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Cellular Microbiology May 2021
Topics: Animals; Bacteria; Bacterial Infections; Host-Pathogen Interactions; Humans; Immune Evasion; Virulence
PubMed: 33369087
DOI: 10.1111/cmi.13300 -
Toxins Apr 2020Leukotoxins are the critical virulence factors of several Gram-positive and Gram-negative bacteria [...].
Leukotoxins are the critical virulence factors of several Gram-positive and Gram-negative bacteria [...].
Topics: Animals; Exotoxins; Gram-Negative Bacteria; Gram-Positive Bacteria; Host-Pathogen Interactions; Humans; Virulence; Virulence Factors
PubMed: 32272577
DOI: 10.3390/toxins12040231 -
Virulence Dec 2020Trehalose is a disaccharide of two D-glucose molecules linked by a glycosidic linkage, which plays both structural and functional roles in bacteria. Trehalose can be... (Review)
Review
Trehalose is a disaccharide of two D-glucose molecules linked by a glycosidic linkage, which plays both structural and functional roles in bacteria. Trehalose can be synthesized and degraded by several pathways, and induction of trehalose biosynthesis is typically associated with exposure to abiotic stress. The ability of trehalose to protect against abiotic stress has been exploited to stabilize a range of bacterial vaccines. More recently, there has been interest in the role of this molecule in microbial virulence. There is now evidence that trehalose or trehalose derivatives play important roles in virulence of a diverse range of Gram-positive and Gram-negative pathogens of animals or plants. Trehalose and/or trehalose derivatives can play important roles in host colonization and growth in the host, and can modulate the interactions with host defense mechanisms. However, the roles are typically pathogen-specific. These findings suggest that trehalose metabolism may be a target for novel pathogen-specific rather than broad spectrum interventions.
Topics: Animals; Bacteria; Bacterial Infections; Host-Pathogen Interactions; Humans; Plants; Stress, Physiological; Trehalose; Virulence
PubMed: 32862781
DOI: 10.1080/21505594.2020.1809326 -
International Journal of Molecular... Aug 2021The strong decoration of tRNAs with post-transcriptional modifications provides an unprecedented adaptability of this class of non-coding RNAs leading to the regulation... (Review)
Review
The strong decoration of tRNAs with post-transcriptional modifications provides an unprecedented adaptability of this class of non-coding RNAs leading to the regulation of bacterial growth and pathogenicity. Accumulating data indicate that tRNA post-transcriptional modifications possess a central role in both the formation of bacterial cell wall and the modulation of transcription and translation fidelity, but also in the expression of virulence factors. Evolutionary conserved modifications in tRNA nucleosides ensure the proper folding and stability redounding to a totally functional molecule. However, environmental factors including stress conditions can cause various alterations in tRNA modifications, disturbing the pathogen homeostasis. Post-transcriptional modifications adjacent to the anticodon stem-loop, for instance, have been tightly linked to bacterial infectivity. Currently, advances in high throughput methodologies have facilitated the identification and functional investigation of such tRNA modifications offering a broader pool of putative alternative molecular targets and therapeutic avenues against bacterial infections. Herein, we focus on tRNA epitranscriptome shaping regarding modifications with a key role in bacterial infectivity including opportunistic pathogens of the human microbiome.
Topics: Anticodon; Bacteria; Humans; Nucleosides; Protein Biosynthesis; RNA Processing, Post-Transcriptional; RNA, Transfer; Transcriptome; Virulence
PubMed: 34445114
DOI: 10.3390/ijms22168409 -
Annual Review of Microbiology Sep 2023Bacteria are single-celled organisms that carry a comparatively small set of genetic information, typically consisting of a few thousand genes that can be selectively... (Review)
Review
Bacteria are single-celled organisms that carry a comparatively small set of genetic information, typically consisting of a few thousand genes that can be selectively activated or repressed in an energy-efficient manner and transcribed to encode various biological functions in accordance with environmental changes. Research over the last few decades has uncovered various ingenious molecular mechanisms that allow bacterial pathogens to sense and respond to different environmental cues or signals to activate or suppress the expression of specific genes in order to suppress host defenses and establish infections. In the setting of infection, pathogenic bacteria have evolved various intelligent mechanisms to reprogram their virulence to adapt to environmental changes and maintain a dominant advantage over host and microbial competitors in new niches. This review summarizes the bacterial virulence programming mechanisms that enable pathogens to switch from acute to chronic infection, from local to systemic infection, and from infection to colonization. It also discusses the implications of these findings for the development of new strategies to combat bacterial infections.
