-
Frontiers in Cellular and Infection... 2019
Topics: Host-Pathogen Interactions; Mycobacterium tuberculosis; Tuberculosis; Virulence
PubMed: 31649893
DOI: 10.3389/fcimb.2019.00331 -
Journal of Mathematical Biology Jul 2022This study explores the coevolutionary dynamics of host-pathogen interaction based on a susceptible-infected population model with density-dependent mortality. We assume...
This study explores the coevolutionary dynamics of host-pathogen interaction based on a susceptible-infected population model with density-dependent mortality. We assume that both the host's resistance and the pathogen's virulence will adaptively evolve, but there are inevitable costs in terms of host birth rate and disease-related mortality rate. Particularly, it is assumed that both the host resistance and pathogen virulence can affect the transmission rate. By using the approach of adaptive dynamics and numerical simulation, we find that the finally coevolutionary outcome depends on the strength of host-pathogen asymmetric interaction, the curvature of trade-off functions, and the intensity of density-dependent natural mortality. To be specific, firstly, we find that if the strengths of host-pathogen asymmetric interaction and disease-related mortality are relatively weak, or the density-dependent natural mortality is relatively strong, then the host resistance and pathogen virulence will evolve to a continuously stable strategy. However, if the strength of host-pathogen asymmetric interaction and disease-related mortality becomes stronger, then the host resistance and pathogen virulence will evolve periodically. Secondly, we find that if the intensities of both the birth rate trade-off function and the density-dependent natural mortality are relatively weak, but the strength of host-pathogen asymmetric interaction becomes relatively strong, then the evolution of host resistance will have a relatively strongly accelerating benefit, the evolutionary branching of host resistance will first arise. However, if the strength of host-pathogen asymmetric interaction is relatively weak, but the intensity of the trade-off function of disease-related mortality becomes relatively strong, then the evolution of pathogen virulence will have a relatively strongly decelerating cost, and the evolutionary branching of pathogen virulence will first arise. Thirdly, after the evolutionary branching of host resistance and pathogen virulence, we further study the coevolutionary dynamics of two-hosts-one-pathogen interaction and one-host-two-pathogens interaction. We find that if the evolutionary branching of host resistance arises firstly, then the finally evolutionary outcome contains a dimorphic host and a monomorphic pathogen population. If the evolutionary branching of pathogen virulence arises firstly, then the finally evolutionary outcome may contain a monomorphic host and a dimorphic pathogen population.
Topics: Biological Evolution; Computer Simulation; Host-Pathogen Interactions; Models, Biological; Virulence
PubMed: 35877051
DOI: 10.1007/s00285-022-01782-8 -
Proceedings of the Japan Academy.... 2015Influenza A virus (IAV) causes significant morbidity and mortality. The knowledge gained within the last decade on the pandemic IAV(H1N1)2009 improved our understanding... (Review)
Review
Influenza A virus (IAV) causes significant morbidity and mortality. The knowledge gained within the last decade on the pandemic IAV(H1N1)2009 improved our understanding not only of the viral pathogenicity but also the host cellular factors involved in the pathogenicity of multiorgan failure (MOF), such as cellular trypsin-type hemagglutinin (HA0) processing proteases for viral multiplication, cytokine storm, metabolic disorders and energy crisis. The HA processing proteases in the airway and organs for all IAV known to date have been identified. Recently, a new concept on the pathogenicity of MOF, the "influenza virus-cytokine-trypsin" cycle, has been proposed involving up-regulation of trypsin through pro-inflammatory cytokines, and potentiation of viral multiplication in various organs. Furthermore, the relationship between causative factors has been summarized as the "influenza virus-cytokine-trypsin" cycle interconnected with the "metabolic disorders-cytokine" cycle. These cycles provide new treatment concepts for ATP crisis and MOF. This review discusses IAV pathogenicity on cellular proteases, cytokines, metabolites and therapeutic options.
Topics: Animals; Antiviral Agents; Cytokines; Host-Pathogen Interactions; Humans; Influenza A virus; Peptide Hydrolases; Virulence
PubMed: 26460316
DOI: 10.2183/pjab.91.351 -
Molecular Plant Pathology Feb 2022Decay due to fungal infection is a major cause of postharvest losses in fruits. Acidic fungi may enhance their virulence by locally reducing the pH of the host. Several... (Review)
Review
Decay due to fungal infection is a major cause of postharvest losses in fruits. Acidic fungi may enhance their virulence by locally reducing the pH of the host. Several devastating postharvest fungi, such as Penicillium spp., Botrytis cinerea, and Sclerotinia sclerotiorum, can secrete gluconic acid, oxalic acid, or citric acid. Emerging evidence suggests that organic acids secreted by acidic fungi are important virulence factors. In this review, we summarized the research progress on the biosynthesis of organic acids, the role of the pH signalling transcription factor PacC in regulating organic acid, and the action mechanism of the main organic acid secreted via postharvest pathogenic fungi during infection of host tissues. This paper systematically demonstrates the relationships between tissue acidification and postharvest fungal pathogenicity, which will motivate the study of host-pathogen interactions and provide a better understanding of virulence mechanisms of the pathogens so as to design new technical strategies to prevent postharvest diseases.
