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PubMed1996

[Cat scratch disease. Bartonella henselae antibodies and DNA detection in regional lymphadenopathy].

HISTORY AND CLINICAL FINDINGS: Two hard, pressure-sensitive nodules developed in the lower jaw of a 22-year-old woman. After a dental cause had been excluded, she was treated for suspected tonsillitis with Ceftibuten. Erythrocyte sedimentation rate was increased to 18 mm in the first hour. There were no other significant biochemical findings and fine-needle biopsy of one of the nodules showed nonspecific inflammatory reaction. INVESTIGATIONS: Sonography revealed two lymph nodes, 7 and 22 mm in diameter. Suspected cat scratch disease was confirmed by immunofluorescence with Bartonella (Rochalimaea) henselae and quintana antigens. TREATMENT AND COURSE: After a course of Clarithromycin (250 mg twice daily) for 6 weeks the lymph nodes had shrunk and the overlying skin was thin and discoloured brown. One node was incised and drained and the material examined. Microbiology was negative, but DNA sequencing confirmed Bartonella henselae. As a consequence, Rifampicin was given for 2 months (600 mg daily). Wound healing was very slow and the scar had regressed little after 9 months.

Adult↗
PubMed2004

A family of variably expressed outer-membrane proteins (Vomp) mediates adhesion and autoaggregation in Bartonella quintana.

Bartonella species are fastidious, Gram-negative human pathogens that can persist in the host bloodstream for years and bind to and invade several types of host cells. For many pathogens, adhesion to host cells and extracellular matrix (ECM) components is a critical virulence determinant. Bacteria often vary expression of surface adhesins by phase or antigenic variation to subvert the host immune response and permit adaptive interaction with different host structures. We developed a macaque animal model for Bartonella quintana infection to detect changes in bacterial outer-membrane proteins (OMP) during prolonged bloodstream infection. We identified a gene family encoding four highly conserved, 100-kDa, variably expressed OMP (Vomp), two of which function as adhesins. The variable expression of Vomp family members appears to be mediated by deletion of one or more vomp genes during chronic bloodstream infection. vomp deletion was observed also in isolates from humans with chronic B. quintana infection. The Vomp are closely related to the afimbrial adhesin, YadA, a virulence factor of Yersinia enterocolitica. The surface-expressed Vomp contain conserved structural features of YadA, including collagen-binding motifs. We demonstrate that the B. quintana Vomp are multifunctional OMP involved in binding to collagen and autoaggregation: VompC confers the ability to bind collagen IV, and VompA is necessary and sufficient for autoaggregation. The B. quintana Vomp are members of the newly recognized family of YadA-like trimeric autotransporters; the Vomp constitute a multigene family, they are variably expressed, and different virulence properties are attributable to individual Vomp family members.

Adhesins, Bacterial↗
PubMed1996

Bartonella (Rochalimaea) quintana causing fever and bacteremia in an immunocompromised patient with non-Hodgkin's lymphoma.

A 48-yr-old man with stage IV non-Hodgkin's lymphoma, became neutropenic following chemotherapy and developed a fever. His blood cultures were processed to enhance the yield of fastidious bacteria. A slow-growing, capnophilic Gram-negative rod was isolated. The febrile episode was treated with cefotaxime, imipenem and vancomycin and resolved. The bacterial isolate was identified as Bartonella (Rochalimaea) quintana by 16S-rDNA gene sequencing. The isolate showed 99.8% sequence homology with the type strain. This is the first isolation of Bartonella (Rochalimaea) quintana from a bacteremic patient in Australia. This bacterium is a fastidious Gram-negative rod requiring prolonged culture for its isolation. Patients with culture-negative pyrexia, especially immunocompromised patients, may need to be investigated for infection with this agent.

Bacteremia↗
PubMed1999

Serologic response to Bartonella henselae in patients with cat scratch disease and in sick and healthy children.

