Journal of clinical microbiology
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J. Clin. Microbiol. · Dec 2014
Severity-related changes of bronchial microbiome in chronic obstructive pulmonary disease.
Bronchial colonization by potentially pathogenic microorganisms (PPMs) is often demonstrated in chronic obstructive pulmonary disease (COPD), but culture-based techniques identify only a portion of the bacteria in mucosal surfaces. The aim of the study was to determine changes in the bronchial microbiome of COPD associated with the severity of the disease. The bronchial microbiome of COPD patients was analyzed by 16S rRNA gene amplification and pyrosequencing in sputum samples obtained during stable disease. ⋯ The most prevalent phyla in sputum were Proteobacteria (44%) and Firmicutes (16%), followed by Actinobacteria (13%). A greater microbial diversity was found in patients with moderate-to-severe disease, and alpha diversity showed a statistically significant decrease in patients with advanced disease when assessed by Shannon (ρ = 0.528; P = 0.029, Spearman correlation coefficient) and Chao1 (ρ = 0.53; P = 0.028, Spearman correlation coefficient) alpha-diversity indexes. The higher severity that characterizes advanced COPD is paralleled by a decrease in the diversity of the bronchial microbiome, with a loss of part of the resident flora that is replaced by a more restricted microbiota that includes PPMs.
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J. Clin. Microbiol. · Nov 2014
Single-molecule long-read 16S sequencing to characterize the lung microbiome from mechanically ventilated patients with suspected pneumonia.
In critically ill patients, the development of pneumonia results in significant morbidity and mortality and additional health care costs. The accurate and rapid identification of the microbial pathogens in patients with pulmonary infections might lead to targeted antimicrobial therapy with potentially fewer adverse effects and lower costs. Major advances in next-generation sequencing (NGS) allow culture-independent identification of pathogens. ⋯ Overall, a significant diversity of bacterial species was identified from the same genus as the predominant cultured pathogens. The numbers of NGS-identifiable bacterial genera were consistently higher than identified by standard microbiological methods. As technical advances reduce the processing and sequencing times, NGS-based methods will ultimately be able to provide clinicians with rapid, precise, culture-independent identification of bacterial, fungal, and viral pathogens and their antimicrobial sensitivity profiles.
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J. Clin. Microbiol. · Nov 2014
Comparative StudyClinical evaluation of multiple inflammation biomarkers for diagnosis and prognosis for patients with systemic inflammatory response syndrome.
A multiplexed biomarker bundle consisting of nine different inflammation markers was evaluated regarding their diagnostic and prognostic performances in 159 adult systemic inflammatory response syndrome (SIRS) patients enrolled at the emergency department. Fibronectin, interleukin-8 (IL-8), biotin, and neutrophil gelatinase-associated lipocalin (NGAL) were the most robust markers but were not superior to the already established markers IL-6, C-reactive protein (CRP), procalcitonin (PCT), and soluble urokinase plasminogen activator receptor (suPAR).
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J. Clin. Microbiol. · Nov 2014
Comparative StudyReassessment of genotype 1 hepatitis C virus subtype misclassification by LiPA 2.0: implications for direct-acting antiviral treatment.
The accuracy of LiPA 2.0 for hepatitis C virus 1 (HCV-1) subtype classification was analyzed. LiPA 2.0 genotype results from 101 HCV-1-infected patients were compared to genotype findings determined by direct core sequencing. Eleven (11%) samples were misclassified. Given the influence of the HCV-1-subtype in the anti-HCV therapy response, an alternative classification method is warranted.
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J. Clin. Microbiol. · Oct 2014
Comparative StudyAnalysis of culture-dependent versus culture-independent techniques for identification of bacteria in clinically obtained bronchoalveolar lavage fluid.
The diagnosis and management of pneumonia are limited by the use of culture-based techniques of microbial identification, which may fail to identify unculturable, fastidious, and metabolically active viable but unculturable bacteria. Novel high-throughput culture-independent techniques hold promise but have not been systematically compared to conventional culture. We analyzed 46 clinically obtained bronchoalveolar lavage (BAL) fluid specimens from symptomatic and asymptomatic lung transplant recipients both by culture (using a clinical microbiology laboratory protocol) and by bacterial 16S rRNA gene pyrosequencing. ⋯ We present two case studies in which culture-independent techniques identified a respiratory pathogen missed by culture and clarified whether a cultured "oral flora" species represented a state of acute infection. In summary, we found that bacterial culture of BAL fluid is largely effective in discriminating acute infection from its absence and identified some specific limitations of BAL fluid culture in the diagnosis of pneumonia. We report the first correlation of quantitative BAL fluid culture results with culture-independent evidence of infection.