I.S.I. AL-Adham, P. , " Effect of Polyvinylpyrrolidone molecular weight upon the antimicrobial activity of povidone iodine antiseptics. International Journal of Pharmaceutics, 34: 45-49. " , "International Journal of Pharmaceiutics",Vol.34,,No., , , 08/15/1986
Abstract:
1- The antimicrobial activity of various povidone-iodine formulations has been assessed against Escherichia coli, where the molecular weight of the polyvinylpyrrolidone has been varied between 10 000 and 360 000. Bactericidal activity was directly related to polymer molecular weight and could be attributed to molecular-weight-dependent changes in the proportions of free and available iodine. When bactericidal activities were related to those of diluted Lugol's iodine solutions, then formulation as an iodophor was observed to give an approximate doubling of activity. It is suggested that this molecular-weight-independent potentiation of iodine action could be related to alteration of membrane-conformation, rather than to concentration, by the polymer, of iodine at its target.
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A.J.. Dinning,I.S.I., " Pyrithione biocide interactions with bacterial phospholipid head groups, " , "Journal of Applied Nicrdbiology",Vol.85,,No., , , 09/15/1998
Abstract:
3-Sodium pyrithione and zinc pyrithione (NaPT and ZnPT, respectively) are antimicrobial agents widely used in both the cosmetics and fuel industries. They are also utilized in the mining industry because of their metal chelating properties. They have been shown to depolarize membrane electropotential in fungi and are also known to inhibit fungal and bacterial substrate transport processes. Recent work has shown that both pyrithiones cause the leakage of intracellular material (potassium ions and O.D.260 nm absorbing material) from exposed bacterial cells. The work here reports studies on the interactions between the pyrithiones and the bacterial phospholipid head group structures, at both a practical and a theoretical level, utilizing tube dilution neutralizer studies, scanning spectrophotometry and molecular modelling. The tube dilution neutralizer studies exhibited a decrease in minimum inhibitory concentration (MIC) for both pyrithiones in the presence of extracellular phosphatidyl-ethanolamine and EDTA. Scanning spectrophotometry exhibited the chelation of the central zinc atom from the ZnPT chelate by the addition of EDTA. Molecular modelling studies exhibited the chelation of the phosphatidyl-ethanolamine head group by ZnPT. Zinc pyrithione also exhibited an interaction with the ammonium tail of the head group structures. Sodium pyrithione exhibited electrostatic interactions with the phospholipid head groups in the molecular modelling studies.
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A.J.. Dinning,I.S.I, " Pyrithione biocides as inhibitors of bacterial ATP synthesis, " , "Journal of Applied Microbiology",Vol.85,,No., , , 11/15/1998
Abstract:
4-Sodium pyrithione and zinc pyrithione (NaPT and ZnPT, respectively) are widely used as cosmetic preservatives and general antimicrobial agents. They have been shown to be active against fungal cell walls, associated membranes and bacterial transport processes. Investigations were undertaken into the effect of these antimicrobial agents on substrate catabolism and intracellular ATP levels using an oxygen electrode and luciferin-luciferase technology, respectively. Results indicate that, while both compounds are poor inhibitors of substrate catabolism, sub-inhibitory concentrations of biocide greatly reduces intracellular ATP levels in both Escherichia coli NCIMB 10000 and Pseudomonas aeruginosa NCIMB 10548. This is thought to be due to the action of NaPT and ZnPT on the Gram-negative bacterial membrane.
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I.S.I. AL-Adham, A., " Cell membrane effects of some common Biocides. " , "Journal of Industrial Microbiology and Biotechnology.",Vol.21,No., , , 12/15/1998
Abstract:
5-Many antimicrobial compounds exhibit bacterial cell membrane activity as either potassium ion leakage and/or leakage of material that absorbs at 260 nm from the cell. In this experiment a potassium ion selective electrode and spectophotometric observation of 260-nm leakage were used in order to examine cell membrane effects in a selection of common biocides upon both Escherichia coli NCIMB 10000 and Pseudomonas aeruginosa NCIMB 10548. The observation of potassium ion leakage for pyrithione biocides yielded results which were initially difficult to interpret, but are thought to suggest a species-dependent combination of potassium ion leakage from affected membranes and chelation of those leaked ions in the bathing suspension. Such a result is not, however, supported by the 260-nm material leakage results, which indicate very similar levels of membrane active effects for both species of bacteria.
