Isolated respiratory tract microorganisms and clinical characteristics in asthma exacerbation of obese patients: a multicenter study.

BACKGROUND: Viral infection is a risk factor for asthma exacerbation (AE). However, bacterial infections related to AE in adults are poorly known. On the other hand, obese patients with asthma have their own clinical and biological characteristics compared with non-obese patients. METHODS: We investigated the differences in isolated pathogens for AE between obese and non-obese patients with asthma. We included 407 patients with AE from 24 medical centers in Korea. Microorganisms isolated from culture, RT-PCR or serologic tests using lower respiratory tract specimens were retrospectively investigated. RESULTS: A total of 171 obese and 236 non-obese patients with asthma were included for analysis. Compared to non-obese patients, obese patients were associated with women (77.2% vs. 63.6%), never smoker (82.5% vs. 73.9%), shorter duration of asthma (7.9 ± 8.4 vs. 10.5 ± 10.1 years), less history of pulmonary tuberculosis (8.8% vs. 17.4%), and more comorbidity of allergic rhinitis (48.5% vs. 0.8%). Viral and/or bacterial infections were detected in 205 patients (50.4%) with AE. The numbers of patients with viral only, bacterial only, or both infections were 119, 49, and 37, respectively. The most commonly isolated bacterium was Streptococcus pneumoniae, followed by Pseudomonas aeruginosa and Chlamydia pneumoniae. Obese patients showed a lower incidence of Chlamydia pneumoniae infection. In the non-obese group, bacterial infection, especially Chlamydia pneumoniae infection, was significantly associated with the duration of systemic corticosteroid use (13.6 ± 19.8 vs. 9.7 ± 6.7 days, p = 0.049). CONCLUSION: Bacterial infection was associated with a longer period of corticosteroid use in the non-obese group. Acute Chlamydia pneumoniae infection was less associated with obese patients with AE. Further well-designed studies are needed to evaluate microorganisms and the efficacy of antibiotics in patients with AE.

Longitudinal analysis of quality of life in primary lung cancer patients with chlamydia pneumoniae infection: a time-to-deterioration model.

BACKGROUND: Chlamydia pneumoniae (Cpn) IgG and IgA has been strongly linked to lung cancer, but its impact on patients' quality of life remains unclear. Our objective was to investigate the relationship between pre-treatment Cpn IgG and IgA and time to deterioration (TTD) of the HRQoL in patients with primary lung cancer. METHODS: A prospective hospital-based study was conducted from June 2017 to December 2018, enrolling 82 patients with primary lung cancer admitted to the First Affiliated Hospital of Fujian Medical University for questionnaire surveys. Cpn IgG and IgA was detected by microimmunofluorescence method. HRQoL was assessed at baseline and during follow-up using the EORTC Quality of Life Questionnaire version 3.0 (EORTC QLQ-C30) and EORTC Quality of Life Questionnaire-Lung Cancer (EORTC QLQ-LC13). HRQoL scores were calculated using the QoLR package, and TTD events were determined (minimum clinically significant difference = 5 points). Cox regression analysis was used to evaluate the effect of Cpn IgG and IgA on HRQoL. RESULTS: We investigated the relationship between Cpn IgG and IgA and quality of life in patients with primary lung cancer. The study was found that 75.61% of cases were Cpn IgG + and 45.12% were Cpn IgA + . Cpn IgA + IgG + was 41.46%. For EORTC QLQ-C30, Physical function (PF) and Pain (PA) TTD events on the functional scale and Symptom scale were the most common during follow-up. After adjusting for gender and smoking status, Pre-treatment Cpn IgA + was found to signifcantly delay TTD of Physical functioning(HR = 0.539, 95% CI: 0.291-0.996, P = 0.048). In addition, Cpn IgG + before treatment significantly delayed TTD in Emotional functioning (HR = 0.310, 95% CI: 0.115-0.836, P = 0.021). For EORTC QLQ-LC13, deterioration of dyspnea (LC-DY) was the most common event. However, Cpn IgG and IgA before treatment had no effect on the TTD of EORTC QLQ-LC13 items. CONCLUSIONS: According to EORTC QLQ-C30 and EORTC QLQ-LC13, Cpn IgA delayed TTD in Physical functioning and Cpn IgG delayed TTD in Emotional functioning.

