree oil (TTO) against multidrug resistant uropathogens. TTO was analysed by GC-MS studies. 16 compounds representing approximately 99% of the oil were characterized. The major compounds were Limonene, γ -Terpinene, α- Terpinene, Cineol and α- Terpinolene. Further the antimicrobial effect of whole TTO was tested against the isolated uropathogens like Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus vulgaris, P. mirabilis and Staphylococcus aureus. The antibacterial action of TTO was determined by disc diffusion method and MIC was determined by broth microdilution method. The ZOI (mm) and MIC (%) was in the range of 16±4 mm and 0.075% (v/v equivalent) for E. Coli; 20±2 mm and 0.03% for S. aureus; 19±2 mm and 0.10% for K. pneumoniae; 19±2 mm and 0.03% for Proteus mirabilis; 20±2 mm and 0.038% for Proteus vulgaris. TTO showed low MIC values and high growth inhibition zone diameter in comparison to broad spectrum antibiotics - erythromycin, ampicillin, kanamycin, streptomycin and gentamycin. The result of the bioassay showed that oil possesses potent antibacterial and bacteriostatic property. This paper reviews the classical methods commonly used for evaluation of antibacterial activity of TTO and gives an overview on the susceptibility of human pathogens towards TTO and their constituents.

Antimicrobial activity of disinfectant agents incorporated into type IV dental stone

This study evaluated the antimicrobial activity of two disinfectant agents, 2% chlorhexidine digluconate solution (CHX) and 98% chlorhexidine hydrochloride powder (HYD), incorporated into type IV dental stone at the time of mixing. Agar diffusion test was used for the following microorganisms: Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Candida albicans. The specimens were grouped in: (1) dental stone mixed with sterile distilled water; (2) paper disc soaked with CHX; (3) dental stone mixed with CHX; and (4) dental stone with incorporation of HYD, in 1% proportion of the dental stone mass and mixed with sterile distilled water. The culture medium was inoculated with microbial suspensions 1 and 24 h after pouring of the dental stone. The antimicrobial activity was evaluated by the average diameter of microbial growth inhibition zones. The data were analysed with a nested anova (p < 0.05) and Tukey test for specific comparisons. The disinfectant agents demonstrated antimicrobial activity against all microorganisms, with the exception of C. albicans, against which the CHX was ineffective in two periods of analysis. Significant differences between disinfectants were found with all microorganisms. The disinfectant agents analysed were effective against most of the microorganisms tested, except C. albicans.

Antifungal Activity of Essential Oils from Two Varieties of Sweet Basil (Ocimum basilicum L.)

Antifungal Activity of Essential Oils from Two Varieties of Sweet Basil (Ocimum basilicum L.) The aim of this work was an evaluation of the antifungal activity of essential oils from two cultivars of sweet basil (Ocimum basilicum L.): ‘Wala’ and ‘Fine Verde’. The essential oils from dried, ground herbs were extracted with the hydro-distillation method using Deryng apparatus. The composition of the oils was analyzed by gas chromatography. The antifungal activity of the oils was tested against the following strains: Alternaria sp., Aspergillus flavus, Botrytis cinerea, Cladosporium herbarum, Eurotium amstelodami and Eurotium chevalieri. The disc diffusion agar method was applied. Each oil was used in two doses, 10 and 5 μl/disc. A disc (6 mm dia.), soaked with oil, was placed on agar plates, which had been previously inoculated with spores of the different strains. The diameters of fungal growth inhibition zones were measured after 72h of incubation at 25°C and expressed in millimeters. The obtained results showed that the diameter of the mycelium growth inhibition zone significantly depended on the source of oil, the dose of oil, and the species of fungi. The essential oil from the ‘Wala’ variety was more effective against the tested fungi than the oil from ‘Fine Verde’ and the inhibition zones were greater when the dose of the oils was higher. E. chevalieri was the most sensitive to both of the oils and A. flavus was the most resistant. The differences in the antifungal activity of the tested oils were probably the result of their different chemical compositions. In comparison with the ‘Fine Verde’ oil, the oil from ‘Wala’ had more than twice the amount of linalool, more 1,8-cineole, and contained geraniol and methyl chavicol. In the conditions of the experiment both oils showed greater antifungal activity than cycloheximide (actidion) and methyl thiophanate (Topsin M 500 SC) used as controls.