Indirect fluorescent antibody assay (IFA) is the most reliable test for detecting antibody to Bartonella henselae in the diagnosis of cat scratch disease (CSD). Recently, an ELISA test has been proposed, but conflicting results are reported. We compared IgG-IFA and IgG-IgM ELISA methods in CSD patients and in healthy children. We also tested ELISA specificity in a large group of healthy controls and in children with lymphoma-associated lymphadenopathy and with pyogenic lymphadenitis. The ELISA procedure was positive in 69/78 patients with CSD (sensitivity 89.6%), in 5/100 healthy children (specificity 95%), in 2/51 patients with non-Hodgkin's lymphoma or pyogenic lymphadenitis (specificity 96%) and in 27/296 blood donors (specificity 91.6%). In 34 patients with CSD, ELISA IgM and IgG responses decreased significantly between time of diagnosis of the disease and recovery. We found significantly higher IgG-ELISA titres in cat-owners, whether blood donors or healthy children, than in non-cat-owners. The IgG-IFA test gave positive results in 69/78 patients with CSD (sensitivity 89.6%) and in 5/62 healthy controls (specificity 92.5%). The ELISA method is a cheap, sensitive method for determining antibody response to Bartonella henselae infection and is also important for evaluating the clinical course of the disease and the efficacy of antibiotic therapy. The high specificity of ELISA in patients with non-Hodgkin's lymphoma will help the clinician to exclude a potentially life-threatening disease associated with lymphadenopathy.

Adolescent↗
PubMed2002

Bartonella quintana Bacteremia among Homeless People.

Bartonella quintana infections have recently reemerged, predominantly among the homeless populations in cities in both Europe and the United States. B. quintana can cause trench fever, endocarditis, and chronic bacteremia; the human body louse is the only known vector. Homeless people who presented to the emergency departments of University Hospital in Marseilles, France, were studied, as were those who had been admitted to other medical facilities in the city since 1 January 1997. Samples of blood and body lice were collected for culture for B. quintana and for serological testing. Bartonella bacteremia was associated with sweats, evidence of louse infestation, serological tests that were positive for B. quintana, and high titers of B. quintana antibody. Bacteremia was also associated with being homeless for <3 years. Asymptomatic, prolonged bacteremia (duration, up to 78 weeks) and intermittent bacteremia were found to occur. Data obtained regarding antibiotic regimens showed that treatment with gentamicin and doxycycline was effective in preventing relapses of bacteremia.

Bacteremia↗
PubMed1997

Experimental infection of young specific pathogen-free cats with Bartonella henselae.

Eighteen 12-week-old specific pathogen-free cats, blood culture- and serum antibody-negative for Bartonella henselae, were randomly allocated to groups and were intravenously inoculated with 10(10) (group 1), 10(8) (group 2), or 10(6) (group 3) B. henselae or with saline (group 4) or were not inoculated (group 5). Cats were humanely killed at 2, 4, 8, 16, and 32 weeks after inoculation. All B. henselae-inoculated cats were bacteremic by 2 weeks after infection. Bacteremia persisted until 32 weeks after infection in 1 cat. Cats in groups 1 and 2 had fever (>39.7 degrees C) and partial anorexia by 2 weeks after infection that lasted 2-7 days. All infected cats had Bartonella-specific IgM and IgG serum antibodies and lymphocyte blastogenic responses. Histopathologic lesions were observed in multiple organs of infected cats through 8 weeks after infection. Cats were readily infected with B. henselae by intravenous inoculation, developed histopathologic lesions that apparently resolved, and developed B and T lymphocyte responses to infection.

Animals↗
PubMed2003

Molecular cloning and analysis of a region of the Bartonella bacilliformis genome encoding NlpD, L-isoaspartyl methyltransferase and YajC homologs.

The NlpD/LppB homolog of the human pathogen, Bartonella bacilliformis, is an immunogenic 43-kDa protein that is encoded by a 1206-bp open reading frame (ORF-401). The regions flanking the nlpD/lppB gene of B. bacilliformis were sequenced to determine if it is located within the rpoS operon, as it is in most bacteria. We report that the B. bacilliformis nlpD/lppB gene is located immediately downstream of pcm, a gene encoding a 25-kDa protein, L-isoaspartyl protein carboxyl methyltransferase, that is a component of the rpoS operon in other bacteria. However, the genomic organization downstream of the B. bacilliformis nlpD/lppB gene appears to be distinct. In other bacteria, the third gene in the operon is rpoS, a gene that codes for an alternative sigma factor of RNA polymerase. In B. bacilliformis, an open reading frame encoding a protein homologous to the immunodominant YajC protein is located directly downstream of the nlpD/lppB gene. We show that Bartonella henselae, a close relative of B. bacilliformis, also shares this unusual organizational feature. Thus, the genomic organization of the nlpD/lppB genes of B. bacilliformis, and B. henselae appears to be unique among all bacteria for which the sequence of this region has been reported.

Amino Acid Sequence↗
PubMed2006

Co-detection of Bartonella henselae, Borrelia burgdorferi, and Anaplasma phagocytophilum in Ixodes pacificus ticks from California, USA.

