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PubMed2006

Etiology of tick-borne febrile illnesses in adult residents of North-Eastern Poland: report from a prospective clinical study.

Febrile tick-borne diseases can be caused by different pathogens. The study objective was to prospectively determine the etiology of infection among adults exposed to tick bite and to detect acute human granulocytic anaplasmosis (HGA), a recently emerging infection, in north-eastern Poland. We evaluated 68 patients (34 males and 34 females, mean age 44.2+/-15 years) who had fever within 4 weeks after a tick bite. Paired sera were tested for antibodies against tick-borne encephalitis virus, Borrelia burgdorferi and Anaplasma phagocytophilum. Microscopic examination of EDTA whole blood and nested PCR targeting A. phagocytophilum 16S rDNA gene fragment were carried out at enrolment. Tick-borne infections were diagnosed in 57 individuals (84%). Sixty-four patients were hospitalised. Tick-borne encephalitis (TBE) was revealed in 49 cases; in 39 patients as a single infection, in three patients concurrent with erythema migrans or other Lyme borreliosis symptoms, in five patients concurrent with probable or possible Lyme borreliosis, and in two patients concurrent with A. phagocytophilum infection. Diagnosis of HGA was confirmed in one patient by PCR and in another one by seroconversion. In two further individuals, A. phagocytophilum infection was confirmed by immunofluorescence (antibody titers > or = 1:128), which, however, does not fulfil the ESCAR (European Society of Clinical Microbiology and Infectious Diseases Study Group on Coxiella, Anaplasma, Rickettsia, and Bartonella) criteria for HGA case definition. Lyme borreliosis was diagnosed in 16 patients; in six of them as a single infection. Both confirmed HGA cases and seropositive individuals had A. phagocytophilum infection concurrent either with Lyme borreliosis (two cases) or with TBE (two cases). The clinical course was severe in three and moderate to mild in the remaining TBE cases, as well as in all Lyme borreliosis and HGA cases. TBE was found the most prevalent disease among adults with febrile illnesses occurring after a tick bite in north-eastern Poland. Concurrent tick-borne infections were frequent with multiple pathogens involved. Two confirmed acute HGA cases (fulfilling the European case definition criteria defined by ESCAR) were detected for the first time in a prospective manner in Poland.

Adolescent↗
PubMed2006

Model structure of the prototypical non-fimbrial adhesin YadA of Yersinia enterocolitica.

Non-fimbrial adhesins, such as Yersinia YadA, Moraxella UspA1 and A2, Haemophilus Hia and Hsf, or Bartonella BadA represent an important class of molecules by which pathogenic proteobacteria adhere to their hosts. They form trimeric surface structures with a head-stalk-anchor architecture. Whereas head and stalk domains are diverse and appear (frequently repetitively) in different combinations, the anchor domains are homologous and display the properties of autotransporters. We have built a molecular model for the prototypical non-fimbrial adhesin, YadA, by combining the crystal structure of the head (PDB:1P9H) with theoretical models for the stalk and the anchor. The head domain is a single-stranded, left-handed beta-helix, connected to the stalk by a conserved trimerization element (the neck). The stalk consists of a right-handed coiled coil, containing ten 15-residue repeats with a C-terminal stutter (insertion of four residues). The stalk continues into the conserved anchor domain, which is formed by four heptads of a left-handed coiled coil, followed by four transmembrane beta-strands. Our model of the YadA coiled coil, generated with the program BeammotifCC, combines these periodicities into a structure that starts with a pronounced right-handed supercoil and ends with a canonical, left-handed conformation. The last two heptads of the coiled coil are located within a 12-stranded beta-barrel, formed by trimerization of the four transmembrane beta-strands in each monomer. We propose that this pore assembles in the outer membrane to form the opening through which the monomer chains exit the cell. After export is completed, the fiber folds and the pore is occluded by the coiled coil. Our model explains how these proteins can act as autotransporters in the absence of any homology to classical, single-chain autotransporters.

Adhesins, Bacterial↗
PubMed2006

Do dogs harbour risk factors for human breast cancer?

