Azithromycin decreases Chlamydia pneumoniae-mediated Interleukin-4 responses but not Immunoglobulin E responses

BACKGROUND

Chlamydia pneumoniae is an obligate intracellular bacterium that causes respiratory infection. There may exist an association between C. pneumoniae, asthma, and production of immunoglobulin (Ig) E responses in vitro. Interleukin (IL-4) is required for IgE production.

OBJECTIVE

We previously demonstrated that doxycycline suppresses C. pneumoniae-induced production of IgE and IL-4 responses in peripheral blood mononuclear cells (PBMC) from asthmatic subjects. Whereas macrolides have anti-chlamydial activity, their effect on in vitro anti-inflammatory (IgE) and IL-4 responses to C. pneumoniae have not been studied.

METHODS

PBMC from IgE- adult atopic subjects (N = 5) were infected +/- C. pneumoniae BAL69, +/- azithromycin (0.1, 1.0 ug/mL) for 10 days. IL-4 and IgE levels were determined in supernatants by ELISA. IL-4 and IgE were detected in supernatants of PBMC (day 10).

RESULTS

When azithromycin (0.1, 1.0 ug/ml) was added, IL-4 levels decreased. At low dose, IgE levels increased and at high dose, IgE levels decreased. When PBMC were infected with C. pneumoniae, both IL-4 and IgE levels decreased. Addition of azithromycin (0.1, 1.0 ug/mL) decreased IL-4 levels and had no effect on IgE levels.

CONCLUSIONS

These findings indicate that azithromycin decreases IL-4 responses but has a bimodal effect on IgE responses in PBMC from atopic patients in vitro.

Diagnosis and Treatment of Adults with Community-acquired Pneumonia. An Official Clinical Practice Guideline of the American Thoracic Society and Infectious Diseases Society of America

Background: This document provides evidence-based clinical practice guidelines on the management of adult patients with community-acquired pneumonia.

Methods: A multidisciplinary panel conducted pragmatic systematic reviews of the relevant research and applied Grading of Recommendations, Assessment, Development, and Evaluation methodology for clinical recommendations.

Results: The panel addressed 16 specific areas for recommendations spanning questions of diagnostic testing, determination of site of care, selection of initial empiric antibiotic therapy, and subsequent management decisions. Although some recommendations remain unchanged from the 2007 guideline, the availability of results from new therapeutic trials and epidemiological investigations led to revised recommendations for empiric treatment strategies and additional management decisions.

Conclusions: The panel formulated and provided the rationale for recommendations on selected diagnostic and treatment strategies for adult patients with community-acquired pneumonia.

A prolonged antibiotic protocol to treat persistent Chlamydophila pneumoniae infection improves the extracranial venous circulation in multiple sclerosis

Objective Chronic cerebrospinal venous insufficiency (CCSVI) is a condition associated with multiple sclerosis (MS). One mechanism that has been proposed is that the venous obstructions found in MS are due to a chronic persistent venulitis caused by the intra-cellular bacterial parasite, Chlamydophila pneumoniae (Cpn). The objective of the current study is to determine the effect of a combined antibiotic protocol (CAP) on the venous flow in MS patients as measured by a quantitative duplex ultrasound examination (QDUS). Method A non-randomised before-after cohort study was conducted to investigate differences in blood flow volumes pre and 6-months post antibiotic treatment for Cpn infection. Flow volume data were measured by QDUS across affected and unaffected sides from multiple veins segments, including internal jugular vein (IJV) segments J2 and J3, and vertebral vein (VV), as well as global arterial blood flow (GABF). Results 91 patients were included in the study. 64 (70%) were found to have positive Cpn serology. There was a statistically significant post-treatment difference seen for the affected side of Cpn infected patients (mean difference = 56 mL/min, p = 0.02). There was a non-significant increase seen for the affected side of uninfected patients (mean difference = 23 mL/min, p = 0.2). The difference in these effects (34 mL/min) was not statistically significant ( p = 0.3). The mean flow rate decreased in the unaffected side for both infected (-27 mL/min, p = 0.5) and uninfected patients (-69 mL/min, p = 0.01). There was a statistically significant post-treatment increase in GABF for the infected patients (mean difference = 90 mL/min, p = 0.02) and a difference of 76 mL/min for non-infected patients ( p = 0.01). Conclusion A CAP appears to improve the extra-cranial circulation in patients diagnosed with MS. This effect is statistically significant in patients with positive Cpn serology, although patients with negative Cpn serology also show some benefit, betraying a lack of specificity of this effect.

Infection-mediated asthma: etiology, mechanisms and treatment options, with focus on Chlamydia pneumoniae and macrolides

Asthma is a chronic respiratory disease characterized by reversible airway obstruction and airway hyperresponsiveness to non-specific bronchoconstriction agonists as the primary underlying pathophysiology. The worldwide incidence of asthma has increased dramatically in the last 40 years. According to World Health Organization (WHO) estimates, over 300 million children and adults worldwide currently suffer from this incurable disease and 255,000 die from the disease each year. It is now well accepted that asthma is a heterogeneous syndrome and many clinical subtypes have been described. Viral infections such as respiratory syncytial virus (RSV) and human rhinovirus (hRV) have been implicated in asthma exacerbation in children because of their ability to cause severe airway inflammation and wheezing. Infections with atypical bacteria also appear to play a role in the induction and exacerbation of asthma in both children and adults. Recent studies confirm the existence of an infectious asthma etiology mediated by Chlamydia pneumoniae (CP) and possibly by other viral, bacterial and fungal microbes. It is also likely that early-life infections with microbes such as CP could lead to alterations in the lung microbiome that significantly affect asthma risk and treatment outcomes. These infectious microbes may exacerbate the symptoms of established chronic asthma and may even contribute to the initial development of the clinical onset of the disease. It is now becoming more widely accepted that patterns of airway inflammation differ based on the trigger responsible for asthma initiation and exacerbation. Therefore, a better understanding of asthma subtypes is now being explored more aggressively, not only to decipher pathophysiologic mechanisms but also to select treatment and guide prognoses. This review will explore infection-mediated asthma with special emphasis on the protean manifestations of CP lung infection, clinical characteristics of infection-mediated asthma, mechanisms involved and antibiotic treatment outcomes.

Amphipathic β2,2-Amino Acid Derivatives Suppress Infectivity and Disrupt the Intracellular Replication Cycle of Chlamydia pneumoniae

We demonstrate in the current work that small cationic antimicrobial β2,2-amino acid derivatives (Mw < 500 Da) are highly potent against Chlamydia pneumoniae at clinical relevant concentrations (< 5 μM, i.e. < 3.4 μg/mL). C. pneumoniae is an atypical respiratory pathogen associated with frequent treatment failures and persistent infections. This gram-negative bacterium has a biphasic life cycle as infectious elementary bodies and proliferating reticulate bodies, and efficient treatment is challenging because of its long and obligate intracellular replication cycle within specialized inclusion vacuoles. Chlamydicidal effect of the β2,2-amino acid derivatives in infected human epithelial cells was confirmed by transmission electron microscopy. Images of infected host cells treated with our lead derivative A2 revealed affected chlamydial inclusion vacuoles 24 hours post infection. Only remnants of elementary and reticulate bodies were detected at later time points. Neither the EM studies nor resazurin-based cell viability assays showed toxic effects on uninfected host cells or cell organelles after A2 treatment. Besides the effects on early intracellular inclusion vacuoles, the ability of these β2,2-amino acid derivatives to suppress Chlamydia pneumoniae infectivity upon treatment of elementary bodies suggested also a direct interaction with bacterial membranes. Synthetic β2,2-amino acid derivatives that target C. pneumoniae represent promising lead molecules for development of antimicrobial agents against this hard-to-treat intracellular pathogen.

