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Some bacterial pathogens can manipulate the angiogenic response, suppressing or inducing it for their own ends. In humans, Bartonella henselae is associated with cat-scratch disease and vasculoproliferative disorders such as bacillary angiomatosis and bacillary peliosis. Although endothelial cells (ECs) support the pathogenesis of B. henselae, the mechanisms by which B. henselae induces EC activation are not completely clear, as well as the possible contributions of other cells recruited at the site of infection. Mesenchymal stromal cells (MSCs) are endowed with angiogenic potential and play a dual role in infections, exerting antimicrobial properties but also acting as a shelter for pathogens. Here, we delved into the role of MSCs as a reservoir of B. henselae and modulator of EC functions. B. henselae readily infected MSCs and survived in perinuclearly bound vacuoles for up to 8 days. Infection enhanced MSC proliferation and the expression of epidermal growth factor receptor (EGFR), Toll-like receptor 2 (TLR2), and nucleotide-binding oligomerization domain-containing protein 1 (NOD1), proteins that are involved in bacterial internalization and cytokine production. Secretome analysis revealed that infected MSCs secreted higher levels of the proangiogenic factors vascular endothelial growth factor (VEGF), fibroblast growth factor 7 (FGF-7), matrix metallopeptidase 9 (MMP-9), placental growth factor (PIGF), serpin E1, thrombospondin 1 (TSP-1), urokinase-type plasminogen activator (uPA), interleukin 6 (IL-6), platelet-derived growth factor D (PDGF-D), chemokine ligand 5 (CCL5), and C-X-C motif chemokine ligand 8 (CXCL8). Supernatants from B. henselae-infected MSCs increased the susceptibility of ECs to B. henselae infection and enhanced EC proliferation, invasion, and reorganization in tube-like structures. Altogether, these results indicate MSCs as a still underestimated niche for persistent B. henselae infection and reveal MSC-EC cross talk that may contribute to exacerbate bacterium-induced angiogenesis and granuloma formation.

A 37-year-old man with a history of renal transplantation in 2013 due to focal segmental glomerulosclerosis presented to the emergency room with a 2-week history of fever, chills, anorexia, weight loss, abdominal pain, diarrhea, and a new asymptomatic lesion on the right side of the neck. The patient worked as a truck driver and frequently traveled to Wisconsin; he had not traveled internationally in the past year. He lived with his brother who had a pet cat. He was compliant with his anti-rejection medication regimen, which included mycophenolate mofetil, tacrolimus, and prednisone. Physical examination of the neck revealed an 8-mm exophytic, friable, red papule with overlying blood crusts (Figure 1). The remainder of the mucocutaneous examination was unremarkable, and there was no palpable lymphadenopathy. The patient was started on empiric intravenous cefepime and metronidazole and admitted to the hospital for further management. A punch biopsy of the lesion was performed.

Bacillary angiomatosis is an infection determined by Bartonella henselae and B. quintana, rare and prevalent in patients with acquired immunodeficiency syndrome. We describe a case of a patient with AIDS and TCD4+ cells equal to 9/mm3, showing reddish-violet papular and nodular lesions, disseminated over the skin, most on the back of the right hand and third finger, with osteolysis of the distal phalanx observed by radiography. The findings of vascular proliferation with presence of bacilli, on the histopathological examination of the skin and bone lesions, led to the diagnosis of bacillary angiomatosis. Corroborating the literature, in the present case the infection affected a young man (29 years old) with advanced immunosuppression and clinical and histological lesions compatible with the diagnosis.

Bacterial conjugation is a mechanism of horizontal DNA transfer. The relaxase TrwC of the conjugative plasmid R388 cleaves one strand of the transferred DNA at the oriT gene, covalently attaches to it, and leads the single-stranded DNA (ssDNA) into the recipient cell. In addition, TrwC catalyzes site-specific integration of the transferred DNA into its target sequence present in the genome of the recipient bacterium. Here, we report the analysis of the efficiency and specificity of the integrase activity of TrwC in human cells, using the type IV secretion system of the human pathogen Bartonella henselae to introduce relaxase-DNA complexes. Compared to Mob relaxase from plasmid pBGR1, we found that TrwC mediated a 10-fold increase in the rate of plasmid DNA transfer to human cells and a 100-fold increase in the rate of chromosomal integration of the transferred DNA. We used linear amplification-mediated PCR and plasmid rescue to characterize the integration pattern in the human genome. DNA sequence analysis revealed mostly reconstituted oriT sequences, indicating that TrwC is active and recircularizes transferred DNA in human cells. One TrwC-mediated site-specific integration event was detected, proving that TrwC is capable of mediating site-specific integration in the human genome, albeit with very low efficiency compared to the rate of random integration. Our results suggest that TrwC may stabilize the plasmid DNA molecules in the nucleus of the human cell, probably by recircularization of the transferred DNA strand. This stabilization would increase the opportunities for integration of the DNA by the host machinery., This work was supported by grant BIO2013-46414-P from the Spanish Ministry of Economy and Competitiveness to M.L. and in part by grant 31003A_173119 from the Swiss National Science Foundation to C.D. C.G.-P. was a recipient of a predoctoral fellowship from the University of Cantabria, Spain.

