Document Details
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Document Type |
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Project |
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Document Title |
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Studies on the prevention of adherence of biofilm associated bacteria to human cells and implanted medical devices . : دراسات لمنع التصاق البكتريا التي لها القدرة علي تكوين غشاء حيوي، بأسطح خلايا الإنسان والأدوات الطبية الموضوعة داخل الجسم. |
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Subject |
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: Medicinal Product/Pharmaceutical Microbiology |
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Document Language |
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Arabic |
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Abstract |
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The interactions between antimicrobial agents (fluoroquinolones [ciprofloxacin, norfloxacin, and levofloxacin], B-lactam antibiotics [cefoperazone, cefotaxime, cefepime], clindamycin, streptomycin, and vancomycin) or non-antimicrobial agents ( non steroidal anti-inflammatory agents [salicylate, acetylsalicylic acid, diclofenac] and mucolytic agents [N-acetylcysteine, ambroxol, and bromohexine]), and biofilms formed by Pseudomonas aeruginosa and Staphylococcus epidermidis ( each 12 clinical isolates) was studied. The presence of subinhibitory concentrations (1/2, 1/4, or 1/8 MIC) of all the tested antimicrobial agents significantly reduced the biofilm formation and adherence of P. aeruginosa and S. aureus to plastic surfaces, vascular catheter segments, and surfaces of human epithelial A549 cells. Treatment of preformed biofilms with a higher concentrations of the tested antimicrobial agents (25 μg/ml to 200 μg/ml), caused significant reduction in the bacterial adherence of the tested strains. Levofloxacin was the most active agent , while, cefotaxime had the least activity. In case of the non antimicrobial agents (0.5-4.0 mg.ml), salicylate and N-acetyl salicylic acid caused significant reduction in the biofilm formation and adherence of the tested strains to plastic surfaces and vascular catheter segments, while other agents have no significant effect. On the other hand, N-acetylcysteine, bromohexine, and ambroxol (10-40 µg/ml) significantly reduced the bacterial adherence to the surface of human epithelial A549 cells, while, the other agents have no significant effect. The effect of some environmental factors on the activity of levofloxacin was studied. The result showed that the presence of 5 mM Mg++ significantly reduced the antiadherent activity of levofloxacin, while, 5 mM Ca++ has no significant effect. Reduction in the pH of the medium to 5.5 caused slight increased in the activity of levofloxacin as compared to its activity at pH 7. While, increasing the pH of the medium to 8.5 caused slight reduction in its activity. The bactericidal activity of levofloxacin against the tested isolates in biofilm forms was significantly increased in the presence of clindamycin ( 20 µg/ml ) and N-acetylcysteine ( 1 mg/ml). |
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Publishing Year |
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1424 AH
2004 AD |
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Added Date |
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Monday, November 9, 2009 |
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Researchers
| . محمود عبدالمجبد يس | Yassien, Mahmoud Abdul Megead | Investigator | Doctorate | |
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