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Inhibition Zones (inhibition + zone)
Selected AbstractsEvaluation of pre-heating and extraction solvents in antioxidant and antimicrobial activities of garlic, and their application in fresh pork pattiesINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 2 2010Sung Y. Park Summary The objectives of this study were to screen the optimum conditions for antioxidant and antimicrobial activities of garlic as affected by pre-heating and different extraction solvents, and to evaluate the antioxidant and antimicrobial effects of these extracts in ground meat during refrigerated storage. Methanol extracted garlic had a greater total phenolic content, 1,1-diphenyl-2-picrylhydrazyl (DPPH)-radical scavenging activity and reducing power than water extracted one (P < 0.05), whereas the latter had a greater yield and iron chelating ability than the former (P < 0.05). Moreover, water extract from fresh garlic (WEFG) and methanol extract from heated garlic (MEHG) produced an inhibition zone against Escherichia coli O157:H7 and Listeria monocytogenes. The addition of garlic extracts (WEFG, MEHG and their combinations WEFMEHG)) to pork patties decreased the pH, hunter a values (redness), thiobarbituric acid substances values and the number of total plate count and Enterobacteriaceae (P < 0.05), while the hunter b values (yellowness) increased (P < 0.05). Results of this study indicated that the use of the garlic extracts was able to control lipid oxidation and microbial growth in pork patties. [source] Effect of cyclodextrins on the solubility and antimycotic activity of sertaconazole: Experimental and computational studiesJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 11 2002I. Perdomo-López Abstract This study investigated the effects of the complexation of sertaconazole nitrate with different cyclodextrin (CD) derivatives (,-CD, ,-CD, ,-CD, hydroxypropyl-,-CD, and hydroxypropyl-,-CD) on the aqueous solubility and antimycotic activity of the drug. Phase solubility studies indicated that the solubility of sertaconazole in enzyme-free simulated gastric- and enzyme-free simulated enteric fluids was significantly increased in the presence of cyclodextrins. The observed order of solubility increasing effect was: ,-CD,>,HP,-CD,>,HP,-CD,>,,-CD,>,,-CD. Solid-state sertaconazole,cyclodextrin complexes were prepared by freeze drying, and characterized by X-ray powder difractometry, differential scanning calorimetry (DSC), and infrared spectroscopy (FTIR). Freeze-dried complexes showed markedly higher solubility than both physical mixtures and sertaconazole alone. The antimycotic activities of sertaconazole,cyclodextrin complexes in solution were evaluated by inhibition zone assays with Candida albicans. The activity ranking agrees with the solubility ranking observed for these complexes, with the ,-CD,sertaconazole complex showing the strongest antimycotic activity. Finally, molecular modeling studies were carried out using the MM2 force field method, for complexes in vacuum and in water. This enable indentification of the preferred orientation of sertaconazole in the ,-CD cavity and of the main structural features responsible for the enhancement of its solubility and antimycotic activity. © 2002 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 91:2408,2415, 2002 [source] Vancomycin-resistant Enterococcus spp.: validation of susceptibility testing and in vitro activity of vancomycin, linezolid, tigecycline and daptomycinAPMIS, Issue 1 2010MATHIAS RATHE Rathe M, Kristensen L, Ellermann-Eriksen S, Thomsen MK, Schumacher H. Vancomycin-resistant Enterococcus spp.: validation of susceptibility testing and in vitro activity of vancomycin, linezolid, tigecycline and daptomycin. APMIS 2010; 118: 66,73. Vancomycin-resistant enterococci (VRE) have emerged to become a significant nosocomial pathogen. However, detection may be challenging and treatment possibilities are limited. Reports of resistance to linezolide, daptomycin