Chlamydia pneumoniae Lung Infection in Mice Induces Fatty Acid-Binding Protein 4-Dependent White Adipose Tissue Pathology.

Fatty acid-binding protein 4 (FABP4) is a critical immune-metabolic modulator, mainly expressed in adipocytes and macrophages, secreted from adipocytes in association with lipolysis, and plays essential pathogenic roles in cardiovascular and metabolic diseases. We previously reported Chlamydia pneumoniae infecting murine 3T3-L1 adipocytes and causing lipolysis and FABP4 secretion in vitro. However, it is still unknown whether C. pneumoniae intranasal lung infection targets white adipose tissues (WATs), induces lipolysis, and causes FABP4 secretion in vivo. In this study, we demonstrate that C. pneumoniae lung infection causes robust lipolysis in WAT. Infection-induced WAT lipolysis was diminished in FABP4-/- mice or FABP4 inhibitor-pretreated wild-type mice. Infection by C. pneumoniae in wild-type but not FABP4-/- mice induces the accumulation of TNF-α- and IL-6-producing M1-like adipose tissue macrophages in WAT. Infection-induced WAT pathology is augmented by endoplasmic reticulum (ER) stress/the unfolded protein response (UPR), which is abrogated by treatment with azoramide, a modulator of the UPR. C. pneumoniae lung infection is suggested to target WAT and induce lipolysis and FABP4 secretion in vivo via ER stress/UPR. FABP4 released from infected adipocytes may be taken up by other neighboring intact adipocytes or adipose tissue macrophages. This process can further induce ER stress activation and trigger lipolysis and inflammation, followed by FABP4 secretion, leading to WAT pathology. A better understanding of the role of FABP4 in C. pneumoniae infection-induced WAT pathology will provide the basis for rational intervention measures directed at C. pneumoniae infection and metabolic syndrome, such as atherosclerosis, for which robust epidemiologic evidence exists.

Systematic Infection of Chlamydia Pneumoniae.

BACKGROUND: Chlamydia pneumoniae (Cpn) is one of the most common respiratory pathogens in children and adults. It is characterized as an obligate intracellular parasite. Peripheral blood monocytes (PBMC), lymphocytes, and macrophages are involved in spreading chlamydia infection to extrapulmonary organs indicating that Cpn infection can cause systematic symptoms in vivo via blood transmission. METHODS: This review summarizes the mechanisms of Cpn infection in host cells, the immune response of the body, and the relationship between Cpn infection and some chronic diseases. RESULTS: Cpn participation in extrapulmonary chronic diseases has been proven owing to the presence of Cpn DNA in AS plaque, nerve tissues, and synovium tissues of the joints. CONCLUSIONS: Cpn infection is related to the development of chronic diseases such as atherosclerosis, Alzheimer's Disease (AD), and reactive arthritis through in vivo and in vitro experiments.

Epidemiological Study on Mycoplasma pneumoniae and Chlamydia pneumoniae Infection of Hospitalized Children in a Single Center During the COVID-19 Pandemic.

Background: Since the outbreak of COVID-19, a series of preventive and control measures in China have been used to effectively curb the spread of COVID-19. This study aimed to analyze the epidemiological characteristics of Mycoplasma pneumoniae (MP) and Chlamydia pneumoniae (CP) in hospitalized children with acute respiratory tract infection during the COVID-19 pandemic. Methods: MP IgM antibody and CP IgM antibody were detected in all hospitalized children due to acute respiratory tract infection in the Children's Hospital Affiliated to Zhejiang University from January 2019 to December 2020. These data were compared between 2019 and 2020 based on age and month. Results: The overall detection rate of MP and CP in 2020 was significantly lower than that in 2019 (MP: 21.5% vs 32.9%, P<0.001; CP: 0.3% vs 0.9%, P<0.001). This study found a 4-fold reduction in the number of children positive for MP and a 7.5-fold reduction in the number of children positive for CP from 2019 to 2020. The positive cases were concentrated in children aged >1 year old. In 2019, the positive rate of MP was detected more commonly in children 3 years of age or older than in younger children. In 2020, the higher positive rate of MP reached a peak in the 3- to 6-year age group (35.3%). CP was detected predominantly in children aged 6 years older in 2019 and 2020, with positive rates of 4.8% and 2.6%, respectively. Meanwhile, the positive rates of MP in 2019 were detected more commonly in July, August and September, with 47.2%, 46.7% and 46.3%, respectively. Nevertheless, the positive rates of MP from February to December 2020 apparently decreased compared to those in 2019. The positive rates of CP were evenly distributed throughout the year, with 0.5%-1.6% in 2019 and 0.0%-2.1% in 2020. Conclusions: A series of preventive and control measures for SARS-CoV-2 during the COVID-19 pandemic can not only contain the spread of SARS-CoV-2 but also sharply improve the infection of other atypical pathogens, including MP and CP.