We ask consulting patients regularly whether they keep pets in order to identify zoonotic factors. It became apparent that patients with breast carcinoma (N=69) owned significantly more often dogs but not cats compared to age matched female controls. We compared the frequencies of dog and pet ownership with data from public available statistics on women (N=1320) of the same age group in Bavaria. The most striking result was that more than twice the number of patients kept dogs permanently in the last 10 years and at the time of interrogation as compared to control individuals at the time of interrogation (p=0.0000003, relative risk 3.5). Further internet search on the morbidity of breast carcinoma showed in dogs a protracted course of disease and metastases into lung, liver and bones, resembling the course of disease in human breast cancer. In contrast with this, breast cancer presented in cats a dramatically short course and the main but unusual location of metastasis presents in the hind legs. A recent publication in Norway reported on a high frequency (53.3%) of breast carcinomas in 14,401 investigated dogs. Which transmissible factor or factors come into question? Variants of the mouse mammary tumor virus (MMTV) can productively replicate in human cells and in different animals, including dogs. Many investigators, but not all, could identify MMTV-like sequences in sporadic human breast cancer. MMTV or MMTV-like sequences have not been investigated in canine breast carcinomas until now. It is also conceivable that other microbes from the dog, for example bacteria, could participate in the first steps of carcinogenesis in human. It was recently shown that bartonella species promote vascularization and prevent apoptosis of infected cells with the same methods as helicobacter pylori. Our considerations require further research. Epidemiologic cohort studies and identification of potential carcinogenic microbial factors will prove or disprove our hypothesis that risk factors from dogs could contribute to the carcinogenesis of human breast cancer.

Animals↗
PubMed2005

Genome reduction in the alpha-Proteobacteria.

More than 20 alpha-proteobacterial genomes are currently available. These range in size from 1-9 Mb and represent excellent model systems for evolutionary studies of the organizational features of bacterial genomes. Computational inferences have shown that genome reductions have occurred independently in lineages such as Rickettsia and Bartonella that are associated with intracellular lifestyles. Analyses of these reduced genomes have provided insights into the evolution of vector-borne transmission pathways. Further research into the population biology of bacteria, arthropods and vertebrate hosts will help to refine the biology of host-pathogen interactions and will facilitate the design of vaccines and vector-control programs.

Adaptation, Biological↗
PubMed2006

Brucella outer membrane protein Omp31 is a haemin-binding protein.

The expression of haemin-binding proteins (HBPs) in the outer membrane is one of the strategies used by Gram-negative bacteria to obtain iron from the host. No HBP has been described in Brucella spp. We investigated whether Omp31, an outer membrane protein from Brucella with homology to HBPs from Bartonella quintana, is an HBP. Soluble recombinant Omp31 bound specifically to haemin-agarose, while an unrelated Brucella protein (SurA) did not. A similar experiment showed that native Omp31 found in the Brucella suis membrane fraction also binds to haemin-agarose. Recombinant Omp31 was electrophoresed by SDS-PAGE, transferred to nitrocellulose, and incubated with a haemin solution. Haemin bound to Omp31 and to albumin (positive control) but not to SurA. IPTG-induced recombinant Escherichia coli cells expressing Omp31 on their membrane bound significantly more haemin than uninduced cells or controls carrying a similar plasmid without the omp31 gene, showing that Omp31 also binds haemin in a bacterial membrane environment. Viable Brucella ovis cells bound haemin in solution, and this binding was markedly inhibited by preincubation of cells with antibodies to Omp31 and to an exposed prominent loop of the protein, thus showing that Omp31 functions as an HBP in brucellae. To test whether the expression of Omp31 is iron-regulated, B. suis was grown in trypticase-soy broth (TSB) and in iron-depleted TSB. The expression of Omp31, as assessed by Western blot, was significantly higher in bacteria grown under iron limitation. Overall, these results show that Omp31 from B. suis, B. melitensis and B. ovis is an HBP, whose expression seems to be induced by iron limitation.

Animals↗
PubMed2005

Cat-scratch disease: Otolaryngologic manifestations and management.

