ABSTRACT
Indw ellin g m edical devices have become a part of modem medical practices by providing doctors and surgeons with less invasive thera pies to treat diseases, administer nutrients, obtain blood samples, deliver medicines to specific locations in the body, and so forth. How ever, there are some problems associated with indwelling medical devices, among which infection is by far one of the major clinical com plications. In spite of non-septic conditions during the surgical process and systemic administration of antibiotics, the incidence of infections caused by bacteria is still high [1,2]. Even routine replacement (every three days) of central vascular catheters, which is one of the devices with high infection rates, does not solve the problem of catheterrelated infections [3]. Prevention of device-related infections remains a major dilemma in the delivery of quality medical care, and the prob lem causes high rates of mortality and morbidity and significant increases in health care costs [4-8]. In addition, extensive use of antibiotics to treat device-associated infections has contributed to the acceleration of the appearance of antibiotic-resistant bacteria by spreading through contaminated hospital environments to patients
BIOLOGY ON THE SURFACES OF INDWELLING DEVICES
Biofilm Formations The Nature of Bacteria
indwelling medical devices and various tissues [21] and dental decay [22], are known to be involved by surface adhesion of bacteria.