Characteristics of pediatric recurrent acute mastoiditis: A case-control study.

Background: Data on pediatric recurrent acute mastoiditis are lacking, despite its morbidity and clinical significance. Our aim was to describe the incidence, characteristics, and associated factors of recurrent mastoiditis in hospitalized children.

Methods: Using a case-control design, analyzing electronic data of hospitalized children with acute mastoiditis between June 2011 and December 2018, children with recurrent mastoiditis were compared to children with a single episode at the time of hospitalization.

Hyperlactatemia in children following brain tumor resection: prevalence, associated factors, and clinical significance.

Purpose: Hyperlactatemia is associated with worse outcome among critically ill patients. The prevalence of hyperlactatemia in children following craniotomy for intracranial tumor resection is unknown. This study was designed to assess the prevalence, associated factors, and significance of postoperative hyperlactatemia in this context.

Site-Specific Evolutionary Rate Shifts in HIV-1 and SIV.

Site-specific evolutionary rate shifts are defined as protein sites, where the rate of substitution has changed dramatically across the phylogeny. With respect to a given clade, sites may either undergo a rate acceleration or a rate deceleration, reflecting a site that was conserved and became variable, or vice-versa, respectively. Sites displaying such a dramatic evolutionary change may point to a loss or gain of function at the protein site, reflecting adaptation, or they may indicate epistatic interactions among sites.

Drivers of within-host genetic diversity in acute infections of viruses.

Genetic diversity is the fuel of evolution and facilitates adaptation to novel environments. However, our understanding of what drives differences in the genetic diversity during the early stages of viral infection is somewhat limited. Here, we use ultra-deep sequencing to interrogate 43 clinical samples taken from early infections of the human-infecting viruses HIV, RSV and CMV.

Competition between social cheater viruses is driven by mechanistically different cheating strategies.

Cheater viruses, also known as defective interfering viruses, cannot replicate on their own yet replicate faster than the wild type upon coinfection. While there is growing interest in using cheaters as antiviral therapeutics, the mechanisms underlying cheating have been rarely explored. During experimental evolution of MS2 phage, we observed the parallel emergence of two independent cheater mutants.

Inferring population genetics parameters of evolving viruses using time-series data.

With the advent of deep sequencing techniques, it is now possible to track the evolution of viruses with ever-increasing detail. Here, we present Flexible Inference from Time-Series (FITS)-a computational tool that allows inference of one of three parameters: the fitness of a specific mutation, the mutation rate or the population size from genomic time-series sequencing data. FITS was designed first and foremost for analysis of either short-term Evolve & Resequence (E&R) experiments or rapidly recombining populations of viruses.

Correction: Within-patient mutation frequencies reveal fitness costs of CpG dinucleotides and drastic amino acid changes in HIV.

[This corrects the article DOI: 10.1371/journal.pgen.

Within-patient mutation frequencies reveal fitness costs of CpG dinucleotides and drastic amino acid changes in HIV.

HIV has a high mutation rate, which contributes to its ability to evolve quickly. However, we know little about the fitness costs of individual HIV mutations in vivo, their distribution and the different factors shaping the viral fitness landscape. We calculated the mean frequency of transition mutations at 870 sites of the pol gene in 160 patients, allowing us to determine the cost of these mutations.