Reduction of eddy current losses in inductive transmission systems with ferrite sheets.

BACKGROUND: Improvements in eddy current suppression are necessary to meet the demand for increasing miniaturization of inductively driven transmission systems in industrial and biomedical applications. The high magnetic permeability and the simultaneously low electrical conductivity of ferrite materials make them ideal candidates for shielding metallic surfaces. For systems like cochlear implants the transmission of data as well as energy over an inductive link is conducted within a well-defined parameter set. For these systems, the shielding can be of particular importance if the properties of the link can be preserved. RESULTS: In this work, we investigate the effect of single and double-layered substrates consisting of ferrite and/or copper on the inductance and coupling of planar spiral coils. The examined link systems represent realistic configurations for active implantable systems such as cochlear implants. Experimental measurements are complemented with analytical calculations and finite element simulations, which are in good agreement for all measured parameters. The results are then used to study the transfer efficiency of an inductive link in a series-parallel resonant topology as a function of substrate size, the number of coil turns and coil separation. CONCLUSIONS: We find that ferrite sheets can be used to shield the system from unwanted metallic surfaces and to retain the inductive link parameters of the unperturbed system, particularly its transfer efficiency. The required size of the ferrite plates is comparable to the size of the coils, which makes the setup suitable for practical implementations. Since the sizes and geometries chosen for the studied inductive links are comparable to those of cochlear implants, our conclusions apply in particular to these systems.

Construction of a highly flexible and comprehensive gene collection representing the ORFeome of the human pathogen Chlamydia pneumoniae.

BACKGROUND: The Gram-negative bacterium Chlamydia pneumoniae (Cpn) is the leading intracellular human pathogen responsible for respiratory infections such as pneumonia and bronchitis. Basic and applied research in pathogen biology, especially the elaboration of new mechanism-based anti-pathogen strategies, target discovery and drug development, rely heavily on the availability of the entire set of pathogen open reading frames, the ORFeome. The ORFeome of Cpn will enable genome- and proteome-wide systematic analysis of Cpn, which will improve our understanding of the molecular networks and mechanisms underlying and governing its pathogenesis. RESULTS: Here we report the construction of a comprehensive gene collection covering 98.5% of the 1052 predicted and verified ORFs of Cpn (Chlamydia pneumoniae strain CWL029) in Gateway(®) 'entry' vectors. Based on genomic DNA isolated from the vascular chlamydial strain CV-6, we constructed an ORFeome library that contains 869 unique Gateway(®) entry clones (83% coverage) and an additional 168 PCR-verified 'pooled' entry clones, reaching an overall coverage of ~98.5% of the predicted CWL029 ORFs. The high quality of the ORFeome library was verified by PCR-gel electrophoresis and DNA sequencing, and its functionality was demonstrated by expressing panels of recombinant proteins in Escherichia coli and by genome-wide protein interaction analysis for a test set of three Cpn virulence factors in a yeast 2-hybrid system. The ORFeome is available in different configurations of resource stocks, PCR-products, purified plasmid DNA, and living cultures of E. coli harboring the desired entry clone or pooled entry clones. All resources are available in 96-well microtiterplates. CONCLUSION: This first ORFeome library for Cpn provides an essential new tool for this important pathogen. The high coverage of entry clones will enable a systems biology approach for Cpn or host-pathogen analysis. The high yield of recombinant proteins and the promising interactors for Cpn virulence factors described here demonstrate the possibilities for proteome-wide studies.

Sequence homologies between Mycoplasma and Chlamydia spp. lead to false-positive results in chlamydial cell cultures tested for mycoplasma contamination with a commercial PCR assay.

Mycoplasma contamination is a frequent problem in chlamydial cell culture. After obtaining contradictory contamination results, we compared three commercial PCR kits for mycoplasma detection. One kit signaled contamination in mycoplasma-free Chlamydia pneumoniae cultures. Sequencing of cloned PCR products revealed primer homology with the chlamydial genome as the basis of this false-positive result.

Proliferative stimulation of the vascular Endothelin-1 axis in vitro and ex vivo by infection with Chlamydia pneumoniae.

