Search results
Results from the WOW.Com Content Network
Rickettsia typhi is a small, aerobic, obligate intracellular, rod shaped gram negative bacterium. [1] It belongs to the typhus group of the Rickettsia genus, along with R. prowazekii . [ 2 ] R. typhi has an uncertain history, as it may have long gone shadowed by epidemic typhus ( R. prowazekii ). [ 3 ]
Properly, Rickettsia is the name of a single genus, but the informal term "rickettsia", plural "rickettsias," usually not capitalised, commonly applies to any members of the order Rickettsiales. Being obligate intracellular bacteria , rickettsias depend on entry, growth, and replication within the cytoplasm of living eukaryotic host cells ...
Scrub typhus - caused by Orientia tsutsugamushi (formerly classified as a Rickettsia), this disease is transmitted by chigger bites and is common in parts of Asia and the Pacific. Typhus - there are different types of typhus, including epidemic typhus caused by Rickettsia prowazekii (transmitted by lice) and murine typhus caused by Rickettsia ...
However, scrub typhus is still considered a rickettsiosis, even though the causative organism has been reclassified from Rickettsia tsutsugamushi to Orientia tsutsugamushi. [ citation needed ] Examples of rickettsioses include typhus , both endemic and epidemic, Rocky Mountain spotted fever , and Rickettsialpox .
A spotted fever is a type of tick-borne disease which presents on the skin. [1] They are all caused by bacteria of the genus Rickettsia. Typhus is a group of similar diseases also caused by Rickettsia bacteria, but spotted fevers and typhus are different clinical entities.
They are obligate intracellular parasites, and some are notable pathogens, including Rickettsia, which causes a variety of diseases in humans, and Ehrlichia, which causes diseases in livestock. Another genus of well-known Rickettsiales is the Wolbachia , which infect about two-thirds of all arthropods and nearly all filarial nematodes. [ 2 ]
Rickettsia rickettsii is a Gram-negative, intracellular, cocco-bacillus bacterium that was first discovered in 1902. [1] Having a reduced genome, the bacterium harvests nutrients from its host cell to carry out respiration, making it an organo-heterotroph.
Rickettsia rickettsii can be transmitted to human hosts through the bite of an infected tick. As with other bacterium transmitted via ticks, the process generally requires a period of attachment of 4 to 6 hours. However, in some cases a Rickettsia rickettsii infection has been contracted by contact with tick tissues or fluids. [19]