Co-detection of Bordetella pertussis and other respiratory organisms in children hospitalised with lower respiratory tract infection

Multiple potential pathogens are frequently co-detected among children with lower respiratory tract infection (LRTI). Evidence indicates that Bordetella pertussis has an important role in the aetiology of LRTI. We aimed to study the association between B. pertussis and other respiratory pathogens in children hospitalised with severe LRTI, and to assess clinical relevance of co-detection. Nasopharyngeal (NP) swabs and induced sputa (IS) were tested with a B. pertussis specific PCR; additionally, IS was tested for other pathogens using a multiplex PCR. We included 454 children, median age 8 months (IQR 4-18), 31 (7%) of whom tested positive for B. pertussis. Children with B. pertussis had more bacterial pathogens detected (3 versus 2; P < 0.001). While B. pertussis showed no association with most pathogens, it was independently associated with Chlamydia pneumoniae, Mycoplasma pneumoniae and parainfluenza viruses with adjusted risk ratios of 4.01 (1.03-15.64), 4.17 (1.42-12.27) and 2.13 (1.03-4.55), respectively. There was a consistent increased risk of severe disease with B. pertussis. Patterns indicated even higher risks when B. pertussis was co-detected with any of the three organisms although not statistically significant. Improving vaccine coverage against B. pertussis would impact not only the incidence of pertussis but also that of severe LRTI generally.

Diagnostic utility of serology and polymerase chain reaction for detection of Mycoplasma pneumoniae and Chlamydophila pneumoniae in paediatric community-acquired lower respiratory tract infections

Purpose

Mycoplasma pneumoniae (M. pneumoniae) and Chlamydophila pneumoniae (C. pneumoniae) play a significant role in children of all ages with lower respiratory tract infections (LRTIs). This study was conducted to detect M. pneumoniae and C. pneumoniae in children with community-acquired LRTIs employing serology, polymerase chain reaction (PCR) and nested PCR analysis.

Material and Methods

This study included 75 children with acute LRTIs for detection of M. pneumoniae and C. pneumoniae. Blood was obtained for M. pneumoniae and C. pneumoniae antibodies and nasopharyngeal aspirates for M. pneumoniae PCR and C. pneumoniae nested PCR.

Results

M. pneumoniae infection was positive in 9 (64.21%) children aged 2-6 months and in 5 (35.79%) aged 7 months-12 years, and this difference was statistically significant (P = 0.002). C. pneumoniae infection was comparable within the age group and statistically insignificant (P = 0.43). Clinical and radiological profiles of M. pneumoniae- and C. pneumoniae-positive and negative patients were numerically comparable. Serology and PCR together detected M. pneumoniae infection in 14 (18.6%) children. The sensitivity, specificity and positive and negative predictive values of serology were 77.78%, 92.42%, 58.33% and 96.83%, respectively. C. pneumoniae infection was positive in 11 (14.6%) children by serology and nested PCR with 50% sensitivity, 87.67% specificity, 10% positive predictive value and 98.46% negative predictive value.

Conclusions

Our study confirms that M. pneumoniae and C. pneumoniae play a significant role in community-acquired LRTIs and a combination of serology and nested PCR is useful for its diagnosis.

Atypical pathogens in hospitalized patients with community-acquired pneumonia: a worldwide perspective

BACKGROUND

Empirical antibiotic coverage for atypical pathogens in community-acquired pneumonia (CAP) has long been debated, mainly because of a lack of epidemiological data. We aimed to assess both testing for atypical pathogens and their prevalence in hospitalized patients with CAP worldwide, especially in relation with disease severity.

METHODS

A secondary analysis of the GLIMP database, an international, multicentre, point-prevalence study of adult patients admitted for CAP in 222 hospitals across 6 continents in 2015, was performed. The study evaluated frequency of testing for atypical pathogens, including L. pneumophila, M. pneumoniae, C. pneumoniae, and their prevalence. Risk factors for testing and prevalence for atypical pathogens were assessed through univariate analysis.

RESULTS

Among 3702 CAP patients 1250 (33.8%) underwent at least one test for atypical pathogens. Testing varies greatly among countries and its frequency was higher in Europe than elsewhere (46.0% vs. 12.7%, respectively, p < 0.0001). Detection of L. pneumophila urinary antigen was the most common test performed worldwide (32.0%). Patients with severe CAP were less likely to be tested for both atypical pathogens considered together (30.5% vs. 35.0%, p = 0.009) and specifically for legionellosis (28.3% vs. 33.5%, p = 0.003) than the rest of the population. Similarly, L. pneumophila testing was lower in ICU patients. At least one atypical pathogen was isolated in 62 patients (4.7%), including M. pneumoniae (26/251 patients, 10.3%), L. pneumophila (30/1186 patients, 2.5%), and C. pneumoniae (8/228 patients, 3.5%). Patients with CAP due to atypical pathogens were significantly younger, showed less cardiovascular, renal, and metabolic comorbidities in comparison to adult patients hospitalized due to non-atypical pathogen CAP.

CONCLUSIONS

Testing for atypical pathogens in patients admitted for CAP in poorly standardized in real life and does not mirror atypical prevalence in different settings. Further evidence on the impact of atypical pathogens, expecially in the low-income countries, is needed to guidelines implementation.

The Genetic Transformation of Chlamydia pneumoniae

We demonstrate the genetic transformation of Chlamydia pneumoniae using a plasmid shuttle vector system which generates stable transformants. The equine C. pneumoniae N16 isolate harbors the 7.5-kb plasmid pCpnE1. We constructed the plasmid vector pRSGFPCAT-Cpn containing a pCpnE1 backbone, plus the red-shifted green fluorescent protein (RSGFP), as well as the chloramphenicol acetyltransferase (CAT) gene used for the selection of plasmid shuttle vector-bearing C. pneumoniae transformants. Using the pRSGFPCAT-Cpn plasmid construct, expression of RSGFP in koala isolate C. pneumoniae LPCoLN was demonstrated. Furthermore, we discovered that the human cardiovascular isolate C. pneumoniae CV-6 and the human community-acquired pneumonia-associated C. pneumoniae IOL-207 could also be transformed with pRSGFPCAT-Cpn. In previous studies, it was shown that Chlamydia spp. cannot be transformed when the plasmid shuttle vector is constructed from a different plasmid backbone to the homologous species. Accordingly, we confirmed that pRSGFPCAT-Cpn could not cross the species barrier in plasmid-bearing and plasmid-free C. trachomatis, C. muridarum, C. caviae, C. pecorum, and C. abortus However, contrary to our expectation, pRSGFPCAT-Cpn did transform C. felis Furthermore, pRSGFPCAT-Cpn did not recombine with the wild-type plasmid of C. felis Taken together, we provide for the first time an easy-to-handle transformation protocol for C. pneumoniae that results in stable transformants. In addition, the vector can cross the species barrier to C. felis, indicating the potential of horizontal pathogenic gene transfer via a plasmid.IMPORTANCE The absence of tools for the genetic manipulation of C. pneumoniae has hampered research into all aspects of its biology. In this study, we established a novel reproducible method for C. pneumoniae transformation based on a plasmid shuttle vector system. We constructed a C. pneumoniae plasmid backbone shuttle vector, pRSGFPCAT-Cpn. The construct expresses the red-shifted green fluorescent protein (RSGFP) fused to chloramphenicol acetyltransferase in C. pneumoniaeC. pneumoniae transformants stably retained pRSGFPCAT-Cpn and expressed RSGFP in epithelial cells, even in the absence of chloramphenicol. The successful transformation in C. pneumoniae using pRSGFPCAT-Cpn will advance the field of chlamydial genetics and is a promising new approach to investigate gene functions in C. pneumoniae biology. In addition, we demonstrated that pRSGFPCAT-Cpn overcame the plasmid species barrier without the need for recombination with an endogenous plasmid, indicating the potential probability of horizontal chlamydial pathogenic gene transfer by plasmids between chlamydial species.