Fever-triggered Brugada syndrome in an adult patient presenting with hemophagocytic syndrome induced by Chlamydophila pneumoniae

A previously healthy 29-year-old man was admitted to our hospital, with a 4-day history of fever (>39°C), rigours, diaphoresis, fatigue and retro-orbital headache. On examination, he was febrile (37.8°C) and tachycardic (110 bpm). Laboratory work up revealed bicytopenia (white cell count 1.37×10(9)/L, platelets 60×10(9)/L) and an increase in C reactive protein (9 mg/dL). The ECG showed ST segment elevation in V1, V2 and V3 leads. The patient was admitted and investigation was initiated revealing prolonged fever (>7 days), pancytopenia, hepatosplenomegaly, hyperferritinemia, hypertriglyceridemia, hypofibrinogenemia, elevated soluble CD25 and hemophagocytosis in bone marrow. Therefore, the patient presented 7 of the 8 diagnostic criteria of hemophagocytic syndrome. Laboratorial investigation for infectious causes was negative, except for IgA and IgG Chlamydophila pneumoniae. ECG re-evaluation on the day of discharge showed no ST segment elevation and no other abnormalities. Genetic testing for known mutations associated with hemophagocytic syndrome and Brugada syndrome did not show any mutations in these genes.

Dual infection of Mycoplasma pneumoniae and Chlamydophila pneumoniae in patients with atopic predispositions successfully treated by moxifloxacin

We report two cases of dual infection with Mycoplasma pneumoniae and Chlamydophila pneumoniae complicated by atopic dermatitis or allergic rhinitis. After exacerbations of atopic eczema or rhinitis, both patients presented a nocturnal fever with persistent cough for more than two weeks. Although the use of susceptible antibiotics, such as minocycline or azithromycin, failed to work, moxifloxacin completely resolved their prolonged symptoms shortly after the administration together with a dramatic improvement of the atopic symptoms. Since the patients in question were predisposed to atopic disorders and their lymphocytes were hypersensitive, an immunological response was thought to be easily triggered by the organisms. Additionally, due to the lymphocyte-stimulatory nature of M. pneumoniae and C. pneumoniae, enhanced immunity was likely to be involved in the pathogenesis. The immunomodulatory property of moxifloxacin was thought to repress the increased lymphocyte activity, and thus facilitated complete remission of the disease.

AcuteChlamydia pneumoniaeandMycoplasma pneumoniaeInfections in Community-Acquired Pneumonia and Exacerbations of COPD or Asthma: Therapeutic Considerations

Rates of acute Chlamydia pneumoniae and Mycoplasma pneumoniae infections were determined in 115 adults hospitalized for community-acquired pneumonia (CAP), purulent exacerbations of COPD and acute exacerbations of bronchial asthma, by means of serology and molecular methods. Results were compared with those obtained in a matched control group. Common respiratory pathogens were isolated by cultures in 22.5% and 22.2% of CAP and exacerbated COPD patients, respectively. Cultures from exacerbated asthma patients were always negative. Serological and molecular evidence of current C. pneumoniae infection was obtained in 10.0%, 8.9% and 3.3% of CAP, COPD and asthma cases. The corresponding rates of acute M. pneumoniae infection were 17.5%, 6.7% and 3.3%, respectively. Finally, no difference was found between typical and atypical pathogen rates. These findings highlight the importance of taking into account C. pneumoniae and M. pneumoniae infections in guiding the choice of empirical antibacterial treatment for CAP and purulent exacerbations of COPD.

Guideline for the management of acute sore throat

The European Society for Clinical Microbiology and Infectious Diseases established the Sore Throat Guideline Group to write an updated guideline to diagnose and treat patients with acute sore throat. In diagnosis, Centor clinical scoring system or rapid antigen test can be helpful in targeting antibiotic use. The Centor scoring system can help to identify those patients who have higher likelihood of group A streptococcal infection. In patients with high likelihood of streptococcal infections (e.g. 3-4 Centor criteria) physicians can consider the use of rapid antigen test (RAT). If RAT is performed, throat culture is not necessary after a negative RAT for the diagnosis of group A streptococci. To treat sore throat, either ibuprofen or paracetamol are recommended for relief of acute sore throat symptoms. Zinc gluconate is not recommended to be used in sore throat. There is inconsistent evidence of herbal treatments and acupuncture as treatments for sore throat. Antibiotics should not be used in patients with less severe presentation of sore throat, e.g. 0-2 Centor criteria to relieve symptoms. Modest benefits of antibiotics, which have been observed in patients with 3-4 Centor criteria, have to be weighed against side effects, the effect of antibiotics on microbiota, increased antibacterial resistance, medicalisation and costs. The prevention of suppurative complications is not a specific indication for antibiotic therapy in sore throat. If antibiotics are indicated, penicillin V, twice or three times daily for 10 days is recommended. At the present, there is no evidence enough that indicates shorter treatment length.

[Meta-analysis of randomized trials of antimicrobial drugs in the treatment of coronary heart disease]

The meta-analysis of 12 clinical research of application of antibiotics (azithromycin, roxithromycin clarithromycin, gatifloxacin) in 24 949 patients with coronary heart disease were carried out. The obtained results were shown that application of short courses of antibiotic therapy in patients with severe morphological changes in small coronary vessels were not enough effective. Contrariwise, long-term courses of antibiotic therapy could be effective in patients with initial lesions of blood vessels and presence of chronic infections.

Chlamydia pneumoniae-specific IgE is prevalent in asthma and is associated with disease severity

Background

Several Chlamydia pneumoniae (Cp) biomarkers have been associated with asthma but Cp-specific IgE (Cp IgE) has not been investigated extensively. Our objective was to investigate Cp IgE in community adult asthma patients.

Methods

(1) Prevalence of Cp IgE (measured by immunoblotting) and Cp DNA (by polymerase chain reaction) in peripheral blood, and biomarker associations with asthma severity. (2) Case-control studies of Cp IgE association with asthma using healthy blood donor (study 1) and non-asthmatic clinic patient (study 2) controls.