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A.J.. Dinning,I.S.I, " A novel assay for the distribution of pyrithione biocides in bacterial cells, " , "Letters in Applied Microbiology",Vol.27,No., , , 05/15/1998
Abstract:
6- Sodium pyrithione and zinc pyrithione (NaPT and ZnPT, respectively) are widely used as cosmetic preservatives and metal chelating agents. They are commonly assayed using thin layer chromatography (TLC) and high performance liquid chromatography (HPLC). However, a simple quantitative colorimetric assay has not been previously reported for these compounds. This paper describes the development of a spectrophotometric assay for the quantification of the pyrithiones which is based on the chelation of copper (II) ions by the biocides. This assay was developed in order to facilitate the determination of the distribution of these biocides in the Gram-negative bacteria Escherichia coli NCIMB 10,000 and Pseudomonas aeruginosa NCIMB 10,548. Sodium pyrithione was exhibited only in the cytosol of E. coli and Ps. aeruginosa. Zinc pyrithione, however, was assayed in the cytosol of both bacteria and was found in the cell envelope of Ps. aeruginosa. These findings suggest that the pyrithione biocides are active within bacterial cells as well as at the cell membrane.
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I.S.I. AL-Adham, E., " Microemulsions are membrane-active, antimicrobial, self-preserving systems, I " , "Journal of Applied Microbiology",Vol.89,,No., , , 05/15/2000
Abstract:
7- Microemulsions are physically stable oil/water systems that have potential use as delivery systems for many pharmaceuticals which are normally of limited use due to their hydrophobicity, toxicity or inability to access the site of action. It has been suggested that microemulsions are self-preserving antimicrobials in their own right, although there is little evidence to support this. In this experiment, microemulsions of various compositions were formulated and tested for their stability and antimicrobial action. The physical stability of the different microemulsions was assessed by centrifugation at 4000 g and by storage in a water bath at 37 °C for one month, during which no phase separation was observed. The antimicrobial activity of the microemulsions was tested using the compendial method, observation of the kinetics of killing, and transmission electron microscopy (TEM) of microemulsion-exposed cultures of Pseudomonas aeruginosa PA01. These latter experiments on Ps. aeruginosa indicated distinct signs of membrane disruption. The results indicated that the microemulsions are self-preserved, and that their killing of microbial cultures is very rapid and may be the result of membrane activity.
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C.L. Winder, I.S.I., " Outer membrane protein shifts in biocide-resistant Pseudomonas aeroginosa PAO1, " , "Journal of Applied Microbiology",Vol.89,,No., , , 09/15/2000
Abstract:
8- Benzisothiazolone (BIT), N-methylisothiazolone (MIT) and 5-chloro-N-methylisothiazolone (CMIT) are highly effective biocidal agents and are used as preservatives in a variety of cosmetic preparations. The isothiazolones have proven efficacy against many fungal and bacterial species including Pseudomonas aeruginosa. However, some species are beginning to exhibit resistance towards this group of compounds after extended exposure. This experiment induced resistance in cultures of Ps. aeruginosa exposed to incrementally increasing sub-minimum inhibitory concentrations (MICs) of the isothiazolones in their pure chemical forms. The induced resistance was observed as a gradual increase in MIC with each new passage. The MICs for all three test isothiazolones and a thiol-interactive control compound (thiomersal) increased by approximately twofold during the course of the experiment. The onset of resistance was also observed by reference to the altered presence of an outer membrane protein, designated the T-OMP, in SDS-PAGE preparations. T-OMP was observed to disappear from the biocide-exposed preparations and reappear when the resistance-induced cultures were passaged in the absence of biocide. This reappearance of T-OMP was not accompanied by a complete reversal of induced resistance, but by a small decrease in MIC. The induction of resistance towards one biocide resulted in the development of cross-resistance towards other members of the group and the control, thiomersal. It has been suggested that the disappearance of T-OMP from these preparations is associated with the onset of resistance to the isothiazolones in their Kathon™ form (CMIT and MIT).