Use of serology and polymerase chain reaction to detect atypical respiratory pathogens during acute exacerbation of chronic obstructive pulmonary disease

BACKGROUND/AIMS

To use serological and multiplex polymerase chain reaction (PCR) assays to examine sputum samples from patients experiencing acute exacerbation of chronic obstructive pulmonary disease (AECOPD) for the presence of atypical pathogens, including Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella pneumophila.

METHODS

From September 2012 to February 2014, 341 patients with AECOPD attending outpatient clinics were enrolled as part of a randomized, double-blind, multicenter study. A commercial enzyme-linked immunosorbent assay was used to measure serum immunoglobulin M (IgM) and IgG antibody titers on the first day of the study and at 36 days post-enrollment. Multiplex PCR was used to test sputum samples for the presence of atypical pathogens. A urinary antigen test for L. pneumophila was performed on the first day.

RESULTS

Nineteen patients (5.6%) showed serological evidence of acute infection with M. pneumoniae. Also, one and seven patients (2%) showed serological evidence of acute infection with C. pneumoniae and L. pneumophila, respectively. All DNA samples were negative for M. pneumoniae, C. pneumoniae, and L. pneumophila according to PCR. Only one urine sample was positive for L. pneumophila antigen, but serologic evidence was lacking.

CONCLUSION

Serological testing suggested that infection by atypical pathogens during AECOPD was relatively uncommon. In addition, PCR provided no direct evidence of infection by atypical pathogens. Thus, atypical pathogens may not be a major cause of AECOPD in South Korea.

Relationship between peripheral arterial occlusive disease (PAOD) and chronic Chlamydophila (Chlamydia) pneumoniae infection

We carried out a meta-analysis of observational case-control studies published before May 2004 to assess the degree of association between Chlamydophila pneumoniae (Cp) infection and PAOD. A search of the Medline database was performed using atherosclerosis and "Chlamyd* pneumoniae" as keywords. Strict criteria were applied for the selection of case studies, which had to be studies of Cp seroprevalence or of Cp detection in patients versus controls. Forty-three published studies that met these criteria were selected. An association between PAOD and Cp was revealed by immunohistochemical analysis (OR=15.4, 95%CI=5.0–46.9) and nested PCR studies of arterial biopsies (OR=4.3, 95%CI=1.8–10), by PCR study of non-arterial samples (OR=2.9, 95%CI=1.2–7.0), by other direct-detection tests (OR=16.7, 95%CI=7.0–39.8), and by ELISA and MIF tests to detect high IgG (OR=2, 95%CI=1.1–3.5 and OR=1.7, 95%CI=1.0–2.9, respectively) and IgA (OR=1.9, 95%CI=1.1–3.4 and OR=1.5, 95%CI=1.1–2.0, respectively) titers. No significant association was found in simple PCR studies of arterial biopsies, MIF tests to detect low IgG titers or IgM, or ELISA studies to detect IgM. According to this review, the association between Cp infection and PAOD depends on the analytical method adopted. Establishing a relationship between Cp and PAOD will require a case-control study with an adequate number of cases and samples that uses a combination of direct and indirect techniques to identify the presence of the bacterium in different types of sample from the same subjects, correlating the results with the activity of the disease.

Frequency of detection of Chlamydophila pneumoniae using bronchoalveolar lavage fluid in patients with community-onset pneumonia

BACKGROUND

Chlamydophila pneumoniae is a causative pathogen of lower respiratory tract infection, which generally infects healthy, young people. However, it is often difficult to evaluate acute C. pneumoniae infection using upper respiratory tract specimens and/or sputum samples due to its persistent infection or colonization. The interpretation of frequency of detection of C. pneumoniae seems to be insufficient in community-onset pneumonia. The aim of this study was to evaluate the presence of C. pneumoniae using bronchoalveolar lavage fluid (BALF) samples.

METHODS

BALF samples from 147 patients with pneumonia were retrospectively evaluated using C. pneumoniae-specific polymerase chain reaction (PCR) primers.

RESULTS

None of the samples had positive PCR results for C. pneumoniae using two different sets of specific primers. Single and paired serological analyses were performed in 54 (36.7%) and 37 (25.2%) patients, respectively. These analyses revealed that 1 of 37 (2.7%) patients had a presumptive acute infection with C. pneumoniae, 8 of the 54 (14.8%) patients were suspected of having a C. pneumoniae infection, and 7 of the 37 (18.9%) patients were suspected of having past C. pneumoniae infection. In addition, cultivation and/or 16S rRNA gene sequencing detected Haemophilus influenzae in the presumptive case using the serological method.

CONCLUSIONS

The results of the present study revealed that C. pneumoniae might be a minor causative agent of community-onset pneumonia according to an evaluation of specimens obtained from the lower respiratory tract.

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.

High Prevalence of Mycoplasma pneumoniae and Chlamydia pneumoniae in Children with Acute Respiratory Infections from Lima, Peru

BACKGROUND

Mycoplasma pneumoniae and Chlamydia pneumoniae are atypical pathogens responsible for pneumonia and a leading cause of morbidity and mortality in low income countries. The study objective is to determine the prevalence of this pathogens in Peruvian children with acute respiratory infections.

METHODS

A consecutive cross-sectional study was conducted in Lima, Peru from May 2009 to September 2010. A total of 675 children admitted with clinical diagnoses of acute respiratory infections were tested for Mycoplasma pneumoniae and Chlamydia pneumoniae detection by polymerase chain reaction (PCR), and clinical symptoms were registered by the attending physician.

RESULTS

Mycoplasma pneumonia was detected in 25.19% (170/675) of nasopharyngeal samples and Chlamydia pneumonia in 10.52% (71/675). The most common symptoms in patients with these atypical pathogens were rhinorrhea, cough and fever. A higher prevalence of Mycoplasma pneumoniae cases were registered in summer, between December 2009 and March 2010.

CONCLUSIONS

Mycoplasma pneumoniae and Chlamydia pneumonia are a significant cause of morbidity in Peruvian children with acute respiratory infections (ARI). Further studies should evaluate the use of reliable techniques such as PCR in Peru in order to avoid underdiagnoses of these atypical pathogens.

