Table 1

 Investigation and management of rare causes of culture negative endocarditis

PathogenDiagnostic procedureProposed treatment
Adapted from Brouqui and Raoult11 with permission.
PCR, polymerase chain reaction.
Brucella sppBlood cultures; serology; culture, immunohistology, and PCR of surgical materialDoxycycline plus rifampin or cotrimoxazole (>3 months’ treatment)
Coxiella burnetti Serology (IgG phase l, 1 in 800); tissue culture, immunohistology, and PCR of surgical materialDoxycycline plus hydroxychloroquine or doxycycline plus quinolone (>18 months’ treatment)
Bartonella sppBlood cultures; serology; culture, immunohistology, and PCR of surgical materialβ lactams or doxycycline plus aminoglycoside (>6 weeks’ treatment)
Chlamydia sppSerology; culture, immunohistology, and PCR of surgical materialDoxycycline or new fluoroquinolones (long term treatment, optimum duration unknown)
Mycoplasma sppSerology; culture, immunohistology, and PCR of surgical materialDoxycycline or new fluoroquinolones (>12 weeks’ treatment)
Legionella sppBlood cultures; serology; culture, immunohistology, and PCR of surgical materialMacrolides plus rifampicin or new fluoroquinolones (>6 months’ treatment)
Tropheryma whipplei Histology and PCR of surgical materialCotrimoxazole or β lactam plus aminoglycoside (long term treatment, optimum duration unknown)