Bacillary angiomatosis is an infection determined by Bartonella henselae and B. quintana, rare and prevalent in patients with acquired immunodeficiency syndrome. We describe a case of a patient with AIDS and TCD4+ cells equal to 9/mm3, showing reddish-violet papular and nodular lesions, disseminated over the skin, most on the back of the right hand and third finger, with osteolysis of the distal phalanx observed by radiography. The findings of vascular proliferation with presence of bacilli, on the histopathological examination of the skin and bone lesions, led to the diagnosis of bacillary angiomatosis. Corroborating the literature, in the present case the infection affected a young man (29 years old) with advanced immunosuppression and clinical and histological lesions compatible with the diagnosis.

Bartonella henselae is a gram‐negative zoonotic bacterium that causes infections in humans including endocarditis and bacillary angiomatosis. B. henselae has been shown to grow as large aggregates and form biofilms in vitro. The aggregative growth and the angiogenic host response requires the trimeric autotransporter adhesin BadA. We examined the transcriptome of the Houston‐1 strain of B. henselae using RNA‐seq revealing nine novel, highly‐expressed intergenic transcripts (Bartonella regulatory transcript, Brt1‐9). The Brt family of RNAs is unique to the genus Bartonella and ranges from 194 to 203 nucleotides with high homology and stable predicted secondary structures. Immediately downstream of each of the nine RNA genes is a helix‐turn‐helix DNA‐binding protein (transcriptional regulatory protein, Trp1‐9) that is poorly transcribed under the growth conditions used for RNA‐seq. Using knockdown or overexpressing strains, we show a role of both the Brt1 and Trp1 in the regulation of badA and also in biofilm formation. Based on these data, we hypothesize that Brt1 is a trans‐acting sRNA that also serves as a cis‐acting riboswitch to control the expression of badA. This family of RNAs together with the downstream Trp DNA‐binding proteins represents a novel coordinated regulatory circuit controlling expression of virulence‐associated genes in the bartonellae.

Background Both endocarditis and Bartonella infections are neglected public health problems, especially in rural Asia. Bartonella endocarditis has been described from wealthier countries in Asia, Japan, Korea, Thailand and India but there are no reports from poorer countries, such as the Lao PDR (Laos), probably because people have neglected to look. Methodology/Principal Findings We conducted a retrospective (2006–2012), and subsequent prospective study (2012–2013), at Mahosot Hospital, Vientiane, Laos, through liaison between the microbiology laboratory and the wards. Patients aged >1 year admitted with definite or possible endocarditis according to modified Duke criteria were included. In view of the strong suspicion of infective endocarditis, acute and convalescent sera from 30 patients with culture negative endocarditis were tested for antibodies to Brucella melitensis, Mycoplasma pneumoniae, Bartonella quintana, B. henselae, Coxiella burnetii and Legionella pneumophila. Western blot analysis using Bartonella species antigens enabled us to describe the first two Lao patients with known Bartonella henselae endocarditis. Conclusions/Significance We argue that it is likely that Bartonella endocarditis is neglected and more widespread than appreciated, as there are few laboratories in Asia able to make the diagnosis. Considering the high prevalence of rheumatic heart disease in Asia, there is remarkably little evidence on the bacterial etiology of endocarditis. Most evidence is derived from wealthy countries and investigation of the aetiology and optimal management of endocarditis in low income countries has been neglected. Interest in Bartonella as neglected pathogens is emerging, and improved methods for the rapid diagnosis of Bartonella endocarditis are needed, as it is likely that proven Bartonella endocarditis can be treated with simpler and less expensive regimens than “conventional” endocarditis and multicenter trials to optimize treatment are required. More understanding is needed on the risk factors for Bartonella endocarditis and the importance of vectors and vector control., Author Summary Infection of heart valves (endocarditis) with bacteria is an important condition, especially afflicting those with rheumatic heart disease, and has a high mortality if untreated. Most of the evidence for optimal antibiotic and surgical management comes from wealthy countries. There are no published data from poorer countries in SE Asia despite a high burden of rheumatic heart disease. We investigated the bacterial infections of heart valves in the Lao PDR (Laos) through heart ultrasound scans and analysis of patients' blood. We provide evidence of infection with the poorly understood bacteria Bartonella henselae (the cause of cat scratch disease) in two patients from Laos. We argue that it is likely that Bartonella endocarditis is more widespread than appreciated, as there are few laboratories in Asia able to make the diagnosis. This is important as it is likely that proven Bartonella endocarditis can be treated with simpler and less expensive regimens than “conventional” endocarditis. There have been great advances in the wealthy world in the diagnosis and treatment of endocarditis but these have not been assessed or implemented in poorer countries. More evidence on the causes and optimal management of endocarditis in low income countries is needed.