Presence of Bartonella DNA was explored in 168 questing adult Ixodes pacificus ticks from Santa Cruz County, California. Bartonella henselae type I DNA was amplified from 11 ticks (6.55%); previously, two (1.19%) were found to be infected with Borrelia burgdorferi and five (2.98%) with Anaplasma phagocytophilum. Detection of B. henselae was not dependent on co-infection. The present study offers additional evidence that Ixodes spp. ticks may act as hosts and possibly vectors for B. henselae.

Anaplasma phagocytophilum↗
PubMed1997

Immunologic response to Bartonella henselae as determined by enzyme immunoassay and Western blot analysis.

Bartonella henselae is now regarded as the etiologic agent of cat-scratch disease and a cause of bacillary angiomatosis. We examined the human immune response to Bartonella henselae infection using a newly developed enzyme immunoassay (EIA) and a Western blot procedure using outer-membrane proteins. The EIA showed 98.6% and 91.4% agreement with an indirect fluorescence method (IFA) for detection of IgM and IgG antibodies, respectively. By using Western blot analysis, reactivity to an 8-kd band showed significant correlation with positive results by the IgM IFA and EIA. In contrast, reactivity to 209-, 208.5-, 208-, 116-, and 80-kd bands was identified only in positive IgG IFA serum samples. The EIA and Western blot should be useful tests in determining the antibody response to B. henselae infection and may also be important in determining the critical epitopes in the host-parasite interaction of this organism.

Adolescent↗
PubMed1995

Use of the polymerase chain reaction and DNA sequencing for detection of Bartonella quintana in the aortic valve of a patient with culture-negative infective endocarditis.

We used the polymerase chain reaction (PCR) and broad-range bacterial primers, combined with DNA sequencing, to identify Bartonella quintana as the etiologic agent in a case of culture-negative infective endocarditis; all blood cultures, as well as the bacterial cultures of the resected aortic valve and vegetations, remained negative. PCR was used to amplify bacterial 16S rDNA from a template prepared from the aortic valve vegetation. The amplified 16S rDNA produced a nucleotide sequence that was 99.79% identical to the B. quintana rDNA sequence. The patient had a highly elevated level of serum antibodies to Bartonella antigen (1:8,192).

Antibodies, Bacterial↗
PubMed1995

Bartonella (Rochalimaea) antibodies, dementia, and cat ownership among men infected with human immunodeficiency virus.

To determine the association between recent human immunodeficiency virus (HIV)-associated dementia and serum antibodies to Bartonella (Rochalimaea) henselae, we performed a nested case control study within the Multicenter AIDS Cohort Study in Los Angeles. We measured serum IgG and IgM antibodies to B. henselae with use of enzyme immunoassay in 369 HIV-seropositive and HIV-seronegative participants with and without recent neuropsychological deterioration. Data on pet ownership were also collected. IgM antibodies to B. henselae were strongly associated with neuropsychological decline or dementia (OR = 6.6;95% CI = 1.4-31.9;P = .02). Those participants with IgM antibodies to B. henselae were 1.7 times more likely to develop HIV-associated dementia (HAD) or neuropsychological decline over the next 5 years. At least 4% of the new cases of HAD and neuropsychological decline were due to bartonella infection. Cat ownership was associated with the presence of IgM antibodies to B. henselae (OR = 6.4;95% CI = 1.3-30.8;p = .02) and with neuropsychological decline and dementia (OR = 2.4;95% CI = 1.2-5.1;P = .02). This finding suggests that some cases of HAD and neuropsychological decline are associated with potentially treatable B. henselae infections.

AIDS Dementia Complex↗
PubMed2005

Detection of Rickettsia, Borrelia, and Bartonella in Carios kelleyi (Acari: Argasidae).

Carios kelleyi (Colley & Kohls 1941), a tick associated with bats and bat habitats, has been reported to feed on humans, but there is little published data regarding the presence of vector-borne pathogens in these ticks. C. kelleyi nymphs and adults were collected from residential and community buildings in Jackson County, Iowa, and tested by polymerase chain reaction for Rickettsia, Borrelia, Bartonella, Coxiella, and Anaplasma. Rickettsia DNA was detected in 28 of 31 live ticks. Sequences of the 17-kDa and rOmpA genes suggest that this agent is a novel spotted fever group Rickettsia. Transstadial and transovarial transmission of this Rickettsia were demonstrated. The flagellin gene of a Borrelia, closely related to B. turicatae, was detected in one of 31 live ticks. The 16S-23S intergenic spacer region of Bartonella henselae also was detected in one of 31 live ticks. Coxiella or A. phagocytophilum DNA were not detected in these ticks.

