Purpose: Characterization of the respiratory tract bacterial microbiome is in its infancy when compared to the gut microbiota. To limit bias mandates a robust methodology. Specific amplification of the hypervariable (V) region of the 16SrRNA gene is a crucial step. Differences in accuracy exist for one V region to another depending on the sampled environment. We aimed to assess the impact of the primer sequences targeting the V4 region currently used for gut microbiota studies in respiratory samples. Materials and methods: The original 515 F-806R primer pair targets the V4 region of the 16SrRNA gene. We compared two different 515 F-806R primer pairs before Illumina 250 paired-end sequencing for bacterial microbiome analyses of respiratory samples from critically-ill ventilated patients. “S-V4” for “Stringent V4” primer pair is used in two ongoing international projects “the Integrative Human microbiome project (iHMP)” and “the Earth microbiome project (EMP).” “R-V4” for “Relaxed V4” primer pair has been modified to reduce biases against specific environmental taxa. The optimal method was determined by concordance with conventional microbiology. Results: Twenty samples from three patients who developed a ventilator-associated pneumonia (VAP) and four who did not (control ventilated patients) were sequenced. Highly different results were obtained. “S-V4” provided the best agreement with the conventional microbiology for endotracheal aspirate: 89% as compared to 56% for “R-V4.” The main difference related to poor Enterobacteriaceae detection with “R-V4” primers. Conclusions: Accuracy of the bacterial lung microbiome composition was highly dependent on the primers used for amplification of the 16 s rRNA hypervariable sequence. This work validates for future lung microbiome studies the use of the 515 F-806R “S-V4” primer pair associated to Illumina® MiSeq paired-end sequencing.
Local microcirculatory disturbances and fibrosis are thought to contribute to the pathogenesis of erectile dysfunction (ED). The assessment of these disturbances is now possible using non-invasive techniques such as laser Doppler flowmetry (LDF) and measuring transcutaneous pO2 and pCO2. However, these techniques need standardisation (e.g. in terms of equipment, conditions in which the examination is carried out and duration of measurement). Nevertheless, these techniques have a qualitative value. Marked alterations are seen in smokers and hypertensive patients. LDF has also been used to monitor the effect of treatment (e.g. after intracavernosal PGE1). These techniques remain non-diagnostic in individual patients. However, in groups of patients they may produce useful information (e.g. to assess treatments for ED).
Background: The lung microbiome is composed of bacteria, viruses and fungi that interplay with each other and participate in mucosal defense protecting the lungs from colonization and infection by pathogenic microorganisms. In intensive care, a change in the composition of the lung microbiome, called dysbiosis, could be associated to the occurrence of ventilator-associated pneumonia. The objective of the study was to test a method to assess the lung virome.Methods: We applied a protocol including the same nucleic acid extraction methods as used for bacterial lung microbiome and a metagenomic next-generation sequencing (mNGS) to detect eukaryotic RNA, DNA viruses and bacteriophages.Results: Our method was able to detect all viruses identified with multiplex polymerase chain reaction (PCR), other eukaryotic viruses not included in the multiplex PCR panel, and bacteriophages. Notably persistent viruses, mainly Herpesviridae, associated with opportunistic infections and those showing immunodepression such as Anellovirus have been identified.Conclusions: A better description of the global composition and evolution of the lung microbiome, including viruses, could help to better understand ventilator-associated pneumonia occurrence and outcomes.
