Nocardia Stain Partially Acid-Fast, Actinomyces and Streptomyces Are Not Acid-Fast. Actinomyces and Streptomyces Produce Granules. Most Actinomycetes in Tissue...
Nocardia stain partially acid-fast, Actinomyces and Streptomyces are not acid-fast. Actinomyces and Streptomyces produce granules. Most actinomycetes in tissue do not stain with the H & E stain commonly used for general histopathology.
What is the difference between Streptomyces and Actinomyces?
Like Actinomyces and Propionibacterium, Streptomyces belongs to the large group of filamentous bacteria known as actinomycetes, but Streptomyces species have a well-developed substrate mycelium, produce an aerial mycelium with chains of spores, and are strict aerobes.
Nocardia are weakly acid-fast following staining with the modified Ziehl-Neelsen or Kinyoun stain. Cultures may grow in a few days, but typically require 2 to 3 weeks of incubation.