Endothelin-1 (ET-1) is a vasoactive peptide that modifies vascular function via the G-protein coupled transmembrane receptors, Endothelin-A receptor (ETAR) and Endothelin-B receptor (ETBR). Dysregulation of the ET-1 axis plays a role in atherosclerotic development as it triggers cell proliferation, inflammation, and vasoconstriction. The respiratory pathogen Chlamydia pneumoniae (Cp) has been recovered from atherosclerotic lesions, and related to atherogenesis, via activation of vascular small GTPases and leukocyte recruitment. Cp effectively reprograms host cell signalling and is able to enter an intracellular persistent state in vascular cells that is refractory to antibiotics. Upon chlamydial infection, vascular smooth muscle cells, which do not produce significant ET-1 under physiological conditions were switched into a fundamental source of ET-1 mRNA and protein in a p38-MAP-kinase-dependent pathway. Endothelial cells did not overproduce ET-1 but showed upregulation of mitogenic ETAR mRNA and protein while the counterbalancing ETBR, which regulates ET-1 clearance, remained unaffected. This disruption of the ET-1 axis was confirmed in an ex vivo mouse aortic ring model, and resulted in endothelial cell proliferation that could be abrogated by ETAR-siRNA and the selective ETAR-antagonist BQ-123. Chronic chlamydial infection of the vascular wall might represent a permanent noxious stimulus linked to the endothelial cell proliferation characteristic of early atherosclerosis. Suppression of this deleterious paracrine loop by ETAR antagonism opens up a new option of preventing possible vascular sequelae of otherwise untreatable chronic chlamydial infection. In conclusion, this is the first study to demonstrate infection to dysregulate the ET-1 axis towards inducing a proatherogenic proliferative phenotype.

The endogenous antiseptic N-chlorotaurine irreversibly inactivates Chlamydia pneumoniae and Chlamydia trachomatis.

PURPOSE: The antimicrobial activity of N-chlorotaurine (NCT), an endogenous long-lived oxidant applied topically, was tested against Chlamydiae in vitro. METHODOLOGY: Elementary bodies of Chlamydia pneumoniae strain CV-6 and Chlamydia trachomatis serovars A and D were incubated in 0.01, 0.1 and 1 % (w/v) NCT solution at pH 7.1 and 37 °C. After different incubation times, aliquots were removed and grown in cell culture. The number of inclusion forming units was quantified by immunofluorescence and real-time qPCR.Results/Key findings.Chlamydia pneumoniae and Chlamydia trachomatis were inactivated by 1 and 0.1 % NCT within 1 min. Moreover, 0.025-0.1 % NCT significantly reduced the number of intracellularly growing C. pneumoniae within 30 min. CONCLUSIONS: This is the first study demonstrating the antimicrobial activity of NCT against Chlamydiae. Clinical implications of these findings have to be investigated in further trials.

Genetic diversity of the obligate intracellular bacterium Chlamydophila pneumoniae by genome-wide analysis of single nucleotide polymorphisms: evidence for highly clonal population structure.

BACKGROUND: Chlamydophila pneumoniae is an obligate intracellular bacterium that replicates in a biphasic life cycle within eukaryotic host cells. Four published genomes revealed an identity of > 99 %. This remarkable finding raised questions about the existence of distinguishable genotypes in correlation with geographical and anatomical origin. RESULTS: We studied the genetic diversity of C. pneumoniae by analysing synonymous single nucleotide polymorphisms (sSNPs) that are under reduced selection pressure. We conducted an in silico analysis of the four sequenced genomes, chose 232 representative sSNPs and analysed the loci in 38 C. pneumoniae isolates. We identified 15 different genotypes that were separated in four major clusters. Clusters were not associated with anatomical or geographical origin. However, animal lineages are basal on the C. pneumomiae phylogeny, suggesting a recent transmission to humans through successive bottlenecks some 150,000 years ago. A lack of detectable variation in 17 isolates emphasizes the extraordinary genetic conservation of this species and the high clonality of the population. Moreover, the largest cluster, which encompasses 80% of all analysed strains, is an extremely young clade, that went through an important population expansion some 3,300 years ago. CONCLUSION: sSNPs have proven useful as a sensitive marker to gain new insights into genetic diversity, population structure and evolutionary history of C. pneumoniae.

Nod1-mediated endothelial cell activation by Chlamydophila pneumoniae.

