Biomedical subjects

W Solbach

Publications and source records attributed to W Solbach.

At least 19 recordsLinked to original sources

PubMed2006

Detection of Treponema pallidum in the vitreous by PCR.

BACKGROUND: Ocular involvement of syphilis still poses a clinical challenge due to the chameleonic behaviour of the disease. As the serodiagnosis has significant limitations, the direct detection of Treponema pallidum (TP) in the vitreous represents a desirable diagnostic tool. METHODS: Real-time polymerase chain reaction (PCR) for the detection of TP was applied in diagnostic vitrectomies of two patients with acute chorioretinitis. Qualitative verification of TP by real-time PCR and melting point analysis according to a modified protocol was ruled out. Patients underwent complete ophthalmological examination with fundus photographs, fluorescein angiography, serological examination, antibiotic treatment and follow-up. RESULTS: In two cases of acute chorioretinitis of unknown origin, real-time PCR of vitreous specimens of both patients provided evidence of TP and was 100% specific. Initial diagnosis of presumed viral retinitis was ruled out by PCR of vitreous specimen. Patients were treated with systemic antibiotics and showed prompt improvement in visual function and resolution of fundus lesions. CONCLUSIONS: With real-time PCR, detection of TP in the vitreous was possible and delivered a sensitive, quick and inexpensive answer to a disease rather difficult to assess. In cases of acute chorioretinitis, the use of PCR-based assays of vitreous specimens in the diagnostic evaluation of patients is advisable. Although syphilitic chorioretinitis is a rare disease, PCR should include search for TP, as diagnostic dilemmas prolong definitive treatment in a sight-threatening disease.

Adult↗

PubMed2005

Rapid manifestation of cervical vertebral osteomyelitis.

Within 10 days after cystoscopy causing urosepsis this patient developed persistant neckpain as initial symptom of vertebral osteomyelitis. E. coli was isolated from urine, blood cultures and later from bone biopsy. Antibiotic treatment did not stop the progress of the disease. A transverse spinal cord syndrome occurred due to a pathological fracture of C5 and C6 and operative decompression was necessary. The rapid onset of osteomyelitis was impressive. For effective treatment of bacterial osteomyelitis a bone biopsy is sometimes unavoidable and indicated.

Anti-Bacterial Agents↗

PubMed2004

Different patterns of the L-histidine decarboxylase (HDC) gene expression in mice resistant and susceptible to experimental cutaneous leishmaniasis.

OBJECTIVE AND DESIGN: In the present study the experimental murine Leishmania major ( L. major) infection model was used to investigate the role of histamine biosynthesis in cutaneous leishmaniasis. SUBJECTS, TREATMENT AND METHODS: A novel RNase Protection Assay (RPA) was developed and applied for the assessment of L-histidine decarboxylase (HDC) gene expression in organs of resistant C57BL/6 and susceptible BALB/c mice after infection with L. major. RESULTS: In the acute phase of infection a rapid but transient induction of HDC expression was observed in the infected lymph nodes of both strains correlating both temporally and spatially with parasite spread. The signal was present in the draining popliteal lymph nodes of both hosts, however, only susceptible mice known to be unable to control parasite dissemination showed induction of HDC in their distant periaortic lymph nodes as well. During the chronic phase of infection only the heavily parasitized organs of BALB/c mice showed high HDC gene expression. CONCLUSIONS: These data suggest that expression of the histamine-producing enzyme HDC in the decisive acute phase of leishmaniasis is not coupled with development of either appropriate Th1 or inadequate Th2 responses to L. major. We hypothesize, however, that during the chronic phase of infection elevated HDC levels, possibly of mast cell origin, are associated with Th2-dominated responses and serious disease development.

Acute Disease↗

PubMed2004

CD14 promoter polymorphism -159C>T is associated with susceptibility to chronic Chlamydia pneumoniae infection in peripheral blood monocytes.

Chlamydia pneumoniae uses peripheral blood monocytes (PBMC) for systemic dissemination and has been linked to atherogenesis by inflammation mediated via TLR2/4 and CD14. We found 12.8% of 610 coronary artery disease (CAD) patients of Central European background to be chronically infected with C. pneumoniae based on the repeated detection of chlamydial DNA in PBMC. Among those the -159C>T CD14 promoter polymorphism was more frequent (OR 1.7, 95% CI 1.08-2.65, P=0.0224) than among C. pneumoniae-negative subjects matched for age and gender. The Arg753Gln TLR2 and Asp299Gly TLR4 polymorphisms were not related to chlamydial infection. Susceptibility for chronic chlamydial infection of PBMC in CAD patients appears associated with the CD14-159C>T promoter polymorphism encoding for enhanced CD14 expression.

