Etiology of severe childhood pneumonia in the Gambia, West Africa, determined by conventional and molecular microbiological analyses of lung and pleural aspirate samples.
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SUBMITTER: Howie SR
PROVIDER: S-EPMC4130311 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:BackgroundAn improved understanding of childhood pneumonia etiology is required to inform prevention and treatment strategies. Lung aspiration is the gold standard specimen for pneumonia diagnostics. We report findings from analyses of lung and pleural aspirates collected in the Pneumonia Etiology Research for Child Health (PERCH) study.MethodsThe PERCH study enrolled children aged 1-59 months hospitalized with World Health Organization-defined severe or very severe pneumonia in 7 countries in Africa and Asia. Percutaneous transthoracic lung aspiration (LA) and pleural fluid (PF) aspiration was performed on a sample of pneumonia cases with radiological consolidation and/or PF in 4 countries. Venous blood and nasopharyngeal/oropharyngeal swabs were collected from all cases. Multiplex quantitative polymerase chain reaction (PCR) and routine microbiologic culture were applied to clinical specimens.ResultsOf 44 LAs performed within 3 days of admission on 622 eligible cases, 13 (30%) had a pathogen identified by either culture (5/44) or by PCR (11/29). A pathogen was identified in 12/14 (86%) PF specimens tested by either culture (9/14) or PCR (9/11). Bacterial pathogens were identified more frequently than viruses. All but 1 of the cases with a virus identified were coinfected with bacterial pathogens. Streptococcus pneumoniae (9/44 [20%]) and Staphylococcus aureus (7/14 [50%]) were the predominant pathogens identified in LA and PF, respectively.ConclusionsBacterial pathogens predominated in this selected subgroup of PERCH participants drawn from those with radiological consolidation or PF, with S. pneumoniae and S. aureus the leading pathogens identified.
| S-EPMC8662778 | biostudies-literature
Project description:BackgroundPneumonia remains the leading cause of death in young children globally. The changing epidemiology of pneumonia requires up-to-date data to guide both case management and prevention programs. The Gambia study site contributed a high child mortality, high pneumonia incidence, low HIV prevalence, Haemophilus influenzae type b and pneumococcal conjugate vaccines-vaccinated rural West African setting to the Pneumonia Etiology Research for Child Health (PERCH) Study.MethodsThe PERCH study was a 7-country case-control study of the etiology of hospitalized severe pneumonia in children 1-59 months of age in low and middle-income countries. Culture and nucleic acid detection methods were used to test nasopharyngeal/oropharyngeal swabs, blood, induced sputum and, in selected cases, lung or pleural fluid aspirates. Etiology was determined by integrating case and control data from multiple specimens using the PERCH integrated analysis based on Bayesian probabilistic methods.ResultsAt The Gambia study site, 638 cases of World Health Organization-defined severe and very severe pneumonia (286 of which were chest radiograph [CXR]-positive and HIV-negative) and 654 age-frequency matched controls were enrolled. Viral causes predominated overall (viral 58% vs. bacterial 28%), and of CXR-positive cases respiratory syncytial virus (RSV) accounted for 37%, Streptococcus pneumoniae 13% and parainfluenza was responsible for 9%. Nevertheless, among very severe cases bacterial causes dominated (77% bacterial vs. 11% viral), led by S. pneumoniae (41%); Mycobacterium tuberculosis, not included in "bacterial", accounted for 9%. 93% and 80% of controls ≥1 year of age were, respectively, fully vaccinated for age against Haemophilus influenzae and S. pneumoniae.ConclusionsViral causes, notably RSV, predominated in The Gambia overall, but bacterial causes dominated the severest cases. Efforts must continue to prevent disease by optimizing access to existing vaccines, and to develop new vaccines, notably against RSV. A continued emphasis on appropriate case management of severe pneumonia remains important.