OBJECTIVE: The bacteria Bartonella henselae has been known as the principal causative agent of cat-scratch disease (CSD) since 1992. It is an important cause of infectious lymphadenopathies in the head and neck. Nevertheless, CSD often remains unrecognized in cases of cervicofacial lymph node enlargement. STUDY DESIGN: Between January 1997 and May 2003, we conducted a prospective clinical study including 721 patients with primarily unclear masses in the head and neck. RESULTS: CSD was diagnosed by serology and molecular investigations in 99 patients (13.7%; median age 33 years). Cervicofacial lymphadenopathy was the most common manifestation. Atypical manifestation of CSD including Parinaud's oculoglandular syndrome, swelling of the parotid gland and erythema nodosum were diagnosed in 8.1%, 8.1%, and 2.0% of cases, respectively. CONCLUSIONS: Our results demonstrate that CSD is a major cause of enlarged cervicofacial lymph nodes and should therefore be included in the differential diagnosis of lymphadenopathy in the head and neck region.

Adolescent↗
PubMed2005

[Non infectious endocarditis: retrospective study (6 cases)].

PURPOSE: If there is cardiac valve vegetation and the blood cultures are negatives we need to look for slow growing bacteria, fungi, Legionella pneumophilia, Bartonella henselae and quintana, Brucella melitensis and abortus, Coxiella burneti, Chlamydiae pneumoniae by serologic tests. The diagnosis of non- infectious endocarditis could be considered only if these results were negative. The main purpose of this study was to describe the clinical and echocardiographic signs of non-infectious endocarditis cases observed in two different wards. METHODS: This study was done retrospectively during a five-year period in a cardiology and an internal medicine wards. The selection criteria are: the proof of at least one cardiac valve vegetation, observed on echocardiography, negative blood cultures and negative serologic tests as described above. RESULTS: Six non-bacterial endocarditis were described. Four Libman-Sacks endocarditis, two associated with a primary antiphospholipid syndrome revealed by an acute ischemia of leg for one patient and by an eclampsia for another and the other two associated with a systemic lupus erythematous revealed by fever for one patient and by neurologic symptoms for the other. One fibroblastic endocarditis associated to an essential hypereosinophilia and one marastic endocarditis associated to a metastatic mucin-producing cancer. CONCLUSIONS: For these six cases, a complete physical examination, a CBC for hypereosinophylia, a dosage of antiphospholipid antibodies and a thoraco-abdominal CT-scan allowed the etiologic diagnosis of non infectious endocarditis. Libman Sacks endocarditis associated with an antiphospholipid syndrome is the main etiology for which a long-term anticoagulation treatment was not followed.

Adolescent↗
PubMed2005

Tyrosine-phosphorylated bacterial effector proteins: the enemies within.

The tyrosine phosphorylation of proteins has a central role during signal transduction in eukaryotes. Recent progress shows that tyrosine phosphorylation is also a common feature of several effector proteins translocated by bacterial type III and type IV secretion systems. The involvement of these secretion systems in disease development is exemplified by a variety of pathogenic processes: pedestal formation (Tir of EPEC and Citrobacter), cell scattering (CagA of Helicobacter), invasion (Tarp of Chlamydia) and possibly proinflammatory responses and cell proliferation (BepD-F of Bartonella). The discovery that different bacterial pathogens use this common strategy to subvert host-cell function suggests that more examples will soon emerge.

Antigens, Bacterial↗
PubMed2006

The identification of two protective DNA vaccines from a panel of five plasmid constructs encoding Brucella melitensis 16M genes.

Five candidate genes from the Brucella melitensis 16M genome were selected. Eukaryotic expression plasmids encoding these antigens were constructed and expression was verified in vitro from transfected Cos7 cells. Each vaccine was assessed for protective efficacy in a BALB/c mouse brucellosis infection model. From these experiments two protective DNA vaccines were identified: p-omp25 and p-ialB. The Omp25 antigen (BMEI1249) has previously been studied in terms of Brucella virulence, serodiagnosis and as a protective antigen. However, this study represents the first report of a significant protective effect achieved against B. melitensis 16M challenge using the Omp25 antigen in a DNA vaccine approach. The other protective vaccine identified in this study was p-ialB. The ialB candidate (BMEI1584) was selected based upon its' putative function as an invasion protein which was assigned due to shared identity with the invasion protein B (ialB) of Bartonella bacilliformis. This candidate has not previously been investigated with regard to Brucella virulence or pathogenesis. This study is the first report to identify the Brucella invasion protein B (BMEI1584) as a novel protective antigen for brucellosis.