Prevalence of Atypical Pathogens in Patients With Cough and Community-Acquired Pneumonia: A Meta-Analysis

PURPOSE

Community-acquired pneumonia (CAP), acute cough, bronchitis, and lower respiratory tract infections (LRTI) are often caused by infections with viruses or Streptococcus pneumoniae. The prevalence of atypical pathogens Mycoplasma pneumoniae, Chlamydophila pneumoniae, Legionella pneumophila, and Bordetella pertussis among patients with these illnesses in the ambulatory setting has not been previously summarized. We set out to derive prevalence information from the existing literature.

METHODS

We performed a systematic review of MEDLINE for prospective, consecutive-series studies reporting the prevalence of M pneumoniae, C pneumoniae, L pneumophila and/or B pertussis in outpatients with cough, acute bronchitis, LRTI, or CAP. Articles were independently reviewed by 2 authors for inclusion and abstraction of data; discrepancies were resolved by consensus discussion. A meta-analysis was performed on each pathogen to calculate the pooled prevalence estimates using a random effects model of raw proportions.

RESULTS

Fifty studies met our inclusion criteria. While calculated heterogeneity was high, most studies reported prevalence for each pathogen within a fairly narrow range. In patients with CAP, the overall prevalences of M pneumoniae and C pneumoniae were 10.1% (95% CI, 7.1%-13.1%) and 3.5% (95% CI, 2.2%-4.9%), respectively. Consistent with previous reports, M pneumoniae prevalence peaked in roughly 6-year intervals. Overall prevalence of L pneumophila was 2.7% (95% CI, 2.0%-3.4%), but the organism was rare in children, with only 1 case in 1,765. In patients with prolonged cough in primary care, the prevalence of B pertussis was 12.4% (95% CI, 4.9%-19.8%), although it was higher in studies that included only children (17.6%; 95% CI, 3.4%-31.8%).

CONCLUSIONS

Atypical bacterial pathogens are relatively common causes of lower respiratory diseases, including cough, bronchitis, and CAP. Where surveillance data were available, we found higher prevalences in studies where all patients are tested for these pathogens. It is likely that these conditions are underreported, underdiagnosed, and undertreated in current clinical practice.

[Distribution characteristics of Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella pneumophila in hospitalized children with acute respiratory tract infection: an analysis of 13 198 cases]

OBJECTIVE

To investigate the distribution characteristics of Mycoplasma pneumoniae (MP), Chlamydia pneumoniae (CP), and Legionella pneumophila (LP) in hospitalized children with acute respiratory tract infection (ARTI).

METHODS

A total of 13 198 hospitalized children with ARTI were enrolled as study subjects. Whole blood and urine were collected. The passive agglutination was used to detect serum MP-IgM, ELISA was used to detect serum CP-IgM, and immunochromatography was performed to detect urinary LP antigen.

RESULTS

Among the 13 198 hospitalized ARTI children, the detection rates of MP, CP, and LP were 25.31%, 12.74% and 3.27%, suggesting that MP had the highest detection rate (P<0.0125). The detection rates of MP in 2013 and 2014 were significantly higher than that in 2012 (P<0.0125). CP had the highest detection rate in 2013, and LP had the highest detection rate in 2014 (P<0.0125). These three pathogens were detected all around the year, and MP had the highest detection rate in all seasons (P<0.0125). The detection rate of mixed infection with three pathogens was 4.35%, and mixed infection with MP and CP was the most common (P<0.0071). Among the children in different age groups, the patients aged 5-16 years showed the highest overall detection rate of three pathogens (P<0.0071). Among the children with different types of ARTI, the children with bronchopneumonia showed the highest overall detection rate of three pathogens (P<0.0045).

CONCLUSIONS

MP, CP, and LP, particularly MP, are important pathogens for children with ARTI in the local area. LP infection tends to increase year by year and should be taken seriously in clinical practice.

[Distribution characteristics of Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella pneumophila in hospitalized children with acute respiratory tract infection: an analysis of 13 198 cases]

OBJECTIVE

To investigate the distribution characteristics of Mycoplasma pneumoniae (MP), Chlamydia pneumoniae (CP), and Legionella pneumophila (LP) in hospitalized children with acute respiratory tract infection (ARTI).

METHODS

A total of 13 198 hospitalized children with ARTI were enrolled as study subjects. Whole blood and urine were collected. The passive agglutination was used to detect serum MP-IgM, ELISA was used to detect serum CP-IgM, and immunochromatography was performed to detect urinary LP antigen.

RESULTS

Among the 13 198 hospitalized ARTI children, the detection rates of MP, CP, and LP were 25.31%, 12.74% and 3.27%, suggesting that MP had the highest detection rate (P<0.0125). The detection rates of MP in 2013 and 2014 were significantly higher than that in 2012 (P<0.0125). CP had the highest detection rate in 2013, and LP had the highest detection rate in 2014 (P<0.0125). These three pathogens were detected all around the year, and MP had the highest detection rate in all seasons (P<0.0125). The detection rate of mixed infection with three pathogens was 4.35%, and mixed infection with MP and CP was the most common (P<0.0071). Among the children in different age groups, the patients aged 5-16 years showed the highest overall detection rate of three pathogens (P<0.0071). Among the children with different types of ARTI, the children with bronchopneumonia showed the highest overall detection rate of three pathogens (P<0.0045).

CONCLUSIONS

MP, CP, and LP, particularly MP, are important pathogens for children with ARTI in the local area. LP infection tends to increase year by year and should be taken seriously in clinical practice.

Is Chlamydia Pneumoniae a Risk Factor for Peripheral Atherosclerosis?

Seroepidemiological studies have shown a relationship between Chlamydia pneumoniae and coronary atherosclerosis. It is not clear whether Chlamydia pneumoniae is also a risk factor for peripheral atherosclerosis. Chlamydia pneumoniae antibodies were measured by a microimmunofluorescence method in 75 patients who underwent surgery for peripheral atherosclerosis, and the seroprevalence was compared with that in the normal population. Chlamydia pneumoniae immunoglobulin-G seroprevalence was 80% in the study group vs. 40% in controls. More foam cells were noted on light microscopy in atherosclerotic plaques from the infected patients. The 60 infected patients were divided into: group A ( n = 35) given both anti-chlamydial and antiplatelet agents for 1 year; and group B ( n = 25) given antiplatelet therapy only. The groups were compared on the basis of clinical findings, ankle-brachial index, and antibody titers. Decreasing Chlamydia pneumoniae immunoglobulin-G seroprevalence in group A correlated significantly with increasing ankle-brachial index and improvement in clinical findings. It was concluded that Chlamydia pneumoniae may be a risk factor for peripheral atherosclerosis.

