Chlamydia Pneumoniae Research Articles

The Role of Chlamydia Pneumoniae in Human Aortic Disease—A Hypothesis Revisited

Background The role of Chlamydia pneumoniae in the pathogenesis of aortic aneurysm is controversial. We investigated the presence of C. pneumoniae in tissue samples excised from patients and controls. Methods Aortic wall specimens were obtained from 17 patients with acute Stanford type A aortic dissection, 25 patients with thoracic aortic aneurysms (TAA) and 23 patients with abdominal aortic aneurysms (AAA). Eighty-three tissue samples of 73 control patients free of aortic disease were obtained either at surgery or autopsy. The presence of Chlamydia subspecies DNA (sequences specific for all known Chlamydiaceae) and DNA of C. pneumoniae, C. trachomatis and C. psittaci were assessed by a validated highly sensitive and specific real time polymerase chain reaction (PCR) analysis. Atherosclerotic risk factors were assessed in all patients. Results We failed to detect C. pneumoniae and C. psittaci-DNA in any of the 148 vessel specimens. C. trachomatis-DNA was detected in 1/65 patients and in none of 83 controls ( P=0.43). Chlamydia subspecies DNA was found in samples of eight cases and in one control ( P=0.01), however, no significant differences were found between the subgroups aortic dissection ( P=0.09), TAA ( P=0.99) and AAA ( P=0.15) and respective controls. Conclusions C. pneumoniae does not play a clinically relevant role in acute and chronic aortic disease. The impact of other organisms of the family Chlamydiaceae needs further evaluation.

Production of prostaglandin E 2 in monocytes stimulated in vitro by Chlamydia trachomatis, Chlamydophila pneumoniae, and Mycoplasma fermentans

Chlamydia trachomatis (CT) as well as Chlamydophila pneumoniae (CP) cause chronic inflammatory diseases in humans. Persistently infected monocytes are involved in the pathogenesis by inducing mediators of inflammation. An in vitro system of chlamydial persistence in human peripheral blood monocytes (HPBM) was used to investigate prostaglandin E 2 (PGE 2) production and the expression of the key enzyme for prostaglandin production, cyclooxygenase-2 (COX-2). PGE 2 production was determined by PGE 2-ELISA of HPBM-culture supernatants. Cox-2 mRNA expression was measured by real-time RT-PCR of total RNA isolated from HPBM. Both, CT and CP, stimulated PGE 2 production of HPBM in vitro. Equivalent numbers of CT per host cell induced a higher PGE 2-response compared to CP. The amount of synthesized PGE 2 depended on the chlamydial multiplicity of infection (MOI). Even at an MOI of 10 the amount of CT- and CP-induced prostaglandin, respectively, was lower than the amount of prostaglandin induced by E. coli lipopolysaccharide (LPS) at a concentration of 10 μg/ml. In contrast to stimulation with LPS, Chlamydia-induced PGE 2 production as well as cox-2 mRNA decreased after day 1 post infection (p.i.). These data indicate that Chlamydia stimulate PGE 2 production in human monocytes. Since Chlamydia are often contaminated by mycoplasma, the influence of mycoplasma on the prostaglandin production was investigated additionally. Mycoplasma fermentans ( MF) also stimulated PGE 2 production. The co-infection of mycoplasma and Chlamydia resulted in an additive effect in the production of PGE 2. Thus it is important to use host cells and Chlamydia free of mycoplasma contamination for the analysis of Chlamydia-induced prostaglandin production.

<i>Chlamydia</i> as a cause of late neonatal pneumonia at Kenyatta National Hospital, Nairobi