Results

Of 66 asthma subjects (mean age 40.9 years, range 5–75, 59% male, 45% ever-smokers) 33 (50%) were Cp IgE positive and 16 (24%) were Cp DNA positive (P = 0.001 for association of Cp IgE and DNA). Cp IgE was detected in 21% of mild intermittent asthma v 79% of severe persistent asthma (test for trend over severity categories, P = 0.002). Cp IgE detection was significantly (P = 0.001) associated with asthma when compared to healthy blood donor controls but not when compared to clinic controls.

Conclusions

Half of this sample of community asthma patients had detectable IgE against C. pneumoniae. Cp IgE was strongly and positively associated with asthma severity and with asthma when healthy blood donor controls were used. These results support the inclusion of Cp IgE as a biomarker in future studies of infectious contributions to asthma pathogenesis.

Corn mint (Mentha arvensis) extract diminishes acute Chlamydia pneumoniae infection in vitro and in vivo

Corn mint ( Mentha arvensis ) provides a good source of natural phenols such as flavone glycosides and caffeic acid derivatives, which may have prophylactic properties against inflammations. This study investigated whether corn mint extract would be beneficial against a universal respiratory tract pathogen, Chlamydia pneumoniae , infection. The extract inhibited the growth of C. pneumoniae CWL-029 in vitro in a dose-dependent manner. The inhibition was confirmed against a clinical isolate K7. The phenolic composition of the extract was analyzed by UPLC-ESI/Q-TOF/MS, the main components being linarin and rosmarinic acid. These compounds were active in vitro against C. pneumoniae. Linarin completely inhibited the growth at 100 μM. Inbred C57BL/6J mice were inoculated with C. pneumoniae K7. M. arvensis extract was given intraperitoneally once daily for 3 days prior to inoculation and continued for 10 days postinfection. The extract was able to diminish the inflammatory parameters related to C. pneumoniae infection and significantly (p = 0.019) lowered the number of C. pneumoniae genome equivalents detected by PCR at biologically relevant amounts.

Severe A(H1N1)-associated Pneumonia Sequential to Clamidophila pneumoniae Infection in Healthy Subject

BACKGROUND

Pandemic influenza virus has been implicated in serious lower airways illness and death in subjects both with and without underlying medical conditions. Predictive factors for severe disease in healthy individuals have not been identified.

CASE REPORT

Severe A(H1N1)-associated pneumonia occurring in a healthy subject without underlying medical conditions sequential to a Clamidophila pneumoniae infection, is reported.

CONCLUSION

A potential synergistic mechanism by which other pathogens could interfere with the clinical course of A(H1N1) infection, is suggested.

C-reactive protein for discriminating treatment failure from slow responding pneumonia

BACKGROUND

The management of patients with community-acquired pneumonia (CAP) who fail to improve constitutes a challenge for clinicians. This study investigated the usefulness of C-reactive protein (CRP) changes in discriminating true treatment failure from slow response to treatment.

METHODS

This prospective multicenter observational study investigated the behavior of plasma CRP levels on days 1 and 4 in hospitalized patients with CAP. We identified non-responding patients as those who had not reached clinical stability by day 4. Among them, true treatment failure and slow response situations were defined when initial therapy had to be changed or not after day 4 by attending clinicians, respectively.

RESULTS

By day 4, 78 (27.4%) out of 285 patients had not reached clinical stability. Among them, 56 (71.8%) patients were cured without changes in initial therapy (mortality 0.0%), and in 22 (28.2%) patients, the initial empirical therapy needed to be changed (mortality 40.9%). By day 4, CRP levels fell in 52 (92.9%) slow responding and only in 7 (31.8%) late treatment failure patients (p<0.001). A model developed including CRP behavior and respiratory rate at day 4 identified treatment failure patients with an area under the Receiver Operating Characteristic curve of 0.87 (CI 95%, 0.78-0.96).

CONCLUSION

Changes in CRP levels are useful to discriminate between true treatment failure and slow response to treatment and can help clinicians in management decisions when CAP patients fail to improve.

Divergent modulation of Chlamydia pneumoniae infection cycle in human monocytic and endothelial cells by iron, tryptophan availability and interferon gamma

Chlamydia pneumoniae is an obligatory intracellular bacterium causing chronic inflammatory diseases in humans. We studied the role of the nutritive factors, iron and tryptophan, towards the course of infection and immune response pathways in C. pneumoniae infected endothelial cells and monocytes. Human endothelial (EA.hy923) and monocytic cells (THP-1) were infected with C. pneumoniae, supplemented with iron or 1-methyltryptophan (1-MT), an inhibitor of the tryptophan degrading enzyme indoleamine 2,3-dioxygenase (IDO), and subsequently stimulated with IFN-gamma or left untreated. The number of infected cells, the morphology and quantity of C. pneumoniae inclusion bodies, IDO activity and innate immune effector pathways were analysed. While neither iron challenge, IDO inhibition or IFN-gamma treatment had a significant effect on C. pneumoniae morphology or numbers within THP-1 monocytic cells, iron supplementation to EA.hy926 cells resulted in promotion of C. pneumoniae proliferation and differentiation while IFN-gamma had an inhibitory effect. Furthermore, the number of infected endothelial cells was significantly decreased upon 1-MT treatment. C. pneumoniae infection induced a pro-inflammatory immune response as evidenced by increased IDO activity, neopterin formation or TNF-alpha production in THP-1 but not in endothelial cells. These pathways were superinduced upon IFN-gamma treatment and partly modulated by iron supplementation. Our results demonstrate that the infectious cycle of C. pneumoniae behaves differently between monocytic and endothelial cells. While the intracellular pathogen remains in a persistent form within monocytes, it can differentiate and proliferate within endothelial cells indicating that endothelial cells are a preferred environment for Chlamydia. Nutritive factors such as iron have subtle effects on C. pneumoniae biology in endothelial, but not monocytic cells. Our results contribute to a better understanding of C. pneumoniae infection and its role in chronic inflammatory diseases such as atherosclerosis.

Intermittent azithromycin treatment for respiratory symptoms in patients with chronic chlamydia pneumoniae infection

Chlamydia pneumoniae (Cpn) is a common respiratory pathogen with a biphasic replicative cycle and has a tendency to cause chronic infections. Azithromycin is commonly used for the treatment of Cpn infections, but little is known about the optimal dose and duration of therapy. In this prospective double-blind, randomized study the effects of azithromycin and placebo were compared regarding longstanding airway and/or pharyngeal symptoms in patients with chronic Cpn infection. Further, effects on antibody titres and lung function were assessed. 103 patients were treated with either azithromycin 500 mg daily for 5 d, repeated 3 times with a 23-d interval, or placebo. Patients were examined 4 months and 1 y after completed treatment. Evaluation of symptoms showed general improvement and less hawking in patients treated with azithromycin compared to placebo after 4 months, but there was no sustained difference 1 y after completed treatment. The antibody titres remained stable, and there was no influence on lung function. Adverse events, primarily gastrointestinal, were more frequently reported with azithromycin than placebo. In conclusion, azithromycin was effective for reduction of respiratory symptoms in patients with chronic Cpn infection, but prolonged intermittent treatment with high doses did not eradicate the chronic infection.