The prevalence of Chlamydia pneumoniae in the aortic wall and in peripheral blood of patients scheduled for coronary artery bypass grafting

Some reports confirm a potential role of Chlamydia pneumoniae (ChP) in atherogenesis. In order to explore possible association between ChP and atherosclerosis, investigations were carried out in which the frequency of ChP in the arterial wall and peripheral blood was assessed in a group of patients with chronic coronary artery disease (CAD). Fifty-seven patients were enrolled in the study, 13 women and 44 men aged 61.8±6.5 (47-74), with previously diagnosed CAD, scheduled for planned coronary artery bypass grafting due to clinical indications. Vessel specimens retrieved from the ascending aorta (as a part of routine proximal venous graft development procedure) and peripheral blood mononuclear cells (PBMCs) from venous blood were evaluated for the presence of ChP DNA. Genomic DNA was extracted from PBMCs and vessel specimens. Quantitative real-time polymerase chain reaction (qPCR) was performed to detect ChP DNA. A statistically more frequent occurrence of ChP was observed in aortic tissues compared to blood samples (70.2% vs 56.1%, respectively). Similarly, the number of ChP DNA genomic copies [n/1μg genomic DNA] was significantly higher in tissue specimens compared to blood samples (89±91 vs 41±77, respectively; p=0.0046). In patients without ChP in blood specimens, we observed significantly higher amounts of ChP in tissue specimens compared to patients with ChP in blood specimens (156±71 vs 107±88, respectively; p=0.0453). No correlation was found between the number of ChP DNA copies [n/1μg genomic DNA] in blood and in aortic specimens. The infection of ChP in the aortic wall was connected with hypercholesterolemia (p=0.029) and diabetes (p=0.03). We conclude that Chlamydia pneumoniae is a pathogen frequently occurring in the aortic wall of patients with CAD. The occurrence of ChP DNA in the aortic tissue is related to classic CAD risk factors such as diabetes and dyslipidemia.

[THE DIAGNOSTIC VALUE OF MODERN METHODS OF MICROBIOLOGICAL VERIFICATION OF COMMUNITY-ACQUIRED PNEUMONIA IN CLINICAL PRACTICE]

The study was carried out to determine etiological structure and informativeness of different methods of detection of agents of community-acquired pneumonia, the sampling included 274 examined patients aged from 16 to 80 years with community-acquired pneumonia of different degree of severity and being under hospital treatment. Besides of standard laboratory and clinical methods of examination ofpatients with community-acquired pneumonia special techniques of etiological verification were applied: molecular genetic analysis (polymerase chain reaction) of phlegm, qualitative detection of antigen Legionella pneumophila of serogroup 1 and antigen Streptococcus pneumoniae in samples of urine using quick immune chromatographic test, detection of level of serum specific immunoglobulines class M and G to Chlamidophilia pneumoniae, Mycoplasma pListeria monocytogenes in dynamics using immunoenzyme technique. The etiological structure of community-acquired pneumonia was established based of study results. The analysis of informativeness of different methods of etiological verification of diagnosis of community-acquired pneumonia demonstrated that combination ofpolymerase chain reaction and serological method is the optimal one.

Role of Atypical Pathogens and the Antibiotic Prescription Pattern in Acute Bronchitis: A Multicenter Study in Korea

The role of atypical bacteria and the effect of antibiotic treatments in acute bronchitis are still not clear. This study was conducted at 22 hospitals (17 primary care clinics and 5 university hospitals) in Korea. Outpatients (aged ≥ 18 yr) who had an acute illness with a new cough and sputum (≤ 30 days) were enrolled in 2013. Multiplex real-time polymerase chain reaction (RT-PCR) was used to detect five atypical bacteria. A total of 435 patients were diagnosed as having acute bronchitis (vs. probable pneumonia, n = 75), and 1.8% (n = 8) were positive for atypical pathogens (Bordetella pertussis, n = 3; B. parapertussis, n = 0; Mycoplasma pneumoniae, n = 1; Chlamydophila pneumoniae, n = 3; Legionella pneumophila, n = 1). Among clinical symptoms and signs, only post-tussive vomiting was more frequent in patients with atypical pathogens than those without (P = 0.024). In all, 72.2% of the enrolled patients received antibiotic treatment at their first visits, and β-lactams (29.4%) and quinolones (20.5%) were the most commonly prescribed agents. In conclusion, our study demonstrates that the incidence of atypical pathogens is low in patients with acute bronchitis, and the rate of antibiotic prescriptions is high.

Genomic factors related to tissue tropism in Chlamydia pneumoniae infection

BACKGROUND

Chlamydia pneumoniae (Cpn) are obligate intracellular bacteria that cause acute infections of the upper and lower respiratory tract and have been implicated in chronic inflammatory diseases. Although of significant clinical relevance, complete genome sequences of only four clinical Cpn strains have been obtained. All of them were isolated from the respiratory tract and shared more than 99% sequence identity. Here we investigate genetic differences on the whole-genome level that are related to Cpn tissue tropism and pathogenicity.

RESULTS

We have sequenced the genomes of 18 clinical isolates from different anatomical sites (e.g. lung, blood, coronary arteries) of diseased patients, and one animal isolate. In total 1,363 SNP loci and 184 InDels have been identified in the genomes of all clinical Cpn isolates. These are distributed throughout the whole chlamydial genome and enriched in highly variable regions. The genomes show clear evidence of recombination in at least one potential region but no phage insertions. The tyrP gene was always encoded as single copy in all vascular isolates. Phylogenetic reconstruction revealed distinct evolutionary lineages containing primarily non-respiratory Cpn isolates. In one of these, clinical isolates from coronary arteries and blood monocytes were closely grouped together. They could be distinguished from all other isolates by characteristic nsSNPs in genes involved in RB to EB transition, inclusion membrane formation, bacterial stress response and metabolism.

CONCLUSIONS

This study substantially expands the genomic data of Cpn and elucidates its evolutionary history. The translation of the observed Cpn genetic differences into biological functions and the prediction of novel pathogen-oriented diagnostic strategies have to be further explored.

Mycoplasma Pneumoniae and Chlamydophila pneumoniae in hospitalized children with bronchiolitis

Bronchiolitis is an acute lower respiratory tract infection in early childhood caused mainly by different viruses. Etiology of bronchiolitis have been studied in different environments and populations. Respiratory syncytial virus (RSV), human Metapneumovirus (hMPV), human Bocavirus (hBoV), human Rhinoviruses (hRV) have consistently been shown to predominate. Few studies however have attempted to determine whether other pathogens, particularly Mycoplasma Pneumoniae (MP) and Chlamydophila pneumoniae (CP), are associated with bronchiolitis in children under 2 years of age. The aim of this study was to determine the prevalence and clinical features of MP and CP in children under the age of 2 years presenting to the Iashvili Central Children Hospital in Tbilisi with various severities and clinical manifestations of bronchiolitis. Acute and convalescent serum samples were tested by ELISA for IgM and IgG antibodies to RSV, CP and MP.37 children under two years of age were studied. In 19 patients out of 37 (51.35%) etiological diagnosis were established and in 18 patients (48.65%) no pathogens were found. 11 patients (29.72%) had either CP or MP and 8 patients (21.62%) had RSV. Children infected with CP and MP had less severe bronchiolitis than those infected with RSV. Co-infection was not associated with disease severity. There were no statistically significant differences between groups with respect to length of hospital stay. Our study underlines the importance of atypical bacterial pathogens in acute bronchiolitis in children under 2 years and highlights the complex epidemiology and clinical features of these pathogens in this age group.