Seroepidemiological and animal studies, as well as demonstration of viable bacteria in atherosclerotic plaques, have linked Chlamydophila pneumoniae infection to development of chronic vascular lesions and coronary heart disease. Inflammation and immune responses are dependent on host recognition of invading pathogens. The recently identified cytosolic Nod proteins are candidates for intracellular recognition of bacteria, such as the obligate intracellular chlamydia. In the present study, mechanisms of endothelial cell activation by C. pneumoniae via Nod proteins were examined. Viable, but not heat-inactivated, chlamydia activated human endothelial cells, suggesting that invasion of these cells is necessary for their profound activation. Endothelial cells express Nod1. Nod1 gene silencing by small interfering RNA reduced C pneumoniae-induced IL-8 release markedly. Moreover, in HEK293 cells, overexpressed Nod1 or Nod2 amplified the capacity of C pneumoniae to induce nuclear factor kappaB (NF-kappaB) activation. Interestingly, heat-inactivated bacteria were still able to induced a NF-kappaB reporter gene activity via Nod proteins when transfected intracellularly, but not when provided from the extracellular side. In contrast, TLR2 sensed extracellular heat-inactivated chlamydia. In conclusion, we demonstrated that C pneumoniae induced a Nod1-mediated and Nod2-mediated NF-kappaB activation in HEK293 cells. In endothelial cells, Nod1 played a dominant role in triggering a chlamydia-mediated inflammatory process.

Asymptomatic carotid atherosclerosis is associated with circulating chlamydia pneumoniae DNA in younger normotensive subjects in a general population survey.

OBJECTIVE: Chlamydia pneumoniae infection has been associated with atherosclerosis, but serodiagnosis is unreliable in predicting vascular infection. Direct detection of circulating chlamydial DNA in peripheral blood mononuclear cells (PBMCs) was thus evaluated as a marker for cardiovascular risk in a general population survey using the common carotid intima-media thickness (IMT) as surrogate marker of asymptomatic atherosclerosis. METHODS AND RESULTS: C pneumoniae DNA in PBMCs was determined by nested polymerase chain reaction and associated with IMT for 1032 healthy participants of a general population survey who were within the highest or lowest IMT distribution quartile. C pneumoniae DNA was more prevalent in those with increased IMT (13.4% versus 10.7%), but this was not significant in univariate and of borderline significance in multivariate analysis. Testing for potential effect modifications by known strong determinants of an increased IMT in group interaction analysis revealed an independent association between C pneumoniae DNA and IMT in normotensive subjects (odds ratio [OR], 2.06; 95% CI, 1.05 to 4.03; P=0.04) and in those <70 years old (OR, 1.84; 95% CI, 1.06 to 3.19; P=0.03). CONCLUSIONS: Asymptomatic atherosclerosis is associated with circulating C pneumoniae DNA independently of classical cardiovascular risk factors in normotensive subjects and those <70 years old. C pneumoniae has been implicated in atherogenesis. We determined the association of chlamydial DNA in peripheral blood mononuclear cells with the carotid intima-media thickness from 1032 healthy subjects from a general population survey. A stratified group interaction analysis revealed an independent association in normotensive subjects and those <70 years old.

Hydroxymethylglutaryl coenzyme A reductase inhibition reduces Chlamydia pneumoniae-induced cell interaction and activation.

BACKGROUND: Chlamydia pneumoniae stimulates chronic inflammation in vascular cells. Hydroxymethylglutaryl coenzyme A reductase inhibitors (statins) may have an ameliorating effect. We investigated possible mechanisms. METHODS AND RESULTS: We infected human macrophages that in coculture spread infection to vascular smooth muscle cells (VSMCs). Cerivastatin (250 nmol/L) reduced VSMC infection by 33%. Western blotting made it apparent that VSMC infection resulted in increased cell membrane-associated RhoA and Rac1, implying increased prenylation of these proteins. This effect was blocked by statin but circumvented by mevalonate. Cytochrome C assays showed that infected VSMCs produced increased reactive oxygen species that was blocked by statin. Infection increased nuclear transcription factor-kappaB expression in VSMCs that was dose-dependently suppressed by statin. Infected VSMCs produced and released RANTES and MCP-1. Statin dose-dependently blocked this production both at the mRNA and protein levels. Mevalonate and M geranylgeranylpyrophosphate circumvented these effects. CONCLUSIONS: C pneumoniae can be transmitted from macrophages to VSMCs. VSMCs showed an activation profile typical of atherosclerosis, namely Rac1 and RhoA prenylation, nuclear transcription factor-kappaB activation, reactive oxygen species production, and chemokine production. Statin reduces macrophage-mediated C pneumoniae-induced signaling and transmission.

