Characteristics and Treatment of Medical Device Related Infections

Medical device related infections are becoming an increasing prevalent area of infectious disease. They can be attributed to a multitude of factors from an increasing elderly population with reduced immunological status to increasing microbial resistance and evolution. Of greatest significance is the failure of standard antimicrobial regimens to eradicate biomaterial-related infections due to the formation of microbial biofilms consisting of extracellular polymeric substances. Biofilms form and thrive at the abiotic device surface where nutrients are more concentrated and symbiotic colonies can be formed. The formation of a biofilm matrix occurs in a series of steps beginning with reversible attachment of bacteria to the surface of the substrate and terminating in dispersion of mature biofilm microcolonies that aim to colonise fresh surfaces high in nutrients. Mature biofilms can resist 10-1000 times the concentrations of standard antibiotic regimens that are required to kill genetically equivalent planktonic forms. The extent of the infection and the pathogen(s) present can be attributed to both the form and location of the device. It is important that preventative measures and treatment strategies relate to combating the causative microorganisms. Preventative measures include: the use of anti-infective biomaterials that can be coated or incorporated with standard or innovative antimicrobials; modified anti-adhesive medical devices; environmental sterilisation protocols and prophylactic drug therapy. Treatment of established infection may require removal of the device or if deemed possible the device may be salvageable through the initiation of antimicrobial therapy. The increasing spectre of antibiotic resistance and medical device related infections are a large and increasing burden on health care systems and the patient’s quality of life and long term prognosis. As an infectious disease it represents one of the most difficult challenges facing modern science and healthcare.