and tigecycline underline the need for reliable susceptibility testing with respect to these compounds. We evaluated the in vitro activity of vancomycin, linezolid, daptomycin and tigecycline against a panel of VRE and vancomycin-susceptible enterococci by broth microdilution (BMD). Etest for determination of minimum inhibitory concentration of these four antibiotics and two disc diffusion assays for detecting VRE and for susceptibility testing against tigecycline and linezolid were evaluated. Before susceptibility testing, all isolates were classified by polymerase chain reaction as vanA or vanB gene positive or vanA/B gene negative. Linezolid, daptomycin and tigecycline had excellent in vitro activity towards all isolates. For daptomycin and tigecycline, the overall agreement between BMD and Etest was suboptimal. For both disc diffusion assays, use of current break points was inadequate to detect vancomycin resistance for isolates carrying the vanB gene. Inspection of the inhibition zone for a diffuse edge, as recommended, accurately predicted presence of the vanB gene. [source] Optimization of medium composition for the production of antimicrobial activity by Bacillus subtilis B38BIOTECHNOLOGY PROGRESS, Issue 5 2009Olfa Tabbene Abstract An antimicrobial activity produced by Bacillus subtilis B38 was found to be effective against several bacteria, including pathogenic and spoilage microorganisms such as, Listeria monocytogenes, Salmonella enteridis, and clinical isolates of methicillin-resistant Staphylococcus species. Nutrients such as carbon, nitrogen sources, and inorganic salts enhanced the production level of the antibacterial activity by B. subtilis B38. A first screening step showed that lactose, ammonium succinate, and manganese most influenced both cell growth and antibacterial activity production. These three factors varied at two levels in eight experiments using full factorial design. Results indicated that maximum cell growth (OD = 10.2) and maximum production of antibacterial activity (360 AU/mL) were obtained in a modified medium containing 1.5% (w/v) lactose, 0.15% (w/v) ammonium succinate, and 0.3 mg/L manganese. Depending on the indicator strain used, the antibacterial activity was 2- to 4-fold higher in the modified culture medium than in TSB medium under the same conditions. Thin layer chromatography-bioautography assay showed the presence of three active spots with Rf values of 0.47, 0.7, and 0.82 in TSB medium. However, the inhibition zone of two spots (Rf values of 0.7 and 0.82) was slightly larger in the modified medium. Moreover, a large zone of inhibition with an Rf value of 0.3, was observed in this modified medium, instead of the spot having an Rf value of 0.47. These results suggest that the nutrients act as environmental factors, quantitatively and qualitatively affecting the production of antibacterial compounds by B. subtilis B38. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source] Chemical constituents and antimicrobial activities of the essential oil of Acroptilon repens (L.) DCFLAVOUR AND FRAGRANCE JOURNAL, Issue 2 2006Hassan Norouzi-Arasi Abstract The volatile oil from the aerial parts of Acroptilon repens (L.) DC. (Russian knapweed) growing wild in Iran was investigated by GC and GC,MS. Twenty-two components, representing 84.0% of the oil, were identified. The main constituents of the oil were caryophyllene oxide (36.6%), , -copaene (15.6%), , -caryophylene (10.0%) and , -copaene-4- , -ol (5.0%). In addition, the oil was assayed against six Gram-positive and Gram-negative bacteria by measuring the growth inhibitory zone. The oil of A. repens inhibited the growth of Gram-positive bacteria. Staphylococcus saprophyticus and Staphylococcus epidermidis showed strong inhibition zones, while Staphylococcus aureus showed a lower inhibition. The Gram-negative bacteria were insensitive to the oil. Copyright © 2005 John Wiley & Sons, Ltd. [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] ANTIMICROBIAL, PHYSICAL