Chlamydia pneumoniae can infect the central nervous system via the olfactory and trigeminal nerves and contributes to Alzheimer's disease risk.

Chlamydia pneumoniae is a respiratory tract pathogen but can also infect the central nervous system (CNS). Recently, the link between C. pneumoniae CNS infection and late-onset dementia has become increasingly evident. In mice, CNS infection has been shown to occur weeks to months after intranasal inoculation. By isolating live C. pneumoniae from tissues and using immunohistochemistry, we show that C. pneumoniae can infect the olfactory and trigeminal nerves, olfactory bulb and brain within 72 h in mice. C. pneumoniae infection also resulted in dysregulation of key pathways involved in Alzheimer's disease pathogenesis at 7 and 28 days after inoculation. Interestingly, amyloid beta accumulations were also detected adjacent to the C. pneumoniae inclusions in the olfactory system. Furthermore, injury to the nasal epithelium resulted in increased peripheral nerve and olfactory bulb infection, but did not alter general CNS infection. In vitro, C. pneumoniae was able to infect peripheral nerve and CNS glia. In summary, the nerves extending between the nasal cavity and the brain constitute invasion paths by which C. pneumoniae can rapidly invade the CNS likely by surviving in glia and leading to Aß deposition.

Atypical bacterial co-infections among patients with COVID-19: A study from India.

Emerging evidence shows co-infection with atypical bacteria in coronavirus disease 2019 (COVID-19) patients. Respiratory illness caused by atypical bacteria such as Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella pneumophila may show overlapping manifestations and imaging features with COVID-19 causing clinical and laboratory diagnostic issues. We conducted a prospective study to identify co-infections with SARS-CoV-2 and atypical bacteria in an Indian tertiary hospital. From June 2020 to January 2021, a total of 194 patients with laboratory-confirmed COVID-19 were also tested for atypical bacterial pathogens. For diagnosing M. pneumoniae, a real-time polymerase chain reaction (PCR) assay and serology (IgM ELISA) were performed. C. pneumoniae diagnosis was made based on IgM serology. L. pneumophila diagnosis was based on PCR or urinary antigen testing. Clinical and epidemiological features of SARS-CoV-2 and atypical bacteria-positive and -negative patient groups were compared. Of the 194 patients admitted with COVID-19, 17 (8.8%) were also diagnosed with M. pneumoniae (n = 10) or C. pneumoniae infection (n = 7). Confusion, headache, and bilateral infiltrate were found more frequently in the SARS CoV-2 and atypical bacteria co-infection group. Patients in the M. pneumoniae or C. pneumoniae co-infection group were more likely to develop ARDS, required ventilatory support, had a longer hospital length of stay, and higher fatality rate compared to patients with only SARS-CoV-2. Our report highlights co-infection with bacteria causing atypical pneumonia should be considered in patients with SARS-CoV-2 depending on the clinical context. Timely identification of co-existing pathogens can provide pathogen-targeted treatment and prevent fatal outcomes of patients infected with SARS-CoV-2 during the current pandemic.

Neuroprotective effects of some epigenetic modifying drugs' on Chlamydia pneumoniae-induced neuroinflammation: A novel model.

