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Diffusion Test (diffusion + test)
Kinds of Diffusion Test Selected AbstractsInfluence of the pulpal components on human dentine permeability in vitroINTERNATIONAL ENDODONTIC JOURNAL, Issue 3 2005P. Puapichartdumrong Abstract Aim, To examine the influence of the retained pulpal components on permeability of human dentine by monitoring drug diffusion. Methodology, Twelve intact dentine discs were prepared from freshly extracted human third molars. The dentine surface on the enamel side was etched with 10% polyacrylic acid for 30 s. The drug diffusion test was carried out before and after removal of the retained pulpal components. Each dentine disc was inserted between two plastic chambers; enamel- and pulpal-side chambers, which were filled with 0.05 mol L,1 naproxen sodium (NA) and phosphate-buffered saline (PBS), respectively. After 10 min, the solution on the pulpal-side chamber was collected to determine the concentration of NA using a spectrophotometer. To remove the retained pulpal components and residual NA, the pulp chamber of each disc was washed out with PBS and placed in an ultrasonic cleaner. After removal of these components and the residual NA, the drug diffusion test was repeated. The inner surface of the pulp chamber was observed using scanning electron microscopy (SEM) before and after the removal of the retained pulpal components. Results, The amount of NA that diffused through dentine into the pulp was significantly higher after the pulp chamber was washed out with PBS (paired t -test, P < 0.05). SEM observation demonstrated the presence of the retained pulpal components, odontoblastic layer and some parts of subodontoblastic zone, covering the surface of predentine. These components were removed after the pulp chamber was washed out with PBS followed by cleaning in an ultrasonic cleaner. Conclusions, The presence of retained pulpal components had a significant influence on drug diffusion through dentine discs. [source] Antibacterial polyvinyl chloride/antibiotic films: The effect of solvent on morphology, antibacterial activity, and release kineticsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2010Martha Merchan Abstract Medical-grade polyvinyl chloride was modified with sodium ampicillin in a concentration range from 0 to 5 wt % by solvent casting technique using cyclohexanone and N,N -dimethylformamide. The obtained polymeric systems were characterized by optical microscopy, tensile test, and scanning electron microscopy. In addition, in vitro antibacterial activity against Gram-negative and Gram-positive bacteria was determined by an agar diffusion test. Antibiotic release experiments were performed in distilled water and physiological saline solution, which were monitored by UV-vis spectroscopy. The results showed a crucial role of the solvent on the morphology, antibacterial activity, and releasing characteristic of the ampicillin. Furthermore, a mathematical model was applied to data obtained from release study, to characterize the release kinetics of the ampicillin from the polyvinyl chloride-antibiotic systems. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Chlorhexidine release and antibacterial properties of chlorhexidine-incorporated polymethyl methacrylate-based resin cementJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2010N. Hiraishi Abstract This study evaluated chlorhexidine release from experimental, chlorhexidine-incorporated polymethyl methacrylate (PMMA)-based resin cements prepared from Super-Bond C&B (Sun Medical) and examined the antimicrobial activity against Streptococcus mutans and Enterococcus faecalis. Chlorhexidine diacetate was added into PMMA polymer to obtain chlorhexidine concentration of 0.0, 1.0, 2.0, 3.0, and 4.0 wt %. Chlorhexidine-incorporated, cured resin disks were immersed in distilled water at 37°C for 5 weeks, and the chlorhexidine release was analyzed by high-performance liquid chromatography. The antibacterial effect of freshly mixed resin cements was examined using the agar diffusion test. For the direct contact test, the wells (n = 6) of microtiter plates were coated with cements. The coated wells were aged up to 3 weeks prior to the placement of bacterial suspensions directly on cured cements. The 3.0 and 4.0% chlorhexidine-incorporated cement exhibited chlorhexidine release for 5 weeks; however, more than 98% of chlorhexidine was retained in resin matrix. No release was detected from the 1.0 and 2.0% incorporated cement at 1 week and 2 weeks, respectively. The agar diffusion test failed to detect antibacterial effects against Enterococcus faecalis, whereas the direct contact test revealed the antibacterial effect of 3.0 and 4.0% incorporated cements against each microbe for 2 weeks. The 3.0 and 4.0% chlorhexidine-incorporated resin cement possessed prolonged chlorhexidine release and antibacterial properties for 2 weeks. