【用戶】.

【年級】大三上

【評論內容】(3) Rickettsiae：不同的致病菌引發不同疾病，大部分皆使用doxycycline。Rickettsiae are a heterogeneous group of small, obligately intracel- lular, gram-negative coccobacilli and short bacilli, most of which are transmitted by a tick, mite, flea, or louse vector. Pathogenic rickettsial species are very closely related, have small genomes (as a result of reductive evolution, which eliminated many genes for biosynthesis of intracellu- larly available molecules), and are traditionally separated into typhus and spotted fever groups on the basis of lipopolysaccharide antigens. The drug of choice for the treatment of both children and adults with RMSF(Rocky Mountain Spotted Fever) is doxycycline. Tick-Borne Spotted Fevers: Successful therapeutic agents include doxycycline (100 mg bid orally for 1–5 days) and chloramphenicol (500 mg qid orally for 7–10 days).Endemic typhus: When endemic typhus is suspected, patients should be treated empirically with doxycycline.