Chlamydia pneumoniae (Cpn) is a gram-negative intracellular pathogen that causes a variety of pulmonary diseases, and there is growing evidence that it may play a role in Alzheimer's disease (AD) pathogenesis. Cpn can interact functionally with host histones, altering the host's epigenetic regulatory system by introducing bacterial products into the host tissue and inducing a persistent inflammatory response. Because Cpn is difficult to propagate, isolate, and detect, a modified LPS-like neuroinflammation model was established using lyophilized cell free supernatant (CFS) obtained from infected cell cultures, and the effects of CFS were compared to LPS. The neuroprotective effects of Trichostatin A (TSA), givinostat, and RG108, which are effective on epigenetic mechanisms, and the antibiotic rifampin, were studied in this newly introduced model and in the presence of amyloid beta (Aß) 1-42. The neuroprotective effects of the drugs, as well as the effects of CFS and LPS, were evaluated in Aß-induced neurotoxicity using a real-time cell analysis system, total ROS, and apoptotic impact. TSA, RG108, givinostat, and rifampin all demonstrated neuroprotective effects in both this novel model and Aß-induced neurotoxicity. The findings are expected to provide early evidence on neuroprotective actions against Cpn-induced neuroinflammation and Aß-induced neurotoxicity, which could represent a new treatment option for AD, for which there are currently few treatment options.

Chlamydia pneumoniae-associated pleuropericarditis: a case report and systematic review of the literature.

BACKGROUND: Chlamydia pneumoniae is a common cause of atypical community acquired pneumonia (CAP). The diagnostic approach of chlamydial infections remains a challenge. Diagnosis of delayed chlamydial-associated complications, involving complex autoimmune pathophysiological mechanisms, is still more challenging. C. pneumoniae-related cardiac complications have been rarely reported, including cases of endocarditis, myocarditis and pericarditis. CASE PRESENTATION: A 40-year old female was hospitalized for pleuropericarditis following lower respiratory tract infection. The patient had been hospitalized for CAP (fever, dyspnea, chest X-ray positive for consolidation on the left upper lobe) 5 weeks ago and had received ceftriaxone and moxifloxacin. Four weeks after her discharge, the patient presented with fever, shortness of breath and pleuritic chest pain and was readmitted because of pericardial and bilateral pleural effusions (mainly left). The patient did not improve on antibiotics and sequential introduction of colchicine and methylprednisolone was performed. The patient presented impressive clinical and laboratory response. Several laboratory and clinical assessments failed to demonstrate any etiological factor for serositis. Chlamydial IgM and IgG antibodies were positive and serial measurements showed increasing kinetics for IgG. Gold standard polymerase chain reaction of respiratory tract samples was not feasible but possibly would not have provided any additional information since CAP occurred 5 weeks ago. The patient was discharged under colchicine and tapered methylprednisolone course. During regular clinic visits, she remained in good clinical condition without pericardial and pleural effusions relapse. CONCLUSIONS: C. pneumoniae should be considered as possible pathogen in case of pleuritis and/or pericarditis during or after a lower respiratory tract infection. In a systematic review of the literature only five cases of C. pneumoniae associated pericarditis were identified. Exact mechanisms of cardiovascular damage have not yet been defined, yet autoimmune pathways might be implicated.

Chlamydia pneumoniae and chronic asthma: Updated systematic review and meta-analysis of population attributable risk.

BACKGROUND: Chlamydia pneumoniae (Cp) is an obligate intracellular human respiratory pathogen producing persisting lung infection with a plausible link to asthma pathogenesis. The population attributable risk of potentially treatable Cp infection in asthma has not been reported. METHODS: The author searched from 2000 to 2020 inclusive for previously un-reviewed and new cross sectional and prospective controlled studies of Cp biomarkers and chronic asthma in both children and adults. Qualitative descriptive results and quantitative estimates of population attributable risk for selected biomarkers (specific IgG, IgA and IgE) are presented. FINDINGS: No large, long-term prospective population-based studies of Cp infection and asthma were identified. About half of case-control studies reported one or more significant associations of Cp biomarkers and chronic asthma. Heterogeneity of results by age group (pediatric v adult asthma), severity category (severe/uncontrolled, moderate/partly controlled, mild/controlled) and antibody isotype (specific IgG, IgA, IgE) were suggested by the qualitative results and confirmed by meta-analyses. The population attributable risks for Cp-specific IgG and IgA were nul in children and were 6% (95% confidence interval 2%-10%, p = 0.002) and 13% (9%-18%, p<0.00001) respectively in adults. In contrast to the nul or small population attributable risks for Cp-specific IgG and IgA, the population attributable risk for C. pneumoniae-specific IgE (children and adults combined) was 47% (39%-55%, p<0.00001). In the subset of studies that reported on asthma severity categories, Cp biomarkers were positively and significantly (P<0.00001) associated with asthma severity. INTERPRETATION: C. pneumoniae-specific IgE is strongly associated with asthma and asthma severity, suggesting a possible mechanism linking chronic Cp infection with asthma in a subset of individuals with asthma. Infection biomarkers should be included in future macrolide treatment trials for severe and uncontrolled asthma.