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010 [source] Antibiotic-containing hyaluronic acid gel as an antibacterial carrier: Usefulness of sponge and film-formed HA gel in deep infectionJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 3 2006Hiroaki Matsuno Abstract We have developed a novel bioabsorbable antibacterial carrier using hyaluronic acid (HA) gel for prevention and treatment of orthopedic infections. In this study, we investigated the in vivo antibacterial effects of two forms of this new material, an HA gel sponge and an HA gel film. A titanium cylinder was inserted into the intramedullary cavity of each rabbit femur, along with an HA gel sponge or HA gel film containing antibiotics. The HA gel sponge contained gentamycin, vancomycin, tobramycin, or minomycin. The HA gel film contained gentamycin or vancomycin. After 0, 7, and 14 days, the rabbit bone marrow was collected, and the antibacterial activity of the HA gel was determined by agar diffusion test. As a control, we used Septocoll, a commercially available antibacterial carrier. Both the HA gel sponge and HA gel film exhibited antibacterial activity. The present results indicate that HA gel containing antibiotics is a clinically useful bioabsorbable antibacterial carrier. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:321,326, 2006 [source] Cospray dried antibiotics for dry powder lung deliveryJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 8 2008Handoko Adi Abstract The aim of this study was to assess the potential of delivering a combination antibiotic therapy, containing doxycycline and ciprofloxacin (both hydrochloride) as a dry powder (DPI) formulation for inhalation. Single and combination antibiotics were produced by spray drying. Particle size distributions were characterized by laser diffraction and imaging conducted by scanning electron microscopy. Solid-state characterisation of the antibiotics was carried out using differential scanning calorimetry, dynamic vapour sorption, X-ray powder diffraction, and differential scanning calorimetry. Using the Aerolizer® device, the aerosol performance was measured using multistage liquid impinger and analysed using high performance liquid chromatography (R2,=,1.0, CV,=,0.4,1.0%). Furthermore, a disk diffusion test was performed for the assessment of the in vitro antimicrobial activity of the raw and spray dried antibiotics against bacteria. Results showed that cospray drying of the ciprofloxacin and doxycycline produced an antibiotic formulation (in a 1:1 ratio) suitable for inhalation that showed to be physically more stable then the analogous single spray dried antibiotic. The cospray dried powder has improved dispersion over the less stable single spray dried ciprofloxacin. The spray dried antibiotics were observed to have similar antimicrobial activity to the original antibiotics for Staphylococcus aureus, Pseudomonas aeruginosa and Streptococcus pyrogenes, suggesting the spray drying process does not affect the anti-bacterial activity of the drug. Cospray dried antibiotics from a DPI is thus feasible and can potentially be an attractive delivery alternative to the more conventional systemic delivery route. © 2007 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 97: 3356,3366, 2008 [source] Comparison of methods for the detection of methicillin resistance in Staphylococcus aureus isolates from food productsLETTERS IN APPLIED MICROBIOLOGY, Issue 5 2007M. Corrente Abstract Aims:, To compare several methods for detection of methicillin resistance in Staphylococcus aureus isolates from food. Methods and Results:, Two hundred S. aureus isolates from food of animal origin were screened for methicillin resistance by a PCR assay specific for the mecA gene, an oxacillin agar screen test and a cefoxitin disk diffusion test. Six out of 200 strains (3%) were found to be methicillin-resistant Staphylococcus aureus (MRSA) by PCR. The oxacillin agar screen test detected only one of the MRSA isolates (sensitivity of 16·7%) and mischaracterized three additional strains as MRSA (specificity of 98·45%). None of the MRSA strains was detected by the cefoxitin test (sensitivity of 0%), while 15 methicillin-susceptible S. aureus (MSSA) strains were misclassified as resistant (specificity of 92·3%). Fifteen MSSA strains displayed a ,-lactamase hyperproducer-like phenotype. The six MRSA (mecA-positive) strains resembled the characteristics of heteroresistant strains. Conclusions:, As MRSA of animal origin may display atypical phenotypes, PCR appears to be more reliable for detection of methicillin resistance in animal strains. Significance and Impact of the Study:, The study stresses the need for implementing the methods of screening S. aureus from food of animal origin for methicillin resistance. [source] Anticandidal low molecular compounds from higher plants with special reference to compounds from essential oils,MEDICINAL RESEARCH REVIEWS, Issue 2 2006A. Pauli Abstract The most active low molecular weight compounds from higher plants against Candida species are compiled from a database of antimicrobials (Amicbase) to find out new hints on their mechanism of action. The selected compounds possess strong inhibitory activities in vitro against Candida species either in the agar diffusion test, bioautography, agar dilution test, serial dilution test, or activity in the vapour phase. The test