Chlamydophila pneumoniae. Mechanisms of target cell infection and activation.

Chlamydophila (Chlamydia) pneumoniae, a gram-negative obligate intracellular bacterium, is a widespread respiratory pathogen. Chronic C. pneumoniae infection has been suggested as a trigger/promoter of inflammation that may result in vascular lesions. Although the genome of C. pneumoniae has been sequenced completely this information has not yet led to an understanding of the mechanisms of acute infection and target cell activation nor to the identification of potential chlamydial virulence factors. Intriguingly, current antibiotic treatment options for acute chlamydial infection were proven to be ineffective with respect to clinical outcome in different groups of atherosclerotic patients. The reason might be that primary infection of vascular smooth muscle cells and blood monocytes with C. pneumoniae resembles rather a persistent, antibiotic-resistant, than an active infection. In this review we will focus on the importance of putative host cell receptors for C. pneumoniae and subsequently activated signal transduction pathways.

Chlamydophila pneumoniae induces expression of toll-like receptor 4 and release of TNF-alpha and MIP-2 via an NF-kappaB pathway in rat type II pneumocytes.

BACKGROUND: The role of alveolar type II cells in the regulation of innate and adaptive immunity is unclear. Toll-like receptors (TLRs) have been implicated in host defense. The purpose of the present study was to investigate whether Chlamydophila pneumoniae (I) alters the expression of TLR2 and/orTLR4 in type II cells in a (II) Rho-GTPase- and (III) NF-kappaB-dependent pathway, subsequently (IV) leading to the production of (IV) pro-inflammatory TNF-alpha and MIP-2. METHODS: Isolated rat type II pneumocytes were incubated with C. pneumoniae after pre-treatment with calcium chelator BAPTA-AM, inhibitors of NF-kappaB (parthenolide, SN50) or with a specific inhibitor of the Rho-GTPase (mevastatin). TLR2 and TLR4 mRNA expressions were analyzed by PCR. Activation of TLR4, Rac1, RhoA protein and NF-kappaB was determined by Western blotting and confocal laser scan microscopy (CLSM) and TNF-alpha and MIP-2 release by ELISA. RESULTS: Type II cells constitutively expressed TLR4 and TLR2 mRNA. A prominent induction of TLR4 but not TLR2 mRNA was detected after 2 hours of incubation with C. pneumoniae. The TLR4 protein expression reached a peak at 30 min, began to decrease within 1-2 hours and peaked again at 3 hours. Incubation of cells with heat-inactivated bacteria (56 degrees C for 30 min) significantly reduced the TLR4 expression. Treated bacteria with polymyxin B (2 mug/ml) did not alter TLR4 expression. C. pneumoniae-induced NF-kappaB activity was blocked by TLR4 blocking antibodies. TLR4 mRNA and protein expression were inhibited in the presence of BAPTA-AM, SN50 or parthenolide. TNF-alpha and MIP-2 release was increased in type II cells in response to C. pneumoniae, whereas BAPTA-AM, SN50 or parthenolide decreased the C. pneumoniae-induced TNF-alpha and MIP-2 release. Mevastatin inhibited C. pneumoniae-mediated Rac1, RhoA and TLR4 expression. CONCLUSION: The TLR4 protein expression in rat type II cells is likely to be mediated by a heat-sensitive C. pneumoniae protein that induces a fast Ca2+-mediated NF-kappaB activity, necessary for maintenance of TLR4 expression and TNF-alpha and MIP-2 release through possibly Rac and Rho protein-dependent mechanism. These results indicate that type II pneumocytes play an important role in the innate pulmonary immune system and in inflammatory response mechanism of the alveolus.

Transmission of Chlamydia pneumoniae infection from blood monocytes to vascular cells in a novel transendothelial migration model.

Chlamydia pneumoniae uses blood monocytes (PBMC) for systemic dissemination, persists in atherosclerotic lesions, and has been implicated in the pathogenesis of atherosclerosis. During transmigration in a newly developed transendothelial migration model (TEM) C. pneumoniae-infected PBMC spread their infection to endothelial cells. Transmigrated PBMC retained their infectivity and transmitted the pathogen to smooth muscle cells in the lower chamber of the TEM. Detection of chlamydial HSP60 mRNA proved pathogen viability and virulence. We conclude that PBMC can spread chlamydial infection to vascular wall cells and we suggest the TEM as a novel tool to analyze host-pathogen interactions in vascular chlamydial infections.