Antibodies, Bacterial↗

PubMed2004

Phagocytes transmit Chlamydia pneumoniae from the lungs to the vasculature.

Chlamydia pneumoniae, a major cause of community-acquired pneumonia, primarily infects the respiratory tract. Chronic infection of nonrespiratory sites, such as the vascular wall, the brain or blood monocytes, requires evasion from the lungs and spreading via the bloodstream. The cell types involved in dissemination are insufficiently characterised. In this study, New Zealand White rabbits were infected intratracheally with C. pneumoniae, and lung manifestation and systemic dissemination were monitored by polymerase chain reaction and immunohistochemistry. Infection of the lungs was characterised by an early phase dominated by granulocytes and a late phase dominated by alveolar macrophages (AM). Granulocytes, AM and alveolar epithelial cells acted as host cells for chlamydiae, which remained detectable for up to 8 weeks. AM transported the pathogen to the peribronchiolar lymphatic tissue, and subsequently C. pneumoniae entered the spleen and the aorta via dissemination by peripheral blood monocytes. In conclusion, Chlamydia pneumoniae-infected alveolar macrophages transmigrate through the mucosal barrier, and give the pathogen access to the lymphatic system and the systemic circulation. Infected peripheral blood monocytes are the vector system within the bloodstream and transmit the infection to the vascular wall. This is the first description of granulocytes acting as a reservoir for Chlamydia pneumoniae early in infection.

Animals↗

PubMed2003

Sepsis with bullous necrotizing skin lesions due to vibrio vulnificus acquired through recreational activities in the Baltic Sea.

This report describes the case of a 59-year-old woman with a history of non-Hodgkin's lymphoma who developed bacteremia with Vibrio vulnificus. The patient had been swimming in the unusually warm Baltic Sea in the summer of 2002. She presented with symptoms of septicemia and severe bullous necrotizing skin lesions of the extremities. Blood culture revealed Vibrio vulnificus as the pathogenic organism. Under treatment with cefotaxime and gentamicin, she recovered slowly without further complications. Vibrio vulnificus is a marine bacterium that is present in aquatic ecosystems worldwide, especially when water temperatures exceed 20 degrees C. Infections with Vibrio vulnificus are uncommon in Europe, and most cases are reported from subtropical or tropical regions.

Anti-Bacterial Agents↗

PubMed2003

[The influence of a new surface treatment of silicone intracoular lenses with fluoralkylsitan on the adherence of endophthalmitic bacteria in vitro]].

INTRODUCTION: Dynasilan is a fluoroalkylsilan which is able to bind to surface active molecules of intraocular lenses (IOLs), thereby offering a new option for surface modification of silicone lenses. The purpose of this in vitro study was to investigate the influence of this new surface treatment on the adherence of two typical endophthalmitis-inducing bacteria ( Staphylococcus epidermidis, Propionibacterium acnes). MATERIALS AND METHODS: A total of 14 Dynasilan-treated and 14 untreated silicone lenses were incubated at 37 degrees C for 24 h in brain heart infusion broth (10(8) CFU/ml) either with Staphylococcus epidermidis or with Propionibacterium acnes for 1 h. Subsequently, the adherent bacteria were resuspended using ultrasonification at 35 kHz for 3 x 45 s. After a dilution series and incubation at 37 degrees C for 24 h or 3 days the colonies were counted. RESULTS: On untreated IOLs incubated with Staphylococcus epidermidis the average number of bacteria was 3.6 x 10(7)/ml, and on treated IOLs the number of counted colonies was reduced to 1.09 x 10(7)/ml. Incubated with Propionibacterium acnes the average number of adherent bacteria on untreated IOLs was 4.75 x 10(4)/ml and on modified IOLs the number was reduced to 2.94 x 10(4)/ml. CONCLUSION: Dynasilan surface treatment may reduce the adherence of Staphylococcus epidermidis and Propionibacterium acnes on silicone intraocular lenses. Further studies regarding the stability of this treatment, its biocompatibility and influence on lens epithelial cell adhesion are in progress.

Bacterial Adhesion↗

PubMed2003

Rituximab induces remission in refractory HCV associated cryoglobulinaemic vasculitis.

