Disruption of the microbiota across multiple body sites in critically ill children.

Background: Despite intense interest in the links between the microbiome and human health, little has been written about dysbiosis among ICU patients. We characterized microbial diversity in samples from 37 children in a pediatric ICU (PICU). Standard measures of alpha and beta diversity were calculated, and results were compared with data from adult and pediatric reference datasets.

Disturbances of the Perioperative Microbiome Across Multiple Body Sites in Patients Undergoing Pancreaticoduodenectomy.

Objective: The goals of this study were to characterize bacterial communities within fecal samples, pancreatic fluid, bile, and jejunal contents from patients undergoing pancreaticoduodenectomy (PD) and to identify associations between microbiome profiles and clinical variables.

Methods: Fluid was collected from the pancreas, common bile duct, and proximal jejunum from 50 PD patients. Postoperative fecal samples were also collected.

Acute Appendicitis in Children Is Associated With a Local Expansion of Fusobacteria.

Background: Lumenal obstruction has typically been regarded as the cause of acute appendicitis (AA). Recent evidence including data from "antibiotics first" trials suggests that this disease may result from invasion of the appendix by specific pathogens. Small studies have identified an abundance of bacteria from the genus Fusobacterium in appendixes from patients with AA.

Mucosa-associated bacterial diversity in necrotizing enterocolitis.

Background: Previous studies of infant fecal samples have failed to clarify the role of gut bacteria in the pathogenesis of NEC. We sought to characterize bacterial communities within intestinal tissue resected from infants with and without NEC.

Methods: 26 intestinal samples were resected from 19 infants, including 16 NEC samples and 10 non-NEC samples.

Acute appendicitis in children is associated with an abundance of bacteria from the phylum Fusobacteria.

Background: Although luminal obstruction has traditionally been viewed as the underlying cause of appendicitis, recent evidence has suggested that the disease may result directly from invasion by specific pathogens, e.g. Fusobacterium nucleatum.

Intestinal epithelial Toll-like receptor 4 regulates goblet cell development and is required for necrotizing enterocolitis in mice.

Background & Aims: Little is known about factors that regulate intestinal epithelial differentiation; microbial recognition receptors such as Toll-like receptor (TLR)4 might be involved. We investigated whether intestinal TLR4 regulates epithelial differentiation and is involved in development of necrotizing enterocolitis (NEC) of the immature intestine.

Methods: Mice with conditional disruption of TLR4 in the intestinal epithelium and TLR4 knockout (TLR4(-/-)) mice were generated by breeding TLR4(loxp/loxp) mice with villin-cre and Ella-cre, respectively.

Large scale comparison of innate responses to viral and bacterial pathogens in mouse and macaque.

Viral and bacterial infections of the lower respiratory tract are major causes of morbidity and mortality worldwide. Alveolar macrophages line the alveolar spaces and are the first cells of the immune system to respond to invading pathogens. To determine the similarities and differences between the responses of mice and macaques to invading pathogens we profiled alveolar macrophages from these species following infection with two viral (PR8 and Fuj/02 influenza A) and two bacterial (Mycobacterium tuberculosis and Francisella tularensis Schu S4) pathogens.

The role of RNA folding free energy in the evolution of the polymerase genes of the influenza A virus.

Background: The influenza A virus genome is composed of eight single-stranded RNA segments of negative polarity. Although the hemagglutinin and neuraminidase genes are known to play a key role in host adaptation, the polymerase genes (which encode the polymerase segments PB2, PB1, PA) and the nucleoprotein gene are also important for the efficient propagation of the virus in the host and for its adaptation to new hosts. Current efforts to understand the host-specificity of the virus have largely focused on the amino acid differences between avian and human isolates.

Regulatory circuit of human microRNA biogenesis.

miRNAs (microRNAs) are a class of endogenous small RNAs that are thought to negatively regulate protein production. Aberrant expression of many miRNAs is linked to cancer and other diseases. Little is known about the factors that regulate the expression of miRNAs.