The prevalences of antibodies against Bartonella henselae and Ehrlichia canis were determined in sera from 228 dogs in 5 communal lands of Zimbabwe, areas where traditional subsistence agro-pastoralism is practised. The sera were collected from apparently healthy dogs during routine rabies vaccination programmes and tested with indirect fluorescent antibody assays using B. henselae (Houston-I) and E. canis (Oklahoma) as antigens. We found reactive antibodies (1:80) against B. henselae in 14 % of the dogs tested. Seropositive animals were found in Bikita (41 %; 17/42), Omay (13 %; 6/48), Chinamora (5 %; 2/38) and Matusadona (15 %; 7/48). No seropositive dogs were found in Chiredzi (0 %; 0/52). Antibodies reactive with E. canis (1:80) were found in 34%of the dogs tested, from Bikita (88 %; 37/42), Chiredzi (31 %; 16/52), Omay (17 %; 8/48), Chinamora (26 %; 10/38) and Matusadona (15 %; 7/48). Our survey shows dogs in the communal lands of Zimbabwe are frequently exposed to E. canis and B. henselae or closely related species. Further studies are indicated to determine the pathogenicity of the organisms infecting these dogs and their clinical significance.

A 29-year-old man presented with generalized, painless, erythematous lesions and fever. The patient had recently been diagnosed with human immunodeficiency virus (HIV) infection. His CD4 T-cell count at presentation was 14 cells/mm3, and he had been started on antiretroviral therapy 15 days before onset of disease. ..

International audience; We report the first documented case of Bartonella henselae infection in a dog from France and the first isolation of B. henselae from a dog with fever of unknown origin. This observation contributes to the "One Health" concept focusing on zoonotic pathogens emerging from companion animals. A 1-year-old female German shepherd dog was referred for evaluation of fever of unknown origin of 1 month duration. Diagnostic investigations confirmed diffuse pyogranulomatous lymphadenitis. The dog became afebrile, and lymph node size normalized in response to a 6-week course of doxycycline. Retrospectively, Bartonella DNA was amplified from an EDTA-anticoagulated blood sample obtained before antimicrobial therapy, with the gtlA fragment sharing 99 % identity with the 350-bp gtlA fragment of the B. henselae Houston-1 strain. The same strain was isolated in the blood of three healthy cats from the household. Two months after discontinuation of doxycycline, the dog experienced a febrile relapse. Bartonella DNA was again amplified from blood prior to and immediately after administration of a 6-week course azithromycin therapy. However, without administration of additional medications, PCR was negative 9 months after azithromycin therapy and the dog remains clinically healthy 12 months following the second course of antibiotics. The medical management of this case raises several clinically relevant comparative infectious disease issues, including the extent to which Bartonella spp. contribute to fever of unknown origin and pyogranulomatous inflammatory diseases in dogs and humans, and the potential of doxycycline and azithromycin treatment failures. The possibility that dogs could constitute an underestimated reservoir for B. henselae transmission to people is also discussed.

The aim of this case series was to describe the clinical, laboratory and epidemiological characteristics and the presentation of bacillary angiomatosis cases (and/or parenchymal bacillary peliosis) that were identified in five public hospitals of Rio de Janeiro state between 1990 and 1997; these cases were compared with those previously described in the medical literature. Thirteen case-patients were enrolled in the study; the median age was 39 years and all patients were male. All patients were human immunodeficiency virus type 1 (HIV-1) infected and they had previous or concomitant HIV-associated opportunistic infections or malignancies diagnosed at the time bacillary angiomatosis was diagnosed. Median T4 helper lymphocyte counts of patients was 96 cells per mm³. Cutaneous involvement was the most common clinical manifestation of bacillary angiomatosis in this study. Clinical remission following appropriate treatment was more common in our case series than that reported in the medical literature, while the incidence of relapse was similar. The frequency of bacillary angiomatosis in HIV patients calculated from two of the hospitals included in our study was 1.42 cases per 1000 patients, similar to the frequencies reported in the medical literature. Bacillary angiomatosis is an unusual opportunistic pathogen in our setting. Esta série de casos foi conduzida com o objetivo de descrever a apresentação clínica, as características epidemiológicas, os exames laboratoriais e a evolução dos casos de angiomatose bacilar (e/ou peliose parenquimatosa bacilar) ocorridos em cinco hospitais públicos do Rio de Janeiro, no período de 1990 a 1997, comparando a casuística encontrada com a relatada na literatura médica. Foram incluídos 13 pacientes com mediana de idade de 39 anos, sendo todos pertencentes ao sexo masculino. Todos os pacientes apresentaram infecções oportunistas e/ou neoplasias associadas ao vírus da imunodeficiência humana (HIV-1) anteriores (ou concomitantes) ao diagnóstico de angiomatose bacilar. A mediana da contagem de linfócitos T Helper encontrada foi de 96 células por mm³. O acometimento cutâneo foi a apresentação clínica de angiomatose bacilar mais freqüente deste estudo. A freqüência de remissão após tratamento específico foi discretamente maior do que a relatada na literatura médica, enquanto a de recidiva foi semelhante. A freqüência de angiomatose bacilar entre indivíduos infectados pelo HIV de dois hospitais do Rio de Janeiro foi de 1,42 casos por 1.000 pacientes, semelhante ao relatado na literatura médica e sugestivo de que a angiomatose bacilar é relativamente incomum em nosso meio.