Neonatal pneumonia is a common cause of morbidity and mortality all over the world. The problem is known to be higher in resource poor third world countries. Organisms (such as chlamydia) not covered by routine laboratory tests and regular antibiotic regimes may frequently contribute towards the causation of late neonatal pneumonia. It is therefore useful to gather epidemiological evidence to guide in the routine diagnosis and treatment of such infections. To determine the prevalence of chlamydia associated pneumonia among infants developing the disease between the 7th and 30th days of life (late neonatal pneumonia). Cross sectional survey. Newborn Unit, Kenyatta National Hospital. Fifty two newborns clinically diagnosed as having late neonatal pneumonia. They were all subjected to chest X-rays to confirm the clinical diagnosis. Nasopharyngeal aspirates for chlamydia antigen detection tests were then performed on all patients. The study was undertaken during the months of September through to November 2000. The proportion of newborns with late neonatal pneumonia that have chlamydia trachomantis as the sole or contributory causative agent. Fifty two newborns of postnatal age between seven and 30 days were recruited. Their sex distribution was about 1:1. Thirty three (63.5%) of these infants were found with chlamydia in their upper airways. Thirty out of 47 available chest X-rays, representing 63.8% had evidence of interstitial pneumonitis. Chlamydia associated pneumonia indicated by the presence of both interstitial pneumonia and colonization of the upper air ways was present in 24 out of 47 patients, 51% of the total cases of late neonatal pneumonia. When X-rays alone were compared with our gold standard for the diagnosis of chlamydia pneumonia (radiology and colonization), we computed a sensitivity of 100%, specificity 73%, negative predictive value 100% and positive predictive value of 80%. Mode of delivery, birth weight and gestation had no association with nasopharyngeal colonization by chlamydia or actual diagnosis of chlamydia pneumonia. The prevalence of chlamydia associated infection among newborns with late neonatal pneumonia at Kenyatta National Hospital is 51%, eight times more than that reported elsewhere. Chest X-rays appear to be a reliable diagnostic tool in this group. The use of antichlamydial drugs in addition to the regular antibiotics whenever a diagnosis of late neonatal pneumonia is made is justifiable.

Association of Mycoplasma pneumoniae infection with coronary artery disease and its interaction with chlamydial infection

Mycoplasma pneumoniae (MP) seropositivity was reported to be associated with coronary events. MP organisms were detected with Chlamydia pneumoniae (CP) in coronary plaques. We investigated MP and CP seropositivity in 549 patients undergoing coronary angiography. Coronary artery disease (CAD) was found in 396 patients, of whom 154 had myocardial infarction (MI). MP seropositivity was more prevalent in patients with CAD than without CAD (14% versus 6%, P < 0.01). The highest prevalence was found in patients with MI. In contrast, the prevalence of CP seropositivity was similar in patients with and without CAD (62% versus 59%). To clarify interaction with CP infection, 549 patients were divided into two groups with and without CP seropositivity. Among patients with CP seropositivity, MP seropositivity was more prevalent in patients with CAD than without CAD (17% versus 5%, P < 0.01), whereas among patients without CP seropositivity, MP seropositivity did not differ between patients with and without CAD (9% versus 6%). In multivariate analysis, MP seropositivity was associated with CAD only in patients with CP seropositivity (odds ratio = 5.1, 95% CI = 1.8–14.9). Thus, MP seropositivity was associated with CAD. However, this association was confined to patients with CP seropositivity. Coinfection by MP and CP may be an important cofactor for CAD.

Real-Time PCR for Chlamydia pneumoniae Utilizing the Roche Lightcycler and a 16S rRNA Gene Target

Chlamydia pneumoniae (CPN) causes pneumonia in humans, and has emerged as an important respiratory pathogen. There are also established links between CPN infection and coronary artery disease. Traditional culture methods for CPN detection can be time consuming and difficult. There are a variety of molecular-based amplification methods for CPN detection. These methods are more sensitive than culture, but have the disadvantage of being inconsistent and non-comparable across studies. In this paper, we describe the adaptation of the existing primer set CPN 90/CPN91 for use in a real-time PCR assay using the Roche Lightcycler and a Taqman probe. This assay had an analytical sensitivity of between 4 and 0.4 infection-forming units (IFUs)/PCR reaction. A total of 355 samples were tested for validation of the assay. Tested samples included two standardized panels of blinded samples from culture (N = 70), archived specimens consisting of a CPN dilution series, CPN-spiked porcine aortal tissue and endarterectomy specimens (N = 87). The third group consisted of prospectively collected PBMCs from clinical samples (N = 198). Results were compared to nested PCR, which targets the ompA gene of CPN; TETR PCR, which targets the 16S rRNA gene of CPN; or the known result for the sample. Overall, the assay had a sensitivity of 88.5% (69 of 78) and a specificity of 99.3% (275 of 277). This method should prove useful for accurate, high throughput detection of CPN.