[Chlamydia pneumoniae in the etiology of the keratoconjunctivitis sicca in adult patients (a pilot study)]

AIM

In the pilot study the authors refer to the possible connection between the appearance of keratoconjunctivitis sicca (KCS) and Chlamydia pneumoniae (CP) infection.

MATERIALS AND METHODS

At the Department of Ophthalmology, 10 adult patients older than 45 years were followed up during the period of 5.5-7 years, where in the chronic folicular conjunctivitis caused by CP, the KCS was revealed as the same time.

METHODS

The chlamydial infection diagnosis was established due to the positivity to the familiar (anti-LPS) and species (anti-CP) immunoglobulins (IgG, IgM, and IgA) and to the conjunctival impression specimen, using the indirect immunofluorescence of specific monoclonal antibodies. The patients were treated by means of systemically administered macrolide antibiotics Azithromycine. After the termination of the treatment, the signs of the clinical inflammation of the conjunctival inflammation subsided but the KCS problems remained. After 6 years, the control examinations of the familiar and species antibodies of the CP were performed and the clinical findings of the KCS and its treatment were evaluated.

RESULTS

The decrease of the antibody levels was proved and objective findings and subjective symptoms of KCS in all patients subsided. Altogether 7 patients were without clinical signs of the KCS and without regular application of local artificial tears treatment. At the same time, in two thirds of the patients, the levels of the antibodies decreased or remained unchanged. In the last three patients, the signs of the dry eye decreased, but they didn't disappeared permanently. These patients had to apply artificial tears several times a day. The suspect signs of this serologically active infection persisted despite the antibodies levels' decrease.

CONCLUSION

This pilot study until now didn't confirm the direct dependence between the KCS and CP, but it didn't exclude it as well.

Chlamydia pneumoniae and atherosclerosis: current state and future prospectives

Chlamydia pneumoniae, an intracellular bacterial pathogen, is known as a leading cause of human respiratory tract infections worldwide. Over the last decade, several reports in the literature have suggested that infection with C. pneumoniae may contribute to the pathogenesis of atherosclerosis. In order to play a causative role in chronic disease, C. pneumoniae would need to persist within infected tissue for extended periods of time, thereby stimulating a chronic inflammatory response. C. pneumoniae has been shown to disseminate systemically from the lungs through infected peripheral blood mononuclear cells and to localize in arteries where it may infect endothelial cells, vascular smooth muscle cells, monocytes/macrophages and promote inflammatory atherogenous process. The involvement of C. pneumoniae in atherosclerosis was investigated by seroepidemiological and pathological studies, in vivo and in vitro studies, and in clinical antibiotic treatment trials. This review will provide an update on the role of C. pneumoniae in atherosclerosis focusing on the recent insights and suggesting areas for future research.

Chlamydophila pneumoniae myopericarditis in a child

An 11-year-old boy with serologically confirmed Chlamydophila pneumoniae infection presented with clinical, laboratory, and echocardiographic changes consistent with myopericarditis. No reports on C. pneumoniae myopericarditis in children are found in the medical literature. The boy, previously healthy, presented with fever, rash, constitutional symptoms, elevated acute phase reactants, elevated cardiac enzymes, and high brain natriuretic peptide levels. Hemodynamic instabilities, including hypotension and mild hypoxia, were noted. Two-dimensional echocardiographic findings showed mildly depressed left ventricular systolic function and small pericardial effusion. Requiring inotropic support, the boy was treated with azithromycin 10 mg/kg once daily for 7 days and a single dose of intravenous immunoglobulin 2 g/kg. He recovered fully with improved left ventricular systolic function before hospital discharge. An early definitive diagnosis is essential to knowing the etiology of pediatric myocarditis. Specific therapy may play role in the management and prognosis of this disorder.

[Intervention of Huanglian Jiedu decoction on haemorheology and cholesterol-supplemented diet]

OBJECTIVE

To study the influence of Chlamydia pneumonia (Cpn) infection on haemorheology and atherosclerosis and the intervention of Huanglian Jiedu decoction (HJT).

METHOD

At the beginning of the experiment, all the sixty New-Zealand rabbits were token blood to test Cpn IgG and all the results were negative. Eight New-Zealand rabbits were randomized into normal group F, and all other rabbits were fed with forage containing 2.5 g x kg(-1) cholesterol and infected with Cpn via nasophrynx for three times during 6 weeks. At the end of the sixth week, forty-four rabbits with serum Cpn IgG positive were randomized into four groups: Group A treat with HJD 2 g x kg(-1) d(-1) by gastric gavage, group B with HJT 1 g x kg(-1) x d(-1), group C with azithromycin 20 mg x kg(-1) x d(-1), model group D with normal saline for six weeks. Group E was set up in eight rabbits with serum Cpn IgG negative and served as the control. At the end of 18th week, blood was token from middle ear artery to test haemorheology such as whole blood viscosity, plasma viscosity, haematocrit, erythrocyte aggregation index (EAI), erythrocyte rigidity index (IRI), and erythrocyte deformability index (EDI). After that, all the rabbits were executed and the pathological features of aorta tissue were observe under microscope.

RESULT

Haemorheological disorder and atherosclerotic changes were obvious in both group D and E. while maximum intimal thickness (MIT) (23.65 +/- 8.19 vs 12.76 +/- 4.06), atherosclerotic damage percentage (P(LCI)) (41.08 +/- 12.51 vs 22.43 +/- 9.45), plaque area index (I(PA)) (9.57 +/- 1.82 vs 2.84 +/- 0.25) in group D was much higher than that in group E (all P < 0.01). Compare with group D, haemorphological disorder and atherosclerotic changes were much improved in group A, B and C. MIT (6.45 +/- 1.27 vs 23.65 +/- 8.19), (P < 0.01), P(LCI) (22.39 +/- 6.74 vs 41.08 +/- 12.51), (P < 0.05) and I(PA) (1.44 +/- 0.33 vs 9.57 +/- 1.82), (P < 0.01) in group A was much lower than that in group D. And MIT (12.65 +/- 3.63 vs 23.65 +/- 8.19), (P < 0.01) and I(PA) (4.43 +/- 1.17 vs 9.57 +/- 1.82), (P < 0.05) in gruoup B was much lower than that in group D too.

CONCLUSION

Cpn infection could aggravate the haemorheology disorder in cholesterol-supplemented-diet rabbits, and both antidotal decoction of Coptis and azithromycin can alleviate it.