Acid Anhydride Hydrolases↗
PubMed1999

Expression of inducible nitric oxide synthase in human granulomas and histiocytic reactions.

Inducible nitric oxide synthase (iNOS) is required in immune response against infections and is involved in granuloma formation in animals; in murine macrophages, iNOS is induced by lipopolysaccharide and interferon-gamma. In contrast, the role of iNOS in human immune response against infections is still questioned, and its expression in granulomas is poorly investigated. Using Western blotting and immunohistochemistry, we investigated iNOS expression in human lymph nodes with nonspecific reactions and in tissues containing granulomas caused by mycobacteria, Toxoplasma, Cryptococcus neoformans, Leishmania, Bartonella, noninfectious granulomas (sarcoidosis, foreign body), and other hystiocitic reactions (Kikuchi's disease, Omenn syndrome). iNOS was undetectable in nonspecific reactive lymphadenitis, foreign-body granulomas, and Omenn syndrome, whereas it was strongly expressed in infectious granulomas, sarcoidosis, and Kikuchi's diseases. Immunohistochemistry demonstrated that iNOS was selectively expressed by the epithelioid and multinucleated giant cells within the granulomas. Use of an anti-nitrotyrosine antibody, recognizing nitrosilated amino acid residues derived from nitric oxide production, revealed a consistent positivity within the cells expressing iNOS, thus suggesting that iNOS is functionally active. Detection of cytokines by reverse transcriptase-polymerase chain reaction demonstrated that tissues that were positive for iNOS, also expressed the Thl-type cytokine interferon-gamma mRNA, but not the Th2-type cytokine interleukin-4. Taken together, these results indicate that iNOS is involved in different human immune reactions characterized by histiocytic/granulomatous inflammation and associated with Th1-type cytokine secretion.

Adult↗
PubMed1999

Cat scratch disease: posterior segment manifestations.

OBJECTIVE: To evaluate the posterior segment findings seen in ocular cat scratch disease. DESIGN: Retrospective case series. PARTICIPANTS: There were 24 patients (35 eyes) with choroidal, retinal, or optic disc manifestations of Bartonella infection evaluated at the authors' institutions over a 6-year period. MAIN OUTCOME MEASURES: Clinical and photographic records were reviewed for evidence of disc edema, macular star, foci of retinitis or choroiditis, choroidal masses, optic nerve masses, vascular-occlusive events, or other findings. RESULTS: Discrete white retinal or choroidal lesions, 50 to 3000 microm in diameter, were the most common posterior segment findings in this series of patients (83% of eyes, 83% of patients). Optic disc swelling was the second most common finding (46% of eyes, 63% of patients) followed by a macular star (43% of eyes, 63% of patients). Vascular-occlusive events were also seen (14% of eyes, 21% of patients), and the site of occlusion was found to be intimately associated with the aforementioned retinal lesions. Final visual acuity was 20/25 or better in 26 (74%) of 35 eyes and was similar in both treated and untreated patients. CONCLUSION: Isolated foci of retinitis or choroiditis were the most common ocular manifestation of cat scratch disease in the authors' patient population, but an array of posterior segment findings may occur.

Adolescent↗
PubMedDate not supplied

Specific and nonspecific enzymes involved in the catabolism of mononucleoside and dinucleoside polyphosphates.