Pathohistological changes in diffuse coronary atherosclerosis and chronic infection caused by Chlamydia pneumonia.

BACKGROUND AND PURPOSE: To investigate the histopathologic characteristics of atherosclerotic lessions in diffuse coronary artery disease and to evaluate the possible inflammatory role of chronic infection with Chlamydia pneumoniae (CP).MATERIALS AND METHODS: For 10 patients (males, mean age 61 years) who were surgically treated for grave diffuse coronary artery disease, histomorphological analyses of endarterectomized segments of the coronary arteries were performed. Serological analyses for the detection of CP antibodies in peripheral blood were done, preoperatively.RESULTS AND CONCLUSIONS: Diffuse and concentric atherosclerotic changes from VI to VIII stage according to the Stary classification were found. Immunohistochemical methods revealed infiltrates of T-lymphocytes (80% of cases), B-lymphocytes (40% of cases) and macrophages (80%). Using the nuclear marker for proliferation activity MIB-1, single MIB-1 positive cells were found in 40% of cases. Features of arteriologenesis and vasculitis of newly formed arterioles (as well as thickening of the wall of newly formed arterioles) were found in the vessel wall of 8 patients, 7 of them had chronic infection with CP (preoperative micro-immunofluorescent test results: 1:32&lt;IgG ≥1:512 and IgA≥32), one had passed CP infection (1:32 ≤IgG&lt;1:512, IgA negative). These features were absent in 2 patients, both recovered from CP infection and had not the chronic CP infection at the time of surgery. DNA of Chlamydia pneumoniae was detected using the polymerase chain reaction (PCR) method in the vessel wall of 3 patients who were chosen randomly for this method. This study suggests an inflammatory and proatherogenic role of CP in a high grade atherosclerotic coronary artery wall in diffuse coronary artery disease.

Is Chlamydia pneumoniae Infection a Risk Factor for MS Exacerbations

After several years of unresolved controversy about whether Chlamydia pneumoniae (CP) is involved in the etiology of multiple sclerosis (MS), Buljavec and colleagues now address the more limited question of whether acute CP infection can trigger MS exacerbations. A recent report by the same group (Journal Watch Neurology Jun 7 2002) confirmed the association between MS attacks and acute, presumably viral, upper respiratory infections. The current report is the first well-documented study …

Empirical Antibiotics for Patients with Ischemic Heart Disease

Although researchers have suspected a link between bacterial infections (primarily infections with Chlamydia pneumoniae ) and ischemic heart disease (IHD), clinical trials assessing use of antibiotics in the secondary prevention of IHD have produced conflicting results. Now, investigators in South Carolina have conducted a meta-analysis to evaluate …

Serologic markers of persistent chlamydia pneumonia infection and long-term prognosis after successful coronary stenting

Background Previous studies have shown an incremental role of inflammation in late prognosis following coronary stenting (CS). In particular, high preprocedural levels of plasma C-reactive protein (CRP) have been related to increased hazard of late ischemic complications. Persistent Chlamydia pneumoniae (Cp) infection, detected by positive IgA anti-Cp titers, may be associated with this inflammatory process and portend a high risk of late adverse prognosis after CS. Methods A total of 483 consecutive patients with either stable or unstable coronary syndromes were followed-up for 1 year after successful CS. The composite of cardiac death, myocardial infarction, rehospitalization for rest-unstable angina, and exertional angina, whichever occurred first, was the clinical end point. Additionally, the rate of in-stent restenosis and progression of coronary artery disease during this period were evaluated. Anti-Cp titers and plasma CRP levels were measured before the procedure. Results Positive immunoglobulin A (IgA), but not positive immunoglobulin G (IgG), titers were significantly associated with high plasma CRP levels in patients with unstable coronary syndromes ( P = .005), but not in those with stable angina ( P = .7). Moreover, positive IgA titers were significantly related to increased risk of both the composite clinical end point ( P = .04) and progression of coronary artery disease ( P < .001) in patients with unstable coronary syndromes but not in those with stable angina. Neither positive IgA nor positive IgG titers were associated with the rate of in-stent restenosis. Conclusions Persistent Cp infection may drive an inflammatory response in the coronary vasculature and portends an adverse late outcome after CS in patients with unstable coronary syndromes.

