THE ROLE OF COLONIZATION IN THE PATHOGENESIS OF NOSOCOMIAL INFECTIONS

The close relationship between colonization and the development of nos ocomial infections has been demonstrated. Patient-related factors, suc h as underlying illness for all major sites of infection and advanced age, and pathogen-related factors, such as the ability of bacteria to adhere to epithelial cells, play the major roles in the pathogenesis o f colonization. However, exact mechanisms of colonization have not bee n elucidated, and modulation of bacterial adherence as a method of inf ection prevention remains experimental. Current methods of infection p revention, therefore, focus either on preventing growth of colonizing microorganisms or on preventing patient-pathogen contact. Topical anti biotics have been used as a method of colonization prevention. However , their effectiveness may be limited by increases in antibiotic resist ance; moreover, the effects on patient outcome are controversial. Main tenance of the physiologic mucosal environment using nonantimicrobial agents seems a promising approach, but only a few studies demonstratin g efficacy have been published. Prevention of colonization still must rely heavily on basic infection control measures to prevent contact be tween patient and pathogen.