Staining, Culture, and Identification Methods for Acid‐Fast Bacilli and Fungi Recovered from Positive Blood Cultures

Abstract

Fungemia is often a result of disseminated fungal infections in immunosuppressed patients and can be a significant cause of mortality. Candida spp. are the most common cause of fungemia, with filamentous fungi causing fewer cases. Very few filamentous fungi are generally recoverable from blood culture bottles; the most common fungi include Histoplasma capsulatum , Blastomyces spp. Fusarium spp., and Trichosporon spp. Aspergillus spp. are rarely recovered from blood and associated with true fungemia, with the rare exception of Aspergillus terreus . Bloodstream infections with acid fast bacilli typically occur as a result of disseminated disease in immunocompromised individuals. Culture methods of positive blood cultures for acid‐fast bacilli and fungal blood cultures are similar to those followed for bacterial blood cultures. After the blood culture instrument detects growth in the bottle, the appropriate stain(s) is performed and examined and the broth is plated to agar media to allow microorganism growth and identification.