Pneumonies communautaires et infection grippale

Children without chronic or serious medical conditions are at increased risk for hospitalization during influenza seasons, mainly with respiratory tract infections. But influenza virus infections frequently remain undiagnosed, even in hospitalized patients. We prospectively studied the rate of concomitant and preceding influenza infections in children hospitalized with a community acquired pneumonia (CAP). Population and methods. – All 1–15-year-old children with CAP requiring hospitalization between 1st April 2000 and 2002 had nasopharyngeal aspirate for viruses, immunoflorescence and serologies for respiratory pathogens. The peak of influenza IgG measured by complement fixation (CF) is transient, and a titer of 1/64 or more indicates an acute influenza infection in the preceding weeks. Children with chronic disease were excluded and a control group of patients from outpatient clinic was measured. Results. – Among 33 previously healthy children (age 4.9 years, range 1.2–14 years), 8 had a pneumococcal pneumonia, 10 a pneumonia caused by Mycoplasma pneumoniae (MP), 1 by Chlamydia pneumonia, and 8 of unknown origin. In six patients immunoflorescence was positive: Respiratory Syncitial Virus, 2, Adenovirus, 1 and Influenza A, 3 (including a patient with concomitant MP infection). Thirteen of the 33 children (39.4%) had evidence of a recent influenza A infection with CF ab ≥ 1/64: with pneumococcal pneumonia, 5/10 with MP pneumonia, 3/8 with unknown origin pneumonia, 9/13 of these previous influenza infections being clinically inapparent. Only 1/30 children of control group (3.3%) had CF ab ≥ 1/64. Conclusion. – In this study, influenza infection is the direct cause of CAP of children in 12% of cases. In other children with CAP, 39.4% of patients had an influenza infection in the preceding weeks which leads to secondary infection caused by Streptococcus pneumoniae or by MP or other pathogens.

Enigmatic relationship between Chlamydia pneumoniae and atherosclerosis

Pathology InternationalVolume 53, Issue 10 p. 733-734 Enigmatic relationship between Chlamydia pneumoniae and atherosclerosis Yu Shi, Yu Shi Department of Pathology and Biodefense Saga Medical School Saga, JapanSearch for more papers by this authorOsamu Tokunaga, Osamu Tokunaga Department of Pathology and Biodefense Saga Medical School Saga, JapanSearch for more papers by this author Yu Shi, Yu Shi Department of Pathology and Biodefense Saga Medical School Saga, JapanSearch for more papers by this authorOsamu Tokunaga, Osamu Tokunaga Department of Pathology and Biodefense Saga Medical School Saga, JapanSearch for more papers by this author First published: 06 October 2003 https://doi.org/10.1046/j.1440-1827.2003.01545.xCitations: 1Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume53, Issue10October 2003Pages 733-734 RelatedInformation

Coinfection with Mycoplasma pneumoniae and Chlamydia pneumoniae in ruptured plaques associated with acute myocardial infarction.

To study atheromas, Mycoplasma pneumoniae (M. pneumoniae), and Chlamydia pneumoniae (C. pneumoniae). C. pneumoniae was studied with immunohistochemistry and M. pneumoniae with in situ hybridization (ISH), in segments of coronary arteries (SCA) as follows: group A - thrombosed ruptured plaques (TRP) of 23 patients who died due to acute myocardial infarction (AMI); group B - 23 nonruptured plaques (NRP) of group A patients; group C - NRP of 11 coronary patients who did not die due to AMI; and group D - 11 SCA from patients with dilated cardiomyopathy or Chagas' disease without atherosclerosis. The mean number of C. pneumoniae+ cells/400x in groups A, B, C, and D was, respectively, 3.3 +/- 3.6; 1.0 +/- 1.3; 1.2 +/- 2.4; and 0.4 +/- 0.3; and the percentage of M. pneumoniae area was, respectively, 3.9 +/- 3.5; 1.5 +/- 1.6; 0.9 +/- 0.9; and 0.4 +/- 0.2. More M. pneumoniae and C. pneumoniae were found in of group A than in group B (P<0.01). Good correlation was seen between the area of the vessel and the M. pneumoniae area in the plaque (r = 0.46; P=0.001) and between C. pneumoniae+ cells and CD4+ T lymphocytes (r = 0.42; P<0.01). The number of C. pneumoniae+ cells correlated with CD20+ B cells (r=0.48; P<0.01). M. pneumoniae and C. pneumoniae are more frequently found in TRP correlate with the intensity of the inflammation and diameter of the vessel (positive remodeling).