Topics: Fruit; Fungi; Host-Pathogen Interactions; Penicillium; Virulence; Virulence Factors
PubMed: 34820999
DOI: 10.1111/mpp.13159 -
Cells Mar 2023(Lib.) de Bary is a broad host-range fungus that infects an inclusive array of plant species and afflicts significant yield losses globally. Despite being a notorious... (Review)
Review
(Lib.) de Bary is a broad host-range fungus that infects an inclusive array of plant species and afflicts significant yield losses globally. Despite being a notorious pathogen, it has an uncomplicated life cycle consisting of either basal infection from myceliogenically germinated sclerotia or aerial infection from ascospores of carpogenically germinated sclerotia. This fungus is unique among necrotrophic pathogens in that it inevitably colonizes aging tissues to initiate an infection, where a saprophytic stage follows the pathogenic phase. The release of cell wall-degrading enzymes, oxalic acid, and effector proteins are considered critical virulence factors necessary for the effective pathogenesis of . Nevertheless, the molecular basis of pathogenesis is still imprecise and remains a topic of continuing research. Previous comprehensive sequencing of the genome has revealed new insights into its genome organization and provided a deeper comprehension of the sophisticated processes involved in its growth, development, and virulence. This review focuses on the genetic and genomic aspects of fungal biology and molecular pathogenicity to summarize current knowledge of the processes utilized by to parasitize its hosts. Understanding the molecular mechanisms regulating the infection process of will contribute to devising strategies for preventing infections caused by this destructive pathogen.
Topics: Virulence; Virulence Factors; Ascomycota; Genomics
PubMed: 37048136
DOI: 10.3390/cells12071063 -
Sheng Wu Gong Cheng Xue Bao = Chinese... Sep 2017Fungal pathogens represent an important group of human pathogenic microbes that lead to an unacceptably severe global burden especially due to exceptionally high... (Review)
Review
Fungal pathogens represent an important group of human pathogenic microbes that lead to an unacceptably severe global burden especially due to exceptionally high mortality. For many fungal pathogens, they are widespread saprophytes and human host is not the exclusive niche for their proliferation. Their exceptional capability to survive and thrive within infected host likely stems from their sophisticated strategies in adaptation to diverse biotic and abiotic stressors from natural niches or predators. Among these 'environmental pathogens', Cryptococcus neoformans as a model organism claims the lives of more than half a million annually. Some recent studies indicate that cryptococcal survival both inside and outside of hosts can be coordinated by a combination of social behaviors. In this review, we describe and discuss the social behaviors employed by C. neoformans and address their significant impact on biofilm formation, sexual reproduction and pathogenicity.
Topics: Adaptation, Physiological; Cryptococcosis; Cryptococcus neoformans; Humans; Microbial Interactions; Virulence
PubMed: 28956401
DOI: 10.13345/j.cjb.170128 -
Virulence Dec 2023Cysteiniphilum is a newly discovered genus in 2017 and is phylogenetically closely related to highly pathogenic . Recently, it has become an emerging pathogen in humans....
Cysteiniphilum is a newly discovered genus in 2017 and is phylogenetically closely related to highly pathogenic . Recently, it has become an emerging pathogen in humans. However, the complete genome sequence of genus Cysteiniphilum is lacking, and the genomic characteristics of genetic diversity, evolutionary dynamics, and pathogenicity have not been characterized. In this study, the complete genome of the first reported clinical isolate QT6929 of genus Cysteiniphilum was sequenced, and comparative genomics analyses to Francisella genus were conducted to unveil the genomic landscape and diversity of the genus Cysteiniphilum. Our results showed that the complete genome of QT6929 consists of one 2.61 Mb chromosome and a 76,819 bp plasmid. The calculated average nucleotide identity and DNA-DNA hybridization values revealed that two clinical isolates QT6929 and JM-1 should be reclassified as two novel species in genus Cysteiniphilum. Pan-genome analysis revealed genomic diversity within the genus Cysteiniphilum and an open pan-genome state. Genomic plasticity analysis exhibited abundant mobile genetic elements including genome islands, insertion sequences, prophages, and plasmids on Cysteiniphilum genomes, which facilitated the broad exchange of genetic material between Cysteiniphilum and other genera like Francisella and Legionella. Several potential virulence genes associated with lipopolysaccharide/lipooligosaccharide, capsule, and haem biosynthesis specific to clinical isolates were predicted and might contribute to their pathogenicity in humans. Incomplete Francisella pathogenicity island was identified in most Cysteiniphilum genomes. Overall, our study provides an updated phylogenomic relationship of members of the genus Cysteiniphilum and comprehensive genomic insights into this rare emerging pathogen.
