Microbiology
Summary
Rickettsia rickettsii is an obligate intracellular, gram-indeterminate bacterium that stains weakly gram-negative. R. rickettsii relies on host cells for CoA and NAD+ to sustain its growth and reproduction, and is transmitted by the Dermacentor tick.
R. rickettsii is known for causing Rocky Mountain spotted fever, which is responsible for causing Rocky Mountain spotted fever, a disease marked by headache, fever, myalgias, and a distinctive rash. The rash starts on the wrists and ankles, then progresses to the trunk. Doxycycline is the primary treatment choice for infections caused by Rickettsia rickettsii.
Lesson Outline
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FAQs
Rickettsia rickettsii is a bacterium that causes the tick-borne disease known as Rocky Mountain spotted fever. This bacterium belongs to the genus Rickettsia, and is commonly transmitted to humans through the bite of an infected Dermacentor tick.
Individuals infected with Rickettsia rickettsii typically show symptoms including high fever, headache, abdominal pain, muscle aches, and a distinctive spotted rash that begins on the extremities and spreads. However, not all infected individuals develop the rash. Prompt recognition and treatment are crucial to prevent severe or life-threatening complications.
Doxycycline is the standard treatment for most patients with Rocky Mountain spotted fever. This antibiotic is most effective when administered early in the course of illness. It is critical to start treatment immediately upon suspicion of the disease without waiting for confirmation through laboratory testing.
The rash associated with Rocky Mountain spotted fever often begins as small, flat, pink spots on the wrists and ankles. Within a few days, these spots can develop into reddened, raised lesions that resemble small bruises. As time passes, the rash tends to spread centrally towards the trunk, sometimes covering the entire body.