OBJECTIVES: To report the successful induction of remission with the monoclonal anti-CD20 antibody rituximab in a patient with hepatitis C virus (HCV) associated cryoglobulinaemic vasculitis and a non-Hodgkin's lymphoma (NHL) resistant to previously advocated conventional treatments. CASE REPORT: The patient was a 45 year old woman with HCV associated cryoglobulinaemic vasculitis, with purpura, arthralgia, constitutional symptoms, and a polyneuropathy. A malignant NHL was found as underlying lymphoproliferative disease. At this stage the disease was refractory to interferon alpha2b and ribavirin and to subsequent immunosuppressive treatment with cyclophosphamide. Six rituximab infusions targeting the CD20 antigen on cells of the B cell lineage induced remission of the vasculitis. Bone marrow biopsy disclosed absence of the NHL. Remission has subsequently been maintained and HCV eliminated with the new pegylated interferon alpha2b and ribavirin for nearly one year. CONCLUSIONS: Transition of the underlying "benign" lymphoproliferative disease to a malignant lymphoma may result in difficult to treat HCV associated cryoglobulinaemic vasculitis. Rituximab offers a new possibility for inducing remission in refractory HCV associated cryoglobulinaemic vasculitis and the lymphoproliferative disorder. After remission, HCV may subsequently be eliminated with pegylated interferon alpha2b and ribavirin.

Antibodies, Monoclonal↗

PubMed2002

Polarized expression of Tamm-Horsfall protein by renal tubular epithelial cells activates human granulocytes.

In renal bacterial infections granulocytes are of major importance in the primary immune defense against invading pathogens. However, the mechanisms of granulocytic activation in renal interstitial invasion have not been clarified. Renal tubular epithelial cell mechanisms inducing granulocytic activation and bacterial killing may include tubular cell expression of Tamm-Horsfall protein (THP), a urinary protein that is known to enhance cytokine expression in monocytes. We studied the role of THP in granulocytic activation. A strong binding of THP to human granulocytes was demonstrated by fluorescence-activated cell sorter analysis. Urinary THP and supernatants of THP-expressing cultured tubular epithelial cells (MDCK) enhanced interleukin-8 (IL-8) expression by human granulocytes. Renal tubular cells growing polarized on polycarbonate membranes were used to study apical versus basal THP expression. By electron microscopy THP immunoreactivity was exclusively found on the apical surfaces of tubular cells and was absent on the basolateral cell membrane. In the apical cell culture compartment we found significantly more stimulatory activity for granulocytic IL-8 expression. CD62L, a selectin less expressed in activated granulocytes, was decreased in granulocytes incubated with urinary THP and in supernatants of THP-producing renal tubular cells but not in supernatants from THP-negative cells. Again, the effect on CD62L expression was found only in apical culture media and was absent in the basal compartment. In summary our data give evidence that renal tubular cell THP expression may be relevant in kidney diseases since THP is a potent activator of human granulocytes. The regulation of apical versus basal THP expression and release in vivo may be crucial in the induction of the inflammatory response, e.g., in bacterial renal diseases.

Animals↗

PubMed2002

Leishmania promastigotes release a granulocyte chemotactic factor and induce interleukin-8 release but inhibit gamma interferon-inducible protein 10 production by neutrophil granulocytes.

Recent data from our laboratory suggest that neutrophil granulocytes (polymorphonuclear leukocytes [PMN]) can serve as host cells for Leishmania major in the early phase of infection. In line with these findings, an early influx of PMN to the infected tissues was shown by others to be associated with susceptibility to infection with L. major. The mechanisms underlying the initial PMN recruitment to the site of infection is poorly understood. In the present study we investigated whether Leishmania can influence PMN migration. Supernatants of Leishmania promastigotes were tested for their chemotactic activity using an in vitro chemotaxis assay. All Leishmania species tested (L. major, L. aethiopica, and L. donovani) displayed a marked chemotactic effect on human PMN. However, no effect on the migration of macrophages and NK cells was observed. Checkerboard analysis revealed that the observed PMN migration was due to chemotaxis rather than chemokinesis. Most of the chemotactic activity was found in fractions containing molecules with sizes between 10 and 50 kDa. Pretreatment of PMN with N-formyl-methionyl-leucyl-phenylalanine blocked the chemotactic activity of Leishmania supernatants up to 75%. In addition, we found that leishmanial contact induced the release of interleukin-8 (IL-8) and inhibited the production of gamma interferon-inducible protein 10 (IP-10) by PMN. These data suggest that infection with Leishmania promastigotes leads to PMN accumulation via the production of a chemotactic factor by the parasites, and this effect is amplified by the induction of IL-8 production in PMN. On the other hand, the inhibition of IP-10 production can lead to prevention of NK cell activation.

