Which one of the following organisms is NOT an obligate intracellular parasite and, therefore, can grow on bacteriological media?
Which one of the following organisms is NOT an obligate intracellular parasite and, therefore, can grow on bacteriological media?
Select an option to attempt
Correct Answer: Option A
Explanation
Mycoplasma vs. obligate intracellular organisms — culture on bacteriological media:Mycoplasma:• Wall-less bacteria (smallest self-replicating organisms)• CAN grow on specialised bacteriological media: PPLO (Pleuropneumonia-Like Organism) broth and agar, enriched with cholesterol, serum, and yeast extract.• Forms characteristic 'fried egg' colonies on solid media.Obligate intracellular pathogens (CANNOT grow on bacteriological media):• Chlamydia trachomatis: infects epithelial cells; requires cell culture (HeLa, McCoy cells) or embryonated eggs.• Rickettsia: requires living cells for growth; L929 or Vero cell lines.• Adenovirus: a DNA virus; must grow in permissive eukaryotic cells; cannot grow on any bacteriological medium.Answer: Mycoplasma can grow on specialised bacteriological media; the others cannot.