Biomedical subjects

Gassan Chaiban

Publications and source records attributed to Gassan Chaiban.

8 recordsLinked to original sources

PubMed2006

Optimal antimicrobial catheter lock solution, using different combinations of minocycline, EDTA, and 25-percent ethanol, rapidly eradicates organisms embedded in biofilm.

Antimicrobial lock solutions may be needed to salvage indwelling catheters in patients requiring continuous intravenous therapy. We determined the activity of minocycline, EDTA, and 25% ethanol, alone or in combination, against methicillin-resistant Staphylococcus aureus and Candida parapsilosis catheter-related bloodstream infection strains in two established models of biofilm colonization. Biofilm-colonized catheter segments from a modified Robbins device and a silicone disk biofilm colonization model were exposed to these antimicrobial agents for 15 or 60 min, respectively. After exposure, segments were sonicated and cultured. To determine regrowth after incubation at 37 degrees C, following the brief exposure to the antimicrobial agents, an equal number of segments were washed, reincubated for 24 h, and then sonicated and cultured. The triple combination of minocycline-EDTA (M-EDTA) in 25% ethanol was the only antimicrobial lock solution that completely eradicated S. aureus and C. parapsilosis in biofilm of all segments tested in the two models, and it completely prevented regrowth. In addition, M-EDTA in 25% ethanol was significantly more effective in rapidly eradicating the growth or regrowth of methicillin-resistant S. aureus and C. parapsilosis biofilm colonization in the two models than the other solutions--minocycline, EDTA, M-EDTA, 25% ethanol, and EDTA in ethanol. We conclude that M-EDTA in 25% ethanol is highly effective at rapidly eradicating S. aureus and C. parapsilosis embedded in biofilm adhering to catheter segments.

Anti-Bacterial Agents↗

PubMed2006

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↗

PubMed2006

Comparative in vitro efficacies and antimicrobial durabilities of novel antimicrobial central venous catheters.

We investigated the efficacies and durability of novel antimicrobial central venous catheters (CVCs) in preventing the adherence of microbial organisms to the surfaces of the CVCs. Novel antimicrobial CVCs investigated in this in vitro study were impregnated with antibiotics (minocycline and rifampin), with Oligon agent (silver, platinum, and carbon black), with approved antiseptics (chlorhexidine and silver sulfadiazine), or with a novel antiseptic agent, gendine, which contains gentian violet and chlorhexidine. When tested against methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa, gendine-coated CVC segments provided protection against bacterial adherence significantly more than all other types of tested CVCs (P < 0.05). Gendine-coated CVCs also provided better protection against Candida albicans and Candida parapsilosis than CVCs impregnated with antibiotics or with silver, platinum, and carbon (P < 0.02). After 28 days of being soaked in serum, the CVCs impregnated with chlorhexidine and silver sulfadiazine and the CVCs impregnated with silver, platinum, and carbon had lost antimicrobial activity against MRSA, P. aeruginosa, and C. parapsilosis, and the CVCs impregnated with minocycline and rifampin had lost activity against P. aeruginosa and C. parapsilosis. The CVCs impregnated with gendine maintained antimicrobial activities against MRSA, P. aeruginosa, and C. parapsilosis after 28 days of being soaked in serum. Central venous catheters impregnated with the novel investigational antiseptic gendine showed in vitro efficacy and provided protection against bacterial adherence more than other approved novel antimicrobial-coated CVCs.

Anti-Bacterial Agents↗

PubMed2005

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↗

PubMed2004

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↗

PubMed2004

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↗

PubMed2003

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↗

PubMed2003

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↗