Host–Symbiont–Pathogen–Host Interactions: Wolbachia, Vector-Transmitted Human Pathogens, and the Importance of Quantitative Models of Multipartite Coevolution

2015 ◽  
pp. 207-230
Author(s):  
Caetano Souto-Maior
Keyword(s):  
Human Pathogens ◽  
Host Interactions ◽  
Quantitative Models

scholarly journals Prophages and Past Prophage-Host Interactions Revealed by CRISPR Spacer Content in a Fish Pathogen

2020 ◽  
Vol 8 (12) ◽  
pp. 1919
Author(s):  
Elina Laanto ◽  
Janne J. Ravantti ◽  
Lotta-Riina Sundberg
Keyword(s):  
Flavobacterium Columnare ◽  
Strain Atcc ◽  
Human Pathogens ◽  
Fish Pathogen ◽  
Bacterial Strains ◽  
Host Interactions ◽  
Different Strains ◽  
Gene Orthologs ◽  
Similar Genome Organization

The role of prophages in the evolution, diversification, or virulence of the fish pathogen Flavobacterium columnare has not been studied thus far. Here, we describe a functional spontaneously inducing prophage fF4 from the F. columnare type strain ATCC 23463, which is not detectable with commonly used prophage search methods. We show that this prophage type has a global distribution and is present in strains isolated from Finland, Thailand, Japan, and North America. The virions of fF4 are myoviruses with contractile tails and infect only bacterial strains originating from Northern Finland. The fF4 resembles transposable phages by similar genome organization and several gene orthologs. Additional bioinformatic analyses reveal several species in the phylum Bacteroidetes that host a similar type of putative prophage, including bacteria that are important animal and human pathogens. Furthermore, a survey of F. columnare Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) spacers indicate a shared evolutionary history between F. columnare strains and the fF4 phage, and another putative prophage in the F. columnare strain ATCC 49512, named p49512. First, CRISPR spacer content from the two CRISPR loci (types II-C and VI-B) of the fF4 lysogen F. columnare ATCC 23463 revealed a phage terminase protein-matching spacer in the VI-B locus. This spacer is also present in two Chinese F. columnare strains. Second, CRISPR analysis revealed four F. columnare strains that contain unique spacers targeting different regions of the putative prophage p49512 in the F. columnare strain ATCC 49512, despite the geographical distance or genomovar of the different strains. This suggests a common ancestry for the F. columnare prophages and different host strains.

scholarly journals Genome Sequencing and Transposon Mutagenesis of Burkholderia seminalis TC3.4.2R3 Identify Genes Contributing to Suppression of Orchid Necrosis Caused by B. gladioli

2016 ◽  
Vol 29 (6) ◽  
pp. 435-446 ◽  
Author(s):  
Welington L. Araújo ◽  
Allison L. Creason ◽  
Emy T. Mano ◽  
Aline A. Camargo-Neves ◽  
Sonia N. Minami ◽  
...  
Keyword(s):  
Burkholderia Cepacia ◽  
Draft Genome ◽  
Extracellular Polysaccharide ◽  
Disease Suppression ◽  
Burkholderia Cepacia Complex ◽  
Future Research ◽  
Human Pathogens ◽  
Host Interactions ◽  
Fundamental Information ◽  
Transposon Insertions

From a screen of 36 plant-associated strains of Burkholderia spp., we identified 24 strains that suppressed leaf and pseudobulb necrosis of orchid caused by B. gladioli. To gain insights into the mechanisms of disease suppression, we generated a draft genome sequence from one suppressive strain, TC3.4.2R3. The genome is an estimated 7.67 megabases in size, with three replicons, two chromosomes, and the plasmid pC3. Using a combination of multilocus sequence analysis and phylogenomics, we identified TC3.4.2R3 as B. seminalis, a species within the Burkholderia cepacia complex that includes opportunistic human pathogens and environmental strains. We generated and screened a library of 3,840 transposon mutants of strain TC3.4.2R3 on orchid leaves to identify genes contributing to plant disease suppression. Twelve mutants deficient in suppression of leaf necrosis were selected and the transposon insertions were mapped to eight loci. One gene is in a wcb cluster that is related to synthesis of extracellular polysaccharide, a key determinant in bacterial-host interactions in other systems, and the other seven are highly conserved among Burkholderia spp. The fundamental information developed in this study will serve as a resource for future research aiming to identify mechanisms contributing to biological control.