| S-EPMC8448408 | biostudies-literature
Project description:BackgroundPneumonia remains the leading cause of death in young children globally and improved diagnostics are needed to better identify cases and reduce case fatality. Metabolomics, a rapidly evolving field aimed at characterizing metabolites in biofluids, has the potential to improve diagnostics in a range of diseases. The objective of this pilot study is to apply metabolomic analysis to childhood pneumonia to explore its potential to improve pneumonia diagnosis in a high-burden setting.Methodology/principal findingsEleven children with World Health Organization (WHO)-defined severe pneumonia of non-homogeneous aetiology were selected in The Gambia, West Africa, along with community controls. Metabolomic analysis of matched plasma and urine samples was undertaken using Ultra Performance Liquid Chromatography (UPLC) coupled to Time-of-Flight Mass Spectrometry (TOFMS). Biomarker extraction was done using SIMCA-P+ and Random Forests (RF). 'Unsupervised' (blinded) data were analyzed by Principal Component Analysis (PCA), while 'supervised' (unblinded) analysis was by Partial Least Squares-Discriminant Analysis (PLS-DA) and Orthogonal Projection to Latent Structures (OPLS). Potential markers were extracted from S-plots constructed following analysis with OPLS, and markers were chosen based on their contribution to the variation and correlation within the data set. The dataset was additionally analyzed with the machine-learning algorithm RF in order to address issues of model overfitting and markers were selected based on their variable importance ranking. Unsupervised PCA analysis revealed good separation of pneumonia and control groups, with even clearer separation of the groups with PLS-DA and OPLS analysis. Statistically significant differences (p<0.05) between groups were seen with the following metabolites: uric acid, hypoxanthine and glutamic acid were higher in plasma from cases, while L-tryptophan and adenosine-5'-diphosphate (ADP) were lower; uric acid and L-histidine were lower in urine from cases. The key limitation of this study is its small size.Conclusions/significanceMetabolomic analysis clearly distinguished severe pneumonia patients from community controls. The metabolites identified are important for the host response to infection through antioxidant, inflammatory and antimicrobial pathways, and energy metabolism. Larger studies are needed to determine whether these findings are pneumonia-specific and to distinguish organism-specific responses. Metabolomics has considerable potential to improve diagnostics for childhood pneumonia.
| S-EPMC2936566 | biostudies-literature
Project description:Despite recent advances in microbiological techniques, the etiology of community-acquired pneumonia (CAP) is still not well described. We applied polymerase chain reaction (PCR) and conventional methods to describe etiology of CAP in hospitalized adults and evaluated their respective diagnostic yields.267 CAP patients were enrolled consecutively over our 3-year prospective study. Conventional methods (i.e., bacterial cultures, urinary antigen assays, serology) were combined with nasopharyngeal (NP) and oropharyngeal (OP) swab samples analyzed by real-time quantitative PCR (qPCR) for Streptococcus pneumoniae, and by real-time PCR for Mycoplasma pneumoniae, Chlamydophila pneumoniae, Bordetella pertussis and 12 types of respiratory viruses.Etiology was established in 167 (63%) patients with 69 (26%) patients having ?1 copathogen. There were 75 (28%) pure bacterial and 41 (15%) pure viral infections, and 51 (19%) viral-bacterial coinfections, resulting in 126 (47%) patients with bacterial and 92 (34%) patients with viral etiology. S. pneumoniae (30%), influenza (15%) and rhinovirus (12%) were most commonly identified, typically with ?1 copathogen. During winter and spring, viruses were detected more frequently (45%, P=.01) and usually in combination with bacteria (39%). PCR improved diagnostic yield by 8% in 64 cases with complete sampling (and by 15% in all patients); 5% for detection of bacteria; 19% for viruses (P=.04); and 16% for detection of ?1 copathogen. Etiology was established in 79% of 43 antibiotic-naive patients with complete sampling. S. pneumoniae qPCR positive rate was significantly higher for OP swab compared to NP swab (P<.001). Positive rates for serology were significantly higher than for real-time PCR in detecting B. pertussis (P=.001) and influenza viruses (P<.001).Etiology could be established in 4 out of 5 CAP patients with the aid of PCR, particularly in diagnosing viral infections. S. pneumoniae and viruses were most frequently identified, usually with copathogens. Viral-bacterial coinfections were more common than pure infections during winter and spring; a finding we consider important in the proper management of CAP. When swabbing for qPCR detection of S. pneumoniae in adult CAP, OP appeared superior to NP, but this finding needs further confirmation.ClinicalTrials.gov Identifier: NCT01563315 .