The association of Chlamydia pneumoniae infection with atherosclerosis: Review and update of in vitro and animal studies.

Previous studies have tended to relate Chlamydia pneumoniae (Cpn) infection to atherosclerosis. However, while serological studies have mostly reinforced this hypothesis, inconsistent and even contradictory findings have been reported in various researches. Recent papers have pointed to the significance of Cpn in atherosclerotic lesions, which are regarded as the initiator and cause of chronic inflammation. This bacterium develops atherosclerosis by phenotypic changes in vascular smooth muscle cells, dysregulation of endothelin-1 in the vascular wall, and releasing pro-inflammatory cytokines from Toll-like receptor-2 (TLR2). Furthermore, Cpn infection, particularly under hyperlipidemic conditions, enhances monocyte adhesion to endothelium; changes the physiology of the host, e.g., cholesterol homeostasis; and activates the Low-density lipoprotein (LDL) receptor, which is the initial step in atherogenesis. On the other hand, it has been reported that Cpn, even without the immune system of the host, has the ability to stimulate arterial thickening. Moreover, there is evidence that Cpn can increase the impact of the classical risk factors such as hyperlipidemia, pro-inflammatory cytokines, and smoking for atherosclerosis. Furthermore, animal studies have shown that Cpn infection can induce atherosclerotic, which alongside hyperlipidemia is a co-risk factor for cardiovascular disease. Although the exact link between Cpn and atherosclerosis has not been determined yet, previous studies have reported possible mechanisms of pathogenesis for this bacterium. Accordingly, investigating the exact role of this infection in causing atherosclerosis may be helpful in controlling the disease.

Chronic infection with Chlamydia pneumoniae in asthma: a type-2 low infection related phenotype.

BACKGROUND: Chlamydia pneumoniae and Mycoplasma pneumoniae have been implicated in the pathogenesis of asthma and are responsible for chronic inflammation when host immune system fails to eradicate the bacteria. METHOD: We performed a prospective study on 410 patients who underwent a visit at the asthma clinic of CHU of Liege between June 2016 and June 2018 with serology testing for C. pneumoniae and M. pneumoniae. RESULTS: 65% of our asthmatic population had serum IgA and/or IgG towards C. pneumoniae, while only 12.6% had IgM and/or IgG against M. pneumoniae. Compared to seronegative asthmatics, asthmatics with IgA+ and IgG+ against C. pneumoniae were more often male and older with a higher proportion of patients with smoking history. They received higher doses of inhaled corticosteroids (ICS) and displayed lower FEV1/FVC ratio, higher RV/TLC ratio and lower conductance. They had higher levels of fibrinogen, though in the normal range and had lower sputum eosinophil counts. Patients with IgA- and IgG+ against C. pneumoniae were older and had higher blood monocyte counts and alpha-1-antitrypsin levels as compared to seronegative patients. Patients with IgM and/or IgG towards M. pneumoniae were more often males than seronegative asthmatics. In a subpopulation of 14 neutrophilic asthmatics with Chlamydia pneumoniae IgA + /IgG + treated with macrolides, we found a significant decrease in blood neutrophils and normalization of sputum neutrophil count but no effect on asthma quality of life and exacerbations. CONCLUSION: Positive Chlamydia serologic test is more common than positive Mycoplasma serology. Asthmatics with IgA and IgG against C. pneumoniae have more severe disease with increased airway obstruction, higher doses of ICS, more signs of air trapping and less type-2 inflammation.

Case Report: Refractory Acute Respiratory Distress Syndrome Supported by Extracorporeal Membrane Oxygenation due to Coinfection with Chlamydia pneumoniae and Leptospirosis in Reunion Island.