The Human Immunodeficiency Virus Capsid Is More Than Just a Genome Package

2018 ◽  
Vol 5 (1) ◽  
pp. 209-225 ◽  
Author(s):  
Leo C. James ◽  
David A. Jacques
Keyword(s):  
Human Immunodeficiency Virus ◽  
Productive Infection ◽  
Human Pathogens ◽  
Host Interactions ◽  
Global Pandemic ◽  
A Genome ◽  
Immunodeficiency Virus ◽  
Structural Shell ◽  
Hiv 1 ◽  
Replicative Cycle

Human immunodeficiency virus (HIV) is one of the most studied of all human pathogens. One strain—HIV-1 group M—is responsible for a global pandemic that has infected >60 million people and killed >20 million. Understanding the stages of HIV infection has led to highly effective therapeutics in the form of antiviral drugs that target the viral enzymes reverse transcriptase, integrase, and protease as well as biotechnological developments in the form of retroviral and lentiviral vectors for the transduction of cells in tissue culture and, potentially, gene therapy. However, despite considerable research focus in this area, there is much we still do not understand about the HIV replicative cycle, particularly the first steps that are crucial to establishing a productive infection. One especially enigmatic player has been the HIV capsid. In this review, we discuss three aspects of the HIV capsid: its function as a structural shell, its role in mediating host interactions, and its vulnerability to antiviral activity.

scholarly journals Incremental Contributions of FbaA and Other Impetigo-Associated Surface Proteins to Fitness and Virulence of a Classical Group A Streptococcal Skin Strain

2017 ◽  
Vol 85 (11) ◽  
Author(s):  
Candace N. Rouchon ◽  
Anhphan T. Ly ◽  
John P. Noto ◽  
Feng Luo ◽  
Sergio Lizano ◽  
...  
Keyword(s):  
Whole Blood ◽  
Surface Protein ◽  
Surface Proteins ◽  
Human Pathogens ◽  
Humanized Mouse Model ◽  
Host Interactions ◽  
Group A ◽  
Surface Protein Gene ◽  
Epithelial Layers ◽  
Isogenic Mutants

ABSTRACT Group A streptococci (GAS) are highly prevalent human pathogens whose primary ecological niche is the superficial epithelial layers of the throat and/or skin. Many GAS strains with a strong tendency to cause pharyngitis are distinct from strains that tend to cause impetigo; thus, genetic differences between them may confer host tissue-specific virulence. In this study, the FbaA surface protein gene was found to be present in most skin specialist strains but largely absent from a genetically related subset of pharyngitis isolates. In an ΔfbaA mutant constructed in the impetigo strain Alab49, loss of FbaA resulted in a slight but significant decrease in GAS fitness in a humanized mouse model of impetigo; the ΔfbaA mutant also exhibited decreased survival in whole human blood due to phagocytosis. In assays with highly sensitive outcome measures, Alab49ΔfbaA was compared to other isogenic mutants lacking virulence genes known to be disproportionately associated with classical skin strains. FbaA and PAM (i.e., the M53 protein) had additive effects in promoting GAS survival in whole blood. The pilus adhesin tip protein Cpa promoted Alab49 survival in whole blood and appears to fully account for the antiphagocytic effect attributable to pili. The finding that numerous skin strain-associated virulence factors make slight but significant contributions to virulence underscores the incremental contributions to fitness of individual surface protein genes and the multifactorial nature of GAS-host interactions.

scholarly journals Mycobacteria-host interactions in human bronchiolar airway organoids

2020 ◽  
Author(s):  
Nino Iakobachvili ◽  
Stephen Adonai Leon Icaza ◽  
Kèvin Knoops ◽  
Norman Sachs ◽  
Serge Mazères ◽  
...  
Keyword(s):  
Adult Stem Cell ◽  
Human Monocyte ◽  
Tuberculosis Infection ◽  
Human Pathogens ◽  
Host Interactions ◽  
Human Airway ◽  
Low Efficiency ◽  
And Function ◽  
Therapeutic Research

AbstractTuberculosis, one of the oldest human pathogens remains a major global health threat. Recent advances in organoid technology offer a unique opportunity to grow different human “organs” in vitro, including the human airway, that faithfully recapitulate tissue architecture and function. We have explored the potential of human airway organoids (AOs) as a novel system in which to model tuberculosis infection. To this end, we adapted biosafety containment level 3–approved procedures to allow successful microinjection of Mycobacterium tuberculosis, the causative agent of tuberculosis, into AOs. We reveal that mycobacteria infected epithelial cells with low efficiency, and that the organoid microenvironment was able to control, but not eliminate the pathogen. We demonstrate that AOs responded to infection by inducing cytokine and antimicrobial peptide production, and inhibiting mucins. Given the importance of myeloid cells in tuberculosis infection, we co-cultured mycobacteria-infected organoids with human monocyte-derived macrophages, and found that these cells were recruited to the organoid epithelium. We conclude that adult stem cell–derived airway organoids can be used to model early events of tuberculosis infection and offer new avenues for fundamental and therapeutic research.

scholarly journals Microbial Diversity and Phage–Host Interactions in the Georgian Coastal Area of the Black Sea Revealed by Whole Genome Metagenomic Sequencing