Detection of Chlamydia pneumoniae but not of Helicobacter pylori in symptomatic atherosclerotic carotids associated with enhanced serum antibodies, inflammation and apoptosis rate.

BACKGROUND AND PURPOSE: Numerous seroepidemiological and pathological studies linked Chlamydia pneumoniae and Helicobacter pylori with atherosclerosis. However, analyses of these infectious agents in the pathogenesis of stroke are either lacking or contradictory. Therefore, we evaluated the detection rate of C. pneumoniae and H. pylori in normal carotids vs. atherosclerotic carotids and compared these findings with serology, plaque morphology, inflammatory cell infiltrates and apoptosis rate. METHODS: The study was performed on 40 morphological normal carotids from autopsy and 20 advanced atherosclerotic carotids from endarterectomy after stroke. Serum IgG antibody titre was measured by enzyme immunoassay (H. pylori) and microimmunofluorescence (MIF) technique (C. pneumoniae). Immunohistochemistry (IHC) and Western blotting were performed to identify C. pneumoniae, H. pylori, to characterize plaque morphology (macrophages and smooth muscle cells) and the inflammatory infiltrate (T- and B cells) and to detect apoptosis (TUNEL staining). RESULTS: C. pneumoniae was found significantly more frequently in atherosclerotic than in normal carotids (P=0.001), which correlated with elevated C. pneumoniae IgG-antibody titres (P=0.048). Although H. pylori was not detected in carotids, elevated H. pylori antibody titres were significantly associated with the degree of atherosclerosis (P=0.001). The C. pneumoniae infected carotids displayed a slightly enhanced infiltrate of T cells and apoptosis rate, but no morphological changes. CONCLUSION: C. pneumoniae but not H. pylori, was detected by IHC primarily in symptomatic carotids, without specific morphological differences. Correlation of C. pneumoniae in-situ-detection and IgG antibodies suggested a possible connection between respiratory-tract and endovascular infection. The C. pneumoniae associated T-lymphocytes and apoptosis rate indicate an immune-mediated inflammatory process, involving vascular walls.

Micromanipulation of the Chlamydia pneumoniae inclusion: implications for cloning and host-pathogen interactions.

The Chlamydia trachomatis inclusion is fragile, rendering it incompatible to micromanipulation. We show that the Chlamydia pneumoniae inclusion differs, being resistant to micromanipulation as shown by direct microinjection of the infected host cytosol or the inclusion itself. We have used micromanipulation to clone C. pneumoniae and to free it from mycoplasma contamination.

Alveolar epithelial cells type II are major target cells for C. pneumoniae in chronic but not in acute respiratory infection.

Pulmonary presence of Chlamydia pneumoniae is associated with acute and chronic infections. We show that unapparent chlamydial infection in four out of 31 chronic obstructive pulmonary disease (COPD) patients (12.9%) is characterized by a significant increase in infected alveolar epithelial cells type II (18.2 +/- 3.5% vs. 2.3 +/- 0.9; IHC/ISH) compared to a newly established model of acute chlamydial infection (ACIM) in vital lung specimens from pulmonary lobectomy. Expression of cHSP60 demonstrated pathogen viability and virulence in the ACIM. We conclude that target cells differ in acute and chronic chlamydial infection and suggest the ACIM as a novel tool to analyze the host-pathogen-interactions in acute respiratory infections.

Chlamydia pneumoniae infection acts as an endothelial stressor with the potential to initiate the earliest heat shock protein 60-dependent inflammatory stage of atherosclerosis.

We identified increased expression and redistribution of the intracellular protein 60-kDa human heat shock protein (hHSP60) (HSPD1) to the cell surface in human endothelial cells subjected to classical atherosclerosis risk factors and subsequent immunologic cross-reactivity against this highly conserved molecule, as key events occurring early in the process of atherosclerosis. The present study aimed at investigating the role of infectious pathogens as stress factors for vascular endothelial cells and, as such, contributors to early atherosclerotic lesion formation. Using primary donor-matched arterial and venous human endothelial cells, we show that infection with Chlamydia pneumoniae leads to marked upregulation and surface expression of hHSP60 and adhesion molecules. Moreover, we provide evidence for an increased susceptibility of arterial endothelial cells for redistribution of hHSP60 to the cellular membrane in response to C. pneumoniae infection as compared to autologous venous endothelial cells. We also show that oxidative stress has a central role to play in endothelial cell activation in response to chlamydial infection. These data provide evidence for a role of C. pneumoniae as a potent primary endothelial stressor for arterial endothelial cells leading to enrichment of hHSP60 on the cellular membrane and, as such, a potential initiator of atherosclerosis.