Infection with Leptospira spp. is common in Réunion, a tropical island in the Indian Ocean. However, respiratory coinfections between strains of Leptospira spp. and other microorganisms are rarely described. Here, we describe the first reported case of coinfection between Leptospira spp. and Chlamydia pneumoniae, responsible for refractory acute respiratory distress syndrome requiring extracorporeal membrane oxygenation with a favorable outcome. In a case of leptospirosis with severe respiratory illness, testing for respiratory coinfection, especially with atypical pathogens, could explain the seriousness of the clinical condition and lead to specific treatment.

Skin and Mucous Membrane Eruptions Associated with Chlamydophila Pneumoniae Respiratory Infections: Literature Review.

BACKGROUND: Mycoplasma pneumoniae pneumonia is sometimes associated with skin or mucous membrane eruptions. Available reviews do not address the association of Chlamydophila pneumoniae pneumonia with skin eruptions. We therefore conducted a systematic review of the literature addressing this issue. The National Library of Medicine, Excerpta Medica, and Web of Science databases were employed. SUMMARY: In two reports, skin lesions and especially urticaria were more common (p < 0.05) in atypical pneumonia caused by C. pneumoniae as compared with M. pneumoniae. We found 47 patients (<18 years, n = 16; ≥18 years, n = 31) affected by a C. pneumoniae atypical pneumonia, which was associated with erythema nodosum, erythema multiforme minus, erythema multiforme majus, isolated mucositis, or cutaneous vasculitis. We also found the case of a boy with C. pneumoniae pneumonia and acute generalized exanthematous pustulosis. We did not find any case of C. pneumoniae respiratory infection associated with either Gianotti-Crosti syndrome, pityriasis lichenoides et varioliformis acuta Mucha-Habermann, or varicella-like skin eruptions.

Chlamydia pneumoniae and Mycoplasma pneumoniae in children with cystic fibrosis: impact on bacterial respiratory microbiota diversity.

OBJECTIVES: The contribution of intracellular and fastidious bacteria in Cystic fibrosis (CF) pulmonary exacerbations, and progressive lung function decline remains unknown. This project aimed to explore their impact on bacterial microbiota diversity over time in CF children. METHODS: Sixty-one children enrolled in the MUCOVIB multicentre prospective cohort provided 746 samples, mostly nasopharyngeal swabs, throat swabs and sputa which were analysed using culture, specific real-time qPCRs and 16S rRNA amplicon metagenomics. RESULTS: Chlamydia pneumoniae (n = 3) and Mycoplasma pneumoniae (n = 1) were prospectively documented in 6.6% of CF children. Microbiota alpha-diversity in children with a documented C. pneumoniae was highly variable, similarly to children infected with Staphylococcus aureus or Pseudomonas aeruginosa. The transition from routine follow-up visits to pulmonary exacerbation (n = 17) yielded variable changes in diversity indexes with some extreme loss of diversity. CONCLUSIONS: The high rate of C. pneumoniae detection supports the need for regular screenings in CF patients. A minor impact of C. pneumoniae on the microbial community structure was documented. Although detected in a single patient, M. pneumoniae should also be considered as a possible aetiology of lung infection in CF subjects.

Ús de la PCR de bacteris atípics en el maneig ambulatori de pacients amb pneumònia adquirida a la comunitat que acudeixen a urgències / Uso de la PCR de bacterias atípicas en el manejo ambulatorio de pacientes con neumonía adquirida en la comunidad que acuden a urgencias / Use of PCR for atypical bacteria in the ambulatory management of patients with community-acquired pneumonia seen in the emergency departament