AND MECHANICAL PROPERTIES OF CHITOSAN-BASED FILMS INCORPORATED WITH THYME, CLOVE AND CINNAMON ESSENTIAL OILSJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 6 2009M.H. HOSSEINI ABSTRACT Chitosan-based films containing thyme, clove and cinnamon essential oils at 0.5, 1 and 1.5% v/v were prepared to examine their antibacterial, physical and mechanical properties. Scanning electron microscopy was carried out to explain structure,property relationships. Films containing thyme essential oil revealed larger inhibition zones than those containing clove and cinnamon essential oils against gram-positive and gram-negative bacteria tested. Films were more effective against gram-positive bacteria than gram-negative. Incorporating thyme and clove essential oils into chitosan-based films increased moisture content (from 17.80,28.38%), solubility in water (25.97,30.62%), water vapor transmission rate (0.00233,0.00571 g/s/m2) and elongation at break (25.31,42.70%) of films. Cinnamon-enriched films had opposite changes such as increase in tensile strength (from 12.2,21.35 MPa) and decrease in moisture content (17.80,9.36%) and solubility in water (25.9,14.21%) of films. PRACTICAL APPLICATIONS Microbial growth on food surfaces is a major cause of food spoilage. Combining antimicrobial agents such as plant essential oils directly into a food packaging polymer is a form of active packaging. These films possess the potential for improving microbial stability of foods by acting on the food surface upon contact. Because of the effect of direct addition of plant essential oils to food on sensory characteristics of packaged food, incorporation of essential oils into films may have additional applications in food packaging. [source] Agar sublimation test for the in vitro determination of the antifungal activity of morpholine derivativesMYCOSES, Issue 5-6 2004A. Polak Antimykotische Aktivität; Morpholine; Sublimation Summary We studied the in vitro antifungal activities of a wide range of antimycotic agents, including amorolfine, terbinafine, naftifine, five morpholine derivatives, ciclopiroxolamine, bifonazole, clotrimazole, ketoconazole, itraconazole, fluconazole, voriconazole, flucytosine, amphotericin B, nystatin, and caspofungin, against Candida albicans and Trichophyton rubrum by conventional agar diffusion tests and by a novel sublimation method. For the sublimation method, 6 mm filter paper disks were soaked with defined amounts of antimycotic drugs, air dried, placed in the center of the lids of 9 cm Petri dishes, and incubated upside down with inoculated agar plates 10 mm above the disks. The conventional disk diffusion tests produced inhibition zones as previously described. The disk sublimation tests produced large inhibition zones with amorolfine, five amorolfine derivatives, and terbinafine, but with none of the other antifungal agents. Possible therapeutic advantages of agents, which are able to overcome air cavities in mycotic lesions, e.g. in onychomycosis, are discussed. Zusammenfassung Wir untersuchten in vitro die antimykotische Aktivität eines breiten Spektrums von Antimykotika, einschließlich Amorolfin, Terbinafin, Naftifin, fünf Morpholin-Derivaten, Ciclopiroxolamin, Bifonazol, Clotrimazol, Ketoconazol, Itraconazol, Fluconazol, Voriconazol, 5-Fluorcytosin, Amphotericin B, Nystatin und Caspofungin, gegenüber Candida albicans und Trichophyton rubrum mit konventionellen Agardiffusionstesten und mit einer neuartigen Sublimationsmethode. Für die Sublimationsmethode wurden 6 mm-Filterpapier-Blättchen mit definierten Mengen von Antimykotika getränkt, luftgetrocknet, in die Mitte der Deckel von 9 cm-Petrischalen gelegt und mit der inokulierten Agarplatte 10 mm über den Blättchen umgedreht inkubiert. Die konventionellen Agardiffusionsteste produzierten Hemmhöfe wie früher beschrieben. Die Blättchen-Sublimationsteste produzierten große Hemmhöfe mit Amorolfin, fünf Morpholin-Derivaten und Terbinafin, nicht jedoch mit den anderen Antimykotika. Mögliche