This review concerns enzymes that can degrade nucleoside 5'-tetra- and pentaphosphates (p(4)N and p(5)N) and those that can degrade various dinucleoside polyphosphates (Np(3-6)N'). Most of these enzymes are hydrolases, and they occur in all types of organisms. Certain fungi and protozoa also possess specific Np(n)N' phosphorylases. Specific p(4)N hydrolases have been demonstrated in mammals and in plants. In yeast, p(4)N and p(5)N are hydrolyzed by exopolyphosphatases. Among other hydrolases that can degrade these minor mononucleotides are phosphatases, apyrase, and (asymmetrical) Np(4)N' hydrolase, as well as the nonspecific adenylate deaminase. Np(n)N's are good substrates for Type I phosphodiesterases and nucleotide pyrophosphatases, and diadenosine polyphosphates are easily deaminated to diinosine polyphosphates by nonspecific adenylate deaminases. Specific Np(3)N' hydrolases occur in both prokaryotes and eukaryotes. Interestingly, the human fragile histidine triad (Fhit) tumor suppressor protein appears to be a typical Np(3)N' hydrolase. Among the specific Np(4)N' hydrolases are asymmetrically cleaving ones, which are typical of higher eukaryotes, and symmetrically cleaving enzymes found in Physarum polycephalum and in many bacteria. An enzyme that hydrolyzes both diadenosine tetraphosphate and diadenosine triphosphate has been found in the fission yeast Schizosaccharomyces pombe. Its amino acid sequence is similar to that of the human Fhit/Np(3)N' hydrolase. Very recently, a typical (asymmetrical) Np(4)N' hydrolase has been demonstrated for the first time in a bacterium-the pathogenic Bartonella bacilliformis. Another novelty is the discovery of diadenosine 5', 5"'-P(1),P 6-hexaphosphate hydrolases in budding and fission yeasts and in mammalian cells. These enzymes and the (asymmetrical) Np(4)N' hydrolases have the amino acid motif typical of the MutT (or Nudix hydrolase) family. In contrast, the Schizosaccharomyces pombe Ap(4)A/Ap(3)A hydrolase, the human Fhit protein, and the yeast Np(n)N' phosphorylases belong to a superfamily GAFH, which includes the histidine triad proteins.

Animals↗
PubMed2003

Application of broad-range 16S rRNA PCR amplification and DGGE fingerprinting for detection of tick-infecting bacteria.

Ticks play an important role in the transmission of arthropod-borne diseases of viral, protozoal and bacterial origin. The present article describes a molecular-biological based method, which facilitated the broad-range analyses of bacterial communities in ixodid ticks (Ixodes ricinus). DNA was extracted both from single ticks and pooled adult ticks. Eubacterial 16S rRNA gene fragments (16S rDNA) were amplified by polymerase chain reaction (PCR) with broad-range ribosomal primers. Sequences spanning the hypervariable V3 region of the 16S rDNA and representing individual bacterial taxons were separated by denaturing gradient gel electrophoresis (DGGE). For phylogenetic identification, DGGE bands were exised, cloned and sequenced. In addition, we set up a 16S rDNA clone library which was screened by DGGE. Sequences were compared with sequences of known bacteria listed in the GenBank database. A number of bacteria were affiliated with the genera Rickettsia, Bartonella, and Borrelia, which are known to be pathogenic and transmitted by ticks. Two sequences were related to the yet to be cultivated Haemobartonella. To our knowledge, Haemobartonella has never been directly detected in I. ricinus. In addition, members of the genera Staphylococcus, Rhodococcus, Pseudomonas, and Moraxella were detected, which have not been identified in ticks so far. Two bacteria were most closely related to a rickettsial endosymbiont of an Acanthamoeba sp., and to an endosymbiont (Legionellaceae, Coxiella group) of the microarthropod Folsomia candida. The results prove that 16S rDNA genotyping in combination with DGGE analysis is a promising approach for the detection and identification of bacteria infecting ticks, regardless of whether these bacteria are fastidious, obligate intracellular or noncultivable.

Animals↗
PubMed2004

[Cat's cratch disease and Parinaud's oculoglandular syndrome].

By presenting this case report describing Parinaud's oculoglandular syndrome, we review the medical literature on its most frequent etiology: catscratch disease, a self-limited, systemic illness caused by a Gram-negative bacillus, Bartonella henselae, principally affecting children under 15 years of age. Typical symptoms include regional lymphadenopathy, fever, malaise, and fatigue, possibly with more severe complications such as splenomegaly, granulomatous hepatitis, and encephalopathy. Ocular manifestations may include follicular conjunctivitis, Parinaud's oculoglandular syndrome, neuroretinitis, optic neuritis, and chorioretinitis. Diagnosis is based on serologic tests, and when necessary, antimicrobial treatment can be considered.

