scholarly journals Functional Genomics and Comparative Lineage-Specific Region Analyses Reveal Novel Insights into Race Divergence in Verticillium dahliae

2021 ◽  
Vol 9 (3) ◽  
Author(s):  
Dan Wang ◽  
Dan-Dan Zhang ◽  
Toshiyuki Usami ◽  
Lei Liu ◽  
Lin Yang ◽  
...  
Keyword(s):  
Functional Genomics ◽  
Verticillium Dahliae ◽  
Plant Resistance ◽  
Resistance Breeding ◽  
Specific Region ◽  
Host Pathogen Interactions ◽  
Content Type ◽  
Host Pathogen ◽  
Gene For Gene

Deciphering the gene-for-gene relationships during host-pathogen interactions is the basis of modern plant resistance breeding. In the Verticillium dahliae -tomato pathosystem, two races (races 1 and 2) and their corresponding avirulence ( Avr ) genes have been identified, but strains that lacked these two Avr genes exist in nature.

scholarly journals Pseudomonas aeruginosa Contact-Dependent Growth Inhibition Plays Dual Role in Host-Pathogen Interactions

mSphere ◽  
2017 ◽  
Vol 2 (6) ◽  
Author(s):  
Jeffrey A. Melvin ◽  
Jordan R. Gaston ◽  
Shawn N. Phillips ◽  
Michael J. Springer ◽  
Christopher W. Marshall ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Acute Infection ◽  
Multidrug Resistant ◽  
Gram Negative Bacteria ◽  
Microbial Pathogenesis ◽  
Host Pathogen Interactions ◽  
Gram Negative ◽  
Content Type ◽  
Disease Outcomes ◽  
Host Pathogen

ABSTRACT How bacteria compete and communicate with each other is an increasingly recognized aspect of microbial pathogenesis with a major impact on disease outcomes. Gram-negative bacteria have recently been shown to employ a contact-dependent toxin-antitoxin system to achieve both competition and regulation of their physiology. Here, we show that this system is vital for virulence in acute infection as well as for establishment of chronic infection in the multidrug-resistant pathogen Pseudomonas aeruginosa. Greater understanding of the mechanisms underlying bacterial virulence and infection is important for the development of effective therapeutics in the era of increasing antimicrobial resistance. Microorganisms exist in a diverse ecosystem and have evolved many different mechanisms for sensing and influencing the polymicrobial environment around them, utilizing both diffusible and contact-dependent signals. Contact-dependent growth inhibition (CDI) is one such communication system employed by Gram-negative bacteria. In addition to CDI mediation of growth inhibition, recent studies have demonstrated CDI-mediated control of communal behaviors such as biofilm formation. We postulated that CDI may therefore play an active role in host-pathogen interactions, allowing invading strains to establish themselves at polymicrobial mucosal interfaces through competitive interactions while simultaneously facilitating pathogenic capabilities via CDI-mediated signaling. Here, we show that Pseudomonas aeruginosa produces two CDI systems capable of mediating competition under conditions of growth on a surface or in liquid. Furthermore, we demonstrated a novel role for these systems in contributing to virulence in acute infection models, likely via posttranscriptional regulation of beneficial behaviors. While we did not observe any role for the P. aeruginosa CDI systems in biofilm biogenesis, we did identify for the first time robust CDI-mediated competition during interaction with a mammalian host using a model of chronic respiratory tract infection, as well as evidence that CDI expression is maintained in chronic lung infections. These findings reveal a previously unappreciated role for CDI in host-pathogen interactions and emphasize their importance during infection. IMPORTANCE How bacteria compete and communicate with each other is an increasingly recognized aspect of microbial pathogenesis with a major impact on disease outcomes. Gram-negative bacteria have recently been shown to employ a contact-dependent toxin-antitoxin system to achieve both competition and regulation of their physiology. Here, we show that this system is vital for virulence in acute infection as well as for establishment of chronic infection in the multidrug-resistant pathogen Pseudomonas aeruginosa. Greater understanding of the mechanisms underlying bacterial virulence and infection is important for the development of effective therapeutics in the era of increasing antimicrobial resistance.

scholarly journals Draft Genome Sequences of 12 Monophasic Salmonella enterica subsp. enterica Serotype Typhimurium 1,4,[5],12:i:− Strains Isolated from Wild Griffon Vultures in Eastern Spain