Infection and atherosclerosis. An alternative view on an outdated hypothesis

Already at the beginning of the 20th century, a potential role for microbes in vascular diseases was suggested. However, until the late '70 of that century, not much attention has been paid to this infection hypothesis. Then, predominantly based on the pioneering work of Fabricant et al., evidence for a contributing or even initiating role for microbes in atherosclerosis, as well as other vascular diseases, was accumulating. Also, the seminal paper by Saikku and co-workers, demonstrating serological evidence of an association of Chlamydia pneumoniae, an obligate intracellular respiratory gram-negative bacterium, with chronic coronary heart disease and acute myocardial infarction, significantly boosted the research on the infection hypothesis. Since then, numerous papers have been published demonstrating associations between a large variety of pathogens and atherosclerotic disease. Furthermore, many molecular mechanisms have been suggested by which microbes may affect atherogenesis. Nevertheless, in recent large randomised prospective trials, evaluating the efficacy of antibiotic treatment for the secondary prevention of coronary events, no reduction in the rate of cardiovascular events was observed, thereby seriously challenging the validity of the infection hypothesis. Nevertheless, the large body of supporting evidence, which has accumulate over the past decades, should not be ignored and maybe we should look at the hypothesis, and in particular the mechanisms by which microbes affect the disease, from a different angle.

Acute exacerbation of idiopathic pulmonary fibrosis: role of Chlamydophila pneumoniae infection

BACKGROUND AND OBJECTIVES

Patients with idiopathic pulmonary fibrosis (IPF) may experience acute exacerbations of their illness. The actual trigger(s) of such exacerbations is unknown. Chlamydophila pneumoniae infection can cause exacerbation of asthma and COPD. A prospective study was conducted to investigate the possible role of C. pneumoniae infection in triggering acute exacerbations of IPF.

METHODS

A prospective observational study over 5 years of consecutive IPF patients who fulfilled the criteria for acute exacerbation. Sputum, blood cultures and acute and convalescent serology for C. pneumoniae IgG and IgA (ELISA) were performed.

RESULTS

Previous infection with C. pneumoniae is common. Of the 27 study patients, 15 had a C. pneumoniae IgG index of 1.10-2.99 (positive) and 3 had a C. pneumoniae IgG index of >2.99 (strongly positive) at the time of presentation with an acute exacerbation. In addition, 15 subjects had a C. pneumoniae IgA index of 1.10-2.99 (positive) and 6 subjects had a C. pneumoniae IgA index of >2.99 (strongly positive). However, only two of the 15 subjects (13%) for whom paired sera were tested exhibited a significant rise in antibody response (change in index of 1.90 for C. pneumoniae IgG and 1.54 for IgA, respectively) indicating either acute or reactivated infection with C. pneumoniae. There were 15 deaths (56%) despite supportive care that included high-dose corticosteroid therapy and oxygen supplementation.

CONCLUSIONS

Mortality is high with acute exacerbation of IPF. Acute infection with C. pneumoniae is uncommon at the time of presentation with acute exacerbation of IPF.

Chlamydia pneumoniae-based atherosclerosis: a smoking gun

Chronic and acute infectious diseases have been implicated in modifying the risk of atherosclerosis independently or in collaboration with conventional risk factors. During the past two decades, the discussion on microbial agents and atherosclerosis has mainly been centred on Chlamydia pneumoniae. The strongest evidence linking Chlamydia pneumoniae and atherosclerotic disease comes from in vitro experimental studies. In this review, we summarize and critically evaluate the available data of human diagnostic and therapeutic studies on the association of Chlamydia pneumoniae with atherosclerosis. Taking into account the human in vivo data, there is currently insufficient proof linking Chlamydia pneumoniae to atherosclerosis. At present, there are no indications for antibiotic treatment targeted at Chlamydia pneumoniae in the management of atherosclerosis.

[Chlamydial infections]

Chlamydiae are a singular group of bacteria, with a vital cycle that is intracellular in part. These microorganisms adhere to epithelia, where they may provoke infection. There are three pathogenic species for humans: Chlamydia trachomatis, which produce infections mainly in the genital and urinary tracts, and C. psittaci and C. pneumoniae, which mostly produce respiratory infections. The last two microorganisms are now classified in a different genus, known as Chlamydophila.

[Coinfection with Mycoplasma pneumoniae and Chlamydophila pneumoniae in a middle-aged adult]

A 47-year-old man who suffered from fever and dry cough visited a local clinic. His symptoms temporarily improved with oral administration of ciprofloxacin, however, he was admitted to our hospital because of exacerbation. IgM antibody for Mycoplasma pneumoniae was positive and IgM antibody titer for Chlamydophila pneumoniae showed a high value of 7.12 index. Thus, coinfection was diagnosed. The findings of chest X-ray and computed tomography were compatible with atypical pneumonia. Clarithromycin improved his condition, and 10 weeks later, antibody values for Mycoplasma pneumoniae by the particle agglutination test decreased from 10,240 times to 640 times and those by the complement-fixation test also decreased from 1024 times to 256 times. The IgM antibody for Chlamydophila pnetumoniae decreased to 0.13. This is the first case developing coinfection with Mycoplasma pneumoniae and Chlamydophila pneumoniae in a middle-aged patient to date.

Azithromycin for the secondary prevention of coronary artery disease: a meta-analysis

PURPOSE

A meta-analysis of randomized, controlled trials that evaluated the effect of the macrolide antibiotic, azithromycin, on clinical outcomes in patients with coronary artery disease (CAD) was conducted.

METHODS

A systematic literature search of MEDLINE, EMBASE, Web of Science, and the Cochrane Database of Systematic Reviews was conducted using specific search terms. Randomized, controlled trials comparing azithromycin or placebo in secondary CAD patients with adequately reported data on mortality and clinical cardiac endpoints were included. A random-effects model was used.

RESULTS

Six studies (n=13,778) met the inclusion criteria. The trials varied in their design. On meta-analysis, azithromycin resulted in a nonsignificant reduction in mortality versus placebo (odds ratio [OR], 0.91; 95% confidence interval [CI], 0.77-1.09; p=0.31). Four trials reported the rate of nonfatal myocardial infarction (MI). Azithromycin did not have an effect on the rate of nonfatal MI versus placebo (OR, 0.95; 95% CI, 0.80-1.13; p=0.57). Five trials reported rates of hospitalization in which no significant difference was seen with azithromycin versus placebo (OR, 0.97; 95% CI, 0.80-1.17; p=0.76). Six trials were used to evaluate the composite cardiovascular endpoint. Again, no significant benefit was seen with azithromycin versus placebo (OR, 0.93; 95% CI, 0.84-1.03; p=0.218).

CONCLUSION

Meta-analysis showed that azithromycin does not appear to reduce the frequency of recurrent cardiac events in patients with CAD. Results from ongoing trials may clarify the role of azithromycin in the secondary prevention of coronary events.

Can long-term antibiotic treatment prevent progression of peripheral arterial occlusive disease? A large, randomized, double-blinded, placebo-controlled trial

PURPOSE

The purpose was to investigate in a large, randomized, double-blinded, placebo-controlled trial, whether antibiotic treatment can prevent progression of peripheral arterial disease (PAD).

MATERIAL AND METHODS

Five hundred and seven patients were included; all patients had an established diagnosis of PAD. Their mean age was 66 years (36-85), and 59% were males. Patients were randomized to Roxithromycin 300 mg daily for 28 days. Baseline investigations were ankle blood pressure, ankle-brachial blood pressure index (ABPI), walking distance, C. pneumoniae serology, cholesterol and medical history. Follow-up was performed every 6 months. Primary events were defined as death, peripheral revascularization and major lower limb amputation. Secondary events were thrombosis, stroke, transient cerebral ischaemic attack and myocardial infarction. Change in ABPI was also investigated. Data were analyzed mainly by Cox regression and linear regression.