No Benefit of Azithromycin in ACS

In small studies, treating Chlamydia pneumoniae with macrolide antibiotics has limited recurrent ischemic events in patients with acute coronary

A family with abdominal aortic aneurysms.

This investigation focused on 7 siblings to 2 brothers with abdominal aortic aneurysm (AAA), with respect to AAA, Chlamydia pneumoniae (CP) serology, serum cholesterol, and smoking habits. Five male and 4 female siblings were included. All siblings underwent ultrasonography, and surgical specimens from the aorta were prepared for immunohistochemical (IHC) analysis. Blood was obtained from all living siblings and serum cholesterol level was analyzed. Serologic analysis was done by microimmunofluorescence (MIF). Smoking habits were recorded. In addition to the 2 known siblings with AAA, 2 other brothers with AAA were found. Four of 8 siblings had IgG 1/512 or greater and 7 of 8 had IgA 1/64 or greater. Two of 3 were positive for CP in IHC obtained from aortic specimens. Two of 8 had hypercholesterolemia; 7 of 9 were smokers. C. pneumoniae as well as smoking seems to be important in the pathogenesis of AAA in this small cohort; however, larger patient cohorts are needed.

Importance of methodology in chlamydia pneumoniae serology

Importance of methodology in chlamydia pneumoniae serology

C-reactive protein, Helicobacter pylori, Chlamydia pneumoniae, cytomegalovirus and risk for myocardial infarction.

C-reactive protein (CRP), Chlamydia pneumonia, Helicobacter pylori, and cytomegalovirus (CMV) have each been associated with atherosclerosis. We assessed how infection and CRP related to risk for subsequent myocardial infarction (MI). Using a nested case-control design, we assessed how these factors independently and jointly affected risk for myocardial infarction (MI). Cases of first MI (N = 121) were identified from among participants in a multiphasic health check-up cohort. Controls without MI (N = 204) were matched to cases by gender, age, race, and date of serum collection. Sera collected at enrollment were tested for antibodies to infection and for CRP. In multivariate analysis (mean follow-up of 5.1 years), CRP was associated with MI only in subjects older than 51 years (p = 0.004). Although H. pylori infection increased risk for MI, this association was modest (OR = 1.90, 95% CI = 0.97-3.71) and was not evident in non-smokers or when adjusted for education. No association between C. pneumoniae or cytomegalovirus and MI was observed, nor was the association between CRP and MI explained by these infections. Elevated CRP is a risk factor for subsequent MI in older individuals. The relationship between Hp and MI may be due to confounding or co-linearity with socioeconomic status.

Combined role of the Lewis antigenic system, Chlamydia pneumoniae, and C-reactive protein in unstable angina

ObjectivesThe goal of this study was to assess the prognostic role of the Lewis antigenic system, Chlamydia pneumoniae(CP) seropositivity (CP+), and C-reactive protein (CRP) levels in unstable angina (UA). BackgroundThe role of CP infection in acute coronary syndromes is contradictory. The Lewis antigenic system, a genetically determined blood group system associated with infections and several disorders, including ischemic heart disease, might influence the susceptibility to CP infection, inflammatory response, and risk of cardiac ischemic events. MethodsThe CRP levels, Lewis antigens, and CP+ were measured in 54 patients with Braunwald’s class IIIB UA. All patients were followed up for one year, and the occurrence of new coronary events (coronary death, myocardial infarction, and recurrence of instability) were recorded. ResultsTwenty-five coronary events occurred during follow-up. At univariate analysis CRP >3 mg/l (CRP+) (p = 0.0056), Lewis antigen b (Leb+) (p = 0.028), and the combination of Leb+ and CP+ (p = 0.006) and of CRP+ and Leb+ (p = 0.003) were associated with new coronary events, while CP+ alone was not. At multivariate analysis, CRP+ (p = 0.008) and combined Leb+CP+ (p = 0.03) were independent predictors of worse outcome. The event rate was 64% in CRP+ patients, 67% in Leb+CP+ patients, and 86% in CRP+Leb+CP+ patients. Combined Leb+CP+, but not Leb+ and CP+ alone, was related to CRP levels (p = 0.03). Among CP+ patients, CRP levels were higher in Leb+ than Leb- (p = 0.028). ConclusionsOur data demonstrate that in UA the Lewis antigenic system plays an important role, probably determining individual susceptibility to the detrimental effects of CP infection and by determining an enhanced inflammatory response.