High-resolution melting analysis of the single nucleotide polymorphism hot-spot region in the rpoB gene as an indicator of reduced susceptibility to rifaximin in Clostridium difficile.

Clostridium difficile, a Gram-positive, spore-forming, anaerobic bacterium, is the main causative agent of hospital-acquired diarrhoea worldwide. In addition to metronidazole and vancomycin, rifaximin, a rifamycin derivative, is a promising antibiotic for the treatment of recurring C. difficile infections (CDI). However, exposure of C. difficile to this antibiotic has led to the development of rifaximin-resistance due to point mutations in the ß-subunit of the RNA polymerase (rpoB) gene. In the present study, 348 C. difficile strains with known PCR-ribotypes were investigated for respective single nucleotide polymorphisms (SNPs) within the proposed rpoB hot-spot region by using high-resolution melting (HRM) analysis. This method allows the detection of SNPs by comparing the altered melting behaviour of dsDNA with that of wild-type DNA. Discrimination between wild-type and mutant strains was enhanced by creating heteroduplexes by mixing sample DNA with wild-type DNA, leading to characteristic melting curve shapes from samples containing SNPs in the respective rpoB section. In the present study, we were able to identify 16 different rpoB sequence-types (ST) by sequencing analysis of a 325 bp fragment. The 16 PCR STs displayed a total of 24 different SNPs. Fifteen of these 24 SNPs were located within the proposed 151 bp SNP hot-spot region, resulting in 11 different HRM curve profiles (CP). Eleven SNPs (seven of which were within the proposed hot-spot region) led to amino acid substitutions associated with reduced susceptibility to rifaximin and 13 SNPs (eight of which were within the hot-spot region) were synonymous. This investigation clearly demonstrates that HRM analysis of the proposed SNP hot-spot region in the rpoB gene of C. difficile is a fast and cost-effective method for the identification of C. difficile samples with reduced susceptibility to rifaximin and even allows simultaneous SNP subtyping of the respective C. difficile isolates.

Investigation of bacterial and viral agents and immune status in Behcet's disease patients from Iran.

AIM: Behçet's disease (BD) is an autoimmune disorder associated with HLA-B51 positivity. Serologic/genomic findings have suggested microbes as possible causative agents and the geographical distribution suggests environmental influences. METHODS: We performed comparative analyses of 40 patients with BD or related symptoms not fulfilling BD criteria. Patients originating from different regions of Iran were tested by molecular/serological methods for human herpes viruses and parvovirus B19, two Chlamydiae species, as well as Coxiella, Listeria, Yersinia, Leptospira and Mycobacterium paratuberculosis. Human leukocyte antigen-typing was performed: testing of cytokine profiles and immune mediators representative for the cellular immune system, including neopterin/kynurenine production. RESULTS: No apparent differences in interleukin (IL)-4, 6, 8 and 10 were observed, whereas production of soluble IL-2-receptor and tumor necrosis factor (TNF)-alpha were more pronounced in the BD group. Neopterin/kynurenine production was comparable, although both groups showed twice the levels of healthy people. No significant differences of herpes simplex virus (HSV) antibody titres were observed but higher titres against Chlamydophila pneumoniae were found in the controls. In 20 BD patients and controls neither parvovirus B19 DNA was detected nor bacterial DNA. Viral DNA of Epstein-Barr virus (EBV), cytomegalovirus (CMV) and human herpes virus (HHV)8 was detected more frequently in the BD group, whereas HSV DNA was only found in the controls, indicating that stomatitis might be caused by HSV. CONCLUSION: Although no significant association of BD was detected with a single pathogen, our findings suggest that detection of HSV DNA or Chlamydiae would rather argue against classic BD. Whether there is a discriminative potential of the tested immune mediators/receptors has to be elucidated in further studies.