therapeutische Vorteile von Agentien, die luftgefüllte Hohlräume in mykotischen Läsionen überbrücken können, z. B. im Nagel bei Onychomykose, werden diskutiert. [source] In Vitro antifungal activity of extract and plumbagin from the stem bark of Diospyros crassiflora Hiern (Ebenaceae)PHYTOTHERAPY RESEARCH, Issue 7 2007J. P. Dzoyem Abstract In this study the methanol/dichloromethane (1:1) extract and plumbagin isolated from extract of stem barks of Diospyros crassiflora were tested for their antifungal activity against 12 strains of yeast pathogens and filamentous fungi: Candida albicans, Candida glabrata, Candida krusei, Candida tropicalis, Cryptococcus neoformans, Aspergillus niger, Aspergillus flavus, Alternaria sp., Cladosporium sp., Geotrichum candidum, Fusarium sp. and Penicillium sp. The growth of all fungi strains tested was inhibited by the extract and plumbagin. The diameter of inhibition zones varied from 12 to 18 mm and from 21 to 35 mm for the extract and plumbagin, respectively. The MIC values ranged from 12.5 to 25 mg/mL for the extract and 0.78,3.12 µg/mL for plumbagin. It is therefore suggested that extracts from the stem bark of Diospyros crassiflora could be used traditionally in the treatment of fungal infections. Compared with ketoconazole used as a standard antifungal, plumbagin could be considered as a promising antifungal agent. Copyright © 2007 John Wiley & Sons, Ltd. [source] Synthesis and Evaluation of Novel Indolylthiadiazinoazetidinones and Indolylthiadiazinothiazolidinones as Antimicrobial AgentsARCHIV DER PHARMAZIE, Issue 2 2010Vikas Kumar Abstract Some new 5-methoxy/ethoxy-2,3-[2,-(3,,-chloro-2,,-oxo-4,,-substituted-aryl-1,,-azetidinyl)-1,,3,,4,-thiadiazino]indoles 13,20 and 5-methoxy/ethoxy-2,3-[2,-(2,,-substituted-aryl-4,,-oxo-1,,,3,,-thiazolidin-3,,-yl)-1,,3,,4,-thiadiazino]indoles 21,28 have been synthesized from 5-methoxy/ethoxy-2,3-[2,-(substituted-benzylidinylimino)-1,,3,,4,-thiadiazino]indoles 5,12. These newly synthesized compounds were characterized by elemental and spectral analysis. Further, compounds 5,28 of the present series have been screened for their antibacterial and antifungal activities. Both minimal inhibitory concentration (MIC) and inhibition zones were determined in order to monitor the efficacy of the synthesized compounds. Compounds 14 and 16 were found to be the most potent members of the present series, they showed maximal antibacterial and antifungal properties much better than the standard drugs. [source] Antifungal and Antibacterial Activity of the Newly Synthesized 2-Xanthone DerivativesARCHIV DER PHARMAZIE, Issue 1 2009Henryk Marona Abstract A series of 2-substituted xanthone derivatives 8,20 containing selected allyl, cinnamyl, morpholine, and imidazole moieties were synthesized and tested for their antifungal and antibacterial in-vitro properties. Of the newly synthesized derivatives, ten revealed antifungal activity especially against Trichophyton mentagrophytes (the biggest inhibition zones ranged 35 mm for 11 and 13). 2-(3-(Allylamino)propoxy)-9H -xanthen-9-one hydrochloride 9 inhibited growth of all of the examined fungal species. Significant efficacy against evaluated yeasts and dermatophytes was also observed for 6-chloro-2-methyl-9H -xanthen-9-one derivatives 11,13 containing encyclic amine moieties. Additionally, compounds 9, 11, and 12 hindered development of bacteria species but in a lesser degree. They were efficacious against Staphylococcus aureus, Escherichia coli, and Enterococcus faecalis. [source] An in vitro study of the antimicrobial activity of some endodontic medicaments and their bases using an agar well diffusion assayAUSTRALIAN DENTAL JOURNAL, Issue 2 2009B Athanassiadis ABSTRACT Background:, 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. Methods:, 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. Results:,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. Conclusions:, 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. [source] | |||||||||||||