RESULTS

Included patients with PAD were randomized. Two patients withdrew. Of the remaining, 248 received roxithromycin and 257 placebo. In the treatment group 55% were seropositive and 53% in the placebo group. Mean follow-up was 2.1 years (range 0.06-5.1 years). In the placebo group, 26 died and 80 primary events occurred in total. In the treatment group, 28 died and 74 primary events were observed. The hazard ratio of death was 1.13 (95% CI: 0.68; 1.90), and of primary events 0.92 (95% CI: 0.67; 1.26). Also on secondary events and ABPI changes, no significant differences were found.

CONCLUSION

Long-term treatment with roxithromycin is ineffective in preventing death, amputation, peripheral revascularization, myocardial infarction, stroke, transient cerebral ischaemic attack, thrombosis and decline in ABPI in patients with an established diagnosis of PAD.

Pharmacokinetics of enrofloxacin and its efficacy in comparison with doxycycline in the treatment of Chlamydophila felis infection in cats with conjunctivitis

The concentrations of enrofloxacin were measured in the tears, saliva and serum of 14 cats with signs of upper respiratory tract infection and eight with no signs, after daily doses of 5 mg/kg. Enrofloxacin concentrations above the minimum inhibitory concentration of Chlamydophila felis were found in the saliva and tears of the cats with and without signs of upper respiratory tract infection. In a prospective randomised clinical trial, the efficacy of enrofloxacin against C. felis infection in cats with conjunctivitis was compared with the efficacy of doxycycline. Twenty-five cats were randomly assigned to treatment with either enrofloxacin or doxycycline for 14 days; 15 of the cats tested positive for C. felis by an immunofluorescent antibody test on conjunctival swabs. The two treatment groups showed equal improvements in the clinical signs of conjunctivitis and C. felis infection status; in each group three cats were still C. felis antigen-positive after the 14-day course of treatment, indicating a persistent infection. No side effects were observed in the cats treated with enrofloxacin.

Effect of PEX, a noncatalytic metalloproteinase fragment with integrin-binding activity, on experimental Chlamydophila pneumoniae infection

Chlamydophila pneumoniae is a pathogen that is involved in acute and chronic respiratory infections and that is associated with asthma and coronary artery diseases. In this study, we evaluated the effects of PEX, a noncatalytic metalloproteinase fragment with integrin-binding activity, against experimental infections caused by C. pneumoniae. Moreover, we investigated the relationships between C. pneumoniae and alpha(v)beta(3) integrin functions in order to explain the possible mechanism of action of PEX both in vitro and in vivo. For the in vitro experiments, HeLa cells were infected with C. pneumoniae and treated with either PEX or azithromycin. The results obtained with PEX were not significantly different (P > 0.05) from those achieved with azithromycin. Similar results were also obtained in a lung infection model. Male C57BL/J6 mice inoculated intranasally with 10(6) inclusion-forming units of C. pneumoniae were treated with either PEX or azithromycin plus rifampin. Infected mice treated with PEX showed a marked decrease in C. pneumoniae counts versus those for the controls; this finding did not differ significantly (P > 0.05) from the results observed for the antibiotic-treated group. Integrin alpha(v)beta(3) plays an important role in C. pneumoniae infection. Blockage of integrin activation led to a significant inhibition of C. pneumoniae infection in HeLa cells. Moreover, CHO(DHFR) alpha(v)beta(3)-expressing cells were significantly (P < 0.001) more susceptible to C. pneumoniae infection than CHO(DHFR) cells. These results offer new perspectives on the treatment of C. pneumoniae infection and indicate that alpha(v)beta(3) could be a promising target for new agents developed for activity against this pathogen.

Érythème polymorphe majeur et infection à Chlamydia pneumoniae

BACKGROUND

Erythema multiforme majus of infectious origin is an acute eruptive syndrome seen more commonly in young subjects and characterised by an appearance of round target lesions. In most cases, it is associated with infection involving Herpes simplex virus or Mycoplasma pneumoniae. We report an original case of erythema multiforme majus subsequent to infection with Chlamydia pneumoniae.

CASE REPORT

An 18 year-old man was hospitalised for management of generalised skin rash comprising lesions in rings, associated with bullous and post-bullous lesions, chiefly in the oral (preventing eating) and genital areas in a setting of febrile cough. Various bacterial agents (Mycoplasma pneumoniae, Chlamydia pneumoniae) and viral agents were suspected, but serological testing for Chlamydia pneumoniae alone was positive with IgM of 128 IU and IgG of 64 IU. The outcome was favourable within several days following administration of symptomatic treatment (rehydration, mouthwashes, etc.) and aetiological treatment (acyclovir: 30 mg/kg/d, ofloxacine: 400 mg/d). At D15, serologic tests for Mycoplasma pneumoniae continued to be negative. Anti-Chlamydia pneumoniae IgM and IgG were 256 IU. At D30, IgM was 128 IU while IgG remained at 256 IU.

DISCUSSION

The existence of a systematic skin rash comprising typical target lesions and mucosal lesions in the oral and genital areas suggested to us a diagnosis of erythema multiforme majus. Screening for the agents generally responsible was negative and drug-induced rash was ruled out. Serological tests for Chlamydia pneumoniae were positive at various times, resulting in diagnosis of erythema multiforme majus secondary to infection with Chlamydia pneumoniae. Following demonstration of the presence of Chlamydia pneumoniae using reliable methods and the elimination of other causes of erythema multiforme majus, dermatologists should opt for this aetiology in order to optimise treatment.

Recurrent optic neuritis associated with Chlamydia pneumoniae infection of the central nervous system

It has been suggested that Chlamydia pneumoniae (C. pneumoniae) is involved in the pathogenesis of diverse diseases of the central nervous system (CNS), including multiple sclerosis. We report the case of a 12-year-old male with isolated recurrent optic neuritis and an associated CNS infection with C. pneumoniae. The patient presented with three attacks of optic neuritis within 5 months. A positive polymerase chain reaction for C. pneumoniae in the cerebrospinal fluid led to the diagnosis of a CNS infection with C. pneumoniae. After treatment with the antibiotic rifampicin, he experienced no further attacks during the follow-up period of 6 years. These findings suggest the possibility of a C. pneumoniae infection as a contributing factor or even causative event for the development of optic neuritis.

Acute Tonsillopharyngitis Associated with Atypical Bacterial Infection in Children: Natural History and Impact of Macrolide Therapy

This study evaluated the natural history of acute tonsillopharyngitis associated with atypical bacterial infections, showing that Mycoplasma pneumoniae and Chlamydia pneumoniae organisms are frequently found in children with acute tonsillopharyngitis. The study also demonstrated, for what we believe to be the first time, that, unless adequately treated, acute tonsillopharyngitis associated with infection with M. pneumoniae and C. pneumoniae may have a negative outcome with a high risk of recurrence of respiratory illness.

