Question

Rickettsia form a group under

(a) viruses

(b) bacteria

(c) fungi

(d) a category between viruses and bacteria.

Answer 1

(b) bacteria

Rickettsia is a   Gram-negative (possess true cell walls), nonmotile bacteria, which is present with either as cocci, or rods, or thread-like appearance. Rickettsia are obligate intracellular parasites (symbiotes), they enter eukaryotic cells, where they grow and replicates (generally in endothelial cells). So, Rickettsia cannot survive in artificial nutrient environments. In general, Rickettsia is susceptible to tetracyclin antibiotics.