Antimicrobial flush solutions

#1. Field of the Invention

#The present invention relates generally to the fields of medicine and microbiology. More particularly, it concerns methods of reducing microbial organisms from indwelling medical devices, medical equipment and other surfaces.

#2. Description of Related Art

#The following drawings form part of the present specification and are included to further demonstrate certain aspects of the present invention. The invention may be better understood by reference to one or more of these drawings in combination with the detailed description of specific embodiments presented herein.

#FIG. 1. Ethanol in combination with M-EDTA as a flush solution used for 15 minutes or 24 hours, as indicated, tested against MRSA in biofilm.

#Microorganisms that attach themselves to inert surfaces, such as medical devices including, vascular catheters, endotracheal tubes, Foley catheters, biliary stents, nephrostomy tubes, prosthetic valves, ventriculostomy or epidural catheters, or fluid pipelines, such as oil pipelines or water pipelines, produce a layer made of exopolysaccharide called microbial biofilm. These organisms embed themselves in this layer. This biofilm layer ultimately becomes the protective environment that shields these organisms on the inert surface from the antimicrobial activity of various antibiotics or antiseptics. In U.S. Pat. Nos. 5,362,754 and 5,688,516, incorporated herein by reference in their entirety, the present inventor demonstrated that a combination of one or more antimicrobial agent with one or more chelator and/or anticoagulant (such as EDTA or heparin) reduces or eradicates these antibiotic-resistant biofilm embedded microorganisms if the antimicrobial and chelator combination is allowed to dwell on the surface for at least 4 hours. However, in both clinical and environmental situations, it is typically not feasible to allow a 4 hour dwell time for the chelator and antimicrobial agent to reduce or eradicate the microbes. For example, it is not possible to interrupt the therapy of critically ill patients receiving continuous infusion therapy through a vascular catheter for 4 hours. It is also not possible to interrupt an environmental situation involving fluid pipelines for 4 hours to allow for such a prolonged dwell time of antimicrobial/chelator solution.

#The present invention allows rapid reduction and/or eradication of microorganisms embedded in a biofilm in a time as short as about 15 minutes of exposure to combinations of at least one antimicrobial and at least one chelator/anticoagulant, if this combination is prepared in an alcohol. This is exemplified in one embodiment by minocycline-EDTA in an ethanol solution, which is described in detail in the application. However, one of skill in the art will recognize that one may use any antimicrobial agent, any chelator/anticoagulant and any alcohol.

#In addition, the present invention provides antimicrobial solutions comprising one or more antimicrobial agents, one or more chelator/anticoagulant, and an alcohol solution. The present invention also provides methods for the rapid reduction or eradication of microorganisms embedded in a biofilm on a surface comprising contacting or exposing the surface to a flush solution of the invention. Thus, the invention provides methods for reducing or eradicating microbes from the surfaces of medical devices, including indwelling medial devices, as well as other surfaces, pipelines and the like.