ABSTRACT
Colonization of microbes in and on humans is normally a commensal relationship that is beneficial for both. However, cancer itself and its treatment disrupts the healthy balance between microbe and host. Because ofdamage to the skin, mucous membrane barriers and the immune system by the cancer itself, chemotherapy, radiation therapy, and intravenous catheters internal and external microbes can cause disease. Patients frequently develop nosocomial infections that are caused by normal endogenous flora at the time of admission, or by exogenous pathogens that are acquired and subsequently colonize the patient after admission to the hospital [1].