| S-EPMC4334764 | biostudies-literature
Project description:BackgroundCommunity-acquired pneumonia (CAP) is an extraordinarily heterogeneous illness, both in the range of responsible pathogens and the host response. Metagenomic next-generation sequencing (mNGS) is a promising technology for pathogen detection. However, the clinical application of mNGS for pathogen detection remains challenging.MethodsA total of 205 patients with CAP admitted to the intensive care unit were recruited, and broncho alveolar lavage fluids (BALFs) from 83 patients, sputum samples from 33 cases, and blood from 89 cases were collected for pathogen detection by mNGS. At the same time, multiple samples of each patient were tested by culture. The diagnostic performance was compared between mNGS and culture for pathogen detection.ResultsThe positive rate of pathogen detection by mNGS in BALF and sputum samples was 89.2% and 97.0%, which was significantly higher (P < 0.001) than that (67.4%) of blood samples. The positive rate of mNGS was significantly higher than that of culture (81.0% vs. 56.1%, P = 1.052e-07). A group of pathogens including Mycobacterium abscessus, Chlamydia psittaci, Pneumocystis jirovecii, Orientia tsutsugamushi, and all viruses were only detected by mNGS. Based on mNGS results, Escherichia coli was the most common pathogen (15/61, 24.59%) of non-severe patients with CAP, and Mycobacterium tuberculosis was the most common pathogen (21/144, 14.58%) leading to severe pneumonia. Pneumocystis jirovecii was the most common pathogen (26.09%) in severe CAP patients with an immunocompromised status, which was all detected by mNGS only.ConclusionmNGS has higher overall sensitivity for pathogen detection than culture, BALF, and sputum mNGS are more sensitive than blood mNGS. mNGS is a necessary supplement of conventional microbiological tests for the pathogen detection of pulmonary infection.
| S-EPMC10061305 | biostudies-literature
Project description:Quantitative PCR on nasopharyngeal aspirate (NPA) can achieve high sensitivity and specificity in diagnosing Pneumocystis pneumonia (PCP) compared to microscopic examination of bronchoscopic specimens in a population with low HIV prevalence. Since NPA is a minimally invasive procedure, it is ideal as a screening test for PCP.
| S-EPMC3647954 | biostudies-literature
Project description:BACKGROUND:To compare the microbiological culture within endotracheal aspirate specimens (ETAs) and endotracheal tube specimens (ETTs) in patients undergoing mechanical ventilation (MV) by statistical tools. METHOD:ETAs and ETTs from a total number of 81 patients, who were undergoing MV at the intensive care unit (ICU) of Jiading Central Hospital Affiliated Shanghai University of Medicine & Health Sciences from September 1st, 2017 to August 31st, 2018, were collected for microbiological culture analysis. Correlation of ETAs and ETTs cultures were obtained by Spear-men correlation analysis, while the consistency of the two specimens was determined by Kappa analysis and principal component analysis (PCA). RESULTS:Microbiological culture from both ETAs and ETTs showed that Acinetobacter baumannii, Pseudomonas aeruginosa, Staphylococcus aureus, and Klebsiella pneumoniae were the main pathogens, with Spear-man correlation coefficients of 0.676, 0.951, 0.730 and 0.687 respectively (all P < 0.01), and the overall Spear-man correlation coefficient is 0.757 (P < 0.01). This result shows that two samples were positively correlated. Kappa analysis also revealed high consistency of the microbial culture results from the ETAs and the ETTs (overall κ = 0.751, P < 0.01). The κ values for the four bacteria detected were 0.670, 0.949, 0.723, and 0.687, respectively (all P < 0.001). PCA also revealed high similarity. CONCLUSION:Combining microbiological culture and statistical analysis of samples collected from 81 patients who were undergoing MV in ICU, we showed that microbe found in the ETAs had high similarity with that found in the ETTs which collected at the end of the catheters. In clinical practice, ETAs analysis is easily accessible meanwhile provides a valuable information for MV patients.
