Which of the following is not caused by Rickettsia?

Typhoid fever is not caused by Rickettsia; it is caused by the bacterium Salmonella enterica serotype Typhi. Rickettsia are a genus of bacteria that are primarily known for causing diseases such as Rocky Mountain spotted fever, typhus, and scrub typhus, all of which are transmitted by arthropods like ticks and fleas.

Rocky Mountain spotted fever is characterized by fever, rash, and a history of tick exposure, while typhus is typically associated with lice or fleas. Scrub typhus is caused by Orientia tsutsugamushi, which is a member of the Rickettsiaceae family, and also involves vector transmission through mites. Understanding the differences between these diseases is crucial for diagnosis and treatment in microbiology. Thus, recognizing that typhoid fever is due to a different pathogen entirely highlights the importance of differentiating between similar-sounding diseases caused by different infectious agents.