BLACK FUNGUS WHITE FUNGUS AND YELLOW FUNGUS.

BLACK FUNGUS WHITE FUNGUS AND YELLOW FUNGUS.
What is the black, white and yellow fungus

COVID -19 second wave and journalism in India have introduced us to Black,  white and yellow fungus.  What are these originally?  Let’s decode some terminilogy.

Before delving in let’s look at ways to differentiate two major opportunistic infections in COVID-19 patients based on morphology- MUCOR and ASPERGILLUS.

1. BLACK FUNGUS

What is being referred to as black fungus?

Mucor is being referred to as the black fungus.

Is the fungus itself black in colour?

No,  in a setting of immunosuppression, mucor grows rapidly causing angioinvasion and tissue necrosis.  This results in a blackish appearance of the affected area,  giving rise to the name.

What is the real black fungus?

BLACK FUNGUS WHITE FUNGUS AND YELLOW FUNGUS.
Dermataceous fungi

Some fungii have excess melanin, also called melanized or dermaticious fungi.  They are the real black fungi.  Moreover,  presence of melanin is not uncommon in Histoplasma spp,  Aspergillus spp (especially Aspergillus niger)  and even candida spp.

2. WHITE FUNGUS

What is being referred to as white fungus?

BLACK FUNGUS WHITE FUNGUS AND YELLOW FUNGUS.
White patches in candida

Candida albicans.  This fungus has the tendency to produce patchy white coloured lesions,  hence the name.

3. YELLOW FUNGUS

What is being referred to as yellow fungus?

Mucor septicus.  This fungus has not been associated with any human infections till now.  It’s identification is still a mystery.

What is the real yellow fungus?

BLACK FUNGUS WHITE FUNGUS AND YELLOW FUNGUS.
Aspergillus in culture central blackish pigment and peripheral yellow to white

Aspergillus– When cultured, aspergillus has a blackish center due to the melanin, and whitish or yellowish body.

Actinomycetes has a unique feature, pus in this infection has a yellow color due to the presence of sulfur granules.

That’s it for now! Thank you.

For Morphologic differences between Mucor and aspergillus check this out!

For more articles

Some gastrointestinal pathogens and their differentiating features.

Gastrointestinal pathogens are very common in routine practice. It takes experience and keen observation to differentiate gastrointestinal pathogens from one another. In case of confusion, go with your ‘GUT’ feeling.

Lets look at a few differentiating features of Giardia lamblia, Cryptosporidium parvum and Isospora belli.

  1. GIARDIA LAMBLIA:

Pear shaped trophozoites with 2 ovoid nuclei, present in the luminal surface. They are 10-15 microns in length and 5-9 microns in width.

GIARDIA IS SEEN IN THE LUMINAL SURFACE

CRYPTOSPORIDIUM IS SEEN ATTACHED TO ENTEROCYTES LIKE SMALL BEADS.

2. CRYPTOSOPORIDIUM PARVUM

In tissue biopsies, 2 – 5 μm basophilic round bodies are seen protruding from the apex of enterocytes (“blue beads”) within the cell membrane. Parasites bulge out of apex of epithelial cells

ISOSPORA IS LARGEST AMONG THE THREE. IN CONTRAST TO GIARDIA AND CRYPTOSPORIDIUM – ISOSPORA DOES NOT HAVE AN APICAL LOCATION, INSTEAD LOCATED IN THE TIP OF VILLI.

3. ISOSPORA BELLI

Oocysts are generally ovoid to ellipsoid in shape, range from 10-40µm in length by 10-30µm in width. Cysts are present in PARASITO-
PHOROUS VACUOLE. Does not have an apical location.

Look below for a quick summary