2019 ◽  
Vol 8 (42) ◽  
Author(s):  
Clara Marin ◽  
Giuseppe D’Auria ◽  
Llúcia Martínez-Priego ◽  
Francisco Marco-Jiménez
Keyword(s):  
Salmonella Enterica ◽  
Draft Genome ◽  
Wild Animals ◽  
Genome Sequences ◽  
Host Pathogen Interactions ◽  
Content Type ◽  
Zoonotic Pathogens ◽  
Host Pathogen ◽  
Serovar Typhimurium ◽  
Insight Into

Monophasic Salmonella enterica subsp. enterica serovar Typhimurium is one of the most common zoonotic pathogens. Salmonella species reside in a wide variety of hosts, including wild animals. Thus, we report here the genome sequences of 12 monophasic S. Typhimurium strains isolated from healthy wild vultures to gain better insight into their epidemiology and host-pathogen interactions.

scholarly journals Clinical Candida albicans Vaginal Isolates and a Laboratory Strain Show Divergent Behaviors during Macrophage Interactions

mSphere ◽  
2020 ◽  
Vol 5 (4) ◽  
Author(s):  
Franziska Gerwien ◽  
Christine Dunker ◽  
Philipp Brandt ◽  
Enrico Garbe ◽  
Ilse D. Jacobsen ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Fungal Infections ◽  
Laboratory Strain ◽  
Infection Process ◽  
Vulvovaginal Candidiasis ◽  
Host Immune System ◽  
Host Pathogen Interactions ◽  
Content Type ◽  
Host Pathogen

ABSTRACT Typically, established lab strains are widely used to study host-pathogen interactions. However, to better reflect the infection process, the experimental use of clinical isolates has come more into focus. Here, we analyzed the interaction of multiple vaginal isolates of the opportunistic fungal pathogen Candida albicans, the most common cause of vulvovaginal candidiasis in women, with key players of the host immune system: macrophages. We tested several strains isolated from asymptomatic or symptomatic women with acute and recurrent infections. While all clinical strains showed a response similar to the commonly used lab strain SC5314 in various in vitro assays, they displayed remarkable differences during interaction with macrophages. This coincided with significantly reduced β-glucan exposure on the cell surface, which appeared to be a shared property among the tested vaginal strains for yeast extract/peptone/dextrose-grown cells, which is partly lost when the isolates faced vaginal niche-like nutrient conditions. However, macrophage damage, survival of phagocytosis, and filamentation capacities were highly strain-specific. These results highlight the high heterogeneity of C. albicans strains in host-pathogen interactions, which have to be taken into account to bridge the gap between laboratory-gained data and disease-related outcomes in an actual patient. IMPORTANCE Vulvovaginal candidiasis is one of the most common fungal infections in humans with Candida albicans as the major causative agent. This study is the first to compare clinical vaginal isolates of defined patient groups in their interaction with macrophages, highlighting the vastly different outcomes in comparison to a laboratory strain using commonly applied virulence-determining assays.

scholarly journals mSphere of Influence: Clearing a Path for High-Resolution Visualization of Host-Pathogen Interactions In Vivo

mSphere ◽  
2019 ◽  
Vol 4 (4) ◽  
Author(s):  
Shumin Tan
Keyword(s):  
Single Cell ◽  
Dimensional Space ◽  
Whole Body ◽  
Host Pathogen Interactions ◽  
Content Type ◽  
3 Dimensional ◽  
Host Interactions ◽  
Host Pathogen ◽  
Tissue Optical Clearing

ABSTRACT Shumin Tan works in the field of Mycobacterium tuberculosis-host interactions. In this mSphere of Influence article, she reflects on how the paper “Single-cell phenotyping within transparent intact tissue through whole-body clearing” by B. Yang et al. (Cell 158:945–958, 2014, https://doi.org/10.1016/j.cell.2014.07.017) impacted her ideas on approaches to visualize and understand heterogeneous host-pathogen interactions in vivo in 3-dimensional space at the single-cell level, through the tractable and broadly compatible tissue optical clearing methods developed.

scholarly journals MARTX Toxin-Stimulated Interplay between Human Cells and Vibrio vulnificus

mSphere ◽  
2020 ◽  
Vol 5 (4) ◽  
Author(s):  
Byoung Sik Kim ◽  
Jong-Hwan Kim ◽  
Sanghyeon Choi ◽  
Shinhye Park ◽  
Eun-Young Lee ◽  
...  
Keyword(s):  
Immune Responses ◽  
Immune Cells ◽  
Vibrio Vulnificus ◽  
Expression Profiles ◽  
Host Cells ◽  
Iron Limitation ◽  
Host Pathogen Interactions ◽  
Content Type ◽  
Host Pathogen ◽  
Ht 29

