ABSTRACT

The bacterium Listeria monocytogenes infrequently causes illness in the general population.  In some groups, however, including pregnant women, newborns, elderly persons, and those with impaired cell-mediated immunity, including many cancer patients, it is an important cause of invasive disease, particularly bacteremia, meningitis, encephalitis, and brain abscess. Nocardia species are aerobic, gram-positive, branching, filamentous, bacterial rods which is most often in the environment in soil, water, and vegetable matter.  The key host defense against developing nocardiosis is cell mediated immunity; the humoral immune response offers little protection.  These organisms are considered opportunistic pathogens, causing infection in patients with impaired cell-mediated immune response, including patients with lymphoreticular neoplasia, organ transplantation, HIV/AIDS, diabetes mellitus, and alcoholism.  In particular, there is a well documented association between nocardiosis and chronic granulomatous disease (CGD). In this chapter we present a details review of epidemiology, clinical presentation and maganment of these opportunistic infections in immunosuppressed patients with cancer.