It is a report of disseminated bacillary angiomatosis (BA) in a 23-year-old female patient, who is HIV-positive and with fever, weight loss, hepatomegaly, ascites, and papular-nodular skin lesions. The clinical and diagnostic aspects involved in the case were discussed. Bacillary angiomatosis must always be considered in the diagnosis of febrile cutaneous manifestations in AIDS. Relato de angiomatose bacilar (AB) disseminada em paciente do sexo feminino de 23 anos, HIV positiva, com febre, emagrecimento, hepatomegalia, ascite e lesões de pele pápulo-nodulares. Foram discutidos os aspectos clínicos e diagnósticos envolvidos no caso. Angiomatose bacilar deve sempre ser considerada no diagnóstico de doença febril com manifestações cutâneas na AIDS.

The VirB/D4 type IV secretion system (T4SS) of the bacterial pathogen Bartonella henselae (Bhe) translocates seven effector proteins (BepA–BepG) into human cells that subvert host cellular functions. Two redundant pathways dependent on BepG or the combination of BepC and BepF trigger the formation of a bacterial uptake structure termed the invasome. Invasome formation is a multi-step process consisting of bacterial adherence, effector translocation, aggregation of bacteria on the cell surface and engulfment, and eventually, complete internalization of the bacterial aggregate occurs in an F-actin-dependent manner. In the present study, we show that Bhe-triggered invasome formation depends on integrin-β1-mediated signaling cascades that enable assembly of the F-actin invasome structure. We demonstrate that Bhe interacts with integrin β1 in a fibronectin- and VirB/D4 T4SS-independent manner and that activated integrin β1 is essential for both effector translocation and the actin rearrangements leading to invasome formation. Furthermore, we show that talin1, but not talin2, is required for inside-out activation of integrin β1 during invasome formation. Finally, integrin-β1-mediated outside-in signaling by FAK, Src, paxillin and vinculin is necessary for invasome formation. This is the first example of a bacterial entry process that fully exploits the bi-directional signaling capacity of integrin receptors in a talin1-specific manner.

Background: Bartonella henselae is the zoonotic agent of cat scratch disease and causes potentially fatal infections in immunocompromised patients. Understanding the complex interactions between the host’s immune system and bacterial pathogens is central to the field of infectious diseases and to the development of effective diagnostics and vaccines. Methodology: We report the development of a microarray comprised of proteins expressed from 96% (1433/1493) of the predicted ORFs encoded by the genome of the zoonotic pathogen Bartonella henselae. The array was probed with a collection of 62 uninfected, 62 infected, and 8 ‘‘specific-pathogen free’’ nao ¨ve cat sera, to profile the antibody repertoire elicited during natural Bartonella henselae infection. Conclusions: We found that 7.3% of the B. henselae proteins on the microarray were seroreactive and that seroreactivity was not evenly distributed between predicted protein function or subcellular localization. Membrane proteins were significantly most likely to be seroreactive, although only 23% of the membrane proteins were reactive. Conversely, we found that proteins involved in amino acid transport and metabolism were significantly underrepresented and did not contain any seroreactive antigens. Of all seroreactive antigens, 52 were differentially reactive with sera from infected cats, and 53 were equally reactive with sera from infected and uninfected cats. Thirteen of the seroreactive antigens were found to be differentially seroreactive between B. henselae type I and type II. Based on these results, we developed a classifier algorithm that was capable of accurately discerning 93% of the infected animals using the microarray platform. The seroreactivity and diagnostic potential of these antigens was then validated on an immunostrip platform, which correctly identified 98% of the infected cats. Our protein microarray platform provides a high-throughput, comprehensive analysis of the feline humoral immune response to natural infection with the alpha-proteobacterium B. henselae at an antigen-specific, sera-specific, and genome-wide level. Furthermore, these results provide novel insight and utility in diagnostics, vaccine development, and understanding of host-pathogen interaction.

