Search results
Results From The WOW.Com Content Network
Rickettsia is a genus of nonmotile, gram-negative, nonspore-forming, highly pleomorphic bacteria that may occur in the forms of cocci (0.1 μm in diameter), bacilli (1–4 μm long), or threads (up to about 10 μm long).
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 prowazekii is a species of gram-negative, obligate intracellular parasitic, aerobic bacilliform bacteria of class Alphaproteobacteria that is the etiologic agent of epidemic typhus, transmitted in the feces of lice. In North America, the main reservoir for R. prowazekii is the flying squirrel.
It contains Gram-negative bacteria, very sensitive to environmental exposure, thus is adapted to obligate intracellular infection. Rickettsia rickettsii is considered the prototypical infectious organism in the group.
Rickettsia typhi is a small, gram-negative intracellular bacterium that establishes the murine typhus infection in mammals and fleas. [30] Murine typhus was once one of the most prevalent rickettsial diseases in the world, [8] [9] [10] having isolated the R. typhi causative agent from nearly every continent around the globe except for Antarctica.
Rickettsia conorii is a Gram-negative, obligate intracellular bacterium of the genus Rickettsia that causes human disease called boutonneuse fever, Mediterranean spotted fever, Israeli tick typhus, Astrakhan spotted fever, Kenya tick typhus, Indian tick typhus, or other names that designate the locality of occurrence while having distinct clinical features.
Rickettsia parkeri (abbreviated R. parkeri) is a gram-negative intracellular bacterium. The organism is found in the Western Hemisphere and is transmitted via the bite of hard ticks of the genus Amblyomma .
Orientia tsutsugamushi is a Gram-negative bacterium and is a permanent (obligate) parasite in mites. Within a single host cell, O. tsutsugamushi rapidly divides into many individuals. A unicellular organism, it is oval shaped and measures 0.5 to 0.8 μm wide and 1.2 to 3.0 μm long.