Adult↗

PubMed2001

[Mitral valve endocarditis caused by Erysipelothrix rhusiopathiae].

HISTORY AND CLINICAL FINDINGS: A 67 year-old country woman was admitted to the hospital because of a four weeks history of continuous catarrh, arthralgia and fever. Recently, she had also developed upper abdominal pain after oral ibuprofen treatment. The clinical examination showed a patient of impaired general condition. The heart and lungs were auscultatory normal and there were no signs of dyspnea, cyanosis or inflammatory skin lesions. EXAMINATIONS: Physical examination of heart and lung, electrocardiography and transthoracic echocardiography were without pathological findings. CLINICAL COURSE: Gastroscopy revealed acute antral gastritis and duodenitis with presence of Helicobacter pylori. Eradication therapy resolved the abdominal symptoms but fever returned after the antibiotic therapy was stopped. The patient developed a severe endocarditis with progressive mitral regurgitation within a few days. Erysipelothrix rhusiopathiae was isolated from blood cultures and identified by conventional and molecular methods. The patient was treated successfully with 3 x 2 g ampicillin daily, applied parenterally for six weeks, and a mitral valve replacement. CONCLUSION: This was an unusual manifestation of systemic Erysipelothrix rhusiopathiae infection. The bacterium Erysipelothrix rhusiopathiae has still to be considered in the diagnosis and treatment of endocarditis in patients with increased risk of exposure (e.g. farmers, butchers and fishermen).

Aged↗

PubMed2001

Novel multi-probe RNase protection assay (RPA) sets for the detection of murine chemokine gene expression.

Chemokines play an essential role in immune and inflammatory reactions via the recruitment of leukocytes. Studying the role of chemokines in vivo is complicated by the redundancy of their action and by their promiscuous receptor usage. The simultaneous analysis of several chemokines is, therefore, advantageous in order to obtain a comprehensive view of chemokine participation in inflammatory and infectious processes. At present, no multi-probe detection systems are available for the analysis of recently described chemokines. In this study, new multi-probe RNase protection assay (RPA) template sets were developed for the analysis of murine chemokines. Chemokine cDNA fragments were generated by RT-PCR and individually subcloned into the plasmid pGEM-T providing a T7 promotor. In this way, two multi-probe template sets were constructed each containing six chemokine sequences (CXCL12/SDF-1, XCL1/lymphotactin, CCL20/exodus-1, CCL25/TECK, CX3CL1/fractalkine, CXCL1/KC, and CCL20/MDC, CXCL9/MIG, CCL9/10/MIP-1gamma, CXCL13/BLC, CCL12/MCP-5, CCL19/ELC, respectively) and templates for the two house-keeping genes L32 and GAPDH. The evaluation of these RPA template sets in various murine models demonstrated their suitability for the analysis of the above chemokines both under constitutive and infection-induced conditions. To reduce the personal radiation hazard, we found that 32P could be replaced by 33P without any loss of assay-sensitivity. These new RPA multi-probe sets provide valuable tools for the simultaneous quantitative determination of gene expression of multiple murine chemokines of both constitutive and inducible type.

Animals↗

PubMed2001

Chlamydia pneumoniae infection in circulating human monocytes is refractory to antibiotic treatment.

BACKGROUND: Recovery of the intracellular bacterium Chlamydia pneumoniae from atherosclerotic plaques has initiated large studies on antimicrobial therapy in coronary artery disease. The basic concept that antibiotic therapy may eliminate and prevent vascular infection was evaluated in vitro and in vivo by examining the antibiotic susceptibility of C pneumoniae in circulating human monocytes, which are thought to transport chlamydiae from the respiratory tract to the vascular wall. METHODS AND RESULTS: Blood monocytes (CD14+) from 2 healthy volunteers were obtained before and after oral treatment with azithromycin or rifampin and then inoculated with a vascular C pneumoniae strain and continuously cultured in the presence of the respective antibiotic. Progress of infection and chlamydial viability was assessed by immunogold-labeling and detection of C pneumoniae-specific mRNA transcripts. Circulating monocytes from patients undergoing treatment with experimental azithromycin for coronary artery disease were examined for C pneumoniae infection by cell culture. Antibiotics did not inhibit chlamydial growth within monocytes. Electron microscopy showed development of chlamydial inclusion bodies. Reverse transcription-polymerase chain reaction demonstrated continuous synthesis of chlamydial mRNA for 10 days without lysis of the monocytes. The in vivo presence of viable pathogen not eliminated by azithromycin was shown by cultural recovery of C pneumoniae from the circulating monocytes of 2 patients with coronary artery disease. CONCLUSIONS: C pneumoniae uses monocytes as a transport system for systemic dissemination and enters a persistent state not covered by an otherwise effective antichlamydial treatment. Prevention of vascular infection by antichlamydial treatment may be problematic: circulating monocytes carrying a pathogen with reduced antimicrobial susceptibility might initiate reinfection or promote atherosclerosis by the release of proinflammatory mediators.