Initial empiric antimicrobial treatment of Chlamydia pneumoniae: a study of 54 cases in the Republic of Macedonia

Analysis of the adequacy of the initial empiric antimicrobial treatment of patients with acute Chlamydia pneumoniae (CP) infection, admitted to the Infectious Diseases Clinic, Clinical Centre, Medical Faculty, Skopje, Republic of Macedonia, for community-acquired pneumonia.

MATERIAL AND METHODS

A total number of 407 patients with community-acquired pneumonia (CAP) hospitalized at the Clinic between September 1997 and June 2002, with an average age of x=46.44 years, of whom 53.56% were male. Acute Chlamydia pneumoniae infection was proven serologically with MIF assay in 54 (13.27%) patients.

RESULTS

Initial empiric treatment with antibiotics in patients with CP pneumonia was provided with antimicrobial agents with intracellular activity in 26 (48.15%) patients; with fluoroquinolones in 19 (35.19%); macrolides in 5 (9.26%) and tetracyclines in 2 (3.7%). The treatment was conducted as monotherapy in 6 patients (11.11%) and in 20 patients (37.04%) in combination with betalactams. For 28 (51.85%) patients who were treated only with betalactams, empiric treatment was re-evaluated and new therapy with fluoroquinolon was conducted in 16 (29.63%), with macrolides in 8 (14.81%) and with tetracyclines in 4 (7.41%) patients.

CONCLUSION

Adequate empiric treatment with antimicrobial agents with intracellular activity was performed in only 48.15% of the patients with acute CP infection. Therefore, when designing the initial empiric treatment of patients hospitalized with pneumonia, attention should be paid to this atypical pathogen of CAP.

Antibiotic use and risk of multiple sclerosis

Some reports suggest that bacteria, including Chlamydophila pneumoniae, could be involved in the etiology of multiple sclerosis. If that is true, persons who used antibiotics active against these bacteria, compared with nonusers, might be at lower risk of multiple sclerosis. Using a 1993-2000 case-control study nested in the United Kingdom-based General Practice Research Database cohort, the authors identified 163 multiple sclerosis cases who were followed up for at least 3 years before their first symptoms (the index date). Up to 10 controls matched to the cases by age, sex, general practice, and time in the cohort were selected. Exposure to antibiotics was assessed through computerized medical records. Overall antibiotic use or use of antibiotics against C. pneumoniae was not associated with multiple sclerosis risk. However, use of penicillins in the 3 years before the index date decreased the risk of developing a first attack of multiple sclerosis (odds ratio=0.5, 95% confidence interval: 0.3, 0.9 for those who used penicillins for >or=15 days compared with no use). In conclusion, use of antibiotics active against C. pneumoniae was not associated with a decreased risk of short-term multiple sclerosis. The observed lower risk of multiple sclerosis for penicillin users needs to be confirmed in other populations.

The atypical pneumonias: clinical diagnosis and importance

The most common atypical pneumonias are caused by three zoonotic pathogens, Chlamydia psittaci (psittacosis), Francisella tularensis (tularemia), and Coxiella burnetii (Q fever), and three nonzoonotic pathogens, Chlamydia pneumoniae, Mycoplasma pneumoniae, and Legionella. These atypical agents, unlike the typical pathogens, often cause extrapulmonary manifestations. Atypical CAPs are systemic infectious diseases with a pulmonary component and may be differentiated clinically from typical CAPs by the pattern of extrapulmonary organ involvement which is characteristic for each atypical CAP. Zoonotic pneumonias may be eliminated from diagnostic consideration with a negative contact history. The commonest clinical problem is to differentiate legionnaire's disease from typical CAP as well as from C. pneumoniae or M. pneumonia infection. Legionella is the most important atypical pathogen in terms of severity. It may be clinically differentiated from typical CAP and other atypical pathogens by the use of a weighted point system of syndromic diagnosis based on the characteristic pattern of extrapulmonary features. Because legionnaire's disease often presents as severe CAP, a presumptive diagnosis of Legionella should prompt specific testing and empirical anti-Legionella therapy such as the Winthrop-University Hospital Infectious Disease Division's weighted point score system. Most atypical pathogens are difficult or dangerous to isolate and a definitive laboratory diagnosis is usually based on indirect, i.e., direct flourescent antibody (DFA), indirect flourescent antibody (IFA). Atypical CAP is virtually always monomicrobial; increased IFA IgG tests indicate past exposure and not concurrent infection. Anti-Legionella antibiotics include macrolides, doxycycline, rifampin, quinolones, and telithromycin. The drugs with the highest level of anti-Legionella activity are quinolones and telithromycin. Therapy is usually continued for 2 weeks if potent anti-Legionella drugs are used. In adults, M. pneumoniae and C. pneumoniae may exacerbate or cause asthma. The importance of the atypical pneumonias is not related to their frequency (approximately 15% of CAPs), but to difficulties in their diagnosis, and their nonresponsiveness to beta-lactam therapy. Because of the potential role of C. pneumoniae in coronary artery disease and multiple sclerosis (MS), and the role of M. pneumoniae and C. pneumoniae in causing or exacerbating asthma, atypical CAPs also have public health importance.

Chlamydia pneumoniae infection as a trigger for a Cogan's syndrome

Cogan's syndrome is often preceded by upper respiratory tract symptoms. The only reported specific agent possibly involved in pathogenesis of the Cogan's syndrome was Chlamydia pneumoniae. Positive IgA, IgM and IgG antibodies against C. pneumoniae in our patient suggest possibility of Chlamydia's role as a trigger for the vasculitis.

Usefulness of sparfloxacin against Chlamydia pneumoniae infection in patients with bronchial asthma

The efficacy of sparfloxacin (SPFX) for the control of bronchial asthma was evaluated in 26 patients with suspected Chlamydia pneumoniae infection. Patients were randomly allocated to receive SPFX 200 mg/day (n = 14) or control treatment (n = 12) for 21 days. Significant improvements in serum C-reactive protein levels, and significant decreases in peripheral eosinophil counts, serum eosinophil cationic protein (ECP) and sputum ECP were observed in the SPFX-treated group at day 21. SPFX-treated patients also had a significantly reduced frequency of asthma symptoms, reduced inhalant beta2-stimulant use, and significant increases in morning peak expiratory flow. At the end of the study, C. pneumoniae was undetectable in two SPFX-treated patients who underwent polymerase chain reaction testing, but one control patient who was tested still had detectable levels of C. pneumoniae. These results suggest that SPFX could be used to control bronchial asthma in patients with suspected persistent C. pneumoniae infection.

Randomised placebo controlled multicentre trial to assess short term clarithromycin for patients with stable coronary heart disease: CLARICOR trial

OBJECTIVE

To determine if the macrolide clarithromycin affects mortality and cardiovascular morbidity in patients with stable coronary heart disease.

DESIGN

Centrally randomised multicentre trial. All parties at all stages were blinded. Analyses were by intention to treat.