[Serological evidence of infection by three species of Chlamydia in pregnant women in Mexico]

Background: Chlamydiales are obligate intracellular pathogens causing a wide range of diseases in humans and animals.

BACKGROUND

Chlamydiales are obligate intracellular pathogens causing a wide range of diseases in humans and animals.

OBJECTIVE

To evaluate the seroprevalence of IgG antibodies to Chlamydophila psittaci, Chlamydophila pneumoniae and Chlamydia trachomatis in a group of pregnant women few hours before resolution of gestation, thus allowing for assessment of the potential effects in their pregnancy outcomes.

MATERIAL AND METHODS

A cross-sectional study was done involving 110 hospitalized women for pregnancy resolution in two secondary care hospitals, one of Mexico City and other of Cuernavaca, Mor. Obstetric outcomes were followed in every case. Serum antibody measures were performed by microimmunofluorescence. Possible associations between seropositivity and pregnancy outcomes were analyzed.

RESULTS

110 pregnant women were studied, 85 were seropositive for any of the species (77.3%), of which 39 (46%) had antibodies to the three species, 27 against two (32%) and 19 (22%) against one. No associations of serologic results with obstetric complications were observed in these pregnant women. High socioeconomic status was found as a risk factor for seropositivity against C trachomatis.

CONCLUSIONS

This study reveals high exposure to three species of Chlamydiaceae in Mexican pregnant women. Demonstrating complex interactions in two different places where all species are present. No correlation was found between seropositivity towards these Chlamydia species and pregnancy complications.

[Chlamydial infection of the central nervous system. Laboratory diagnosis and clinic and morphological features]

The paper presents data on the diagnosis, clinical and pathomorphological changes in the central nervous system (CNS) in neurochlamydiasis according to clinical, autoptic, and experimental evidence. It discusses the possible implication of Ch. trachomatis, Ch. pneumoniae, and Ch. psittaci in the development and course of different diseases with CNS involvement: atherosclerosis, vasculitis, multiple sclerosis, Alzheimer's disease, schizophrenia, autism, vegetative state, sequels of perinatal lesions in childhood and adolescence, HIV infection, etc. Considerable attention is paid to the specific features of diagnosis of Chlamydia-induced CNS lesions. Purposeful pathomorphological investigations are shown to be needed.

Comparison of Five PCR Assays for DetectingChlamydophila pneumoniaeDNA

We compared five different polymerase chain reaction (PCR) assays for the detection of Chlamydophila pneumoniae DNA using highly purified elementary bodies (EBs) and peripheral blood mononuclear cells (PBMCs) from healthy blood donors. The primers were as follows; two targeting the 16S rRNA gene, one targeting the ompA gene, one targeting the Pst-I gene, and one targeting the 53 kDa outer membrane protein gene. The 16S rRNA touchdown enzyme time release (TETR) PCR, the ompA nested PCR and the 53 kDa nested PCR were the most sensitive assays and could detect one or more EB per assay. These three PCRs also had the same reproducibility, but the minimal amount of C. pneumoniae that could be reproducibly detected (10 of 10 testing positive) was 20 EBs. In a sample of specimens from healthy blood donors, we found 5 of 77 (6.5%) PBMCs specimens to have C. pneumoniae DNA according to the nested ompA PCR. Specimens with the 16S rRNA TETR and 53 kDa nested assays were found to have C. pneumoniae DNA 7 of 77 (9.1%) and 18 of 77 (23.4%) specimens, respectively. The other two assays failed to detect even a single positive. However, the detection rate decreased with repeated testing of the same samples. Our newly designed 53 kDa nested PCR may be as useful as the other four recommended PCR assays and may be a more useful assay for the detection of C. pneumoniae DNA from PBMCs.

Chlamydia pneumoniaeRespiratory Infections in Taiwan

To understand the epidemiology of Chlamydia pneumoniae acute infections in Taiwan, we collected 116 paired and 244 single sera from patients suspected of C. pneumoniae infection and conducted microimmunofluorescence test. Eighty-three patients (83/360, 23%) met the diagnostic criteria of current C. pneumoniae infection. The C. pneumoniae infections were significantly higher in men than in women (P< or =0.0001) and were most frequent in the group of 40-49 year-olds, and the people older than 70 years old. C. pneumoniae infection often occurred in the late autumn lasting to the cold winter and in the transition period between the spring and summer.

An improved method on isolation and serial passage of Chlamydia pneumoniae from human peripheral blood mononuclear cells

BACKGROUND

Conventional method for Chlamydia pneumoniae (Cpn) isolation and propagation is technically challenging and time-consuming. Here, we developed a method to improve the isolation and passage of Cpn collected from human peripheral blood mononuclear cells (PBMCs).

METHODS

PBMCs positive with Cpn antigen (Cpn-Ag) were isolated, then centrifuged and cultured with Hep-2 cells after being broken. Cells were broken again and put into new Hep-2 cells to finish totally four passages with isolated and imported Cpn. Microimmunofluorescence method was used to detect Cpn. Inclusion forming unit (IFU) number was counted for each passage. Polymerase chain reaction (PCR) method was used to detect Cpn DNA. Efficiency of different centrifugation modes was compared.

RESULTS

Hep-2 cells of the first and second passages were strong positive with Cpn-Ag, the third passage was positive, and the fourth negative. Degeneration appeared in the fourth passage for isolated Cpn and third passage for imported strain. Centrifugation mode of 1,000 rpm for 2 h was the most efficient for Cpn propagation and passage.

CONCLUSION

This simplified method achieved efficient isolation, propagation, and passage of Cpn from PBMCs, and isolated strain was superior to imported strain on propagating ability.

Causal inference regarding infectious aetiology of chronic conditions: a systematic review

BACKGROUND

The global burden of disease has shifted from communicable diseases in children to chronic diseases in adults. This epidemiologic shift varies greatly by region, but in Europe, chronic conditions account for 86% of all deaths, 77% of the disease burden, and up to 80% of health care expenditures. A number of risk factors have been implicated in chronic diseases, such as exposure to infectious agents. A number of associations have been well established while others remain uncertain.

METHODS AND FINDINGS

We assessed the body of evidence regarding the infectious aetiology of chronic diseases in the peer-reviewed literature over the last decade. Causality was assessed with three different criteria: First, the total number of associations documented in the literature between each infectious agent and chronic condition; second, the epidemiologic study design (quality of the study); third, evidence for the number of Hill's criteria and Koch's postulates that linked the pathogen with the chronic condition. We identified 3136 publications, of which 148 were included in the analysis. There were a total of 75 different infectious agents and 122 chronic conditions. The evidence was strong for five pathogens, based on study type, strength and number of associations; they accounted for 60% of the associations documented in the literature. They were human immunodeficiency virus, hepatitis C virus, Helicobacter pylori, hepatitis B virus, and Chlamydia pneumoniae and were collectively implicated in the aetiology of 37 different chronic conditions. Other pathogens examined were only associated with very few chronic conditions (≤ 3) and when applying the three different criteria of evidence the strength of the causality was weak.

