Mycobacterium Runyon Classifications Quiz

Mycobacterium Runyon Classifications

• Mycobacteria are categorized into different groups based on their pigment production in the presence or absence of light.

Runyon Group I

• Known as photochromagens, these mycobacteria develop pigment only when exposed to light.
• Notable species include:
  • M. marinum: Associated with fish tank granuloma.
  • M. kansasii: Known to cause pulmonary infections.

Runyon Group II

• Classified as scotochromagens, these mycobacteria can produce pigment in both light and dark environments.
• Key species include:
  • M. gordonae: Often found in water sources, considered less pathogenic.
  • M. scrofulaceum: Linked to cervical lymphadenitis, particularly in children.
  • M. szulgazi: Less commonly discussed but included in this group.

Runyon Group III

• These mycobacteria are non-pigmented or nonphotochromogens, meaning they do not produce pigment regardless of light exposure.
• Important species consist of:
  • M. avium: Commonly associated with HIV/AIDS patients, causes systemic infections.
  • M. xenopi: Usually linked to pulmonary disease, typically found in water systems.
  • M. ulcerans: Causes Buruli ulcer, leading to necrotizing skin disease.
  • M. haemophilum: Associated with skin infections, especially in immunocompromised individuals.

Runyon Group IV

• Comprises the rapid growers, which are distinguished by their quick growth rates.
• Specific species within this group are not listed but are characterized by their ability to form colonies within days.

Test your knowledge on Mycobacterium Runyon classifications with these flashcards. Each group is defined clearly, with examples of species that belong to each category. Perfect for microbiology students looking to deepen their understanding of mycobacterial pigmentation.