SETTING

Five Copenhagen University cardiology departments and a coordinating centre.

PARTICIPANTS

13,702 patients aged 18 to 85 years who had a discharge diagnosis of myocardial infarction or angina pectoris in 1993-9 and alive in August 1999 were invited by letter; 4373 were randomised.

INTERVENTIONS

Two weeks' treatment with clarithromycin 500 mg/day or matching placebo.

PRIMARY OUTCOME

composite of all cause mortality, myocardial infarction, or unstable angina pectoris during three years' follow-up. Secondary outcome: composite of cardiovascular mortality, myocardial infarction, or unstable angina pectoris. The outcomes were obtained from Danish registers and were blindly assessed by the event committee.

RESULTS

2172 participants were randomised to clarithromycin and 2201 to placebo. We found no significant effects of clarithromycin on the primary outcome (hazard ratio 1.15, 95% confidence interval 0.99 to 1.34) or secondary outcome (1.17, 0.98 to 1.40). Mortality was significantly higher in the clarithromycin arm (1.27, 1.03 to 1.54; P = 0.03) as a result of significantly higher cardiovascular mortality (1.45, 1.09 to 1.92; P = 0.01).

CONCLUSIONS

Short term clarithromycin in patients with stable coronary heart disease may cause significantly higher cardiovascular mortality. The long term safety of clarithromycin in patients with stable ischaemic heart disease should be examined. Trial registration ClinicalTrials.gov NCT00121550.

Antibiotic therapy for coronary heart disease: the myth and the reality

Atherosclerosis is acknowledged as an active inflammatory and thrombotic disease, as opposed to simple degeneration. Infection with microorganisms may contribute to this inflammation and hence the atherosclerotic process. The "infective" hypothesis - first proposed more than a century ago by Virchow - has been revisited in recent years and has implicated numerous microorganisms as potential stimuli. The greatest body of evidence points to Chlamydia pneumoniae, a respiratory pathogen, as the "culprit" microorganism. Consistent finding of bacterial antigens, DNA and occasionally live "viable" organisms within human atherosclerotic plaque support the evidence for the concept linking C. pneumoniae to atherosclerosis. Although original seroepidemiological studies indicated an association, more recent prospective and larger studies suggest that there may be only a weak link between elevated antibodies and immune complexes to C. pneumoniae and coronary heart disease (CHD). Animal models have shown how atherogenesis can be induced by endovascular infection with C. pneumoniae; in vitro studies have explored various immunological and inflammatory pathways linking infection and atherothrombosis. On the basis of this, antibiotic trials have been explored to assess whether there is any role for antichlamydial agents in the treatment of cardiovascular events. Here, we focus on the main antibiotic studies and explores patient criteria and choice, duration of therapy, and whether effects on clinical events could be reduced.

Prospective surveillance for atypical pathogens in children with community-acquired pneumonia in Japan

A total of 141 children with community-acquired pneumonia (CAP) were studied prospectively to determine the causative microorganisms. Microbial investigations included examination of postnasal swabs, cultures, polymerase chain reaction (PCR), and serology. The atypical pathogens occurring most frequently were Mycoplasma pneumoniae (58 patients [41.1%]), Chlamydia pneumoniae (4 patients [2.8%]), and concurrent occurrence of both pathogens (1 patient [0.7%]). Patients aged under 4 years showed a relatively lower rate of atypical bacterial etiology compared with those aged 4 years or older. Major bacterial pathogens were detected in 89 patients (atypical pathogens were detected in 28 patients simultaneously), including Streptococcus pneumoniae in 34 patients, Haemophilus influenzae in 60, Moraxella catarrhalis in 48, and multiple pathogens in 42. In patients suspected of having atypical pneumonia, macrolides are recommended.

Disseminated invasive aspergillosis in a patient with acute leukaemia

A 46-year-old previously healthy woman was diagnosed with acute lymphoblastic leukaemia. The induction phase was complicated by alpha-haemolytic streptococcal bacteremia which responded to antibacterial therapy. Subsequently, the patient developed pneumonie due to Chlamydiapneumoniae which responded to macrolides. Following this infection the patient developed recurrent fever and new pulmonary infiltrates were noted. Bronchoscopy was performed and treatment was administered with liposomal amphotericin B (L-AmB, AmBisome) for two days, but was complicated by acute renal failure. Aspergillus fumigatus was cultured from bronchoalveolar lavage fluid [corrected] L-AmB was discontinued and voriconazole and caspofungin were administered. Despite aggressive antifungal therapy the patient developed progressive invasive infection, with central nervous system involvement as well as lesions appearing in the kidneys and liver. The patient died one week following the diagnosis of aspergillosis.

Antibiotics active against Chlamydia do not reduce the risk of myocardial infarction

OBJECTIVE

There is evidence that Chlamydia pneumoniae (CP) is involved in the aetiology of myocardial infarction (MI). Randomised trials do not support a beneficial effect of antibiotics in secondary prevention of MI, but the evidence for an effect on primary prevention is conflicting. We investigated if past use of antibiotics active against CP is associated with a decreased risk of developing MI.

METHODS

We conducted a population-based case-control study of 4166 patients hospitalised due to MI from 1 January 1994 to 1 September 1999 in the County of Funen, Denmark. Controls (n=16,664) were a random sample of inhabitants, matched for age and sex. Confounders controlled for in the analysis were gender, age, obstructive pulmonary disease, diabetes, previous MI and known atherosclerotic antecedents. Previous use of antibiotics active against CP (macrolides, tetracyclines and quinolones) and of antibiotics not active against CP (penicillins) was analysed among the cases and controls.

RESULTS

The risk of MI was not associated with previous exposure to macrolides (OR: 1.0; CI: 0.9-1.1), tetracyclines (OR: 1.0; CI: 0.9-1.2) or quinolones (OR: 1.0; CI: 0.9-1.2) or combinations of the three drugs (OR: 1.0; CI: 0.9-1.1). There was no sign of a protective effect in subgroups defined by high cumulative doses of antibiotics, various time-windows of exposure, risk factors of MI or other co-morbidity. OR was 1.1 (0.9-1.3) in persons with no atherosclerotic antecedents.

CONCLUSION

The study does not support the hypothesis of a decreased risk of MI in patients exposed to antibiotics active against CP.

Chlamydophila pneumoniae and Mycoplasma pneumoniae: a role in asthma pathogenesis?

The potential role of atypical bacterial infection in the pathogenesis of asthma is a subject of continuing debate. There is an increasing body of literature concerning the association between the atypical bacteria Chlamydophila pneumoniae and Mycoplasma pneumoniae and asthma pathogenesis; however, many studies investigating such a link have been uncontrolled and have provided conflicting evidence, in part due to the difficulty in accurately diagnosing infection with these atypical pathogens. This article reviews the evidence for an association between atypical bacterial respiratory pathogens and the pathogenesis of asthma, and discusses the biological mechanisms that could account for such a link. The possible role of antibacterial therapy in the management of asthma and the need for well-designed studies to investigate this is also discussed.