Understanding biofilm formation in intravascular device-related infections

Excerpt

The use of indwelling devices is constantly increasing in modern medicine. Although they improve patients’ care, it is recognised that their use is associated with the risk of infection. Device-related infections represent a significant part of hospital-acquired infections and are due to device contamination by microorganisms subsequently forming biofilms. These biofilms are formed by sessile communities encased in a self-produced matrix that protects them from external insults including the host immune system and antimicrobial agents. Historically the first description of the involvement of biofilms in a device-related infection was provided in 1982 by the observation of a pacemaker colonised by Staphylococcus aureus [1]. Since then, formation of biofilms has been described in all indwelling devices and is especially problematic in intensive care units (ICU) where intravascular devices are extensively used and critically ill patients may require the concomitant use of several devices. In part because of their repeated manipulation, the use of such devices is associated with bloodstream infection incidence densities ranging from 0.8 to 3.7 episodes per 1000 catheter-days, depending on the definitions used, ICU units, and infection control practices [2]. Main microorganisms responsible for intravascular catheter colonisation and subsequent infections depend on local epidemiology and type of ICU but mostly include Staphylococcus spp., Gram-negative rods and yeasts. …