Antimicrobial activity of 10-(diphenylmethylene)-4-azatricyclo[5.2.1.02,6]dec-8-ene-3,5-dione derivatives

Antibacterial and antifungal activity of 10-(diphenylmethylene)-4-azatricyclo[5.2.1.02,6]dec-8-ene-3,5-dione derivatives were examined by the disk diffusion method (growth inhibition zone diameter in agar medium). The minimal inhibitory concentrations (MICs) for the most active agents were determined. Title compounds were also evaluated in vitro against HIV-1 virus and their cytotoxicity was determined. Aminoalkanol derivatives exhibited activity against the majority of microorganisms studied.

Andmicrobial Activity and Volatile Constituents of Essential Oils from Leaf and Stem of Stachys byzantina C.Koch.

Hydrodistillation of leaves and stems of Stachys byzantina C.Koch. (Lamiaceae) yielded 0.1 %and 0.08 %( v/w) essential oils, respectively. GC-MS analysis allowed identification of 15 components, which made up 94.6 % of the total oil from the leaves, while only 10 compounds (95.6 %) were identified in the stems. The main components of the leaf oil were germacrene- D (37.0 %), valeranone (11.9 %), n- nonadecane(6.8 %), 2-pentadecanone-6,10,14-trimethyl (6.5 %), β-elemene (6.4 %) and α-bisabolol (4.8 %). In the stem oil, the main constituents were nerolidol (57.8 %), thymol (19.0 %) and n-nonadecane (4.8 %). 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: Enterococcus faecalis > Pseudomonas aeruginosa > Klebsiella pneumoniae > Bacillus subtilis > Candida albicans (ATCC 10259) > Candida albicans (ATCC 24433) > Staphylococcus aureus > Escherichia coli.

In vitro antimicrobial activity of phytotherapic Uncaria tomentosa against endodontic pathogens

The aim of this study was to evaluate the antimicrobial activity of Uncaria tomentosa (Willd.) DC (cat's claw) against Enterococcus faecalis, Staphylococcus aureus, and Candida albicans. Suspensions with 10(8) cells/ml of each microorganism were plated in triplicate on Mueller-Hinton agar. Wells in the agar were made and filled with 2% chlorhexidine (CHX) gel, 2% cat's claw (CC) gel, 2% CHX+CC, and 1% hydroxyethylcellulose (NAT) gel. Inhibition halos were measured after 24 h at 37°C and differences were analyzed using one-way ANOVA. The mean diameter of the microbial growth inhibition zones of 2% CHX+CC against the tested microbial strains ranged from 21.7 to 33.5 mm. This was the most effective substance against E. faecalis and C. albicans, followed by CHX and CC. Against S. aureus, CHX+CC, CHX, and CC showed similar antimicrobial activity (P > 0.05). The results indicate that all the investigated compounds had antimicrobial activity against microorganisms frequently found in infected root-filled teeth.

Biological evaluation of 10-(diphenylmethylene)- 4-azatricyclo[5.2.1.02,6]dec-8-ene-3,5-dione derivatives

AbstractAntibacterial and antifungal activity of 10-(diphenylmethylene)-4-azatricyclo[5.2.1.02,6]dec-8-ene-3,5-dione derivatives were examined by the disc-diffusion method (growth inhibition zone diameter in agar medium). The MIC’s for the most active agents were determined. Title compounds were also evaluated in vitro against representatives of different virus classes. Most of the tested compounds exhibit activity against CVB-2 virus.

An in vitro study of the antimicrobial activity of some endodontic medicaments and their bases using an agar well diffusion assay

The aim of this study was to determine the in vitro antimicrobial activities of various endodontic medicaments and their bases against selected organisms using an agar diffusion assay. An agar well diffusion assay was used to test the antimicrobial action of some commonly used endodontic medicaments (Ledermix paste, Pulpdent paste, Ultracal paste, and a 50:50 mix of Ledermix and Pulpdent pastes) and their bases. Three bacterial species (E. faecalis, P. micros, P. intermedia) and one yeast (C. albicans) were selected. The diameters of growth inhibition zones and pH were assessed. P. micros demonstrated the highest level of in vitro resistance. Pulpdent and Ultracal pastes had the highest pH (12.64 and 12.53, respectively). The addition of Pulpdent to Ledermix did not increase the zone sizes significantly. All the commercial products showed some in vitro antimicrobial activity. Ledermix paste and the 50:50 Ledermix/Pulpdent mixture being the most effective in this model. The known anti-inflammatory/analgesic properties of Ledermix and the results from this agar model suggest that the 50:50 Ledermix/Pulpdent combination would be the preferred medicament for clinical use in symptomatic cases, even though the addition of calcium hydroxide to Ledermix did not appear to be synergistic in terms of enhancing the antimicrobial action.