CONCLUSIONS

Prevention and treatment of these five pathogens lend themselves as effective public health intervention entry points. By concentrating research efforts on these promising areas, the human, economic, and societal burden arising from chronic conditions can be reduced.

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.

Chlamydia pneumoniae and osteoporosis-associated bone loss: a new risk factor?

We found an association between the presence of Chlamydia pneumoniae DNA both in osteoporotic bone tissue and peripheral blood mononuclear cells (PBMCs) and the increase in circulating resorptive cytokines.

INTRODUCTION

Our study was designed to determine whether C. pneumoniae infection may be involved in osteoporosis-associated bone loss.

METHODS

The study included 59 women undergoing hip joint replacement surgery for femoral neck fracture: 32 with osteoporosis and 27 with osteoarthritis. A total of 118 tissue specimens (59 bone tissues, 59 PBMCs) were examined for C. pneumoniae DNA by real-time polymerase chain reaction (PCR). Serum levels of soluble receptor activator of nuclear factor kappa B ligand (sRANKL), osteoprotegerin (OPG), interleukin (IL)-1β, tumor necrosis factor-α, and IL-6 were also measured.

RESULTS

C. pneumoniae DNA was detected in osteoporotic bone tissue whereas it was not found in non-osteoporotic bone tissue (p < 0.05). A significantly higher rate of C. pneumoniae DNA (p < 0.05) was found in PBMCs of osteoporotic patients than in those of osteoarthritis patients. Among osteoporotic patients, serum sRANKL, IL-1, and IL-6 concentrations as well as sRANKL/OPG ratio significantly differ between patients with bone tissue and PBMCs positive to C. pneumoniae and C. pneumoniae-negative patients.

CONCLUSION

The association between the presence of C. pneumoniae DNA, both in bone tissue and PBMCs, and the increase in sRANKL/OPG ratio as well as in IL-1β and IL-6 levels observed in osteoporotic patients suggests C. pneumoniae infection as a new risk factor for osteoporosis.

Low yield by molecular detection of Chlamydophila pneumoniae in respiratory samples in Belgium questioning its etiological role in respiratory tract infections

The actual burden of respiratory infections due to Chlamydophila pneumoniae is difficult to assess due to the major differences in positivity rates between PCR- and serology-based methods. The aim of the current study was to objectively analyse the yield of PCRs for the detection of C. pneumoniae in respiratory samples and to evaluate the additional value of performing laboratory diagnosis for C. pneumoniae in a setting of respiratory infection. The data based on routine analysis of respiratory samples with request for C. pneumoniae detection were collected from 4 large Belgian hospitals during 2 consecutive years. In total 3560 respiratory samples have been analysed and overall only 7 samples (0.2%) were found positive. Based on these observations, the critical evaluation of the actual role of C. pneumoniae in the etiology of lower respiratory infections and consequently of the extensive use of diagnostic tools for the detection of C. pneumoniae is needed.

[Medical and social characteristics of the families having patients with ENT pathology and verified Chlamydia infection]

The objective of the present study was to evaluate the medico-social status of 44 families having patients with ENT pathology; special attention was given to the patients with this condition and concomitant verified Chlamydia infection in the upper respiratory tract. The results of their examination were compared with those obtained in the control group of 43 families including the patients with ENT pathology and unconfirmed respiratory chlamydiasis. Chlamydia infection was diagnosed by combining standard laboratory techniques such as direct immunofluorescent and immunoenzymatic assays alomg with polymerase chain reaction. The results of the present study indicate that the medical and social status of the families having a member with respiratory chlamydiasis is inferior to that of the families unaffected by this infection.

Azithromycin in treatment of patients with asthma and C. Pneumoniae infection

Chronic C. pneumoniae infection has been suggested as a cause for adult onset of asthma. There are data to suggest that infectious organisms, particularly the atypical bacteria C. pneumoniae, may be involved in asthma pathogenesis. The significance of these organisms is as yet unclear. It is not known whether this organism was allowed to persist after an infection, or was present prior to the development of asthma. The purpose of this study was to determine whether anti-chlamydial treatment with azithromycin will improve asthma symptoms and lung function in asthmatic patients positive for C. pneumoniae. For this purpose, 20 patients (mean age 39.8 years) with mild asthma were treated a median of 8 weeks with azithromycin 1000 mg once weekly. All patients had C. pneumoniae infection detected by Seeplex Multiplex PCR in sputum and positive IgG titre>1:64 and IgA titre>1:16 antibodies against C. pneumoniae. Post treatment lung function, symptom score (cough, wheezing, dyspnea), morning and evening PEF values and β2-agonist use were compared with baseline values. After 8 weeks of treatment with azithromycin there was a significant reduction in symptom score (p<0.001) and a significant improvement in lung function FEV1 (p<0.001), morning and evening PEF values p<0.05 Wilcoxon matched Pairs test. We also found a reduction in β2-agonist use, but it was not statistically significant. Treatment with azithromycin significantly improved asthma symptoms and lung function, indicating that C. pneumoniae may play an important role in enhancing the inflammatory processes in the lower airways.

Chlamydia pneumoniae in the atherosclerotic plaques of coronary artery disease patients

An association between Chlamydia pneumoniae (C. pneumoniae) and cardiovascular disease has been demonstrated. In this study, we aimed to study this potential relationship in 105 Iranian patients. Coronary artery specimens from 105 Iranian patients undergoing CABG were analyzed by PCR method for C. pneumoniae. Serological evaluation for C. pneumoniae IgG and IgM was performed using ELISA. 53 specimens from mamillary artery were also investigated. C. pneumoniae PCR test result was positive for 23 (21.9%) of patients with coronary artery atherosclerosis, but none of the specimens from the mamillary artery was positive for C. pneumoniae when it was evaluated by the PCR (P<0.001). Coronary artery disease patients with and without a history of unstable angina or myocardial infarction were comparable in C. pneumoniae PCR test positive rates (P=0.618). Relevance of IgG and IgM positivity were also studied by correlating it to the study parameters, but no difference was found. CRP was significantly higher in the IgM positive group (P<0.001). A significant proportion of coronary atherosclerotic plaques are infected with C. pneumoniae while no infection was found in the normal mamillary artery specimens. No association was found between acute coronary syndromes and serological and PCR positivity. Further prospective randomized controlled studies with large patient population are needed to confirm our findings.

Development and evaluation of a MAb-based ELISA for detection of Chlamydophila pneumoniae infection with variable domain 2 and 3 of the major outer membrane protein

OBJECTIVE

This paper aims to develop a monoclonal antibodies (MAbs)- based ELISA for detecting Chlamydophila pneumoniae (C. pneumoniae) antigens in humans with the variable domains (VD) 2 and 3 of the major outer membrane protein (MOMPVD2-VD3) and to assess its sensitivity and specificity by comparing with a widely used MAb that is able to recognize the elementary bodies of C. pneumoniae.