conditions are listed thoroughly and aspects of the different methods and recent developments in the testing of anticandidal drugs are discussed. The anticandidal spectra of drugs, antiseptics, and disinfectants licensed on the major markets are given for comparision of activities with compounds from natural sources. So far known mechanisms of action are described and some new structure,activity relationships are deduced from relationships between biological activities and chemical and physical parameters. Main specific targets of natural anticandidals are the ergosterol pathway, respiratory chain, and chitin biosynthesis. © 2005 Wiley Periodicals, Inc. Med Res Rev [source] Effectiveness of dentine bonding agents against cariogenic bacteria in vitro: a comparison of two methodsMOLECULAR ORAL MICROBIOLOGY, Issue 3 2003O. A. Schmidlin Data obtained from studies on the antimicrobial properties of bonding agents are the subject of controversy, probably because of methodological differences. This study compared two commonly used in vitro methods, the disc agar diffusion test and the well agar diffusion test. Agar plates were seeded with Streptococcus sobrinus, Lactobacillus gasseri, or Actinomyces naeslundii. For the well diffusion test, wells cut out of the agar were filled with the test material, and for the disc method, discs impregnated with the test material were applied to the agar; the discs and wells were both 9 mm in diameter. After incubation, measurements of the zones of inhibition showed little agreement between the two methods when bonding agents were tested; the mean differences (± sdiff) in the zones of inhibition between the methods were 0.7 ± 3.4 mm (P = 0.40, one sample t -test against zero), 4.9 ± 4.4 mm (P = 0.97), and 0.8 ± 4.3 mm (P = 0.47) for S. sobrinus, L. gasseri, and A. naeslundii, respectively. Mean differences were less contrasting when chlorhexidine and pure components were tested (P < 0.05 for S. sobrinus and L. gasseri). These results indicate the need for a gold standard method to evaluate the antimicrobial properties of bonding agents. [source] Disc diffusion test in the identification of Candida speciesMYCOSES, Issue 5-6 2000Thangam Menon A total of 448 clinical isolates and seven reference strains of Candida species were tested for their susceptibility to a group of dyes and chemicals. All strains were also identified by conventional methods. The chemicals/dyes used in the disc diffusion tests were brilliant green, janus green, cycloheximide, fast green, rhodamine 6 G, ethidium bromide and 2, 3, 5 triphenyl tetrazolium chloride. Sensitivity to the chemicals was coded by a seven-figure code. Resistogram patterns obtained were found to be specific for each species. The disc diffusion test was found to be inexpensive, quick and gave reliable results within 18 h. [source] Mueller,Hinton agar is superior to PDM blood agar for detection of methicillin-resistant Staphylococcus aureusCLINICAL MICROBIOLOGY AND INFECTION, Issue 1 2003T. Monsen The aim of this study was to compare the expression of oxacillin resistance in methicillin-resistant Staphylococcus aureus (MRSA) on Paper Disc Method agar supplemented with 5% defibrinated blood (PDM blood agar) and Mueller,Hinton agar supplemented with 2% NaCl (MH NaCl agar) using different susceptibility tests. Fifty mecA- containing isolates of S. aureus, exhibiting 46 different pulsed-field gel electrophoresis patterns, were comparatively tested using the E test, the single disk diffusion test, and the multipoint inoculation technique, under various culture conditions. The E test incubated at 35 °C for 24 h (breakpoint of resistance ,2.0 mg/L) detected 94% of the isolates on MH NaCl agar, compared with 28% for PDM blood agar (P < 0.05). The disk diffusion test (breakpoint ,,10 mm in diameter) under these incubation conditions detected resistance in 100% of the isolates on MH NaCl agar and in 80% of the isolates on PDM blood agar (P < 0.05). The multipoint technique (breakpoint ,1 mg/L), applied at 35 °C for 24 h, detected 100% on MH NaCl agar and 46% on PDM blood agar (P < 0.05). Irrespective of the method of susceptibility testing evaluated, MH NaCl agar was superior to PDM blood agar for the detection of oxacillin resistance in mecA -containing S. aureus. [source] Antibacterial effects of MDPB against anaerobes associated with endodontic infectionsINTERNATIONAL ENDODONTIC JOURNAL, Issue 8 2010N. Izutani Izutani N, Imazato S, Noiri Y, Ebisu S. Antibacterial effects of MDPB against anaerobes associated with endodontic infections. International Endodontic Journal. Abstract Aim, To investigate the antibacterial effects of 12-methacryloyloxydodecylpyridinium bromide (MDPB), an antibacterial monomer synthesized by combining quaternary ammonium with a methacryloyl group, against three anaerobes associated with endodontic infections using planktonic and biofilm cells. Methodology, The antibacterial activity of unpolymerized MDPB against Enterococcus faecalis, Fusobacterium nucleatum and Prevotella nigrescens was examined by agar-disc diffusion tests and determination of the minimum inhibitory/bactericidal concentrations (MIC/MBC). Rapid