FONAMENT: Mycoplasma pneumoniae I Chlamydophila pneu-moniae són agents causals freqüents de la pneumònia adquirida a la comunitat (PAC) en pediatria, I les tècniques com la reacció en cadena de la polimerasa (PCR) poden facilitar-ne el diagnòstic etiològic precoç, adequant l'antibioteràpia emprada. OBJECTIU: Descriure l'ús d'aquesta tècnica en el maneig ambulatori dels pacients pediàtrics amb PAC que acudeixen a urgències. MÈTODE: Estudi observacional, retrospectiu I descriptiu de pacients pediàtrics diagnosticats de PAC a urgències amb maneig ambulatori. RESULTATS: De 67 pacients, el 32,8% va obtenir un resultat positiu per a bacteris atípics. El percentatge de resultats positius en <4 anys va ser del 10,0% I en ≥4 anys del 42,6% (p = 0,021). Van rebre antibiòtic empíric a l'alta 49 pacients dels 67 (73,1%): 31 macròlids, 12 betalactàmics I 6 ambdós. Amb el resultat de la PCR, per resultat negatiu es van retirar els macròlids a 25 dels 37 als quals se'ls havia pautat (67,6%) I es va pautar a 10 dels 22 casos positius que no els estaven rebent (45,5%). CONCLUSIONS: La PCR de bacteris atípics facilita el diagnòstic microbiològic ràpid I l'adequació de l'antibioteràpia, i, sobretot, evita l'excés de tractament amb macròlids a les urgències pediàtriques

FUNDAMENTO: Mycoplasma pneumoniae y Chlamydophila pneumoniae son agentes causales frecuentes de la neumonía adquirida en la comunidad (NAC) en pediatría, y las técnicas como la reacción en cadena de la polimerasa (PCR) pueden facilitar su diagnóstico etiológico precoz, adecuando la antibioterapia utilizada. OBJETIVO: Describir el uso de esta técnica en el manejo ambulatorio de los pacientes pediátricos con NAC que acuden a urgencias. MÉTODO: Estudio observacional, retrospectivo y descriptivo de pacientes pediátricos diagnosticados de NAC en urgencias manejados ambulatoriamente. RESULTADOS: De 67 pacientes, el 32,8% obtuvo resultado positivo para bacterias atípicas. El porcentaje de resultados positivos en <4 años fue del 10,0% y en ≥4 años de 42,6% (p = 0,021). Recibieron antibiótico empírico 49 pacientes de los 67 (73,1%): 31 macrólidos, 12 betalactámicos y 6 ambos. Con el resultado de la PCR, por resultado negativo se retiraron los macrólidos a 25 de los 37 a los que se les había pautado (67,6%) y se pautó a 10 de los 22 casos positivos que no los estaban recibiendo (45,5%). CONCLUSIONES: La PCR de bacterias atípicas facilita el diagnóstico microbiológico rápido y la adecuación de la antibioterapia, evitando sobre todo el exceso de tratamiento con macrólidos en urgencias

BACKGROUND: Mycoplasma pneumoniae and Chlamydophila pneu-moniae are frequent causative agents of community-acquired pneumonia (CAP) in children. Techniques such as the polymerase chain reaction (PCR) can facilitate early diagnosis and adequacy of antibiotic therapy. OBJECTIVE: To describe the use of this test in the ambulatory management of children with CAP seen in the emergency room. METHOD: Observational, retrospective and descriptive study of children diagnosed with CAP in the emergency room and managed as outpatients. RESULTS: Sixty-seven patients were recruited and 22 (32.8%) had a positive PCR for atypical bacteria. The percentage of positive results in children <4 years was 10.0% and it was 42.6% in children ≥4 years (p = 0.021). Forty-nine (73.1%) patients received antibiotic treatment: 31 received macrolides, 12 beta-lactams and 6 both. The results of the PCR test resulted in discontinuation of macrolide treatment in 25 of 37 patients (67.6%) after a negative PCR test and in its prescription to 10 of the 22 (45.5%) positive cases that were not receiving it. CONCLUSIONS: The use of PCR for atypical bacteria in the emergency department facilitates rapid microbiological diagnosis and the adequacy of antibiotic therapy, avoiding over-treatment with macrolides

Chlamydia pneumoniae infection in patients hospitalised for community-acquired pneumonia in Southern Jordan.