| S-EPMC6712863 | biostudies-other
Project description:Coronavirus disease 2019 (COVID-19), which reported in an outbreak in 2019 in Wuhan, Hubei province, China, is caused by the SARS-CoV-2 virus. The virus belongs to the beta-coronavirus class, along with the Middle East Respiratory Syndrome coronavirus and Severe Acute Respiratory Syndrome coronavirus. Interestingly, the virus binds with angiotensin-converting enzyme-2 found in host cells, through the spike (S) protein that exists on its surface. This binding causes the entry of the virus into cells of the host organism. The actual mechanism used by the COVID-19 virus to induce disease is still speculative. A total of 44,322,504 cases, a 1,173,189 death toll and 32,486,703 recovery cases have been reported in 217 countries globally as of 28 October 2020. Symptoms from the infection of the virus include chest pain, fever, fatigue, nausea, and others. Acute respiratory stress syndrome, arrhythmia, and shock are some of the chronic manifestations recorded in severe COVID-19. Transmission is majorly by individual-to-individual through coughing, sneezing, etc. The lack of knowledge regarding the mechanism of and immune response to the virus has posed a challenge in the development of a novel drug and vaccine. Currently, treatment of the disease involves the use of anti-viral medications such as lopinavir, remdesivir, and other drugs. These drugs show some efficacy in the management of COVID-19. Studies are still on-going for the development of an ideal and novel drug for treatment. In terms of natural product intervention, Traditional Chinese Medicines (TCM) have been employed to alleviate the clinical manifestation and severity of the disease and have shown some efficacy. This review presents an updated detailed overview of COVID-19 and the virus, concerning its structure, epidemiology, symptoms and transmission, immune responses, and current interventions, and highlights the potential of TCM. It is anticipated that this review will further add to the understanding of COVID-19 and the virus, hence opening new research perspectives.
| S-EPMC7662254 | biostudies-literature
Project description:Lung cancer is the leading cause of cancer-related death worldwide yet in vitro disease models have been limited to traditional 2D culture utilizing cancer cell lines. In contrast, recently developed 3D models (organoids) have been adopted by researchers to improve the physiological relevance of laboratory study. We have hypothesized that 3D hydrogel-based models will allow for improved disease replication and characterization over standard 2D culture using cells taken directly from patients. Here, we have leveraged the use of 3D hydrogel-based models to create lung cancer organoids using a unique cell source, pleural effusion aspirate, from multiple lung cancer patients. With these 3D models, we have characterized the cell populations comprising the pleural effusion aspirate and have tracked phenotypic changes that develop during short-term in vitro culture. We found that isolated, patient cells placed directly into organoids created anatomically relevant structures and exhibited lung cancer specific behaviors. On the other hand, cells first grown in plastic dishes and then cultured in 3D did not create similar structures. Further, we have been able to compare chemotherapeutic response of patient cells between 2D and 3D cell culture systems. Our results show that cells in 2D culture were more sensitive to treatment when compared with 3D organoids. Collectively, we have been able to utilize tumor cells from pleural effusion fluid of lung cancer patients to create organoids that display in vivo like anatomy and drug response and thus could serve as more accurate disease models for study of tumor progression and drug development.
| S-EPMC6853614 | biostudies-literature
Project description:BackgroundProsthetic valve endocarditis (PVE) is a feared complication after heart valve surgery. Studies on differences in bacteriology in various types of PVE are limited.ObjectivesThis study aimed to investigate the microbiology of PVE depending on the type of prosthetic valve and timing of diagnosis.MethodsA retrospective study based on the Swedish Registry on Infective Endocarditis focusing on PVE was conducted. The cohort was divided into mechanical and bioprosthetic valves; into endocarditis localization in the aortic, mitral, or tricuspid valve; and into early and late PVE. The microbiology in these groups was compared. Predictors of Staphylococcus aureus as the cause of PVE were examined by multivariable logistic regression.ResultsA total of 780 episodes of PVE in 749 patients were compared regarding the distribution of causative microbiological agents. The most common agents included alpha-hemolytic streptococci (29%), S. aureus (22%), enterococci (14%), coagulase-negative staphylococci (CoNS) (12%), and Cutibacterium acnes (6%). S. aureus was more commonly found on mechanical valves compared to bioprosthetic ones (36% vs. 17%, p < 0.001) whereas alpha-hemolytic streptococci, enterococci, and CoNS were more common on bioprosthetic valves. There were no significant differences in the microbiology of PVE affecting mitral or aortic valves or in cases of early and late PVE. Predictors for S. aureus as the cause of PVE were end-stage renal disease, intravenous drug use, mechanical valve, and tricuspid localization of endocarditis.ConclusionsThe type of prosthetic heart valve is associated with the causative pathogen. Patients with mechanical valves are more likely to have PVE caused by S. aureus.
| S-EPMC9541636 | biostudies-literature