Marine Drugs ◽  
2020 ◽  
Vol 18 (11) ◽  
pp. 558
Author(s):  
Ekaterine Jaiani ◽  
Ia Kusradze ◽  
Tamar Kokashvili ◽  
Natia Geliashvili ◽  
Nino Janelidze ◽  
...  
Keyword(s):  
Microbial Diversity ◽  
Black Sea ◽  
Coastal Area ◽  
Marine Ecology ◽  
The Black Sea ◽  
Metagenomic Sequencing ◽  
Human Pathogens ◽  
Bacterial Phyla ◽  
Host Interactions ◽  
Metagenomic Approach

Viruses have the greatest abundance and highest genetic diversity in marine ecosystems. The interactions between viruses and their hosts is one of the hot spots of marine ecology. Besides their important role in various ecosystems, viruses, especially bacteriophages and their gene pool, are of enormous interest for the development of new gene products with high innovation value. Various studies have been conducted in diverse ecosystems to understand microbial diversity and phage–host interactions; however, the Black Sea, especially the Eastern coastal area, remains among the least studied ecosystems in this regard. This study was aimed at to fill this gap by analyzing microbial diversity and bacteriophage–host interactions in the waters of Eastern Black Sea using a metagenomic approach. To this end, prokaryotic and viral metagenomic DNA from two sampling sites, Poti and Gonio, were sequenced on the Illumina Miseq platform and taxonomic and functional profiles of the metagenomes were obtained using various bioinformatics tools. Our metagenomics analyses allowed us to identify the microbial communities, with Proteobacteria, Cyanobacteria, Actinibacteria, and Firmicutes found to be the most dominant bacterial phyla and Synechococcus and Candidatus Pelagibacter phages found to be the most dominant viral groups in the Black Sea. As minor groups, putative phages specific to human pathogens were identified in the metagenomes. We also characterized interactions between the phages and prokaryotic communities by determining clustered regularly interspaced short palindromic repeats (CRISPR), prophage-like sequences, and integrase/excisionase sequences in the metagenomes, along with identification of putative horizontally transferred genes in the viral contigs. In addition, in the viral contig sequences related to peptidoglycan lytic activity were identified as well. This is the first study on phage and prokaryote diversity and their interactions in the Eastern coastal area of the Black Sea using a metagenomic approach.

scholarly journals Molecular basis for inhibition of adhesin-mediated bacterial-host interactions through a novel peptide-binding domain

2020 ◽  
Author(s):  
Shuaiqi Guo ◽  
Hossein Zahiri ◽  
Corey Stevens ◽  
Daniel C. Spaanderman ◽  
Lech-Gustav Milroy ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Molecular Basis ◽  
Bacterial Colonization ◽  
Peptide Binding ◽  
Binding Domain ◽  
Human Pathogens ◽  
Conceptual Approach ◽  
Host Interactions ◽  
X Ray Crystallography ◽  
Ligand Interactions

AbstractModulation of protein-protein interactions (PPIs) with small-molecules is a promising conceptual approach in drug discovery. In the area of bacterial colonization, PPIs contribute to adhesin-mediated biofilm formation that cause most infections. However, the molecular basis underlying these adhesin-ligand interactions is largely unknown. The 1.5-MDa adhesion protein, MpIBP, uses a peptide-binding domain (MpPBD) to help its Antarctic bacterium form symbiotic biofilms on sea ice with microalgae such as diatoms. X-ray crystallography revealed MpPBD uses Camdependent interactions to self-associate with a crystal symmetry mate via the C-terminal threonine-proline-aspartate sequence. Structure-guided optimization derived penta-peptide ligands that bound MpPBD 1,000-fold more tightly, with affinities in the nano-molar range. These ligands act as potent antagonists to block MpPBD from binding to the diatom cells. Since adhesins of some human pathogens contain peptide-binding module homologs of MpPBD, this same conceptual approach could help develop ligand-based PPI modulators to disrupt harmful bacteria-host interactions.

Non-host interactions to detect anti-Fusarium substances

Planta Medica ◽  
2011 ◽  
Vol 77 (12) ◽  
Author(s):  
O Schumpp ◽  
N Bruderhofer ◽  
K Gindro ◽  
J Wolfender
Keyword(s):  
Host Interactions

Plasminogen Activation by Invasive Human Pathogens

1997 ◽  
Vol 77 (01) ◽  
pp. 001-010 ◽  
Author(s):  
Michael D P Boyle ◽  
Richard Lottenberg
Keyword(s):  
Plasminogen Activators ◽  
Plasminogen Activation ◽  
Potential Importance ◽  
Human Pathogens

SummaryIn this review the interaction between invasive human pathogens expressing plasmin(ogen) receptors and/or producing plasminogen activators with the human plasmin(ogen) system is described. Evidence is presented for multiple mechanisms by which human pathogens can acquire a surface bound form of plasmin that cannot be regulated by host serpins. The potential importance of these pathways in providing the organisms with the ability to cross tissue barriers is discussed.

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