Animals↗
PubMed2004

The Bartonella henselae sucB gene encodes a dihydrolipoamide succinyltransferase protein reactive with sera from patients with cat-scratch disease.

Bartonella henselae is a recently recognized pathogenic bacterium associated with cat-scratch disease, bacillary angiomatosis and bacillary peliosis. A recombinant clone expressing an immunoreactive antigen of B. henselae was isolated by screening a genomic DNA cosmid library by Western blotting with sera pooled from patients positive for B. henselae IgG antibodies by indirect immunofluorescence (IFA). The deduced amino acid sequence of the 43.7 kDa encoded protein was found to be 76.3 % identical to the dihydrolipoamide succinyltransferase enzyme (SucB) of Brucella melitensis. SucB has been shown to be an immunogenic protein during infections by Brucella melitensis, Coxiella burnetii and Bartonella vinsonii. The agreement between reactivity with a recombinant SucB fusion protein on immunoblot analysis and the results obtained by IFA was 55 % for IFA-positive sera and 88 % for IFA-negative sera. Cross-reactivity was observed with sera from patients with antibodies against Brucella melitensis, Mycoplasma pneumoniae, Francisella tularensis, Coxiella burnetii and Rickettsia typhi.

Acyltransferases↗
PubMed2004

The VirB type IV secretion system of Bartonella henselae mediates invasion, proinflammatory activation and antiapoptotic protection of endothelial cells.

Bartonella henselae is an arthropod-borne zoonotic pathogen causing intraerythrocytic bacteraemia in the feline reservoir host and a broad range of clinical manifestations in incidentally infected humans. Remarkably, B. henselae can specifically colonize the human vascular endothelium, resulting in inflammation and the formation of vasoproliferative lesions known as bacillary angiomatosis and bacillary peliosis. Cultured human endothelial cells provide an in vitro system to study this intimate interaction of B. henselae with the vascular endothelium. However, little is known about the bacterial virulence factors required for this pathogenic process. Recently, we identified the type IV secretion system (T4SS) VirB as an essential pathogenicity factor in Bartonella, required to establish intraerythrocytic infection in the mammalian reservoir. Here, we demonstrate that the VirB T4SS also mediates most of the virulence attributes associated with the interaction of B. henselae during the interaction with human endothelial cells. These include: (i) massive rearrangements of the actin cytoskeleton, resulting in the formation of bacterial aggregates and their internalization by the invasome structure; (ii) nuclear factor kappaB-dependent proinflammatory activation, leading to cell adhesion molecule expression and chemokine secretion, and (iii) inhibition of apoptotic cell death, resulting in enhanced endothelial cell survival. Moreover, we show that the VirB system mediates cytostatic and cytotoxic effects at high bacterial titres, which interfere with a potent VirB-independent mitogenic activity. We conclude that the VirB T4SS is a major virulence determinant of B. henselae, required for targeting multiple endothelial cell functions exploited by this vasculotropic pathogen.

Actin Cytoskeleton↗
PubMed2005

Unusual trafficking pattern of Bartonella henselae -containing vacuoles in macrophages and endothelial cells.

Bartonella henselae, the agent of cat-scratch disease and vasculoproliferative disorders in humans, is a fastidious facultative intracellular pathogen, whose interaction with macrophages and endothelial cells (ECs) is crucial in the pathogenesis of these diseases. However, little is known about the subcellular compartment in which B. henselae resides. Two hours after infection of murine macrophages and human ECs, the majority of B. henselae-containing vacuoles (BCVs) lack typical endocytic marker proteins, fail to acidify, and do not fuse with lysosomes, suggesting that B. henselae resides in a non-endocytic compartment. In contrast to human umbilical vein endothelial cells, bacterial death and lysosomal fusion with BCVs is apparent in J774A.1 macrophages at 24 h. This phenomenon of delayed lysosomal fusion requires bacterial viability, and is confined to the BCV itself. Using magnetic selection, we enriched for transposon-mutagenized B. henselae trapped in lysosomes of macrophages 2 h after infection. Genes affected appear to be relevant to the intracellular lifestyle in macrophages and ECs and include some previously implicated in Bartonella pathogenicity. We conclude that B. henselae has a specific capacity to actively avoid the host endocytic pathway after entry of macrophages and ECs, from within a specialized non-endocytic membrane-bound vacuole.