Characterization of the respiratory tract bacterial microbiome is in its infancy when compared to the gut microbiota. To limit bias mandates a robust methodology. Specific amplification of the hypervariable (V) region of the 16SrRNA gene is a crucial step. Differences in accuracy exist for one V region to another depending on the sampled environment. We aimed to assess the impact of the primer sequences targeting the V4 region currently used for gut microbiota studies in respiratory samples. Materials and methods: The original 515 F-806R primer pair targets the V4 region of the 16SrRNA gene. We compared two different 515 F-806R primer pairs before Illumina 250 paired-end sequencing for bacterial microbiome analyses of respiratory samples from critically-ill ventilated patients. "S-V4" for "Stringent V4" primer pair is used in two ongoing international projects "the Integrative Human microbiome project (iHMP)" and "the Earth microbiome project (EMP)." "R-V4" for "Relaxed V4" primer pair has been modified to reduce biases against specific environmental taxa. The optimal method was determined by concordance with conventional microbiology. Results: Twenty samples from three patients who developed a ventilator-associated pneumonia (VAP) and four who did not (control ventilated patients) were sequenced. Highly different results were obtained. "S-V4" provided the best agreement with the conventional microbiology for endotracheal aspirate: 89% as compared to 56% for "R-V4." The main difference related to poor Enterobacteriaceae detection with "R-V4" primers. Conclusions: Accuracy of the bacterial lung microbiome composition was highly dependent on the primers used for amplification of the 16 s rRNA hypervariable sequence. This work validates for future lung microbiome studies the use of the 515 F-806R "S-V4" primer pair associated to Illumina® MiSeq paired-end sequencing.
Rationale For veno-arterial extracorporeal membrane oxygenation (ECMO), the femoral artery is the preferred cannulation site (femoro-femoral: Vf-Af). This results in retrograde aortic flow, which increases the left ventricular afterload and can lead to severe pulmonary edema and thrombosis of the cardiac chambers. Right axillary artery cannulation (femoral-axillary: Vf-Aa) provides partial anterograde aortic flow, which may prevent some complications. This study aimed to compare the 90-day mortality and complication rates between VF-AA and VF-AF. Methods Consecutive adult patients with cardiogenic shock who received peripheral VA-ECMO between 2013 and 2019 at our institution were retrospectively included. The exclusion criteria were refractory cardiac arrest, multiple VA-ECMO implantations due to vascular access changes, weaning failure, or ICU readmission. A statistical approach using inverse probability of treatment weighting was used to estimate the effect of the cannulation site on the outcomes. The primary endpoint was the 90-day mortality. The secondary endpoints were vascular access complications, stroke, and other complications related to retrograde blood flow. Outcomes were estimated using logistic regression analysis. Results VA-ECMO was performed on 534 patients. Patients with refractory cardiac arrest ( n = 77 (14%)) and those supported by multiple VA-ECMO ( n = 92, (17%)) were excluded. Out of the 333 patients studied ( n = 209 Vf-Aa; n = 124 VF-AF), the main indications for VA-ECMO implantation were post-cardiotomy (33%, n = 109), dilated cardiomyopathy (20%, n = 66), post-cardiac transplantation (15%, n = 50), acute myocardial infarction (14%, n = 46) and other etiologies (18%, n = 62). The median SOFA score was 9 [7-11], and the crude 90-day mortality rate was 53% ( n = 175). After IPTW, the 90-day mortality was similar in the Vf-Aa and VF-AF groups (54% vs 58%, IPTW-OR = 0.84 [0.54-1.29]). Axillary artery cannulation was associated with significantly fewer local infections (OR = 0.21, 95% CI:0.09-0.51), limb ischemia (OR = 0.37, 95% CI:0.17-0.84), bowel ischemia (OR = 0.16, 95% CI:0.05-0.51) and pulmonary edema (OR = 0.52, 95% CI:0.29-0.92) episodes, but with a higher rate of stroke (OR = 2.87, 95% CI:1.08-7.62) than femoral artery cannulation. Conclusion Compared to VF-AF, axillary cannulation was associated with similar 90-day mortality rates. The high rate of stroke associated with axillary artery cannulation requires further investigation.
Spontaneous coronary artery dissection (SCAD), an intramural hemorrhage leading to a separation of the layers of the coronary artery wall, is traditionally considered a rare condition associated mainly with pregnancy but is likely underdiagnosed in other settings. Its recognition by coronary angiography is key. Medical management is usually indicated, except in certain circumstances in which coronary artery bypass grafting or percutaneous coronary intervention should be considered.
