scholarly journals Clostridium difficilealters the structure and metabolism of distinct cecal microbiomes during initial infection to promote sustained colonization

2017 ◽  
Author(s):  
Matthew L. Jenior ◽  
Jhansi L. Leslie ◽  
Vincent B. Young ◽  
Patrick D. Schloss

AbstractSusceptibility toClostridium difficileinfection is primarily associated with previous exposure to antibiotics, which compromise the structure and function of the gut bacterial community. Specific antibiotic classes correlate more strongly with recurrent or persistentC. difficileinfection. As such, we utilized a mouse model of infection to explore the effect of distinct antibiotic classes on the impact that infection has on community-level transcription and metabolic signatures shortly following pathogen colonization and how those changes may associate with persistence ofC. difficile. Untargeted metabolomic analysis revealed thatC. difficileinfection had significantly larger impacts on the metabolic environment across cefoperazone and streptomycin-pretreated mice, which become persistently colonized compared to clindamycin-pretreated mice where infection quickly became undetectable. Through metagenome-enabled metatranscriptomics we observed that transcripts for genes associated with carbon and energy acquisition were greatly reduced in infected animals, suggesting those niches were instead occupied byC. difficile. Furthermore, the largest changes in transcription were seen in the least abundant species indicating thatC. difficilemay “attack the loser” in gut environments where sustained infection occurs more readily. Overall, our results suggest thatC. difficileis able to restructure the nutrient-niche landscape in the gut to promote persistent infection.

2011 ◽  
Vol 21 (3) ◽  
pp. 112-117 ◽  
Author(s):  
Elizabeth Erickson-Levendoski ◽  
Mahalakshmi Sivasankar

The epithelium plays a critical role in the maintenance of laryngeal health. This is evident in that laryngeal disease may result when the integrity of the epithelium is compromised by insults such as laryngopharyngeal reflux. In this article, we will review the structure and function of the laryngeal epithelium and summarize the impact of laryngopharyngeal reflux on the epithelium. Research investigating the ramifications of reflux on the epithelium has improved our understanding of laryngeal disease associated with laryngopharyngeal reflux. It further highlights the need for continued research on the laryngeal epithelium in health and disease.


2021 ◽  
Vol XXXVII (1) ◽  
pp. 89-100
Author(s):  
Dorota Kondej

This paper presents basic information on a structure and function of biological membranes. Types of biomimetic membranes modelling properties of biological membranes were introduced. The method of testing surface properties of a lipid monolayer, which is the basic type of biomimetic membranes, was described. The presented method makes it possible to evaluate the effect of nanoparticles on the surface activity of biomimetic membranes based on the determination of the surface index MA. This article discusses the problems of occupational safety and health, which are covered by health sciences and environmental engineering.


2016 ◽  
Vol 14 (1) ◽  
pp. nrs.14002 ◽  
Author(s):  
Shailaja D. Divekar ◽  
Deanna M. Tiek ◽  
Aileen Fernandez ◽  
Rebecca B. Riggins

Estrogen-related receptors (ERRs) are founding members of the orphan nuclear receptor (ONR) subgroup of the nuclear receptor superfamily. Twenty-seven years of study have yet to identify cognate ligands for the ERRs, though they have firmly placed ERRα (ESRRA) and ERRγ (ESRRG) at the intersection of cellular metabolism and oncogenesis. The pace of discovery for novel functions of ERRβ (ESRRB), however, has until recently been somewhat slower than that of its family members. ERRβ has also been largely ignored in summaries and perspectives of the ONR literature. Here, we provide an overview of established and emerging knowledge of ERRβ in mouse, man, and other species, highlighting unique aspects of ERRβ biology that set it apart from the other two estrogen-related receptors, with a focus on the impact of alternative splicing on the structure and function of this receptor.


2013 ◽  
Vol 448-453 ◽  
pp. 529-531
Author(s):  
Jing Bo Zhao ◽  
Li Bo Hao

Analysis of the causes of dust brick and tile production enterprises, from the impact on human health, the factory machinery and equipment wear, impact on environment protection, expounds the harmfulness of dust, and discusses the type, structure and function of the filter, as well as the precipitator combined use method and way to control dust.


2018 ◽  
Vol 285 (1890) ◽  
pp. 20181717 ◽  
Author(s):  
Denon Start ◽  
Stephen De Lisle

Intraspecific variation can have important consequences for the structure and function of ecological communities, and serves to link community ecology to evolutionary processes. Differences between the sexes are an overwhelmingly common form of intraspecific variation, but its community-level consequences have never been experimentally investigated. Here, we manipulate the sex ratio of a sexually dimorphic predacious newt in aquatic mesocosms, then track their impact on prey communities. Female and male newts preferentially forage in the benthic and pelagic zones, respectively, causing corresponding reductions in prey abundances in those habitats. Sex ratio differences also explained a large proportion (33%) of differences in the composition of entire pond communities. Ultimately, we demonstrate the impact of known patterns of sexual dimorphism in a predator on its prey, uncovering overlooked links between evolutionary adaptation and the structure of contemporary communities. Given the extreme prevalence of sexual dimorphism, we argue that the independent evolution of the sexes will often have important consequences for ecological communities.


Amino Acids ◽  
2019 ◽  
Vol 51 (10-12) ◽  
pp. 1409-1431 ◽  
Author(s):  
Luigi Grassi ◽  
Chiara Cabrele

Abstract Peptides and proteins are preponderantly emerging in the drug market, as shown by the increasing number of biopharmaceutics already approved or under development. Biomolecules like recombinant monoclonal antibodies have high therapeutic efficacy and offer a valuable alternative to small-molecule drugs. However, due to their complex three-dimensional structure and the presence of many functional groups, the occurrence of spontaneous conformational and chemical changes is much higher for peptides and proteins than for small molecules. The characterization of biotherapeutics with modern and sophisticated analytical methods has revealed the presence of contaminants that mainly arise from oxidation- and elimination-prone amino-acid side chains. This review focuses on protein chemical modifications that may take place during storage due to (1) oxidation (methionine, cysteine, histidine, tyrosine, tryptophan, and phenylalanine), (2) intra- and inter-residue cyclization (aspartic and glutamic acid, asparagine, glutamine, N-terminal dipeptidyl motifs), and (3) β-elimination (serine, threonine, cysteine, cystine) reactions. It also includes some examples of the impact of such modifications on protein structure and function.


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