Animals↗
PubMed2000

Contact-dependent hemolytic activity distinct from deforming activity of Bartonella bacilliformis.

Although Bartonella bacilliformis causes a severe anemia in humans, this study presents the first report of hemolytic activity by B. bacilliformis. The activity was not apparent in culture supernatants but was reliably detected when B. bacilliformis cells were centrifuged onto erythrocytes prior to incubation. Abrogation of hemolytic activity by proteinase K treatment suggested the hemolysin was a Bartonella protein. Even though hemolysis required relatively long incubation times, de novo protein synthesis was not required to produce the protein. A preparation containing factors released by B. bacilliformis, including deformin, a B. bacilliformis protein able to induce pits and invaginations in erythrocyte membranes, had some ability to lyse erythrocytes. However, pre-deformed erythrocytes did not lyse faster or to a greater extent than control erythrocytes after the addition of B. bacilliformis cells. Inhibition of deformation caused by B. bacilliformis cells with the erythrocyte ATPase inhibitor, vanadate, did not affect hemolytic activity. This study suggests hemolytic activity and deforming activity are attributable to different B. bacilliformis proteins.

Animals↗
PubMed2004

Identification of Bartonella species in rodents, shrews and cats in Denmark: detection of two B. henselae variants, one in cats and the other in the long-tailed field mouse.

Small mammals and stray cats were trapped in two areas of North Zealand, Denmark, and their blood cultured for hemotrophic bacteria. Bacterial isolates were recovered in pure culture and subjected to 16S rDNA gene sequencing. Bartonella species were isolated from five mammalian species: B. grahamii from Microtus agrestis (field vole) and Apodemus flavicollis (yellow-necked field mouse); B. taylorii from M. agrestis, A. flavicollis and A. sylvaticus (long-tailed field mouse); B. tribocorum from A. flavicollis; B. vinsonii subsp. vinsonii from M. agrestis and A. sylvaticus; and B. birtlesii from Sorex vulgaris (common shrew). In addition, two variant types of B. henselae were identified: variant I was recovered from three specimens of A. sylvaticus, and B. henselae variant II from 11 cats; in each case this was the only B. henselae variant found. No Bartonella species was isolated from Clethrionomys glareolus (bank vole) or Micromys minutus (harvest mouse). These results suggest that B. henselae occurs in two animal reservoirs in this region, one of variant I in A. sylvaticus, which may be transmitted between mice by the tick Ixodes ricinus, and another of variant II in cats, which may be transmitted by the cat flea (Ctenocephalides felis). To our knowledge, this is the first report of the occurrence of B. henselae and B. tribocorum in Apodemus mice.

Animals↗
PubMed1998

Mutations in Bartonella bacilliformis gyrB confer resistance to coumermycin A1.

This study describes the first isolation and characterization of spontaneous mutants conferring natural resistance to an antibiotic for any Bartonella species. The Bartonella bacilliformis gyrB gene, which encodes the B subunit of DNA gyrase, was cloned and sequenced. The gyrB open reading frame (ORF) is 2,079 bp and encodes a deduced amino acid sequence of 692 residues, corresponding to a predicted protein of approximately 77.5 kDa. Sequence alignment indicates that B. bacilliformis GyrB is most similar to the GyrB protein from Bacillus subtilis (40.1% amino acid sequence identity) and that it contains the longest N-terminal tail (52 residues) of any GyrB characterized to date. The cloned B. bacilliformis gyrB was expressed in an Escherichia coli S30 cell extract and was able to functionally complement a temperature-sensitive E. coli Cour gyrB mutant (strain N4177). We isolated and characterized spontaneous mutants of B. bacilliformis resistant to coumermycin A1, an antibiotic that targets GyrB. Sequence analysis of gyrB from 12 Cour mutants of B. bacilliformis identified single nucleotide transitions at three separate loci in the ORF. The predicted amino acid substitutions resulting from these transitions are Gly to Ser at position 124 (Gly124-->Ser), Arg184-->Gln, and Thr214-->Ala or Thr214-->Ile, which are analogous to mutated residues found in previously characterized resistant gyrB genes from Borrelia burgdorferi, E. coli, Staphylococcus aureus, and Haloferax sp. The Cour mutants are three to five times more resistant to coumermycin A1 than the wild-type parental strain.

Amino Acid Sequence↗