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Bartonellae are vector-borne gram-negative, aerobic, intracellular bacteria with a tropism for erythrocytes and endothelial cells (1). These bacteria, many of which are zoonotic, infect a wide range of domestic and [...]

Streptococcus suis, an emerging zoonotic pathogen, causes invasive infections in persons who are in close contact with infected pigs or contaminated pork-derived products (1). On the basis of capsular polysaccharides, [...]

The immune mechanisms that provoke concomitant inflammation of synovial joints and cardiac valves in disorders such as rheumatic fever and systemic lupus erythematosus remain poorly defined. Here, we report the discovery of spontaneous endocarditis--in addition to their well-studied autoimmune arthritis--in K/BxN T cell receptor (TCR) transgenic mice. The same adaptive immune system elements were required for initiation of arthritis and endocarditis, and both diseases were dependent on autoantibodies. In contrast, the participation of key innate immune system molecules and perhaps T cells as effectors of inflammation differed between the 2 target tissues. Arthritis in K/BxN TCR transgenic mice depended primarily on complement C5 and not FcR[gamma]-using receptors; conversely, endocarditis depended essentially on FcR[gamma] receptors and not C5. Elucidating how a single systemic autoimmune disease engages distinct immune effector pathways to damage different target tissues is essential for optimizing the treatment of such disorders. autoimmunity | complement | Fc receptor | rheumatic | lupus

Enterococcus faecalis, a common cause of endocarditis and known for its capacity to transfer antibiotic resistance to other pathogens, has recently emerged as an important, multidrug-resistant nosocomial pathogen. However, knowledge of its lineages and the potential of particular clones of this species to disseminate and cause disease is limited. Using a nine-gene multilocus sequence typing (MLST) scheme, we identified an evolving and widespread clonal complex of E. faecalis that has caused outbreaks and life-threatening infections. Moreover, this unusual clonal complex was found to contain isolates of unexpected relatedness, including the first known U.S. vancomycin-resistant enterococcus (E. faecalis strain V583), the first known penicillinase-producing ([Bla.sup.+]) E. faecalis isolate, and the previously described widespread clone of penicillinase producers, a trait found in

To the Editor: In Rosario, Argentina, during June 2005, a 15-year-old boy was hospitalized because of a 2-month history of fever. The patient had no history of cardiac disease or [...]