Macrolides as Biological Response Modifiers in Cystic Fibrosis and Bronchiectasis

For 50 years, macrolide antibiotics have been used to treat community acquired pneumonia and atypical infections such as Chlamydia pneumonia and Mycoplasma. In the late 1960s it was noted that when the 14-member ring macrolide antibiotic troleandomycin was given to asthma patients who required large doses of systemic corticosteroids, they could often reduce their steroid dose or even stop steroids completely without exacerbation of their asthma. Because of this experience, Prof. S. Kodoh and colleagues first used erythromycin as an immunomodulatory agent to treat diffuse panbronchiolitis (DPB). DPB is a cystic fibrosis (CF)-like condition seen predominantly in young, nonsmoking adults in Japan and Korea. The introduction of erythromycin profoundly improved survival, and in many of these very ill patients the illness disappeared. Since then, research has focused attention on many non-antibacterial, disease modifying effects of this class of compounds. These include downregulation of proinflammatory cytokines via an effect on nuclear transcription factors, reduction in adhesion molecule expression, suppression of inducible nitric oxide synthase (iNOS), reduced neutrophil chemotaxis and degranulation, inhibition of neutrophil elastase, cytoprotection against bioactive phospholipids, improvement in the rheological properties of mucus, reduction in bronchial hyperreactivity, and, perhaps, modulation of neutrophil death by apoptosis pathways, and in the end, airway remodeling. Additionally, they have unconventional effects on microorganisms, including inhibiting Pseudomonas aeruginosa twitching motility and thus biofilm formation. There are small case series and three large randomized controlled trials that have established unequivocal evidence of benefit in CF. There is less evidence for an immunomodulatory effect in bronchiectasis. Future work is likely to focus on the development of macrolides with disease-specific modes of action.

Detection of Chlamydia Pneumoniae in the Cerebrospinal Fluid of Patients with Multiple Sclerosis by Combination of Cell Culture and PCR

Detection of Chlamydia Pneumoniae in the Cerebrospinal Fluid of Patients with Multiple Sclerosis by Combination of Cell Culture and PCR

Étude séro-épidémiologique de chlamydia pneumoniae au cours des infections respiratoires aiguës basses communautaires à Casablanca (hors pneumopathies)

Many studies report the considerable frequency of respiratory infections due to Chlamydiae pneumoniae (CP), especially in patients with asthma and chronic obstructive broncho-pneumonia COBP. Objective. – The aim of this prospective study was to define the seroprevalence of CP infection in acute episodes in the adult. Methods. – 265 patients were involved in this study, presenting with a non-severe community acquired acute lower respiratory tract infections (acute bronchitis, exacerbation of the COBP) over a 13 month period, from November 1997 to December 1998. These patients were divided in 3 groups: Group 1–103 healthy patients, Group 2–59 patients with COBP, Group III–103 patients with asthma. The CP serology was made on admission, on D30 after admission, and on D45, using an immuno-enzymatic technique. A recent infection or CP was proved by a rate of IgG > 1/512 or for a seroconversion (4 times the initial rate of IgG antibodies). A rate of IgG ranging between 1/16 and 1/512 revealed positive serology but without diagnosis criteria of a recent infection. Results. – The latter was noted in 34% of the patients that were studied, all groups included. The CP seroprevalence was 33.3% in healthy patients, 27.8% in asthmatic patients and 54.5% in patients with COBP. A positive serology without diagnosis criteria of a recent infection was noted in 25.8% of the healthy patients, 25% of the asthmatic patients and 9.1% of the patients with COBP.