ABSTRACT To understand toxin-stimulated host-pathogen interactions, we performed dual-transcriptome sequencing experiments using human epithelial (HT-29) and differentiated THP-1 (dTHP-1) immune cells infected with the sepsis-causing pathogen Vibrio vulnificus (either the wild-type [WT] pathogen or a multifunctional-autoprocessing repeats-in-toxin [MARTX] toxin-deficient strain). Gene set enrichment analyses revealed MARTX toxin-dependent responses, including negative regulation of extracellular related kinase 1 (ERK1) and ERK2 (ERK1/2) signaling and cell cycle regulation in HT-29 and dTHP-1 cells, respectively. Further analysis of the expression of immune-related genes suggested that the MARTX toxin dampens immune responses in gut epithelial cells but accelerates inflammation and nuclear factor κB (NF-κB) signaling in immune cells. With respect to the pathogen, siderophore biosynthesis genes were significantly more highly expressed in WT V. vulnificus than in the MARTX toxin-deficient mutant upon infection of dTHP-1 cells. Consistent with these results, iron homeostasis genes that limit iron levels for invading pathogens were overexpressed in WT V. vulnificus-infected dTHP-1 cells. Taken together, these results suggest that MARTX toxin regulates host inflammatory responses during V. vulnificus infection while also countering host defense mechanisms such as iron limitation. IMPORTANCE V. vulnificus is an opportunistic human pathogen that can cause life-threatening sepsis in immunocompromised patients via seafood poisoning or wound infection. Among the toxic substances produced by this pathogen, the MARTX toxin greatly contributes to disease progression by promoting the dysfunction and death of host cells, which allows the bacteria to disseminate and colonize the host. In response to this, host cells mount a counterattack against the invaders by upregulating various defense genes. In this study, the gene expression profiles of both host cells and V. vulnificus were analyzed by RNA sequencing to gain a comprehensive understanding of host-pathogen interactions. Our results suggest that V. vulnificus uses the MARTX toxin to subvert host cell immune responses as well as to oppose host counterattacks such as iron limitation.

Seedling and adult plant evaluation of race variability in Leptosphaeria maculans on Brassica species in Australia

1996 ◽  
Vol 36 (4) ◽  
pp. 485 ◽  
Author(s):  
DJ Ballinger ◽  
PA Salisbury
Keyword(s):  
Plant Resistance ◽  
Adult Plant Resistance ◽  
Leptosphaeria Maculans ◽  
Brassica Species ◽  
Adult Plant ◽  
Host Pathogen Interactions ◽  
Differential Host ◽  
Host Pathogen ◽  
Napus Line ◽  
Plant Evaluation

Seedling and adult plant studies were used to identify the race structure of Leptosphaeria maculans (the cause of blackleg) on oilseed Brassica species in Australia. Host-pathogen interactions using a set of 12 differential host lines identified 14 seedling relationship, however, between seedling and adult plant reactions to individual isolates, indicating that seedling and adult plant resistance are under different genetic control. While non-specific adult plant resistance was observed in the B. napus line Jet Neuf, host-pathogen interactions confirmed the existence of race-specific adult plant resistances in other differential lines.

scholarly journals Host-Pathogen Interactions in Gram-Positive Bacterial Pneumonia

2019 ◽  
Vol 32 (3) ◽  
Author(s):  
Jennifer A. Grousd ◽  
Helen E. Rich ◽  
John F. Alcorn
Keyword(s):  
Virulence Factors ◽  
Secondary Infection ◽  
Community Acquired Pneumonia ◽  
Inflammasome Activation ◽  
Host Pathogen Interactions ◽  
Content Type ◽  
Host Immune Responses ◽  
Pathogen Virulence ◽  
Host Cell Death ◽  
Host Pathogen

