[rasheed]

What are the Acid Fast positive microorganisms?

The following will stain RED with Ziehl-Neelson Stain:

• Mycobacteria (all species including Mycobacterium leprae)
• Nocardia
• Cryptospordium parvum, isospora, cyclospora cysts
• Legionella micdadei
• Head of sperm

There's another method of staining acid fast structures called Kinyoun, in that method the background will stain green.

Here's an image of red stained acid fast bacilli against a background of blue everything else

image from CDC, public domain