Case Reports; Journal Article; Bacillary angiomatosis is a recently described infectious disease that usually affects immunosupressed hosts with a previous history of contact with cats. We report a rare case of bacillary angiomatosis in an immunocompetent 59-year-old woman with no history of previous exposure to cats, and atypical clinical features (fever and subcutaneous nodules with ulceration on the left ankle). Histopathology of the lesion showed extensive ulceration and reactive tumor-like vascular proliferation of the blood vessels with swollen endothelial cells and an inflammatory infiltrate including neutrophils and lymphocytes in the dermis and subcutis. Staining with the Warthin-Starry method demonstrated the presence of clustered bacilli located in the extracellular matrix adjacent to the proliferating endothelial cells. Diagnosis was confirmed with the detection of Bartonella spp. DNA in the affected skin and in bone marrow using polymerase chain reaction. Yes

Bacillary angiomatosis (BA) is an infectious disease which occurs predominantly in immunosuppressive patients and rarely in immunocompetent individuals. We had a case of BA who presented with a red cutaneous nodule on his left leg of which histopathological examination revealed marked lobular proliferation of capillaries throughout the interstitium and clusters of bacilli with hematoxylin-eosin and Warthin-Starry stains, respectively. Antibody titer against Bartonella henselae was 1/32. The only systemic disease the patient had was chronic hepatitis B. HIV was negative and no other immunosuppressive status was established. In this case we believe that the immunological differences secondary to chronic hepatitis B could have caused a tendency for the disease development. © 2010 Japanese Dermatological Association.

Using Bartonella henselae isolates from cats and a human, the activity of pradofloxacin was compared with those of enrofloxacin and azithromycin. By Etest and disc diffusion assay, pradofloxacin showed greater antimicrobial activity than did other antibiotics. We conclude that pradofloxacin may prove useful for the treatment of B. henselae infections.

A duplex PCR (dPCR) assay was developed to simultaneously detect and differentiate Bartonella quintana, Bartonella henselae, and Coxiella burnetii from surgical heart valve tissue specimens with an analytic sensitivity of 10 copies/reaction. Among 17 specimens collected from patients with a clinical diagnosis of culture-negative endocarditis, 2, 4, and 2 were positive for B. quintana, B. henselae, and C. burnetii, respectively, by the dPCR assay, which matched the results obtained by universal bacterial 16S rRNA gene amplification and sequencing.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2014-02-26T17:00:34Z No. of bitstreams: 1 WOS000249779400004.pdf: 246700 bytes, checksum: 36ca4c3afd3d0bae7e058c16b79a5320 (MD5) Made available in DSpace on 2014-02-26T17:00:34Z (GMT). No. of bitstreams: 1 WOS000249779400004.pdf: 246700 bytes, checksum: 36ca4c3afd3d0bae7e058c16b79a5320 (MD5) Previous issue date: 2007-09-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T15:27:32Z No. of bitstreams: 1 WOS000249779400004.pdf: 246700 bytes, checksum: 36ca4c3afd3d0bae7e058c16b79a5320 (MD5) Made available in DSpace on 2014-05-20T15:27:32Z (GMT). No. of bitstreams: 1 WOS000249779400004.pdf: 246700 bytes, checksum: 36ca4c3afd3d0bae7e058c16b79a5320 (MD5) Previous issue date: 2007-09-01 The purpose of this study was to determine the serological and molecular prevalence of Bartonella spp. infection in a sick dog population from Brazil. At the São Paulo State University Veterinary Teaching Hospital in Botucatu, 198 consecutive dogs with clinicopathological abnormalities consistent with tick-borne infections were sampled. Antibodies to Bartonella henselae and Bartonella vinsonii subsp. berkhoffii were detected in 2.0% ( 4/197) and 1.5% ( 3/197) of the dogs, respectively. Using 16S-23S rRNA intergenic transcribed spacer ( ITS) primers, Bartonella DNA was amplified from only 1/198 blood samples. Bartonella seroreactive and/or PCR positive blood samples ( n = 8) were inoculated into a liquid pre-enrichment growth medium ( BAPGM) and subsequently sub-inoculated onto BAPGM/blood-agar plates. PCR targeting the ITS region, pap31 and rpoB genes amplified B. henselae from the blood and/or isolates of the PCR positive dog ( ITS: DQ346666; pap31 gene: DQ351240; rpoB: EF196806). B. henselae and B. vinsonii subsp. berkhoffii ( pap31: DQ906160; rpoB: EF196805) co-infection was found in one of the B. vinsonii subsp. berkhoffii seroreactive dogs. We conclude that dogs in this study population were infrequently exposed to or infected with a Bartonella species. The B. henselae and B. vinsonii subsp. berkhoffii strains identified in this study are genetically similar to strains isolated from septicemic cats, dogs, coyotes and human beings from other parts of the world. To our knowledge, these isolates provide the first Brazilian DNA sequences from these Bartonella species and the first evidence of Bartonella co-infection in dogs. N Carolina State Univ, Sch Vet Med, Ctr Comparat Med & Translat Res, Dept Clin Sci,Intracellular Pathogens Res Lab, Raleigh, NC 27606 USA Univ Estadual Paulista, FMVZ, Sch Vet Med & Anim Sci, São Paulo, Brazil Univ Estadual Paulista, FMVZ, Sch Vet Med & Anim Sci, São Paulo, Brazil