Topics: Virulence; Bacteria
PubMed: 37406345
DOI: 10.1146/annurev-micro-032521-025954 -
Phytopathology Jan 2021Population genomics is transforming our understanding of pathogen biology and evolution, and contributing to the prevention and management of disease in diverse crops.... (Review)
Review
Population genomics is transforming our understanding of pathogen biology and evolution, and contributing to the prevention and management of disease in diverse crops. We provide an overview of key methods in bacterial population genomics and describe recent work focusing on three topics of critical importance to plant pathology: (i) resolving pathogen origins and transmission pathways during outbreak events, (ii) identifying the genetic basis of host specificity and virulence, and (iii) understanding how pathogens evolve in response to changing agricultural practices.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
Topics: Bacteria; Crops, Agricultural; Metagenomics; Plant Diseases; Virulence
PubMed: 33179999
DOI: 10.1094/PHYTO-09-20-0412-RVW -
Biomolecules Sep 2022Two-component signal transduction systems (TCSs) are widespread types of protein machinery, typically consisting of a histidine kinase membrane sensor and a cytoplasmic... (Review)
Review
Two-component signal transduction systems (TCSs) are widespread types of protein machinery, typically consisting of a histidine kinase membrane sensor and a cytoplasmic transcriptional regulator that can sense and respond to environmental signals. TCSs are responsible for modulating genes involved in a multitude of bacterial functions, including cell division, motility, differentiation, biofilm formation, antibiotic resistance, and virulence. Pathogenic bacteria exploit the capabilities of TCSs to reprogram gene expression according to the different niches they encounter during host infection. This review focuses on the role of TCSs in regulating the virulence phenotype of , an intracellular pathogen responsible for severe human enteric syndrome. The pathogenicity of is the result of the complex action of a wide number of virulence determinants located on the chromosome and on a large virulence plasmid. In particular, we will discuss how five TCSs, EnvZ/OmpR, CpxA/CpxR, ArcB/ArcA, PhoQ/PhoP, and EvgS/EvgA, contribute to linking environmental stimuli to the expression of genes related to virulence and fitness within the host. Considering the relevance of TCSs in the expression of virulence in pathogenic bacteria, the identification of drugs that inhibit TCS function may represent a promising approach to combat bacterial infections.
Topics: Bacterial Proteins; Escherichia coli; Gene Expression Regulation, Bacterial; Histidine Kinase; Humans; Shigella; Signal Transduction; Virulence
PubMed: 36139160
DOI: 10.3390/biom12091321 -
Nature Microbiology May 2022Fungal pathogens cause more than a billion human infections every year, resulting in more than 1.6 million deaths annually. Understanding the natural history and... (Review)
Review
Fungal pathogens cause more than a billion human infections every year, resulting in more than 1.6 million deaths annually. Understanding the natural history and evolutionary ecology of fungi is helping us understand how disease-relevant traits have repeatedly evolved. Different types and mechanisms of genetic variation have contributed to the evolution of fungal pathogenicity and specific genetic differences distinguish pathogens from non-pathogens. Insights into the traits, genetic elements, and genetic and ecological mechanisms that contribute to the evolution of fungal pathogenicity are crucial for developing strategies to both predict emergence of fungal pathogens and develop drugs to combat them.
Topics: Fungi; Humans; Life Style; Virulence
PubMed: 35508719
DOI: 10.1038/s41564-022-01112-0 -
Proceedings of the National Academy of... Apr 2022Bacterial pathogen identification, which is critical for human health, has historically relied on culturing organisms from clinical specimens. More recently, the...
Bacterial pathogen identification, which is critical for human health, has historically relied on culturing organisms from clinical specimens. More recently, the application of machine learning (ML) to whole-genome sequences (WGSs) has facilitated pathogen identification. However, relying solely on genetic information to identify emerging or new pathogens is fundamentally constrained, especially if novel virulence factors exist. In addition, even WGSs with ML pipelines are unable to discern phenotypes associated with cryptic genetic loci linked to virulence. Here, we set out to determine if ML using phenotypic hallmarks of pathogenesis could assess potential pathogenic threat without using any sequence-based analysis. This approach successfully classified potential pathogenetic threat associated with previously machine-observed and unobserved bacteria with 99% and 85% accuracy, respectively. This work establishes a phenotype-based pipeline for potential pathogenic threat assessment, which we term PathEngine, and offers strategies for the identification of bacterial pathogens.
Topics: Bacteria; Genome, Bacterial; Machine Learning; Phenotype; Virulence; Virulence Factors; Whole Genome Sequencing
PubMed: 35363569
DOI: 10.1073/pnas.2112886119 -
Advances in Experimental Medicine and... 2020Calcium (Ca) is a universal signaling ion, whose major informational role shaped the evolution of signaling pathways, enabling cellular communications and responsiveness... (Review)
Review
Calcium (Ca) is a universal signaling ion, whose major informational role shaped the evolution of signaling pathways, enabling cellular communications and responsiveness to both the intracellular and extracellular environments. Elaborate Ca regulatory networks have been well characterized in eukaryotic cells, where Ca regulates a number of essential cellular processes, ranging from cell division, transport and motility, to apoptosis and pathogenesis. However, in bacteria, the knowledge on Ca signaling is still fragmentary. This is complicated by the large variability of environments that bacteria inhabit with diverse levels of Ca. Yet another complication arises when bacterial pathogens invade a host and become exposed to different levels of Ca that (1) are tightly regulated by the host, (2) control host defenses including immune responses to bacterial infections, and (3) become impaired during diseases. The invading pathogens evolved to recognize and respond to the host Ca, triggering the molecular mechanisms of adhesion, biofilm formation, host cellular damage, and host-defense resistance, processes enabling the development of persistent infections. In this review, we discuss: (1) Ca as a determinant of a host environment for invading bacterial pathogens, (2) the role of Ca in regulating main events of host colonization and bacterial virulence, and (3) the molecular mechanisms of Ca signaling in bacterial pathogens.
Topics: Bacteria; Bacterial Infections; Calcium; Host Microbial Interactions; Humans; Virulence
PubMed: 31646536
DOI: 10.1007/978-3-030-12457-1_33