Anti-infection dip suggestions for the Coloplast Titan Inflatable Penile Prosthesis in the era of the infection retardant coated implant.

INTRODUCTION: Infection is the worst complication seen with inflatable penile prosthesis (IPP). Both the American Medical Systems (AMS) and Coloplast IPP have infection retardant coatings. AMS is coated at the factory with rifampicin and minocycline (InhibiZone). The Coloplast IPP has a hydrophilic coating covalently bonded to its components that will absorb any aqueous solution before implantation and provides increased surface lubricity to decrease bacterial adherence. AIM: We tested several antibiotic dips comparing zones of inhibition (ZOI) against five commonly infecting bacteria with coated Coloplast implants. Results were compared with those ZOI created with strips of an AMS IPP precoated with InhibiZone. METHODS: Pieces of sterile Coloplast Titan IPP were dipped in (i) trimethoprim/polymixin B ophthalmic solution; (ii) trimethoprim/sulfamethoxazole infusion solution; (iii) bacitracin; (iv) rifampicin/minocycline; and (v) rifampin/trimehtoprim/sulfamethoxazole. ZOI for the Titan strips and for AMS InhibiZone coated strips were tested against Staphylococcus epidermidis, Staphylococcus lugdunensis, Staphylococcus aureus, Pseudomonas, and Enterococcus. MAIN OUTCOME MEASURE: ZOIs of the Coloplast Titan for each of the medicated solutions were compared with ZOI created by undipped strips of a sterile InhibiZone coated IPP placed on plates of the identical bacteria. RESULTS: All dips except bacitracin showed ZOI≥InhibiZone (P≥0.005) for most organisms. Because of broad-spectrum effectiveness, ease of handling, and cost, infusion vial of trimehtoprim/sulfamethoxazole seemed optimal at this time. If trimehtoprim/sulfamethoxazole is unavailable; the ZOI with Polytrim ophthalmic solution zones were almost as good. CONCLUSIONS: The Coloplast strips when dipped in several solutions showed equal or significantly larger ZOI against commonly infecting organisms than the InhibiZone coated strips. At the present time using off the shelf trimethoprim sulfamethoxazole infusion solution seems optimum. The flexibility of choosing the drug eluting from the Coloplast device seems promising in the changing bacterial environment.

Molecular techniques to detect biofilm bacteria in long bone nonunion: a case report.

BACKGROUND: Biofilms cause chronic infections including those associated with orthopaedic hardware. The only methods that are Food and Drug Administration-approved for detecting and identifying bacterial infections are cultures and selected DNA-based polymerase chain reaction methods that detect only specific pathogens (eg, methicillin-resistant Staphylococcus aureus). New DNA-based technologies enable the detection and identification of all bacteria present in a sample and to determine the antibiotic sensitivities of the organisms. CASE DESCRIPTION: A 34-year-old man sustained an open tibia fracture. He experienced 3 years of delayed healing and episodic pain. In addition to his initial treatment, he underwent three additional surgeries to achieve fracture healing. During the last two procedures, cultures were taken and samples were tested with the IBIS T5000 and fluorescence in situ hybridization (FISH). In both cases, the cultures were negative, but the IBIS and FISH confirmed the presence of a biofilm within the tibial canal. LITERATURE REVIEW: Examinations of tissues from biofilm infections, by DNA-based molecular methods and by direct microscopy, have often found bacteria present despite negative cultures. Infections associated with orthopaedic hardware may be caused by bacteria living in biofilms, and these biofilm organisms are particularly difficult to detect by routine culture methods. PURPOSES AND CLINICAL RELEVANCE: Rapid DNA-based detection methods represent a potentially clinically useful tool in the detection of bacterial biofilms. The sensitivity and clinical impact of the technology has yet to be established.

Prospecting gene therapy of implant infections.