Topics: Humans; Virulence; Genome, Bacterial; Francisella tularensis; Phylogeny; Genomics; DNA Transposable Elements; Genetic Variation
PubMed: 37246787
DOI: 10.1080/21505594.2023.2214416 -
International Journal of Molecular... Aug 2022Kiwifruit bacterial canker is a recent epidemic disease caused by pv. (), which has undergone worldwide expansion in a short time and resulted in significant economic...
Kiwifruit bacterial canker is a recent epidemic disease caused by pv. (), which has undergone worldwide expansion in a short time and resulted in significant economic losses. 'Hongyang' (), a widely grown cultivar because of its health-beneficial nutrients and appreciated red-centered inner pericarp, is highly sensitive to . In this work, ten strains were isolated from 'Hongyang' and sequenced for genome analysis. The results indicated divergences in pathogenicity and pathogenic-related genes among the strains. Significantly, the interruption at the 596 bp of in two low-pathogenicity strains reemphasized this gene, expressing a transcriptional regulator for the effector secretion system, as an important pathogenicity-associated locus of . The transcriptome analysis of 'Hongyang' infected with different strains was performed by RNA-seq of stem tissues locally (at the inoculation site) and systemically. infection re-programmed the host genes expression, and the susceptibility to might be attributed to the down-regulation of several genes involved in plant-pathogen interactions, especially calcium signaling transduction, as well as fatty acid elongation. This suppression was found in both low- and high-pathogenicity inoculated tissues, but the effect was stronger with more virulent strains. Taken together, the divergences of pv. in pathogenicity, genome, and resulting transcriptomic response of . provide insights into unraveling the molecular mechanism of -kiwifruit interactions and resistance improvement in the kiwifruit crop.
Topics: Actinidia; Genomics; Plant Diseases; Pseudomonas syringae; Virulence
PubMed: 36077140
DOI: 10.3390/ijms23179743 -
Virulence Dec 2019is a member of a group of fungal pathogens called thermally dimorphic fungi, all of which respond to mammalian body temperature by converting from an environmental mold... (Review)
Review
is a member of a group of fungal pathogens called thermally dimorphic fungi, all of which respond to mammalian body temperature by converting from an environmental mold form into a parasitic host form that causes disease. is a primary fungal pathogen, meaning it is able to cause disease in healthy individuals. We are beginning to understand how host temperature is utilized as a key signal to facilitate growth in the parasitic yeast form and promote production of virulence factors. In recent years, multiple regulators of morphology and virulence have been identified in . Mutations in these regulators render the pathogen unable to convert to the parasitic yeast form. Additionally, several virulence factors have been characterized for their importance in survival and pathogenesis. These virulence factors and regulators can serve as molecular handles for the development of effective drugs and therapeutics to counter infection.
Topics: Animals; Body Temperature; Gene Expression Regulation, Fungal; Histoplasma; Histoplasmosis; Host-Pathogen Interactions; Humans; Mice; Mutation; Virulence; Virulence Factors
PubMed: 31560240
DOI: 10.1080/21505594.2019.1663596 -
Archives of Virology Feb 2022Soybean mosaic virus (SMV) is the most prevalent viral pathogen in soybean. In China, the SMV strains SC and N are used simultaneously in SMV resistance assessments of...
Soybean mosaic virus (SMV) is the most prevalent viral pathogen in soybean. In China, the SMV strains SC and N are used simultaneously in SMV resistance assessments of soybean cultivars, but the pathogenic relationship between them is unclear. In this study, SMV strains N1 and N3 were found to be the most closely related to SC18. Moreover, N3 was found to be more virulent than N1. A global pathotype classification revealed the highest level of genetic diversity in China. The N3 type was the most frequent and widespread worldwide, implying that SMV possibly originated in China and spread across continents through the dissemination of infected soybean. It also suggests that the enhanced virulence of N3 facilitated its spread and adaptability in diverse geographical and ecological regions worldwide. Phylogenetic analysis revealed prominent geographical associations among SMV strains/isolates, and genomic nucleotide diversity analysis and neutrality tests demonstrated that the whole SMV genome is under negative selection, with the P1 gene being under the greatest selection pressure. The results of this study will facilitate the nationwide use of SMV-resistant soybean germplasm and could provide useful insights into the molecular variability, geographical distribution, phylogenetic relationships, and evolutionary history of SMV around the world.
Topics: Phylogeny; Plant Diseases; Potyvirus; Sequence Analysis; Glycine max; Virulence
PubMed: 35024966
DOI: 10.1007/s00705-021-05271-z