Document Details
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Document Type |
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Article In Journal |
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Document Title |
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INTERACTIONS BETWEEN BIOFILMS FORMED BY PSEUDOMONAS AERUGINOSA AND DIFFERENT ANTIMICROBIAL A GENTS INTERACTIONS BETWEEN BIOFILMS FORMED BY PSEUDOMONAS AERUGINOSA AND DIFFERENT ANTIMICROBIAL A GENTS |
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Document Language |
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English |
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Abstract |
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ABSTRACT'
The interactions between antimicrobial agents (fluoroquinolones [ciprofloxacin, ofloxacin, and levofloxacin], β-lactams [cefoperazone, cefotaxime, cefepime], clindamycin, and streptomycin) and biofilms formed by Pseudomonas aeruginosa (12 clinical isolates) were studied. The presence of sub inhibitory concentrations (1/2, 1/4, or 1/8 MIC) of the tested antimicrobial agents reduced the optical density of the biofilm adherent to plastic surfaces to 31.1-60.1%, 37. 7-73.1%, and 50.6-85% of control, respectively. The addition of high concentrations (25 - 200 µg/ml, equivalent to 1/8-125 M1C90) of the tested antimicrobial agents to preformed biofilm (grown for 48 h at 37°C), decreased the optical density of the adherent biofilm to 73.4-87.1% and 55- 71.8% of controls, respectively. In case of an in vitro model of vascular catheter colonization, treatment of the segments with sub inhibitory concentrations (1/2, 1/4 and 1/8 MIC) of tested antimicrobial agents reduced the number of adherent bacteria to 12 - 26, 18 - 32, and 24 - 38 CFU/segment, respectively (control 34-58 CFU/segment). The flushed, unsolicited and unwashed segments that were treated with the used fluoroquinolones and clindamycin (100 ug/ml showed no growth of organisms, while, a few organisms (13-26 CFU/sediment,) were grown on some of the segments that were treated with 50 ug/ml of the tested agents. In case of human epithelial A549 cells, the presence of 1/2, 1/4, and 1/8 MICs of the tested agents caused reduction in the percentage of the number adherent viable cells of P. aeruginosa to 32.9-75.3%, 60.7-88.7% and 71.6-96.1 % of the control, respectively. Treatment of the preformed biofilm attached to A549 cells with higher concentrations (5, 10, and 20 µg/ml) of the tested antimicrobial agents reduced the number (by percentage) of adherent viable cells to 55.9-90.2%, 37.1-83.8%, and 27.9-72.2% of the control, respectively. Among the tested antimicrobial agents, levofloxacin was the most effective antiadherent agent, while, cefotaxime had the least activity. These data show that sub inhibitory concentrations of fluoroquinolones B-lactams, clindamycin, and streptomycin inhibit the adherence of P. aeruginosa to plastic surfaces, vascular catheters, and human epithelial A549 cells. In addition, higher concentrations of the tested agents were able to eradicate the preformed biofilms of P. aeruginosa. |
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ISSN |
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0969-711 |
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Journal Name |
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Egypt. J. Biomed. Sc |
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Volume |
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18 |
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Issue Number |
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2 |
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Publishing Year |
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1425 AH
2005 AD |
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Article Type |
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Article |
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Added Date |
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Sunday, May 30, 2010 |
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Researchers
| سليمان الشيخ | EL-sheikh, Soliman | Researcher | Doctorate | |
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