Clinical Microbiology Revision PDF

Tick transmitted organisms examples: (@2 marks) - Borrelia burgdorferi - Rickettsia rickettsii - Rickettsia typhi Treatment for atypicals = doxycycline / macrolide Atypicals , *...

Tick transmitted organisms examples: (@2 marks) - Borrelia burgdorferi - Rickettsia rickettsii - Rickettsia typhi Treatment for atypicals = doxycycline / macrolide Atypicals , * Centripetal maculopapular Cannot be cultured!! à PCR / Serology ↑I petechial rash amplification of atypical by indirect immunofluoresence - Begin peripherally on ankles & wrist → trunk DNA from blood sample Typical case (R. rickettsia): G– Rickettsial organisms à Weil-Felix test (cross-reaction with Proteus vulgaris) hiking in the woods / bitten bacilli Th ⬢ R. rickettsia: tick-borne, Rocky Mountain Spotted Fever by dog before → bitten by T # Brill-Zinsser disease is the unknown organism → rash ⬢ R. prowazekii: louse-borne, epidemic typhus recrudescent form of epidemic typhus T ⬢ R. typhi: flea-borne, murine typhus · # ⬢ O. tsutsugamushi: 11 mite-borne, scrub typhus typical case: sheep in farm, labour → inhalation of Coxiella burnetii ⬢ Coxiella burnetii: Q fever, culture negative endocarditis Y i.e. pyrexia of unknown origin → chronic state may cause endocarditis usually unable to be cultured Spirochetes à Dark-ground microscopy (Mx: penicillin) G– spirochete 11 pallidum: syphilis F ⬢ Treponema ⬢ Borrelia / burgdorferi: 11 Lyme disease (erythema migrans) also may have: arthritis, facial nerve palsy ⬢ Leptospira interrogans: Weil’s disease (liver and renal failure), contact history with rat / livestock * icteric leptospirosis host of infection: rats / rodents urine can also cause anicteric leptospirosis Dx: serology → leptospira microscopic agglutination test (LMAT), culture of blood, CSF, urine past paper: hiking, walk to creek; water was contaminated by urine of some animals → Leptospira infection 25