International audience; Bartonella henselae is a zoonotic bacterium that infects cats and humans. Several attempts have been made to develop typing techniques for epidemiological purposes; however, most of the techniques developed do not appear to be sufficiently discriminatory or easy to use. In order to develop multilocus variable number tandem repeat (VNTR) analysis (MLVA) for B. henselae, 30 VNTR candidates were selected from the genome sequence of the reference strain Houston 1 (H1). The VNTR candidates were initially tested by PCR on six B. henselae isolates from different geographical areas. Five VNTRs were selected from those that showed two or more alleles. These five B. henselae VNTRs (BHVs) were tested on 42 feline B. henselae isolates and strains from France (23 isolates), Denmark (117 isolates), the Philippines (one isolate) and the USA (F1 strain), on one human isolate from Germany, and on the H1 reference strain. These BHVs were sufficiently discriminatory to obtain 31 different profiles (corresponding to two different groups) among the 44 isolates and strains of B. henselae tested. Thirty-five profiles were obtained using these BHVs and two variant alleles. The combination of the five markers led to a diversity index of 0.98. The stability of the five BHVs was demonstrated on the feline F1 strain, with no change in stability observed after 2, 21 and 41 passages. This is believed to be the first study conducted on B. henselae typing using MLVA, and it demonstrates the high quality of this technique for discriminating between B. henselae isolates.

A hallmark of Bartonella henselae is persistent bacteremia in cats despite the presence of a vigorous host immune response. To understand better the long-term survival of B. henselae in cats, we examined the feline humoral immune response to B. henselae outer membrane (OM) proteins in naturally and experimentally infected cats. Initially, a panel of sera ( n = 42) collected throughout North America from naturally infected cats was used to probe B. henselae total membranes to detect commonly recognized antigens. Twelve antigens reacted with sera from at least 85% of cats, and five were recognized by sera from all cats. To localize these antigens further, OMs were purified on discontinuous sucrose density step gradients. Each membrane fraction (OM, hybrid or inner membrane [IM]) contained less than 1% of the total malate dehydrogenase activity (soluble marker), indicating very little contamination by cytoplasmic proteins. FtsI, an integral IM cell division protein, was used to identify the low-density fraction (ρ = 1.13 g/cm 3 ) as putative IM (Bartonella quintana heme-binding protein A (HbpA), defined the high-density fraction (ρ = 1.20 g/cm 3 ) as putative OM. Additionally, little evidence of cross-contamination between the IM and OM was evident by two-dimensional gel electrophoresis. When purified OMs were probed with feline sera, antigenic proteins profiles were very similar to those observed with total membranes, indicating that many, but not all, of the immunoreactive proteins detected in the initial immunoblots were OM components. Interestingly, two-dimensional immunoblots indicated that B. henselae LPS and members of the Hbp family of proteins did not appear to stimulate an humoral response in any infected cats. Seven proteins were recognized by at least 70% of sera tested, but only three were recognized by all sera. Nanospray-tandem mass spectrometry was used to identify OM components, including the immunodominant OM proteins. Recognition of the nonimmunogenic nature of the major OM components, such as LPS, and identification of the predominant immunogens should elucidate the mechanisms by which B. henselae establishes persistent bacteremic infections within cats. Additionally, the common antigens may serve as potential feline vaccine candidates to eliminate the pathogen from its animal reservoir.

Bartonella henselae is a zoonotic pathogen that usually causes a self-limiting infection in immunocompetent individuals but often causes potentially life-threatening infections, such as bacillary angiomatosis, in immunocompromised patients. Both diagnosis of infection and research into the molecular mechanisms of pathogenesis have been hindered by the absence of a suitable liquid growth medium. It has been difficult to isolate B. henselae directly from the blood of infected humans or animals or to grow the bacteria in liquid culture media under laboratory conditions. Therefore, we have developed a liquid growth medium that supports reproducible in vitro growth (3-h doubling time and a growth yield of approximately 5 × 10 8 CFU/ml) and permits the isolation of B. henselae from the blood of infected cats. During the development of this medium, we observed that B. henselae did not derive carbon and energy from the catabolism of glucose, which is consistent with genome nucleotide sequence data suggesting an incomplete glycolytic pathway. Of interest, B. henselae depleted amino acids from the culture medium and accumulated ammonia in the medium, an indicator of amino acid catabolism. Analysis of the culture medium throughout the growth cycle revealed that oxygen was consumed and carbon dioxide was generated, suggesting that amino acids were catabolized in a tricarboxylic acid (TCA) cycle-dependent mechanism. Additionally, phage particles were detected in the culture supernatants of stationary-phase B. henselae , but not in mid-logarithmic-phase culture supernatants. Enzymatic assays of whole-cell lysates revealed that B. henselae has a complete TCA cycle. Taken together, these data suggest B. henselae may catabolize amino acids but not glucose to derive carbon and energy from its host. Furthermore, the newly developed culture medium should improve isolation of B. henselae and basic research into the pathogenesis of the bacterium.