Adolescent↗
PubMed2005

[Multifocal chorioretinitis, papillitis, and recurrent optic neuritis in cat-scratch disease].

To evaluate the causative factor for multifocal chorioretinitis, papillitis, and recurrent optic neuritis. A 41-year-old patient presenting multifocal choroiditis, papillitis, and recurrent optic neuritis was evaluated with funduscopy, angiography (FA), optical coherence tomography (OCT), visual evoked potentials (VEP), and numerous blood laboratory tests. FA and OCT showed multifocal pigment epithelial detachments. VEP showed typical changes for optic neuritis and papillitis. Indirect fluorescent antibody assay disclosed Bartonella henselae. Although cat-scratch disease frequently presents with optic neuritis or neuroretinitis, additional multifocal chorioretinal lesions associated with serous pigment epithelial detachments may occur. In case of recurrent episodes, a detailed laboratory work-up is mandatory to define the appropriate diagnosis and treatment.

Adult↗
PubMed2003

Canine borreliosis.

A guild of organisms carried by the same vector (Ixodes ticks) in Lyme-endemic areas may be confounding the understanding of Lyme disease in dogs. A new diagnostic method, the C6 peptide test for Lyme, and serology and PCR testing for Ehrlichia, Babesia, and Bartonella species will help to sort out seroprevalence and symptomatology caused by exposure to these agents or by coinfections. In addition, Rickettsia, Leptospira, Mycoplasma species, and more could be involved in dogs diagnosed with a "doxycycline-responsive" disease. The author does not recommend treating asymptomatic Borrelia carrier dogs, but does recommend screening them for proteinuria and for exposure to other agents. A positive Lyme titer is a marker of exposure to Ixodes ticks and the agents they carry. The risk/benefit of vaccination will be understood better as the symptomatology and immunopathogenesis of Lyme disease are defined. Meanwhile, tick control is highly recommended for all dogs in Lyme-endemic areas.

Animals↗
PubMed2002

Regulation of Brucella virulence by the two-component system BvrR/BvrS.

The Brucella BvrR/BvrS two-component regulatory system is highly similar to the regulatory and sensory proteins of Sinorhizobium and Agrobacterium necessary for endosymbiosis and pathogenicity in plants, and very similar to a putative system present in the animal pathogen Bartonella. Mutations in the bvrR or bvrS genes hamper the penetration of B. abortus in non-phagocytic cells and impairs intracellular trafficking and virulence. In contrast to virulent Brucella, BvrR/BvrS mutants do not recruit small GTPases of the Rho subfamily required for actin polymerization and penetration to cells. Dysfunction of the BvrR/BvrS system alters the outer membrane permeability, the expression of several group 3 outer membrane proteins and the pattern of lipid A acylation. Constructs of virulent B. abortus chimeras containing heterologous LPS from the bvrS(-) mutant demonstrated an altered permeability to cationic peptides similar to that of the BvrR/BvrS mutants. We hypothesize that the Brucella BvrR/BvrS is a system devoted to the homeostasis of the outer membrane and, therefore in the interface for cell invasion and mounting the required structures for intracellular parasitism.

Amino Acid Sequence↗
PubMed2002

Diagnostic methods current best practices and guidelines for identification of difficult-to-culture pathogens in infective endocarditis.

Culture-negative endocarditis currently represents a diagnostic challenge for physicians. Traditional methods such as histology, serology, and culture have been improved and new molecular techniques have been developed to improve the detection of difficult-to-culture agents. Serologic tests for the two most frequent etiologic agents, Coxiella burnetii and Bartonella spp, should be performed first because they can usually be identified easily in this way. The sensitivity of culture for intracellular bacteria has been improved by inoculation of samples in shell vials and by the use of novel tissue cell lines. Recently, universal and species-specific primers have been designated to amplify bacterial DNA directly from resected valves, allowing positive identification.

Bacteria↗