Rickettsia rickettsii & other Rickettsia species – causes, symptoms, diagnosis, treatment, pathology

The Rickettsiae are a genus of Gram-negative coccobacilli, which includes two major groups of bacteria. First, there’s the spotted-fever group, the main species in this group is Rickettsia rickettsii, which causes a disease called Rocky Mountain spotted fever. Second, there’s the typhus group of Rickettsia species – which cause different forms of typhus. This group…

Type II hypersensitivity (cytotoxic hypersensitivity) – causes, symptoms, & pathology

Having a hypersensitivity means that the immune system is reacting to something in a way that damages the body rather than protecting it. There are four different types of hypersensitivities, and the second type or type II hypersensitivity is sometimes called cytotoxic hypersensitivity because a lot of disorders caused by this hypersensitivity involve antibody mediated…