PubMedID: 15672717 Bacillary angiomatosis is an infectious disease which usually develops in immunocompromised patients. Contact with cats is implicated in its pathogenesis. We report a seven-year-old immunocompetent boy with bacillary angiomatosis without a history of direct contact with cats. The clinical diagnosis of bacillary angiomatosis was made following histopathological examination of a biopsy sample from the infected facial wound, in the vicinity of which angiomatous lesions had developed. Surprisingly, similar lesions also appeared at the donor site of the skin graft which was grafted on the facial wound. This case demonstrates that bacillary angiomatosis may also be seen in immunocompetent patients and that it may contaminate wounds without the intermediary of cats.

Bartonella (previously Rochalimea ) henselae is the infectious agent causing cat scratch disease, a self limited regional lymphadenopathy associated with flu-like symptoms.1 In approximately 10% of cases, extranodal dissemination of the organism results in a variety of intraocular inflammatory lesions.1,2 We report a patient with acute Bartonella henselae infection in whom the only physical manifestation was multiple, mass-like lesions in the eye which resembled ocular metastases. A 12 year old boy developed daily headaches and blurred vision. Four weeks later, he noted a central grey spot in his left eye. Visual acuity was 20/20 in his right eye and 20/400 left eye. Goldmann perimetry of the left eye revealed a dense central scotoma with steep margins nasally and moderate constriction of the temporal periphery. An afferent pupillary defect was present on …

PubMedID: 12602974 We report a 32-year-old immunocompetent man who had multiple leg ulcers caused by bacillary angiomatosis without a history of direct contact with cats. Bacillary angiomatosis should be kept in mind in the differential diagnosis of leg ulcers in cases of unknown aetiology.

The study of 16S rRNA gene sequences of all isolates ofBartonella henselaeobtained in our laboratory and others from human patients or cats has revealed two genotypes according to the sequence of the 16S rRNA gene. Two isolates of these genotypes have previously been related to two different serotypes, and lack of cross-protection of the two serotypes has been demonstrated in cats. We investigated the grouping of eight strains ofB. henselaeon the basis of 16S ribosomal DNA, 35-kDa protein, Pap 31 protein, and internal transcribed spacer (ITS) gene sequencing; sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) profiles; and monoclonal antibody reactivity studies. Houston-1, 90-615, and SA2 strains showed the same patterns in SDS-PAGE, but they differed from the patterns ofB. henselaeisolates URBHLLY8, URBHLIE9, Cat6, Fizz, and CAL-1. Nine monoclonal antibodies derived from BALB/c mice immunized withB. henselaeHouston-1 strain reacted only with strains Houston-1, 90-615, and SA2, and not with any otherBartonellastrains. The two serogroups corresponded with two genotypes based on differences in the sequences of the genes encoding 16S rRNA, 35-kDa protein, and Pap 31 protein. Sequences of ITS genes were highly divergent among strains, as each had a unique sequence and the subdivision was not supported by DNA-DNA relatedness study. Study of 22 additional strains ofB. henselaeisolated from French bacteremic cats demonstrated that they all belong to one or the other of the proposed serotype or genotype.

Fourteen of 41 patients (34%) with a serological diagnosis of Bartonella henselae infection were found to have prolonged fever or fever of unknown origin, suggesting that generalized systemic B. henselae infection is not rare in immunocompetent healthy individuals.

Bacillary angiomatosis and bacillary peliosis are opportunistic infections caused by Bartonella henselae and Bartonella quintana, which occur in patients with late-stage infection. We report a case of bacillary angiomatosis in an HIV-infected patient with skin, bone, and probably liver involvement, The identification of the agent ( B quintana ) was done by polymerase chain reaction in the skin specimen. The patient had complete regression of all lesions after a 6-month regimen of oral erythromycin. (J Am Acad Dermatol 2000;42:299-301.)

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.

Bartonella (Rochalimaea) henselae causes cat-scratch disease, bacillary angiomatosis, peliosis hepatis, and fever in humans. B. henselae can be difficult to culture axenically, and as many as 5 weeks may be required before colonies are visible. We compared how different methods of blood collection and handling affect isolation of this pathogen. Blood specimens from B. henselae-infected cats were collected in both EDTA and Isolator blood-lysis tubes and were subsequently plated onto rabbit blood-brain heart infusion agar by using three different schedules: plating immediately, plating after 24 h at 25 degrees C, and plating after 26 days at -65 degrees C. Colonies were counted 14 and 35 days after plating. Blood collected in tubes containing EDTA, frozen at -65 degrees C, and then plated on blood agar yielded a median of 60,000 CFU/ml, compared with 25,333 CFU/ml after collection in the Isolator tubes (P < 0.01). Frozen blood yielded the largest number of B. henselae colonies for any of the schedules tested. These results support previous observations that the Isolator system is more sensitive than tubes containing EDTA for isolation of B. henselae and suggest that, for cat blood, collection in tubes containing EDTA and subsequent freezing may further improve the sensitivity of detection of B. henselae.