SUMMARY Community-acquired pneumonia (CAP) is a leading cause of morbidity and mortality worldwide. Despite broad literature including basic and translational scientific studies, many gaps in our understanding of host-pathogen interactions remain. In this review, pathogen virulence factors that drive lung infection and injury are discussed in relation to their associated host immune pathways. CAP epidemiology is considered, with a focus on Staphylococcus aureus and Streptococcus pneumoniae as primary pathogens. Bacterial factors involved in nasal colonization and subsequent virulence are illuminated. A particular emphasis is placed on bacterial pore-forming toxins, host cell death, and inflammasome activation. Identified host-pathogen interactions are then examined by linking pathogen factors to aberrant host response pathways in the context of acute lung injury in both primary and secondary infection. While much is known regarding bacterial virulence and host immune responses, CAP management is still limited to mostly supportive care. It is likely that improvements in therapy will be derived from combinatorial targeting of both pathogen virulence factors and host immunomodulation.

scholarly journals High-Throughput Microfluidic Method To Study Biofilm Formation and Host-Pathogen Interactions in Pathogenic Escherichia coli

2015 ◽  
Vol 81 (8) ◽  
pp. 2827-2840 ◽  
Author(s):  
Yannick D. N. Tremblay ◽  
Philippe Vogeleer ◽  
Mario Jacques ◽  
Josée Harel
Keyword(s):  
Escherichia Coli ◽  
High Throughput ◽  
Biofilm Formation ◽  
Cell Biology ◽  
Shear Force ◽  
Host Pathogen Interactions ◽  
Content Type ◽  
E Coli ◽  
Rpmi Medium ◽  
Host Pathogen

ABSTRACTBiofilm formation and host-pathogen interactions are frequently studied using multiwell plates; however, these closed systems lack shear force, which is present at several sites in the host, such as the intestinal and urinary tracts. Recently, microfluidic systems that incorporate shear force and very small volumes have been developed to provide cell biology models that resemblein vivoconditions. Therefore, the objective of this study was to determine if the BioFlux 200 microfluidic system could be used to study host-pathogen interactions and biofilm formation by pathogenicEscherichia coli. Strains of various pathotypes were selected to establish the growth conditions for the formation of biofilms in the BioFlux 200 system on abiotic (glass) or biotic (eukaryotic-cell) surfaces. Biofilm formation on glass was observed for the majority of strains when they were grown in M9 medium at 30°C but not in RPMI medium at 37°C. In contrast, HRT-18 cell monolayers enhanced binding and, in most cases, biofilm formation by pathogenicE. coliin RPMI medium at 37°C. As a proof of principle, the biofilm-forming ability of a diffusely adherentE. colimutant strain lacking AIDA-I, a known mediator of attachment, was assessed in our models. In contrast to the parental strain, which formed a strong biofilm, the mutant formed a thin biofilm on glass or isolated clusters on HRT-18 monolayers. In conclusion, we describe a microfluidic method for high-throughput screening that could be used to identify novel factors involved inE. colibiofilm formation and host-pathogen interactions under shear force.

scholarly journals An Update on Host-Pathogen Interplay and Modulation of Immune Responses duringOrientia tsutsugamushiInfection

2018 ◽  
Vol 31 (2) ◽  
Author(s):  
Fabián E. Díaz ◽  
Katia Abarca ◽  
Alexis M. Kalergis
Keyword(s):  
Animal Models ◽  
Immune Responses ◽  
Model Development ◽  
Scientific Progress ◽  
Organ Injury ◽  
Effective Vaccine ◽  
Host Pathogen Interactions ◽  
Content Type ◽  
Recent Advances ◽  
Host Pathogen

SUMMARYThe obligate intracellular bacteriumOrientia tsutsugamushiis the causative agent of scrub typhus in humans, a serious mite-borne disease present in a widespread area of endemicity, which affects an estimated 1 million people every year. This disease may exhibit a broad range of presentations, ranging from asymptomatic to fatal conditions, with the latter being due to disseminated endothelial infection and organ injury. Unique characteristics of the biology and host-pathogen interactions ofO. tsutsugamushi, including the high antigenic diversity among strains and the highly variable, short-lived memory responses developed by the host, underlie difficulties faced in the pursuit of an effective vaccine, which is an imperative need. Other factors that have hindered scientific progress relative to the infectious mechanisms of and the immune response triggered by this bacterium in vertebrate hosts include the limited number of mechanistic studies performed on animal models and the lack of genetic tools currently available for this pathogen. However, recent advances in animal model development are promising to improve our understanding of host-pathogen interactions. Here, we comprehensively discuss the recent advances in and future perspectives on host-pathogen interactions and the modulation of immune responses related to this reemerging disease, highlighting the role of animal models.

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