killing effects of MDPB against three bacteria in planktonic form were examined by a cell number counting method, and those against biofilm cells were assessed by a viability staining method. Results, MDPB demonstrated inhibition against all of the bacteria tested by agar-disc diffusion tests. The MIC/MBC values of MDPB for the three anaerobes were much smaller than those of other resin monomers, although greater compared with those of cetylpyridinium chloride or chlorhexidine diacetate for E. faecalis and F. nucleatum. Significant reduction in viable planktonic cells was obtained by contact with 250 ,g mL,1 of MDPB for 20 s (P < 0.05, Fisher's PLSD tests), and 40 s contact with 500 ,g mL,1 or 20 s contact with 1000 ,g mL,1 of MDPB resulted in more than 90% killing. Biofilm cells of all species were completely killed by application of 1000 ,g mL,1 of MDPB for 60 s. Conclusion, MDPB was found to have strong antibacterial effects against E. faecalis, F. nucleatum and P. nigrescens, and such effects were rapidly exhibited even against biofilm cells, suggesting the usefulness of application of MDPB to resin-based materials for root canal filling. [source] Enhancement of the efficacy of erythromycin in multiple antibiotic-resistant gram-negative bacterial pathogensJOURNAL OF APPLIED MICROBIOLOGY, Issue 3 2008S. Saha Abstract Aims:, To improve the efficacy of erythromycin, a hydrophobic antibiotic, against multiple antibiotic-resistant gram-negative bacterial pathogens by enhancing their outer membrane permeability. Methods and Results:, Fifty-one nonrepeat gram-negative bacterial pathogens of various genera, resistant to multiple antibiotics, including erythromycin, were selected by disc agar diffusion tests. The amphiphilic cationic steroid antibiotic, Ceragenin CSA-13, a potent permeabilizer of bacterial outer membranes, reduced the minimum inhibitory concentration of erythromycin in 92% of the bacterial pathogens selected for the test, when supplemented with erythromycin. A synergistic effect of Ceragenin CSA-13 and erythromycin in combination was also observed. Spectrofluorimetric study confirmed that Ceragenin CSA-13 acts by depolarizing the bacterial outer membrane. The toxicity of Ceragenin CSA-13 was evaluated to be insignificant by measuring ,median lethal dose' (LD50) on mouse model. Conclusions:, Ceragenin CSA-13 may be useful as an agent to make erythromycin effective against infections caused by multiple antibiotic resistant gram-negative bacteria. Significance and Impact of the Study:, The outcome of the study suggests erythromycin,Ceragenin combination as a new approach to overcome the problem associated with the rapid emergence of multi-drug-resistant pathogens. The insignificant toxicity of Ceragenin CSA-13, as found, supports the possibility of the application of this compound for human therapeutics. [source] Antibacterial Effects of Allspice, Garlic, and Oregano Essential Oils in Tomato Films Determined by Overlay and Vapor-Phase MethodsJOURNAL OF FOOD SCIENCE, Issue 7 2009W-X. Du ABSTRACT:, Physical properties as well as antimicrobial activities against,Escherichia coli,O157:H7,,Salmonella enterica, and,Listeria monocytogenes,of allspice, garlic, and oregano essential oils (EOs) in tomato puree film-forming solutions (TPFFS) formulated into edible films at 0.5% to 3% (w/w) concentrations were investigated in this study. Antimicrobial activities were determined by 2 independent methods: overlay of the film on top of the bacteria and vapor-phase diffusion of the antimicrobial from the film to the bacteria. The results indicate that the antimicrobial activities against the 3 pathogens were in the following order: oregano oil > allspice oil > garlic oil.,Listeria monocytogenes,was less resistant to EO vapors, while,E. coli,O157:H7 was more resistant to EOs as determined by both overlay and vapor-phase diffusion tests. The presence of plant EO antimicrobials reduced the viscosity of TPFFS at the higher shear rates, but did not affect water vapor permeability of films. EOs increased elongation and darkened the color of films. The results of the present study show that the 3 plant-derived EOs can be used to prepare tomato-based antimicrobial edible films with good physical properties for food applications by both direct contact and indirectly by vapors emanating from the films. [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] Disc diffusion test in the identification of Candida speciesMYCOSES, Issue 5-6 2000Thangam Menon A total of 448 clinical isolates and seven reference strains of Candida species were tested for their susceptibility to a group of dyes and chemicals. All strains were also identified by conventional methods. The chemicals/dyes used in the disc diffusion tests were brilliant green, janus green, cycloheximide, fast green, rhodamine 6 G, ethidium bromide and 2, 3, 5 triphenyl tetrazolium chloride. Sensitivity to the chemicals was coded by a seven-figure code. Resistogram patterns obtained were found to be specific for each species. The disc diffusion test was found to be inexpensive, quick and gave reliable results within 18 h. [source] | |||||||||||||||||||