Infection still represents one of the most serious and ravaging complications associated with prosthetic devices. Staphylococci and enterococci, the bacteria most frequently responsible for orthopedic postsurgical and implant-related infections, express clinically relevant antibiotic resistance. The emergence of antibiotic-resistant bacteria and the slow progress in identifying new classes of antimicrobial agents have encouraged research into novel therapeutic strategies. The adoption of antisense or "antigene" molecules able to silence or knock-out bacterial genes responsible for their virulence is one possible innovative approach. Peptide nucleic acids (PNAs) are potential drug candidates for gene therapy in infections, by silencing a basic gene of bacterial growth or by tackling the antibiotic resistance or virulence factors of a pathogen. An efficacious contrast to bacterial genes should be set up in the first stages of infection in order to prevent colonization of periprosthesis tissues. Genes encoding bacterial factors for adhesion and colonization (biofilm and/or adhesins) would be the best candidates for gene therapy. But after initial enthusiasm for direct antisense knock-out or silencing of essential or virulence bacterial genes, difficulties have emerged; consequently, new approaches are now being attempted. One of these, interference with the regulating system of virulence factors, such as agr, appears particularly promising.

The application of biofilm science to the study and control of chronic bacterial infections.

Unequivocal direct observations have established that the bacteria that cause device-related and other chronic infections grow in matrix-enclosed biofilms. The diagnostic and therapeutic strategies that have served us so well in the partial eradication of acute epidemic bacterial diseases have not yielded accurate data or favorable outcomes when applied to these biofilm diseases. We discuss the potential benefits of the application of the new methods and concepts developed by biofilm science and engineering to the clinical management of infectious diseases.

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.

Influence of the Sonicare toothbrush on the structure and thickness of laboratory grown Streptococcus mutans biofilms.

PURPOSE: To evaluate the effect of powered brushing with the Sonicare electronic toothbrush on the structure and thickness reduction of S. mutans biofilms using digital time-lapse microscopy (DTLM) and confocal microscopy (CM) techniques. MATERIALS AND METHODS: S. mutans biofilms grown on glass microscope slides on BHI and 2% sucrose were exposed to Sonicare for 15 seconds with the bristle tips just contacting the slide, and at distances of 0.5, 1.0, and 1.5 mm above the slide. RESULTS: With direct bristle contact, the reduction in biofilm thickness was greater than 99%. DTLM showed the break up and detachment of biofilm caused by the shear forces generated by the rapid bristle motion in real time. The Sonicare was shown to significantly reduce biofilm thickness even when the bristles were 1 mm above the biofilm. The percent biofilm thickness reduction was inversely proportional to the bristle distance. This study demonstrates the Sonicare toothbrush effectively removed biofilm from hard flat surfaces both by direct bristle contact and by fluid dynamic shear forces alone.

A review of the science regarding dental unit waterlines.

BACKGROUND: The National Institute of Dental and Craniofacial Research, or NIDCR; the American Dental Association, or ADA; and the Organization for Safety & Asepsis Procedures, or OSAP, sponsored a workshop on the topic of dental unit waterlines, or DUWLs, on Sept. 29, 2000, at the National Institutes of Health in Bethesda, Md. These organizations invited a group of experts from the ADA, NIDCR, OSAP, the U.S. Food and Drug Administration, the Centers for Disease Control and Prevention, the U.S. Department of Defense, academia and private industry to participate. TYPES OF STUDIES REVIEWED: The sponsors asked the participants to critically review the scientific literature on the subject in an attempt to determine the evidence basis for management of DUWL contamination and potential health risks, if any, in dental procedures. The ultimate goal of the workshop was to determine if a research agenda in the area of DUWLs should be pursued and what questions such an agenda should involve. RESULTS: The workshop yielded four questions that need to be addressed in future research: What is the safest and most effective agent(s)/device(s) for achieving microbial levels of no more than 200 colony-forming units per milliliter, or CFU/mL, in the effluent dental water? How should these products be evaluated and by whom? What are the adverse health effects, if any, of chronic exposure to dental bioaerosol or to the agents introduced into the dental unit to treat the waterlines for both dental staff members and patients? How could these health issues be evaluated? CLINICAL IMPLICATIONS: Developing evidence-based parameters for the management of biofilm contamination that are efficacious and cost-effective will allow clinicians to meet in proposed ADA standard of no more than 200 CFU/mL of effluent water.