Nanostructured Selenium – A Novel Biologically-Inspired Material for Antibacterial Medical Device Applications - Biomimetics: Advancing Nanobiomaterials and Tissue Engineering - page 202

Figure 8.2 Common sites of biofi lm infection [10]. Once bacteria enter the
circulatory system, they can spread to any moist surface of the human body.
of implant infection relates to catheters, which is the most common and
complicated problem associated with catheter usage. Infections are the most
serious complication of tunneled dialysis catheters, resulting in serious sys-
temic infections, including endocarditis, osteomyelitis, epidural abscess, sep-
tic arthritis, and even death [12]. Infections lead to implant failure, extended
hospital stay, and additional treatment/surgeries. Bacteria infect up to 54%
of all catheters [13] and cause many serious complications including patient
death. For example, catheter infection is associated with a mortality rate of
12% to 25% among critically ill patients [14]. Catheter-associated urinary
tract infection (CAUTI) is the most common type (accounting for 40%) of
hospital-acquired infection resulting in serious complications such as blood-
stream infection, and even death [15]. Each year, in US acute-care hospitals
and extended-care facilities, CAUTI affects approximately 1 million patients
who then will have increased institutional death rates [16]. The cost incurred
by infections in the US is nearly $11 billion annually [17].
Implant associated infections are diffi cult to treat because of biofi lm for-
mation. Bacteria in a biofi lm can escape from the fi lm and enter the blood,
lungs, etc., causing serious problems. Biofi lms tenaciously bind to surfaces.
More importantly, bacteria in biofi lms are extremely resistant to antibiotic
treatment due to the slow transport of antibiotic molecules through the
polymeric-like biofi lm substance, altered micro-environment within the
biofi lm and higher number of “persister” cells (cells that are resistant to
many types of stress) within the biofi lm compared to planktonic cells [18].
Among the most common pathogens found on infected implants,
Staphylococcus aureus is responsible for 20% of catheter infections and 35%
of orthopedic implant infections [19-21]. Staphylococcus aureus is one of the