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Biomedical subjects

Gassan Chaiban

Publications and source records attributed to Gassan Chaiban.

6 recordsLinked to original sources

Chest tube-related empyema due to methicillin-resistant Staphylococcus aureus: could the chest tube be coated with antiseptics?

We reviewed the epidemiology, clinical manifestations, and outcomes of 3 cases of chest tube-related empyema due to methicillin-resistant Staphylococcus aureus (MRSA). Antiseptic-impregnated chest tubes were inserted in cultures containing MRSA isolates from these 3 patients, and zone of inhibition were measured. Chest tube-related MRSA empyema might complicate tube thoracostomy, and coating the chest tube with antiseptic agents could prevent this complication.

Aged↗

Vancomycin-resistant Enterococcus faecium: catheter colonization, esp gene, and decreased susceptibility to antibiotics in biofilm.

To evaluate the molecular characteristics and antibiotic susceptibility in biofilm of vancomycin-resistant Enterococcus faecium (VREF) organisms that had caused catheter-related VREF bacteremia (VREF-CRB), we compared 22 isolates causing bacteremia obtained from patients with VREF-CRB with 30 isolates from control patients with gastrointestinal colonization by VREF. Using pulsed-field gel electrophoresis, we identified 17 unique strains among the 22 VREF-CRB isolates and 23 strains among the gastrointestinal isolates. The esp gene was detected in 53% (9 of 17) of the VREF-CRB and 61% (14 of 23) of the control strains (P = 0.6). VREF-CRB produced heavier biofilm colonization of silicone disks than did control organisms (P < 0.001). Daptomycin, minocycline, and quinupristin-dalfopristin were each independently more active than linezolid in reducing biofilm colonization by VREF-CRB (P < 0.01), with daptomycin being the most active, followed by minocycline. In conclusion, the esp gene in VREF is not associated with heavy biofilm colonization or catheter-related bacteremia. In biofilm, daptomycin and minocycline were the most active antibiotics against VREF, and linezolid was the least active.

Anti-Bacterial Agents↗

A rapid method of impregnating endotracheal tubes and urinary catheters with gendine: a novel antiseptic agent.

OBJECTIVES: To test the efficacy of gendine, a novel antiseptic, containing Gentian Violet and chlorhexidine, in coating different medical devices, including endotracheal tubes (ETT) and urinary catheters (UC). METHODS: We determined the antimicrobial efficacy and cytotoxicity of ETT and UC segments coated, through an instant dip method, with gendine. Using the modified Kirby-Bauer method, gendine-coated devices showed zones of inhibition of >/=15 mm against methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, Escherichia coli and Candida parapsilosis. RESULTS: Gendine-coated endotracheal tubes (GND-ETT) soaked in bronchoalveolar fluid (BAL) and incubated at 37 degrees C maintained a zone of inhibition of >/=15 mm against MRSA and P. aeruginosa for at least 3 weeks. Similarly, gendine-coated urinary catheters (GND-UC), soaked in urine, maintained a zone of inhibition of >/=15 mm against E. coli for 8 weeks. Using the minimum essential media elution method in mouse fibroblast cells, GND-ETT and GND-UC were found to be non-cytotoxic. Gendine-coated UC significantly reduced the amount of viable MRSA, E. coli or C. parapsilosis organisms adhering to their surfaces when compared with silver/hydrogel-coated urinary catheters or control uncoated catheters (P < 0.01). Similarly GND-ETT significantly reduced the adherence of the same organisms as well as P. aeruginosa when compared with control (P </= 0.02). CONCLUSIONS: GND-ETT and GND-UC impregnated using an instantaneous dip method, were shown to have broad-spectrum activity, prolonged antimicrobial durability and high efficacy in inhibiting adherence of organisms commonly causing nosocomial pneumonia and urinary tract infection. Furthermore, these coated devices were shown to be non-cytotoxic.

Animals↗

Clinical-use-associated decrease in susceptibility of vancomycin-resistant Enterococcus faecium to linezolid: a comparison with quinupristin-dalfopristin.

The susceptibility of 135 vancomycin-resistant Enterococcus faecium bacteremic isolates to linezolid and quinupristin-dalfopristin was determined. All were susceptible to linezolid, while 88% were susceptible to quinupristin-dalfopristin prior to the clinical use of the drugs at our hospital. More than 6 months after their clinical use, a decrease in susceptibility was noted for only linezolid at 83%. This was related in part to a single G2576U gene mutation in domain V of the 23S rRNA gene.

Acetamides↗

Clinical experience with minocycline and rifampin-impregnated central venous catheters in bone marrow transplantation recipients: efficacy and low risk of developing staphylococcal resistance.

In this retrospective evaluation of the 4-year clinical use of minocycline and rifampin-impregnated catheters in bone marrow transplantation (BMT) patients, we report low risk of development of staphylococcal resistance to the antibiotics coating the catheters and efficacy in preventing primary staphylococcal bloodstream infections.

Adult↗

In vitro and ex vivo activities of minocycline and EDTA against microorganisms embedded in biofilm on catheter surfaces.

Minocycline-EDTA (M-EDTA) flush solution has been shown to prevent catheter-related infection and colonization in a rabbit model and in hemodialysis patients. We undertook this study in order to determine the activities of M-EDTA against organisms embedded in fresh biofilm (in vitro) and mature biofilm (ex vivo). For the experiment with the in vitro model, a modified Robbin's device (MRD) was used whereby 25 catheter segments were flushed for 18 h with 10(6) CFU of biofilm-producing Staphylococcus epidermidis, Staphylococcus aureus, and Candida albicans per ml. Subsequently, each of the catheter segments was incubated in one of the following solutions: (i) streptokinase, (ii) heparin, (iii) broth alone, (iv) vancomycin, (v) vancomycin-heparin, (vi) EDTA, (vii) minocycline (high-dose alternating with low-dose), or (viii) M-EDTA (low-dose minocycline alternating with high-dose minocycline were used to study the additive and synergistic activities of M-EDTA). All segments were cultured quantitatively by scrape sonication. For the experiment with the ex vivo model, 54 catheter tip segments removed from patients and colonized with bacterial organisms by roll plate were longitudinally cut into two equal segments and exposed to either saline, heparin, EDTA, or M-EDTA (with high-dose minocycline). Subsequently, all segments were examined by confocal laser electron microscopy. In the in vitro MRD model, M-EDTA (with a low concentration of minocycline) was significantly more effective than any other agent in reducing colonization of S. epidermidis, S. aureus, and C. albicans (P < 0.01). M-EDTA (with a high concentration of minocycline) eradicated all staphylococcal and C. albicans organisms embedded in the biofilm. In the ex vivo model, M-EDTA (with a high concentration of minocycline) reduced bacterial colonization more frequently than EDTA or heparin (P < 0.01). We concluded that M-EDTA is highly active in eradicating microorganisms embedded in fresh and mature biofilm adhering to catheter surfaces.

Anti-Bacterial Agents↗