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S.M.A. Abdel Malek,, " Antimicrobial susceptibility changes and T-OMP shifts in pyrithione- passaged planktonic cultures of Pseudomonas aeroginosa PAO1, . " , "Journal of Applied Microbiology",Vol.92,,No., , , 02/15/2002
Abstract:
9- Aims: The aim of this study was to determine whether passaging Pseudomonas aeruginosa PAO1 with sub-MICs of the pyrithione biocides results in both the induction of decreased susceptibility towards these antimicrobials and associated outer membrane profile changes. Methods and Results: Previous work by this group has shown that it is possible to induce susceptibility changes towards the isothiazolone biocides in Ps. aeruginosa PAO1 by successive passages in the presence of increasing sub-MICs of biocide. This procedure was accompanied by the loss of a 35 kDa outer membrane protein, T-OMP. In this experiment, this process was repeated with the biocides sodium pyrithione (NaPT), zinc pyrithione (ZnPT) and cetrimide. The pattern of susceptibility was similar to that observed with the isothiazolone biocides. Upon removal of biocide, the observed MIC did not return to the original pre-exposure value. The onset and development of resistance was accompanied by the loss of T-OMP from outer membrane profiles,,which suggests that this is a non-specific membrane channel whose production within the cell is sensitive to biocide presence. The T-OMP reappeared when the cells were passaged in the absence of pyrithione. Cross-resistance studies indicated that induced resistance to one biocide yields partial resistance towards other members of the group and the positive control. Conclusions: These results indicate that the pyrithione biocides have similar susceptibility profiles in Ps. aeruginosa to those exhibited by the isothiazolones, but that the acquired changes in susceptibility to the pyrithiones is largely irreversible. Significance and Impact of the Study: This study indicates that acquired susceptibility changes towards sub-MICs of selected biocides are multifactorial in nature.
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I.S.I,AL-Adham, N.D, " Microemulsions are Highl Effective Anti-Biofilm . " , "Letters in Applied Microbiology",Vol.36,,No., , , 01/15/2003
Abstract:
10- Aims: The demonstration of the antibiofilm effects of pharmaceutical microemulsions.
Methods and Results: Microemulsions were prepared as physically stable oil/water systems. Previous work by this group has shown that microemulsions are highly effective antimembrane agents that result in rapid losses of viability in planktonic populations of Pseudomonas aeruginosa and Staphylococcus aureus. In this experiment a microemulsion preparation was used upon established biofilm cultures of Ps. aeruginosa PA01 for a period of 4 h. The planktonic MIC of sodium pyrithione and the planktonic and biofilm MICs of cetrimide were used as positive controls and a biofilm was exposed to a volume of normal sterile saline as a treatment (negative) control. Results indicate three log-cycle reductions in viability within the microemulsion treated biofilm, as compared to those observed in control treatments of similar biofilms (one log-cycle reduction in viabilities).
Conclusions: The results indicate that the microemulsions are highly effective antibiofilm agents.
Significance and Impact of the Study: This study suggests that microemulsions may have a role in the treatment of industrial and environmental biofilms.
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F. Qa adan, I.S.I. A, " Characterization of antimicrobial polymeric pocyanidins from juglans regia leaf extract, " , "European Journal of Scientific Research",Vol.11, No.3,No., , , 06/15/2005
Abstract:
11- In this study isolation and identification of different procyanidins structures (catechin, epicatechines .. etc.) from the leaves of Juglans regia and also the polymeric procyanidin fraction, which has shown antimicrobial activities on acne developing microorganisms was also isolated.
