RESUMEN
We evaluated culture-negative, community-acquired endocarditis by using indirect immunofluorescent assays and molecular analyses for Bartonella spp. and Coxiella burnetii and found a prevalence of 19.6% and 7.8%, respectively. Our findings reinforce the need to study these organisms in patients with culture-negative, community-acquired endocarditis, especially B. henselae in cat owners.
Asunto(s)
Infecciones por Bartonella/epidemiología , Bartonella/patogenicidad , Infecciones Comunitarias Adquiridas/epidemiología , Coxiella burnetii/patogenicidad , Endocarditis Bacteriana/diagnóstico , Animales , Anticuerpos Antibacterianos/inmunología , Bartonella/crecimiento & desarrollo , Infecciones por Bartonella/diagnóstico , Brasil/epidemiología , Gatos , Infecciones Comunitarias Adquiridas/diagnóstico , Coxiella burnetii/crecimiento & desarrollo , Endocarditis Bacteriana/epidemiología , Endocarditis Bacteriana/microbiología , Femenino , Humanos , Masculino , Encuestas y CuestionariosRESUMEN
Bartonella spp. and Coxiella burnetii are recognized as causative agents of blood culture-negative endocarditis (BCNE) in humans and there are no studies of their occurrences in Brazil. The purpose of this study is to investigate Bartonella spp. and C. burnetii as a causative agent of culture-negative endocarditis patients at a cardiology hospital in São Paulo, Brazil. From January 2004 to December 2004 patients with a diagnosis of endocarditis at our Institute were identified and recorded prospectively. They were considered to have possible or definite endocarditis according to the modified Duke criteria. Those with blood culture-negative were tested serologically using the indirect immunofluorescent assay (IFA) for Bartonella henselae, B. quintana, and C. burnetii. IFA-IgG titers >800 for Bartonella spp. and C. burnetii were considered positive. A total of 61 patients with endocarditis diagnosis were evaluated, 17 (27%) were culture-negative. Two have had IgG titer greater than 800 (>/=3,200) against Bartonella spp. and one against C. burnetii (phase I and II>/=6,400). Those with Bartonella-induced endocarditis had a fatal disease. Necropsy showed calcifications and extensive destruction of the valve tissue, which is diffusely infiltrated with mononuclear inflammatory cells predominantly by foamy macrophages. The patient with C. burnetii endocarditis received specific antibiotic therapy. Reports of infective endocartitis due to Bartonella spp. and C. burnetii in Brazil reveal the importance of investigating the infectious agents in culture-negative endocarditis.
Asunto(s)
Infecciones por Bartonella/diagnóstico , Endocarditis Bacteriana/microbiología , Fiebre Q/diagnóstico , Adulto , Anticuerpos Antibacterianos/sangre , Válvula Aórtica/microbiología , Válvula Aórtica/patología , Bartonella , Coxiella burnetii , Diagnóstico Diferencial , Femenino , Humanos , Inmunoglobulina G/sangre , Masculino , Persona de Mediana Edad , Estudios RetrospectivosRESUMEN
Rocky Mountain spotted fever (RMSF), a tick-borne zoonosis caused by Rickettsia rickettsii, is among the deadliest of all infectious diseases. To identify the distribution of various genotypes of R. rickettsii associated with fatal RMSF, we applied molecular typing methods to samples of DNA extracted from formalin-fixed, paraffin-embedded tissue specimens obtained at autopsy from 103 case-patients from seven countries who died of RMSF. Complete sequences of one or more intergenic regions were amplified from tissues of 30 (29%) case-patients and revealed a distribution of genotypes consisting of four distinct clades, including the Hlp clade, regarded previously as a non-pathogenic strain of R. rickettsii. Distinct phylogeographic patterns were identified when composite case-patient and reference strain data were mapped to the state and country of origin. The phylogeography of R. rickettsii is likely determined by ecological and environmental factors that exist independently of the distribution of a particular tick vector.