Bacillary angiomatosis associated with myositis in a patient infected with human immunodeficiency virus.
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A man with AIDS presented with a deep soft-tissue mass involving the right thigh. Biopsy of a skin lesion on the back and culture of a specimen from this lesion showed bacillary angiomatosis due to Bartonella (formerly Rochalimaea) quintana. Magnetic resonance imaging revealed a large heterogeneous mass involving the vastus medialis and intermedius muscles. Therapy with erythromycin caused rapid resolution of both the cutaneous lesion and the muscle lesion. Bartonella infection is proposed as an additional cause of bacterial myositis and expands the spectrum of presentation of bacillary angiomatosis. (+info)
Interaction of Bartonella henselae with endothelial cells results in bacterial aggregation on the cell surface and the subsequent engulfment and internalisation of the bacterial aggregate by a unique structure, the invasome.
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Vascular colonisation by Bartonella henselae may cause vaso-proliferative tumour growth with clumps of bacteria found in close association with proliferating endothelial cells. By using B. henselae-infected human umbilical vein endothelial cells as an in vitro model for endothelial colonisation, we report here on a novel mechanism of cellular invasion by bacteria. First, the leading lamella of endothelial cells establishes cellular contact to sedimented bacteria and mediates bacterial aggregation by rearward transport on the cell surface. Subsequently, the formed bacterial aggregate is engulfed and internalised by a unique host cellular structure, the invasome. Completion of this sequence of events requires 24 hours. Cortical F-actin, intercellular adhesion molecule-1 and phosphotyrosine are highly enriched in the membrane protrusions entrapping the bacterial aggregate. Actin stress fibres, which are anchored to the numerous focal adhesion plaques associated with the invasome structure, are typically found to be twisted around its basal part. The formation of invasomes was found to be inhibited by cytochalasin D but virtually unaffected by nocodazole, colchicine or taxol, indicating that invasome-mediated invasion is an actin-dependent and microtubuli-independent process. Bacterial internalisation via the invasome was consistently observed with several clinical isolates of B. henselae, while a spontaneous mutant obtained from one of these isolates was impaired in invasome-mediated invasion. Instead, this mutant showed increased uptake of bacteria into perinuclear localising phagosomes, suggesting that invasome-formation may interfere with this alternative mechanism of bacterial internalisation. Internalisation via the invasome represents a novel paradigm for the invasion of bacteria into host cells which may serve as a cellular colonisation mechanism in vivo, e.g. on proliferating and migrating endothelial cells during Bartonella-induced vaso-proliferative tumour growth. (+info)
Molecular epidemiology of bartonella infections in patients with bacillary angiomatosis-peliosis.
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BACKGROUND: Bacillary angiomatosis and bacillary peliosis are vascular proliferative manifestations of infection with species of the genus bartonella that occur predominantly in patients infected with the human immunodeficiency virus. Two species, B. henselae and B. quintana, have been associated with bacillary angiomatosis, but culture and speciation are difficult, and there has been little systematic evaluation of the species-specific disease characteristics. We studied 49 patients seen over eight years who were infected with bartonella species identified by molecular techniques and who had clinical lesions consistent with bacillary angiomatosis-peliosis. METHODS: In this case-control study, a standardized questionnaire about exposures was administered to patients with bacillary angiomatosis-peliosis and to 96 matched controls. The infecting bartonella species were determined by molecular techniques. RESULTS: Of the 49 patients with bacillary angiomatosis-peliosis, 26 (53 percent) were infected with B. henselae and 23 (47 percent) with B. quintana. Subcutaneous and lytic bone lesions were strongly associated with B. quintana, whereas peliosis hepatis was associated exclusively with B. henselae. Patients with B. henselae infection were identified throughout the study period and were epidemiologically linked to cat and flea exposure (P< or =0.004), whereas those with B. quintana were clustered and were characterized by low income (P=0.003), homelessness (P = 0.004), and exposure to lice (P= 0.03). Prior treatment with macrolide antibiotics appeared to be protective against infection with either species. CONCLUSIONS: B. henselae and B. quintana, the organisms that cause bacillary angiomatosis-peliosis, are associated with different epidemiologic risk factors and with predilections for involvement of different organs. (+info)
Characterization of Bartonella henselae isolated from bacillary angiomatosis lesions in a human immunodeficiency virus-infected patient in Germany.
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Infections with Bartonella (Rochalimaea) henselae can result in a variety of clinical entities, including bacillary angiomatosis in immunocompromised hosts. The fastidious nature of this bacterium has so far prevented the culture of many clinical isolates. We report the recovery of the first European B. henselae isolate associated with bacillary angiomatosis. The isolate was cultured in a frozen skin biopsy specimen from a human immunodeficiency virus (HIV)-infected patient and was characterized by means of biochemical, bacteriologic, immunologic, and molecular biological methods including pulsed-field gel electrophoresis. This strain was compared with two B. henselae strains isolated in the United States to determine the relationship between the isolates. We found that it was phenotypically and genotypically indiscernible from B. henselae Houston-1, a blood culture isolate from an HIV-infected patient in Houston. These data suggest that one B. henselae clone is associated with human infections in Europe and the United States. (+info)
Comparison of different DNA fingerprinting techniques for molecular typing of Bartonella henselae isolates.
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Seventeen isolates of Bartonella henselae from the region of Freiburg, Germany, obtained from blood cultures of domestic cats, were examined for their genetic heterogeneity. On the basis of different DNA fingerprinting methods, including pulsed-field gel electrophoresis (PFGE), enterobacterial repetitive intergenic consensus (ERIC)-PCR, repetitive extragenic palindromic (REP) PCR, and arbitrarily primed (AP)-PCR, three different variants were identified among the isolates (variants I to III). Variant I included 6 strains, variant II included 10 strains, and variant III included only one strain. By all methods used, the isolates could be clearly distinguished from the type strain, Houston-1, which was designated variant IV. A previously published type-specific amplification of 16S rDNA differentiated two types of the B. henselae isolates (16S rRNA types 1 and 2). The majority of the isolates (16 of 17), including all variants I and II, were 16S rRNA type 2. Only one isolate (variant III) and the Houston-1 strain (variant IV) comprised the 16S rRNA type 1. Comparison of the 16S rDNA sequences from one representative strain from each of the three variants (I to III) confirmed the results obtained by 16S rRNA type-specific PCR. The sequences from variant I and variant II were identical, whereas the sequence of variant III differed in three positions. All methods applied in this study allowed subtyping of the isolates. PFGE and ERIC-PCR provided the highest discriminatory potential for subtyping B. henselae strains, whereas AP-PCR with the M13 primer showed a very clear differentiation between the four variants. Our results suggest that the genetic heterogeneity of B. henselae strains is high. The methods applied were found useful for typing B. henselae isolates, providing tools for epidemiological and clinical follow-up studies. (+info)
Murine model of Bartonella henselae infection in the immunocompetent host.
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Bartonella henselae is an emerging pathogen causing cat scratch disease, bacillary angiomatosis, and peliosis hepatis. Progress in understanding the pathogenesis of and the immune response to these infections has been limited by the lack of an animal model. Following intraperitoneal infection of C57BL/6 mice with B. henselae, organs were cleared of cultivatable bacteria within 6 days. In contrast, B. henselae DNA could be detected in liver tissue for at least 3 months. Liver tissue showed granulomatous inflammation reaching its highest degree of intensity during the fourth week of infection and resolving within 12 weeks postinfection. This mouse model is applicable to the study of the pathogenesis of B. henselae and the immune response to this pathogen in the immunocompetent host. (+info)