24 research outputs found
Preterm gut microbiota and metabolome following discharge from intensive care
The development of the preterm gut microbiome is important for immediate and longer-term health following birth. We aimed to determine if modifications to the preterm gut on the neonatal intensive care unit (NICU) impacted the gut microbiota and metabolome long-term. Stool samples were collected from 29 infants ages 1–3 years post discharge (PD) from a single NICU. Additional NICU samples were included from 14/29 infants. Being diagnosed with disease or receiving increased antibiotics while on the NICU did not significantly impact the microbiome PD. Significant decreases in common NICU organisms including K. oxytoca and E. faecalis and increases in common adult organisms including Akkermansia sp., Blautia sp., and Bacteroides sp. and significantly different Shannon diversity was shown between NICU and PD samples. The metabolome increased in complexity, but while PD samples had unique bacterial profiles we observed comparable metabolomic profiles. The preterm gut microbiome is able to develop complexity comparable to healthy term infants despite limited environmental exposures, high levels of antibiotic administration, and of the presence of serious disease. Further work is needed to establish the direct effect of weaning as a key event in promoting future gut health
Improved Cauchy radius for scalar and matrix polynomials
We improve the Cauchy radius of both scalar and matrix polynomials, which is
an upper bound on the moduli of the zeros and eigenvalues, respectively, by
using appropriate polynomial multipliers.Comment: 12 page
Stool bacterial load in preterm infants with necrotising enterocolitis
Resected gut tissue in necrotising enterocolitis (NEC) has a higher bacterial load than controls. Quantitative PCR was performed on longitudinal NEC and control stool samples (n = 72). No significant difference in the total bacterial load was found between samples at diagnosis compared to controls or temporally within NEC
Cytomegalovirus and other common enteric viruses are not commonly associated with NEC
Aim - Changes in gut microbiota may contribute to NEC, but most studies focus on bacteria. Case reports suggest a link between cytomegalovirus (CMV) or other enteric viruses and NEC, but there are few case series systematically looking at common potential viral causes. We aimed to assess the presence of candidate viruses in blood or stool of a case series of infants with NEC managed in one surgical centre.
Methods - We identified 22 infants diagnosed with NEC (from November 2011 to March 2014): 17 had suitable blood stored, of whom 14 also had suitable stool samples stored. Blood was analysed with polymerase chain reaction (PCR) for CMV, Epstein–Barr virus (EBV) and adenovirus, and stool by PCR for norovirus, sappovirus, astrovirus, adenovirus and rotavirus.
Results - All samples were negative.
Conclusion - Although case reports indicate an episodic association of enteric viruses in NEC, the inability to detect any of these viruses in our 17 NEC infants suggests that a viral aetiology is unlikely to be causative for most sporadic forms of NEC
Amérique du Sud : Venezuela : Etat d'Amazonas : L'Orénoque, frontière avec la Colombie : Prise de vue 2/2
Légende manuscrite sur le document original : "Amazonie. Affluent de l'Orénoque. " Géolocalisation : approximative centrée sur l'Etat d'Amazonas
Additional file 5: Figure S3. of Longitudinal development of the gut microbiome and metabolome in preterm neonates with late onset sepsis and healthy controls
Spares partial least squared correlations (sPLS) between dominant bacterial genera and identified metabolites from control infants only. Analysis excludes infants diagnosed with late onset sepsis. Only significant metabolites based on the samples at diagnosis (time point 0) and the top 10 most abundant bacterial taxa were included. (PDF 145Ă‚Â kb
Additional file 4: Figure S2. of Longitudinal development of the gut microbiome and metabolome in preterm neonates with late onset sepsis and healthy controls
Heatmaps of the most dominant bacterial genera per each preterm gut community type (PGCT). (A) PGCT 1. (B) PGCT 2. (C) PGCT 3. (D) PGCT 4. (E) PGCT 15. (F) PGCT 6. Genera shown in bold are dominant in that PGCT. (PDF 348Ă‚Â kb
Elevated levels of circulating cell-free DNA and neutrophil proteins are associated with neonatal sepsis and necrotizing enterocolitis in immature mice, pigs and infants
Preterm infants are highly susceptible to late-onset sepsis (LOS) and necrotizing enterocolitis (NEC), but disease pathogenesis and specific diagnostic markers are lacking. Circulating cell-free DNA (cfDNA) and immune cell-derived proteins are involved in multiple immune diseases in adults but have not been investigated in preterm neonates. We explored the relation of circulating neutrophil-associated proteins and cfDNA to LOS and/or NEC. Using a clinically relevant preterm pig model of spontaneous LOS and NEC development, we investigated neutrophil-associated proteins and cfDNA in plasma, together with cytokines in gut tissues. The changes in cfDNA levels were further studied in preterm pigs and neonatal mice with induced sepsis, and in preterm infants with or without LOS and/or NEC. Fifteen of 114 preterm pigs spontaneously developed both LOS and NEC, and they showed increased intestinal levels of IL-6 and IL-1β and plasma levels of cfDNA, neutrophil-associated proteins, and proteins involved in platelet-neutrophil interaction during systemic inflammation. The abundance of neutrophil-associated proteins highly correlated with cfDNA levels. Further, Staphylococcus epidermidis challenge of neonatal mice and preterm pigs increased plasma cfDNA levels and bacterial accumulation in the spleen. In infants, plasma cfDNA levels were elevated at LOS diagnosis and 1–6 d before NEC. In conclusion, elevated levels of plasma cfDNA and neutrophil proteins are associated with LOS and NEC diagnosis. </jats:p
Additional file 6: Figure S5. of Temporal bacterial and metabolic development of the preterm gut reveals specific signatures in health and disease
Shannon diversity indices overtime of all samples grouped according to preterm community type (PGCT). Grey shading indicates the 95% confidence interval of the mean. (PDF 64 kb