Purpose: Chlamydia pneumoniae is associated with human respiratory diseases. Few reports examined the involvement of this bacterium in community-acquired pneumonia (CAP) in Jordan. This study investigates for the first time the role of C. pneumoniae in the establishment of CAP among nationals residing the southern part of Jordan. Materials and Methods: Nasopharyngeal and sera samples were collected from 70 hospitalised CAP patients and 63 healthy controls from Al-Karak Governorate and examined using the microimmunofluorescence and polymerase chain reaction techniques. The overall prevalence of C. pneumoniae infection was estimated by detecting the chlamydial immunoglobulin G (IgG) antibodies at a titre of 1:16. Rate of acute infection was estimated by detecting chlamydial DNA in nasopharyngeal samples and IgG and IgM at titres of 1:512 and 1:16, respectively. Results: A higher overall seroprevalence of C. pneumoniae IgG was detected in CAP patients than controls (44.3% vs. 30.2%). The rate of acute infection in the entire CAP patients, based on IgG titre of 1:512, was 7.14% compared to 1.58% in the controls. Approximately, three-fold increase in the rate of acute infection was observed in CAP cases, seropositive at IgG titre of 1:16, compared to seropositive controls (16.1% vs. 5.3%). Interestingly, chlamydial IgM antibodies were detectable in 27.1% compared to only 3.2% of the controls. The presence of chlamydial nucleic acids was confirmed in 40% of CAP patients and in 7.9% of controls. Conclusions: The present findings clearly suggest a role of C. pneumoniae in the aetiology of CAP in Southern Jordan. However, coinfections with other respiratory pathogens should not be excluded.

The 1B vaccine strain of Chlamydia abortus produces placental pathology indistinguishable from a wild type infection.

Chlamydia abortus is one of the most commonly diagnosed causes of infectious abortion in small ruminants worldwide. Control of the disease (Enzootic Abortion of Ewes or EAE) is achieved using the commercial live, attenuated C. abortus 1B vaccine strain, which can be distinguished from virulent wild-type (wt) strains by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. Published studies applying this typing method and whole-genome sequence analyses to cases of EAE in vaccinated and non-vaccinated animals have provided strong evidence that the 1B strain is not attenuated and can infect the placenta causing disease in some ewes. Therefore, the objective of this study was to characterise the lesions found in the placentas of ewes vaccinated with the 1B strain and to compare these to those resulting from a wt infection. A C. abortus-free flock of multiparous adult ewes was vaccinated twice, over three breeding seasons, each before mating, with the commercial C. abortus 1B vaccine strain (Cevac® Chlamydia, Ceva Animal Health Ltd.). In the second lambing season following vaccination, placentas (n = 117) were collected at parturition and analysed by C. abortus-specific real-time quantitative PCR (qPCR). Two placentas, from a single ewe, which gave birth to live twin lambs, were found to be positive by qPCR and viable organisms were recovered and identified as vaccine type (vt) by PCR-RFLP, with no evidence of any wt strain being present. All cotyledons from the vt-infected placentas were analysed by histopathology and immunohistochemistry and compared to those from wt-infected placentas. Both vt-infected placentas showed lesions typical of those found in a wt infection in terms of their severity, distribution, and associated intensity of antigen labelling. These results conclusively demonstrate that the 1B strain can infect the placenta, producing typical EAE placental lesions that are indistinguishable from those found in wt infected animals.

The relationship between Chlamydia pneumoniae infection and CD4/CD8 ratio, lymphocyte subsets in middle-aged and elderly individuals.

Chlamydia pneumoniae (C. pneumoniae) is a common respiratory pathogen associated with many inflammatory diseases. There are few data concerning the lymphocyte subsets in middle-aged and elderly individuals with C. pneumoniae infection. A total of 191 patients were included in this study. The study population was categorized into the middle-aged group (40-64 years old) and the elderly group (65-89 years old). Lymphocyte subsets in peripheral blood were examined with multi-colored flow cytometry. Immunological monitoring included lymphocyte subsets, C. pneumoniae IgG and IgM serology. In the middle-aged group, 69.83% individuals presented IgG positivity, which was associated with the inverted CD4/CD8 ratio. Individuals with C. pneumoniae IgG positivity also presented an increased percentage of CD8+CD28- cells and a decreased CD4/CD8 ratio when compared to weakly-positive individuals. In the elderly group, C. pneumoniae IgG positivity was associated with a significant increase in the percentage of CD3+CD56+CD45+ (NKT) cells. In conclusion, altered lymphocyte homeostasis was shown in middle-aged individuals with C. pneumoniae IgG positivity. The senescent phenotypes of T cells might be associated with C. pneumoniae infection in middle-aged individuals.