METHODS

MOMPVD2-VD3 were overexpressed in Escherichia coli and purified by affinity chromatography. Mice were immunized with the recombinant antigen, and hybridomas secreting MAbs were screened. Three stable hybridomas clones were selected and named 5D6, 7G3, and 8C9. The MAbs-based ELISA was scrutinized for species-specific recognition with a number of human throat swab samples from Group I (156 patients with typical respiratory illness clinically confirmed before) and Group II (57 healthy donors).

RESULTS

In Group I, 55 positive cases were detected by anti-EB MAb-based ELISA, 51 cases were positive by MAbs 5D6-based ELISA, and 33 and 38 cases were positive by MAb 8C9 and 7G3-based ELISA respectively. Of the 57 samples from Group II "healthy donors", 5 were positive and 52 were negative with both anti-EB and 5D6-based tests, while 2 and 3 positive cases were identified by the other two MAb-based ELISAs respectively.

CONCLUSION

The novel MOMPVD2-VD3 MAb-based assay may have higher specificity than the anti-EB MAb, which may possibly be used as an alternative tool for the diagnosis of C. pneumoniae infection.

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.

[Mixed infections in children with Mycoplasma pneumoniae pneumonia]

OBJECTIVE

To investigate the incidence and clinical features of mixed infections in children with Mycoplasma pneumoniae (MP) pneumonia.

METHOD

A total of 201 cases diagnosed as MP pneumonia were investigated for mixed infections by sputum bacterial culture, respiratory virus antigen detection and serum Chlamydia pneumoniae antibody test. For those with the indications for bronchoscopy, we also did bronchoalveolar lavage and lavage bacterial culture.

RESULT

A high incidence (103/201, 51.2%) of mixed infections in children with MP pneumonia was revealed. The most frequent co-infected pathogen was Chlamydia pneumoniae (52, 25.9%), followed by viruses (29, 14.4%), and bacteria (22, 10.9%). Among viruses, respiratory syncytial virus was the most common (17, 8.5%), followed by adenovirus (6, 3.0%), parainfluenza virus type III (4, 2.0%) and influenza virus type B (2, 1.0%). Sputum bacterial culture was positive in 14/201 (7.0%) cases, Streptococcus pneumonia being most common (6, 3.0%). BALF culture yielded positive results in 11.6% (8/69), Streptococcus pneumonia was also common (5, 7.3%). Among 29 cases with MP and virus coinfection, 26 were younger than 3 years (89.7%), while for MP and Chlamydia pneumoniae coinfection, most of them were older than 3 years (40/52, 76.9%). Compared with non-mixed infections, those with mixed infections had longer fever duration (24.5% and 40.8% longer than 10 d), more frequently developed pleural effusion (11.2%, 23.3%) and large area of shadow in chest imaging (35.7%, 51.5%). White blood cell [(14.28 ± 4.99) × 10(9)/L], C-reactive protein (CRP) [69(32.5 - 99.5) mg/L] and neutrophil ratio in BALF [0.86 (0.63 - 0.91)] were much higher in children with mixed bacterial infections than that in non-mixed infections [(9.06 ± 3.47) × 10(9)/L, 3 (0 - 31.0) mg/L, 0.44 (0.03 - 0.88)]. But no significant difference was found in peripheral blood neutrophil proportion between mixed bacterial infections (0.38 ± 0.25) and non-mixed infections (0.51 ± 0.19).

CONCLUSION

More than half of cases with MP pneumonia had mixed infections, most commonly caused by Chlamydia pneumonia followed by viruses. The incidence of mixed infections with bacteria was low. Mixed infections with virus were more common in young children, while mixed infection with Chlamydia pneumoniae was more common in older ones. Bacterial infections should be paid more attention, especially those caused by Streptococcus pneumoniae, for those with high peripheral white blood cell counts, high CRP levels and high proportion of neutrophils in BALF.

[Croupous pneumonia: the history of studies (from S.P. Botkin to our days)]

Etiology of croupous pneumonia remaining a challenging problem has a long history of investigations. The term croupous pneumonia is traditionally used in this country to describe the form of the disease characterized by hyperergic inflammation and specific clinical/laboratory parameters. A valuable contribution to the study of this condition was made by S.P. Botkin. This paper deals with evolution of the views of epidemiology, etiology, pathomorphology, and methods of therapy of croupous pneumonia since Botkin's time to these days.

The role of Chlamydia and Chlamydophila infections in reactive arthritis

Chlamydia trachomatis and Chlamydophila pneumoniae are human pathogens; the former being the etiologic agent for trachoma as well as a prevalent sexually transmitted bacterium, while C. pneumoniae is a respiratory pathogen responsible for community-acquired pneumonia. Patients with reactive arthritis show evidence of present or past Chlamydial infection. Chlamydia spp., has been strongly implicated as a triggering factor for reactive arthritis. We describe the simultaneous occurrence of C. pneumoniae and C. trachomatis infections in a subject with reactive arthritis. We suggest treatment for a patient with Chlamydia-associated arthritis to define a means by which persistent organisms can be induced to return to the active developmental cycle, thereby making them more accessible to antibiotic activity.

[Isolation of antibodies to Chlamydia and Mycoplasma pneumoniae during the immunosuppressive therapy of patients with inflammatory bowel disease]

Detection of IgM and IgG Chlamydia and Mycoplasma pneumoniae indicates an aggravation of intracellular infections, including, possibly, due to immunosuppressive therapy. It is possible that the intracellular infection may mediate the occurrence of certain extraintestinal manifestations of inflammatory bowel disease (IBD), such as bronchitis, pneumonia, etc. Chronic persistent chlamydial and mycoplasmal infections lead to disruption of both cellular and humoral immunity, resulting in the formation of autoimmune processes in patients with IBD, and in the future--reduce the immune status against the immunosuppressive therapy. Detection of antibodies to Chlamydia and Mycoplasma pneumoniae accompanies with increased total immunoglobulin IgM, IgG in blood serum. Determining the level of proinflammatory and antiinflammatory cytokines in the acute stage of the disease allows to evaluate the activity of the inflammatory process and the nature of the immune response to intracellular infection.

THE CONCLUSION

to prevent extraintestinal septic complications in patients with IgM antibodies to Chlamydia and Mycoplasma pneumoniae, is recommended to combine the long-term immunosuppressive therapy of IBD with antibiotic therapy, usually with macrolides.

Clinical features and the role of atypical pathogens in nursing and healthcare-associated pneumonia (NHCAP): differences between a teaching university hospital and a community hospital

OBJECTIVE

The Japan Respiratory Society documented a new category of guidelines for nursing and healthcare-associated pneumonia (NHCAP), which is distinct from community acquired pneumonia (CAP). The objective of this study was to determine the epidemiological differences between NHCAP patients in a teaching university hospital and a community hospital. In addition, to clarify the strategy for treatment of NHCAP, we investigated the role of atypical pathogens.

METHODS

We analyzed 250 NHCAP and 421 CAP cases in a university hospital and 349 NHCAP and 374 CAP cases in a community hospital.

