Systematic use of universal 16S rRNA gene polymerase chain reaction (PCR) and sequencing for processing pleural effusions improves conventional culture techniques

Conventional culture of pleural fluid samples frequently provides false-negative results. Universal polymerase chain reaction (PCR) of the 16S ribosomal ribonucleic acid (rRNA) gene (16S PCR) has proven useful in the diagnosis of various bacterial infections. We conducted a prospective study to assess the value of 16S PCR in the etiologic diagnosis of pleural effusion. All pleural fluid samples received for culture were also studied using 16S PCR. Positive samples were sequenced for identification. Clinical records and conventional culture results were analyzed to classify pleural fluid samples as infected or not infected. We studied 723 samples. We excluded 188 samples because they were obtained from a long-term chest tube, there was a diagnosis of mycobacterial infection, or there were insufficient data to classify the episode. Finally, 535 pleural fluid samples were analyzed. According to our criteria, 82 (15.3%) were infected and 453 (84.7%) were not infected. In the infected samples, 16S PCR was positive in 67 samples (81.7%) while conventional culture was positive in 45 (54.9%). There were 4 false positives with 16S PCR (0.9%) and 12 with culture (2.6%). The values for the etiologic diagnosis of bacterial pleural effusion of conventional culture compared with 16S PCR were as follows: sensitivity, 54.9%/81.7%; specificity, 97.4%/99.1%; positive predictive value, 76.3%/94.4%; negative predictive value, 92.6%/96.8%; and accuracy, 90.8%/96.5%.When compared with conventional culture, 16S PCR plus sequencing substantially improves the etiologic diagnosis of infectious pleural effusion. In our opinion, this technique should be added to the routine diagnostic armamentarium of clinical microbiology laboratories.     

Neuregulin-1, the fetal endothelium,and brain damage in preterm newborns

ObjectiveTo assess the potential role for Neuregulin-1 (NRG1) as a systemic endogenous protector in the setting of perinatal inflammatory brain damage.MethodsWe measured NRG1-protein and mRNA levels in human umbilical venous endothelial cells (HUVECs) of different gestational ages at various durations of exposure to lipopolysaccharide (LPS). In parallel, we genotyped the donor individuals for SNP8NRG221533, a disease-related single nucleotide polymorphism in the 5′ region upstream of the NRG1 sequence. Intracellular NRG1 localization was visualized by confocal microscopy. Furthermore we analyzed the relationship between SNP8NRG221533 genotype and neurodevelopmental outcome in children born preterm.ResultsWe observed a positive dose–response-relationship between NRG1-mRNA and intracellular protein levels with both advancing gestational age and duration of LPS exposure in HUVECs. The presence of allele C at the SNP8NRG221533 locus was associated with an increased cellular production of NRG1 in HUVECs, and with a significantly reduced risk for cerebral palsy and developmental delay in children born preterm.InterpretationIn conclusion, our data indicate that gestational age, duration of LPS exposure, and the SNP8NRG221533 genotype affect NRG1 levels. Our results support the hypothesis that NRG1 may qualify as an endogenous protector during fetal development.     

One Health: Eine Sichtweise des informellen ministeriellen Netzwerkes

Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz - Aus Sicht der Bundesregierung ist der One-Health-Ansatz ein wegweisender Kompass für ein inter- und transdisziplinäres...     

Effectiveness of different fiber post removal techniques and their influence on dentinal microcrack formation

Clinical Oral Investigations - The aim of this study was to evaluate the effectiveness of different fiber post removal techniques and to correlate dentinal loss with microcrack formation....