Orthopaedic metal devices coated with a novel antiseptic dye for the prevention of bacterial infections.

Gendine is a novel antiseptic dye with broad-spectrum antimicrobial activity that may be used to coat plastics and metal devices. Our objective was to determine the efficacy of gendine-coated orthopaedic metal devices in preventing methicillin-resistant Staphylococcus aureus (MRSA) colonisation. Stainless steel and titanium Schanz rods were coated with gendine. The zone of inhibition (ZoI) around the rods with and without gamma-irradiation was determined by a modified Kirby-Bauer method. A previously published bioprosthetic biofilm colonisation model, modified Kuhn's method, was used to determine the adherence of MRSA to coated and uncoated rods, with and without irradiation, after insertion into bovine bone and after 3 months shelf life followed by 2 weeks of immersion in serum. The gendine-coated Schanz metal rods showed a net ZoI of 16 mm against MRSA before and after irradiation. Gendine-coated rods showed no biofilm formation (0 colony-forming units (CFU)), which was a significant reduction (P<0.001) compared with uncoated controls (>5000 CFU). Coated rods exposed to high-dose gamma-irradiation and coated rods drilled into bone also showed significant efficacy (P<0.001) in preventing biofilm adherence. After 2 weeks, gendine-coated rods maintained significant durability (P<0.01), resulting in 90% reduction in MRSA biofilm adherence compared with uncoated control rods. Results indicate that gendine-coated metal rods are highly efficacious in the prevention of MRSA biofilm.

Catheter-related Staphylococcus aureus bacteremia in cancer patients: high rate of complications with therapeutic implications.

Risk factors for complications of catheter-related Staphylococcus aureus bacteremia (CRSAB) have been studied in the general patient population but have not been well defined in cancer patients. We investigated potential risk factors for intravascular and extravascular complications in these patients. We retrospectively reviewed the records of patients with CRSAB hospitalized at our institution between January 2001 and December 2004. Demographic, clinical, laboratory, and microbiologic characteristics were extracted for the period of hospitalization and up to 3 months thereafter. Intravascular complications were defined as infective endocarditis and/or septic thrombosis. Extravascular complications included septic arthritis, deep tissue abscess, osteomyelitis, septic pulmonary emboli, septic shock, and CRSAB-related death. Ninety-one patients were included in the current study; 63% had solid tumors and the remainder had hematologic malignancies. The incidence of overall complications was 40% (n = 36); 19% (n = 17) were intravascular. On multivariate analysis, renal failure was associated with an increased risk of overall complications (odds ratio [OR], 12.78; 95% confidence interval [CI], 1.43-114.29; p = 0.0226). Patients with solid tumors were more likely to have intravascular complications (OR, 5.47; 95% CI, 1.11-27.01; p = 0.04369). Risk factors for extravascular complications included hematologic malignancy (OR, 9.56; 95% CI, 2.36-38.77; p = 0.0016) and female sex (OR, 5.25; 95% CI, 1.2-22.99; p = 0.0279). Renal failure is a risk factor for CRSAB complications in patients with cancer. Patients with solid tumors and CRSAB tend to develop intravascular complications, while patients with hematologic malignancies are prone to develop extravascular complications. Hence consideration should be given to extending the duration of therapy beyond 2 weeks.

Antiseptic effect of a novel alcohol-free mouthwash: a convenient prophylactic alternative for high-risk patients.

We developed an efficacious and non-irritant mouthwash that is alcohol-free and that has a low concentration of chlorhexidine, in order to be used for preventing oral cavity infections in immunocompromised and cancer patients. The novel mouthwash solution was tested for its antimicrobial efficacy against both free floating (planktonic) and the biofilm forms of Candida albicans. The solution was also tested against Klebsiella pneumoniae, Pseudomonas aeruginosa, and methicillin-resistant Staphylococcus aureus (MRSA), using a modification of a previously published method. The activity of the novel mouthwash was also compared with that of three commercially available mouthwashes. The experimental mouthwash showed efficacy against C. albicans, both in free-floating form and in biofilm. With higher concentration of chlorhexidine, the solution was also efficacious in inhibiting the growth of K. pneumoniae, P. aeruginosa, and MRSA. The antiseptic activity of the alcohol-free mouthwash against other bacterial organisms and C. albicans was comparable to other commercially available alcohol-based mouthwash solutions. A novel alcohol-free mouthwash solution, that has low concentration of chlorhexidine, showed antiseptic effect against planktonic and biofilm forms of C. albicans and against K. pneumoniae, P. aeruginosa, and MRSA.

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.

EDTA as an adjunct antifungal agent for invasive pulmonary aspergillosis in a rodent model.

Rats immunosuppressed by the administration of cyclophosphamide and cortisone acetate and then infected with Aspergillus fumigatus were treated with an antifungal drug, EDTA, or a combination of one of the antifungal agents, amphotericin B lipid complex (ABLC; 5 mg/kg of body weight/day for 7 days), and EDTA (30 mg/kg/day for 7 days). The mortality rate was reduced, the duration of survival was increased, fewer A. fumigatus organisms were recovered from the lungs, and less-severe lung lesions were seen histopathologically in the rats receiving the combination treatment than in the rats receiving either an antifungal agent or EDTA alone. Further studies regarding the mechanisms of EDTA and its interactions with ABLC are warranted, and further studies are needed to more fully examine the safety, tolerance, and optimal dosing of EDTA in the treatment of this and other fungal infections.