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S.M., Abdel Mallek, , " Pseudomonas aeroginosa PAO1 resistance to Zinc pyrithione: phenotypic changes the involvement of efflux pump. . " , "Curr.Microbiol.",Vol.59, NO. 2.,No., Spinger., , 09/30/2009
Abstract:
12- The aim of this study is to investigate the involvement of an efflux pump in the development of Pseudomonas aeruginosa resistance to zinc pyrithione (ZnPT). In the presence of efflux inhibitor carbonyl cyanide m-chlorophenyl-hydrazone (CCCP), the minimum inhibitory concentration of ZnPT for P. aeruginosa resistant cells is reduced significantly (p < 0.05). In addition, the concentration of ZnPT excluded by the resistant bacteria was reduced significantly (p < 0.01). However, the above reductions did not reach the levels measured for P. aeruginosa PAO1 sensitive strain. Furthermore, such changes in P. aeruginosa resistant cells were correlated with the overexpression of outer membrane proteins, reduced sensitivity toward imipenem (p < 0.01) and increased sensitivity toward sulphatriad and chloramphenicol (p < 0.05). In a continuation to a previous study, we conclude that P. aeruginosa resistance to ZnPT is multifactorial and involves induced efflux systems.
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HADDADIN R.N.S., SAL, " The Effect of Sub-minimal inhibitory concentration of antibiotics on virulence factors expressed by Staphylococcus aureus biofilms. " , "JOURNAL OF APPLIED MICROBIOLOGY",Vol.108,No.4, wiley blackwell, u. k., 03/01/2010
QAADAN, F., MANSOOR,, " Proanthocyanidins from Ginkgo biloba leaf extract and their radicl scavinging activity. " , "Pharmaceutical Biology",Vol.49,No.(5), , Europe, 04/01/2011
AL-ADHAM, I.S.I., AL, " The Antimicrobial Activity of Oil-in- Water Microemulsion is predicted by thrier position within the Microemulsion Stability Zone. " , "International Arabic Journal of Antimicrobial Agents.",Vol.2,No.(2.5), , jORDAN, 06/01/2012
AL-ADHAM, I.S.I., AL, " Antimicrobial tolerence changes in biocide- passaged biofilm cultures of P seudomonas aeriogenosa PAO1. " , "International Arabic Journal ofAntimicrobial Agents.",Vol.2 ,No.(2:5), , Jordan., 06/01/2013
Ibrahim, S.I., Al-Ad, " Studies on the kinetics and the proposed mechanism of action of microemulsions against fungi " , "International Journal of Pharmaceutics",Vol.454,No., , , 08/01/2013
Al-Hmoud N.D., I.S.I, " A novel binary biofilm model for the study of the development of antimicrobial tolerance in Pseudomonas aeroginosa PA0I Escherichia coli " , "The International Arabic Journal of Antimicrobial Agents",Vol.3,No.1, , , 03/01/2013
Abstract:
The synthesis and structural elucidation of α-amino-N-phenylsuccinimide through the IR, hNMR, ORD, and elemental analysis was described as precursor to thionimides, L-(S)-aspartic acid served as starting material and was utilized to investigate routes applicable to the synthesis of α-amino-N-phenyls
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Abstract:
Objective: A new series of 2-{4-(t-amino)-2-(but-2-yn-1-yl)}-1,3-benzothiazole derivatives, 2-[4-(pyrrolidin-1-yl)but-2-yn-1-yl]-1,3-benzothiazole (BZ2), 2-[4-(2-methylpiperidin-1-yl)but-2-yn-1-yl]-1,3-benzothiazole (BZ3), 2-[4-(piperidin-1-yl) but-2-yn-1-yl]-1,3-benzothiazole (BZ4), 2-[4-(azepan-1-
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Ibrahim Al-Adham, Ra, " Types of Microbicidal and Microbistatic Agents " , "Principle and Practice of Disinfection, Preservation and Sterilization",Vol.,No., Wiley-Blackwell, , 01/01/2013
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