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.

Bacillary Angiomatosis (BA) is frequently seen in patients with human immunodeficiency virus (HIV)-induced immunodeficiency. Our patient was a case that developed granuloma-like lesions in the area of a burn, 8 days after being burnt on the upper right arm by scalding water. No indication of immune deficiency was observed and no history of direct contact with cats was evident. By the sixth day of the patient's admission to our clinic, some of the lesions had reached a diameter of 2.5 cm. An excision biopsy was carried out from the lesions present on the patient. Electron microscopy revealed solitary bacilli located close to the capillary wall. Oral erythromycin treatment was implemented at 250 mg, 4 times a day for 2.5 months. Within this period of treatment, the lesions regressed completely, and a complete cure was achieved. This case demonstrates that BA must be considered in the differential diagnosis of both HIV-infected and immunocompetent patients.

Background Although the first clinical descriptions of Bartonella infection were associated with immunocompromised patient with bacillary angiomatosis, we currently know that this organism is directly involved in diseases affecting a large number of patients, regardless of their immune status. Cat scratch disease, hepatic peliosis, and some cases of bacteraemia and endocarditis, are directly caused by some species of the genus Bartonella. The purpose of this study was to determinate the prevalence of IgG antibodies against Bartonella henselae and B. quintana in HIV patients and to identify the epidemiological factors involved. Methods Serum samples were collected from HIV patients treated at Hospital de Sabadell. Antibodies to B. henselae and B. quintana from 340 patients were examined by indirect immunofluorescence assay (IFA). Significance levels for univariate statistical test were determined by the Mann-Whitney U test and χ2 test. Results Of 340 patients, 82 were women and 258 men, with a median age of 42.21 ± 10.35 years (range 16–86 years). Seventy-six (22.3%) patients reacted with one or more Bartonella antigens. Of all the factors concerning the seroprevalence rate being studied (age, sex, intravenous drugs use, alcohol consumption, CD4 levels, AIDS, HCV, HBV, residential area), only age was statistically significant. Conclusion A high percentage of HIV patients presents antibodies to Bartonella and is increasing with age.

Background As a greater number of HIV-infected patients survive despite profound immunodepression due to medical progress, we face complex infection with multiple agents in AIDS-patients. Case presentation We report the case of an AIDS patient with a primary clinical presentation suggestive of bacillary angiomatosis. We also found in cutaneous lesions Mycobacterium avium complex and cytomegalovirus. Conclusion This clinical case illustrates the possibility of multiple coinfections in AIDS patients and the need to be exhaustive in evaluating infectious diseases in severely immunocompromised patients.

Bartonella species are emerging as an important cause of blood culture-negative endocarditis, but the optimal management of this disease has not been fully defined. We describe a case of subacute Bartonella henselae endocarditis of a prosthetic aortic valve in an immunocompetent woman that was cured with long-term antibiotic therapy alone. In addition, we demonstrate that follow-up of serologic titers against B. henselae was helpful in assessing definitive cure of the infection.

Background Bartonella species comprise a group of zoonotic pathogens that are usually acquired by vector transmission or by animal bites or scratches. Methods PCR targeting the Bartonella 16S-23S intergenic spacer (ITS) region was used in conjunction with BAPGM (Bartonella alpha Proteobacteria growth medium) enrichment blood culture to determine the infection status of the family members and to amplify DNA from spiders and woodlice. Antibody titers to B. vinsonii subsp. berkhoffii (Bvb) genotypes I-III, B. henselae (Bh) and B. koehlerae (Bk) were determined using an IFA test. Management of the medical problems reported by these patients was provided by their respective physicians. Results In this investigation, immediately prior to the onset of symptoms two children in a family experienced puncture-like skin lesions after exposure to and presumptive bites from woodlouse hunter spiders. Shortly thereafter, the mother and both children developed hive-like lesions. Over the ensuing months, the youngest son was diagnosed with Guillain-Barre (GBS) syndrome followed by Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP). The older son developed intermittent disorientation and irritability, and the mother experienced fatigue, headaches, joint pain and memory loss. When tested approximately three years after the woodlouse hunter spider infestation, all three family members were Bartonella henselae seroreactive and B. henselae DNA was amplified and sequenced from blood, serum or Bartonella alpha-proteobacteria (BAPGM) enrichment blood cultures from the mother and oldest son. Also, B. henselae DNA was PCR amplified and sequenced from a woodlouse and from woodlouse hunter spiders collected adjacent to the family’s home. Conclusions Although it was not possible to determine whether the family’s B. henselae infections were acquired by spider bites or whether the spiders and woodlice were merely accidental hosts, physicians should consider the possibility that B. henselae represents an antecedent infection for GBS, CIDP, and non-specific neurocognitive abnormalities.