Positive Surveillance Cultures Research Articles

Colonization and infection with Trichosporon species in the immunosuppressed host.

Trichosporon beigelii and Trichosporon capitatum have recently been recognized as systemic pathogens in the immunosuppressed host. We studied the incidence of colonization and systemic infection with these organisms in 353 highly immunocompromised patients over a 37-month period. Thirteen patients (3.7%) had positive surveillance cultures for Trichosporon species in stool, skin, or urine. Three of the 13 patients developed systemic infections after having positive surveillance cultures. In two of these three patients, urine cultures were positive near the time of systemic infection. The route of entry appeared to have been enteric in two patients and cutaneous in one patient. Both colonizing and infecting organisms showed in vitro susceptibility to amphotericin B and nystatin. This study suggests that positive surveillance cultures for Trichosporon species may correlate with systemic infection in the severely immunocompromised patient and that repeated positive urine cultures may indicate dissemination.

Treatment of mycoses in cancer patients

Invasive fungal infections are becoming increasingly frequent among immunocompromised patients and especially among cancer patients. The most common pathogens identified are Candida species, Aspergillus species, Cryptococcus neoformans, and Mucor species. Amphotericin B remains the mainstay of antifungal therapy. However, the toxicity of this drug may limit its use and, in addition, both failures and relapses have been reported. 5-Fluorocytosine and imidazoles, such as miconazole and ketoconazole, have been shown to be active, mainly on yeast organisms. The emergence of 5-fluorocytosine-resistant strains warrants caution for its administration as a single agent. The specific role of ketoconazole has not yet been established in large studies. In our experience, ketoconazole seems to be effective in the treatment of severe oral candidiasis in non-neutropenic cancer patients. Moreover, ketoconazole administered prophylactically to neutropenic patients decreases the number of positive surveillance cultures in these patients. The rare incidence of major toxicity and the ability to administer ketoconazole orally represent also major arguments for further investigation of ketoconazole activity by prospective controlled studies.