Aged↗

PubMed2001

Chemokines, natural killer cells and granulocytes in the early course of Leishmania major infection in mice.

In the present study the early recruitment of leukocytes into the infected skin and into the draining lymph node (LN) was investigated after subcutaneous infection of mice with Leishmania major promastigotes. Flow cytometric analysis of cells recovered from the infected skin revealed that GR-1+ granulocytes were present as early as 10 h after infection, thus representing the first leukocyte population to be recruited to the site of infection. The migration of granulocytes was shown to be associated with a rapid mRNA expression of the neutrophil-attracting chemokine KC in the infected skin. Moreover, L. major promastigotes were found to produce factor(s) that are chemotactic for human neutrophils in vitro. Experiments with human neutrophils revealed that these cells are able to phagocytose the parasites. Natural killer (NK) cells appeared at the site of infection 24 h after infection. The migration of NK cells in resistant mice was found to correlate with the expression of the NK cell-activating chemokine IP-10. Treatment of susceptible BALB/c mice with recombinant mouse IP-10 resulted in a significantly increased NK cell cytotoxic activity in the draining LN. These data suggest that both the early chemokine gene expression and the production of chemotactic factors by the parasites themselves regulate the site-directed migration and activation of cells of the innate immune response, and suggest a role of chemotactic factors in the early defense against the parasites.

Animals↗

PubMed2001

In vitro susceptibility and eradication of Chlamydia pneumoniae cardiovascular strains from coronary artery endothelium and smooth muscle cells.

UNLABELLED: Recovery of viable Chlamydia pneumoniae from atheromas of coronary heart diseases patients has initiated pilot studies to eradicate C. pneumoniae from vascular tissue by antibiotic treatment. To provide data for the selection of effective antibiotics, we investigated the in vitro activity of anti-chlamydial antibiotics to eliminate vascular strains of C. pneumoniae from coronary endothelial and smooth muscle cells, celltypes that are involved in the pathogenesis of atherosclerosis. METHODS: The susceptibility of the obligate intracellular chlamydiae was studied in primary coronary endothelial cells, smooth muscle cells and immortalized epithelial cells. Minimal inhibitory concentrations (MICs) were determined for ofloxacin, levofloxacin, trovafloxacin, moxifloxacin, erythromycin, azithromycin, roxithromycin, rifapentin and rifampin. RESULTS: In vitro, rifampin was the most effective drug overall. Moxifloxacin and trovafloxacin were as effective as the macrolides of which roxithromycin was the most active one. CONCLUSIONS: Actively replicating C. pneumoniae can be eliminated in vitro from cell types, involved in the pathogenesis of atherosclerosis by various antibiotics. These data provide an experimental background for the selection of antibiotics in clinical eradication studies and will help to assess the potential success of prevention and eradication therapies.

Anti-Bacterial Agents↗

PubMed2001

The AMOR study: a randomized, double-blinded trial of omeprazole versus ranitidine together with amoxycillin and metronidazole for eradication of Helicobacter pylori.

