H. Jean Shadomy

Infection due to the fungus Acremonium (cephalosporium).

Human infections due to fungi belonging to the genus Acremonium occur uncommonly, but unlike infections due to other filamentous fungi, usually affect immunocompetent individuals. Mycetoma, which usually develops following trauma, is the most common infection caused by Acremonium spp. Other sites of infection include the eye (generally following abrogation of ocular defenses), colonizing disease of the lung and gastrointestinal tract, as well as locally invasive infections such as osteomyelitis, sinusitis, arthritis, and peritonitis. Pneumonia and disseminated infections including meningitis, endocarditis, and cerebritis rarely have been reported. Optimal treatment of acremonium infections is not well defined both because infections due to these organisms are rare, and because many reports antedate effective antifungal therapy. In addition, susceptibility testing of filamentous fungi is poorly standardized, and in vitro sensitivity may not correlate with clinical response. Based on anecdotal reports, treatment of most invasive acremonium infections requires a combination of surgical intervention, when possible, and a regimen of amphotericin B. Some azoles also display inhibitory activity. Until more details are available regarding susceptibility of these organisms to antifungal agents, amphotericin B is recommended as initial therapy with the addition of either ketoconazole or fluconazole in infections of a life-threatening nature.

Interactions between Macrophages and Fungi

Macrophages play a key role in two important host defense mechanisms: (1) ingestion and inactivation of invading organisms, and (2) macrophage interactions with other immune cells, i.e., T lymphocytes and B lymphocytes, that promote antigen recognition and processing. Among the many functions of macrophages in host defense, attachment to and engulfment of microorganisms are vitally important. After phagocytosis, most organisms are degraded, stored, and transferred by macrophages. Degraded or processed antigen then may be presented to other lymphoid cells on the surface of the macrophage. These factors demonstrate the significant contribution that macrophages make to host immune competence (Fauci, 1978).