RESULTS

Patient age and the incidences of poor general condition were significantly higher in the community hospital compared with those in the university hospital. The distribution and frequency of pathogens, especially multidrug-resistant (MDR) pathogens, were significantly different between the two hospitals. Central nervous system disorders, dementia and poor performance status, which was possibility related to aspiration pneumonia, were significantly more frequent in patients with NHCAP compared with those with CAP in both hospitals. Atypical pathogens were detected in a few cases in patients with NHCAP.

CONCLUSION

There were many differences in the clinical characteristics between NHCAP patients in a university hospital and a community hospital even for hospitals located in the same area. Aspiration pneumonia was thought to be the main characteristic of NHCAP in both hospitals. Thus, all NHCAP patients did not need the same empiric therapy with a multidrug regimen directed against MDR pathogens. In addition, physicians rarely need to consider atypical pathogens in NHCAP treatment.

[Specific distribution patterns and manifestations of respiratory chlamydiosis of the upper respiratory tract in different population groups]

The objective of this study was to elucidate specific distribution patterns and manifestations of respiratory chlamydiosis affecting the upper respiratory tract in different groups of the patients (both children and adults) presenting with otorhinolaryngological problems. Chlamydia were detected with the use of a combination of laboratory methods including PCR, direct immunofluorescent and imunoenzymatic assays. The study included 1329 patients. The data obtained suggest the high prevalence of chlamydial infection of the upper respiratory tract in different groups of the population. The species composition of the identified bacteria was shown to depend on the age and sex of the affected subjects.

[Community-acquired pneumonia: comparison of etiological diagnostic methods in clinical practice]

AIM

Comparison of different methods of community-acquired pneumonia (CAP) etiological diagnosis.

MATERIAL AND METHODS

A total of 20 male and 10 females patients 21 to 75 years of age entered the trial. All of them had CAP running a non-severe course. Microbiological and molecular-genetic methods were used to examine the patients' sputum, blood serum serological tests were made to measure the level of IgM and IgG antibodies (AB) to Chlamydophila pneumoniae and Mycoplasma pneumoniae.

RESULTS

Pathogens were detected in 23 (76.7%) patients. Microbiological examination (MBE) detected monobacterial contamination in 19 patients, polymerase chain reaction (pCR) identified monobacterial infection in 10 patients, mixed bacterial infection in 5 and viral-bacterial mixed contamination in 4 patients. MBE provided 19 positive results, PCR - 30 ones. Serological examination detected IgM AB to Mycoplasma pneumoniae in 6 patients, sputum investigation with PCR detected the pathogen only in 2 patients. IgM AB to Chlamydophila pneumoniae were detected in 4 patients, PCR failed to detect infection agent.

CONCLUSION

Current etiological diagnosis can be made with the highest efficacy with combination of three methods: microbiological -for detection of bacterial pathogens (except atypical agents), molecular-genetic--for identification of both bacterial and viral pathogens and serological--for diagnosis of atypical pathogens.

[Peculiar manifestations of familial chlamydiasis of the upper respiratory tract]

The aim of the present study was to elucidate the frequency of chlamydial infection in the members of the families having the confirmed disease and concomitant ENT pathologies. Another objective was the comparative analysis of otorhinolaryngological morbidity in the families with and without the carriers of respiratory chlamydiasis. A total of 87 families were involved in the study. Chlamydial infection was diagnosed by a set of laboratory methods including direct immunofluoresent and immunoenzyme analysis as well as polymerase chain reaction (PVR). It was shown that the presence of a patient suffering from respiratory chlamydiasis in the family creates the risk of infection for its remaining members. Moreover the frequency of ENT morbidity increases in the families that serve as a hotbed of chlamydiasis of the upper respiratory tract.

[The ethiology structure of community-acquried pneumonia of young adults in closed communities]

Despite of success in ethiology evaluation of community-acquired pneumonia (CAP) and instant improvement of diagnostic methods microbiological spectrum of CAP is still remaining underestimated and is still the problem for the routine clinical practice. In our study we estimated the role of fastidious bacteria which cause atypical CAP such as Chlamydophilla pneumoniae, Mycoplasma pneumoniae, Legionella pneumophila. Furthermore we also defined the role of viral pathogens in ethiology of CAP.

Development of multiplex real-time PCR for the rapid detection of five bacterial causes of community acquired pneumonia

Establishing a microbial diagnosis for patients with community-acquired pneumonia (CAP) is still challenging and is often achieved in only 30-50% of cases. Polymerase chain reaction (PCR) has been shown to be more sensitive than conventional microbiological methods and it could help to increase the microbial yield for CAP patients. This study was designed to develop, optimize and evaluate multiplex real-time PCR as a method for rapid differential detection of five bacterial causes of CAP namely Streptococcus pneumoniae, Burkholderia pseudomallei and atypical bacterial pathogens, Mycoplasma pneumoniae, Chlamydophila pneumoniae and Legionella pneumophila. Duplex and triplex real-time PCR assays were developed using five sets of primers and probes that were designed based on an appropriate specific gene for each of the above CAP pathogens. The performance of primers for each organism was tested using SYBR Green melt curve analysis following monoplex realtime PCR amplification. Monoplex real-time PCR assays were also used to optimize each primers-probe set before combining them in multiplex assays. Two multiplex real-time PCR assays were then optimized; duplex assay for the differential detection of S. pneumoniae and B. pseudomallei, and triplex assay for the atypical bacterial pathogens. Both duplex and triplex real-time PCR assays were tested for specificity by using DNA extracted from 26 related microorganisms and sensitivity by running serial dilutions of positive control DNAs. The developed multiplex real-time PCR assays shall be used later for directly identifying CAP causative agents in clinical samples.

Detection of Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella spp. in clinical specimens using a single-tube multiplex real-time PCR assay

A multiplex real-time PCR assay for the detection of Mycoplasma pneumoniae (MP181), Chlamydia (Chlamydophila) pneumoniae (CP-Arg), Legionella spp. (Pan-Leg), and the human RNase P (RNase P) gene was developed for rapid testing of atypical bacterial respiratory pathogens in clinical specimens. This method uses 4 distinct hydrolysis probes to detect 3 leading causes of community-acquired pneumonia. The assay was evaluated for specificity and sensitivity by testing against 35 related organisms, a dilution series of each specific target and 197 clinical specimens. Specificity testing demonstrated no cross-reactivity. A comparison to previously validated singleplex real-time PCR assays for each agent was also performed. The analytical sensitivity for specific pathogen targets in both the singleplex and multiplex was identical (50 fg), while efficiencies ranged from 82% to 97% for the singleplex assays and from 90% to 100% for the multiplex assay. The clinical sensitivity of the multiplex assay was improved for the Pan-Leg and CP-Arg targets when compared to the singleplex. The MP181 assay displayed equivalent performance. This multiplex assay provides an overall improvement in the diagnostic capability for these agents by demonstrating a sensitive, high-throughput and rapid method. This procedure may allow for a practical and efficient means to test respiratory clinical specimens for atypical pneumonia agents in health care settings and facilitate an appropriate public health response to outbreaks.