BACKGROUND: Besides antibiotics, additionally effective acid inhibition is necessary for the eradication of Helicobacter pylori. OBJECTIVE: To assess the significance of acid suppression and, in particular, treatment with proton pump inhibitors (PPIs) compared with H2 receptor antagonists (H2 RAs). The primary target parameter for the study was H. pylori eradication. In addition, the ulcer healing rate, speed of pain reduction, score for gastritis in the antrum and gastric body, and rate of side effects were recorded. DESIGN: Randomized, double-blinded, multicentre study. PARTICIPANTS: A total of 456 patients between the ages of 18 and 80 years with H. pylori-positive duodenal ulcers were included in the study. METHODS: Using a randomization list, patients were assigned either to a treatment group receiving omeprazole 40 mg once daily, amoxycillin 750 mg three times a day, and metronidazole 500 mg three times a day (OAM), or to a group receiving ranitidine 300 mg once daily, amoxycillin 750 mg three times a day, and metronidazole 500 mg three times a day (RAM). The treatment period was 7 days in both groups. Long-term acid-suppressant treatment was not given. RESULTS: The eradication rate was 87.1% (169/194, intention to treat [ITT]) in the OAM group and 77% (137/ 178, ITT) in the RAM group. The difference of 10.1% (95% CI 2.5-18%) is statistically significant (P= 0.0104). The ulcer healing rate was 93.3% in the OAM group (181/194, ITT) and 92.1% in the RAM group (164/178, ITT, NS). With regard to the speed and intensity of pain reduction, the OAM group was superior to the RAM group. In patients in whom H. pylori eradication was successful, the reduction in the antral and gastric body gastritis score was significantly greater than in patients without eradication. In the OAM group, 39.1% of the patients (n = 90) reported one or more side effects, compared with 44.7% (n = 101) in the RAM group (P= 1.5449, NS). CONCLUSION: Omeprazole (40 mg once daily in the morning) is significantly more effective than ranitidine (300 mg once daily in the morning) with respect to H. pylori eradication when used together with amoxycillin (750 mg three times a day) and metronidazole (500 mg three times a day) for a 7-day treatment period.

Adolescent↗

PubMed2001

Presence of Chlamydia pneumoniae DNA in the cerebral spinal fluid is a common phenomenon in a variety of neurological diseases and not restricted to multiple sclerosis.

Chlamydial DNA and viable organisms have been reported in the cerebrospinal fluid (CSF) of multiple sclerosis (MS) patients. We investigated whether this phenomenon is specific for MS and not occurring in patients with other neurological diseases (OND) or in healthy controls and whether it is caused by infected blood monocytes having crossed the blood-brain barrier. Twelve (21%) of fifty-eight MS patients and 20 (43%) of 47 OND patients had Chlamydia pneumoniae DNA in the CSF as determined by nested polymerase chain reaction. Viable organisms were cultured from one OND patient. We failed to detect C. pneumoniae in the CSF of 67 neurologically healthy persons. C. pneumoniae was detected in parallel in the blood monocytes of 2 of 6 CSF-positive MS patients and in 8 of 10 CSF-positive OND patients. Thus, chlamydial presence cannot exclusively be explained as being caused by contaminating infected monocytes that have crossed the blood-brain barrier. In peripheral blood mononuclear cell-negative patients, chlamydia have been cleared from the circulation but persist in the central nervous system (CNS), indicating the establishment of a chronic process. In summary, the presence of C. pneumoniae in patients with neurological diseases is a common phenomenon and is not restricted to MS patients. The pathogenetic relevance of a chronic chlamydial CNS infection for neurological diseases remains unclear, but the hypothesis that susceptible patients may be impaired in their ability to clear chlamydiae from the CNS requires further examination.

Adolescent↗

PubMed2000

Atherogenetically relevant cells support continuous growth of Chlamydia pneumoniae.

The obligate intracellular bacterium Chlamydia pneumoniae has been implicated in the pathogenesis of atherosclerosis since viable pathogen has been recovered from plaques. Chlamydiae are epithelial pathogens notorious for causing persistent infection. Atherosclerosis, however, is a chronic inflammatory disease involving mesenchymal cells of the vascular wall. A bacterial contribution to atherosclerosis appears more relevant if the resident mesenchymal cells of the vascular wall that constitute the plaque can support chlamydial infection continuously. Therefore we inoculated immortalized and primary mesenchymal cells with a vascular and a respiratory Chlamydia pneumoniae isolate. Primary human coronary artery endothelial and smooth muscle cells, primary human embryonic fibroblasts as well as the immortalized cell lines were permissive for continuous growth of both strains. Thus, the resident vascular cells that produce the atheromatous plaque can acquire permanent productive. Chlamydia pneumoniae infection. Immortalized monocytic cells and peripheral blood monocytes also supported chlamydial growth, though productive infection ceased after 5 passages. Monocytes/macrophages are not resident cells of the vascular wall but have an active role in plaque formation. Systemic circulation and transendothelial migration makes them a potential vector system for chlamydial distribution. These findings add further plausibility to the hypothesis of a chronic infectious component in the multifactorial condition of atherosclerosis. Further studies must precisely define chlamydial target cells in vivo and differentiate infection in resident cells of the vascular wall from a presence limited to migrating macrophages. Endovascular infection might provide an explanation for unclear phenomena of atherogenesis like mesenchymal cell proliferation and its distinct inflammatory component.

Arteriosclerosis↗