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Virulence Dec 2023(Mtb) is the causative agent of tuberculosis, an infectious disease with one of the highest morbidity and mortality rates worldwide. Leveraging its highly evolved... (Review)
Review
(Mtb) is the causative agent of tuberculosis, an infectious disease with one of the highest morbidity and mortality rates worldwide. Leveraging its highly evolved repertoire of non-protein and protein virulence factors, Mtb invades through the airway, subverts host immunity, establishes its survival niche, and ultimately escapes in the setting of active disease to initiate another round of infection in a naive host. In this review, we will provide a concise synopsis of the infectious life cycle of Mtb and its clinical and epidemiologic significance. We will also take stock of its virulence factors and pathogenic mechanisms that modulate host immunity and facilitate its spread. Developing a greater understanding of the interface between Mtb virulence factors and host defences will enable progress toward improved vaccines and therapeutics to prevent and treat tuberculosis.
Topics: Humans; Mycobacterium tuberculosis; Virulence; Tuberculosis; Virulence Factors; Host-Pathogen Interactions
PubMed: 36419223
DOI: 10.1080/21505594.2022.2150449 -
Virulence Dec 2023is the most common cause of nosocomial antibiotic-associated diarrhea, and is responsible for a spectrum of diseases characterized by high levels of recurrence,... (Review)
Review
is the most common cause of nosocomial antibiotic-associated diarrhea, and is responsible for a spectrum of diseases characterized by high levels of recurrence, morbidity, and mortality. Treatment is complex, since antibiotics constitute both the main treatment and the major risk factor for infection. Worryingly, resistance to multiple antibiotics is becoming increasingly widespread, leading to the classification of this pathogen as an urgent threat to global health. As a consummate opportunist, is well equipped for promoting disease, owing to its arsenal of virulence factors: transmission of this anaerobe is highly efficient due to the formation of robust endospores, and an array of adhesins promote gut colonization. produces multiple toxins acting upon gut epithelia, resulting in manifestations typical of diarrheal disease, and severe inflammation in a subset of patients. This review focuses on such virulence factors, as well as the importance of antimicrobial resistance and genome plasticity in enabling pathogenesis and persistence of this important pathogen.
Topics: Humans; Virulence; Clostridioides difficile; Clostridioides; Clostridium Infections; Virulence Factors; Diarrhea; Anti-Bacterial Agents
PubMed: 36419222
DOI: 10.1080/21505594.2022.2150452 -
Virulence Dec 2023The amoeba parasite is the causative agent of human amebiasis, an enteropathic disease affecting millions of people worldwide. This ancient protozoan is an elementary... (Review)
Review
The amoeba parasite is the causative agent of human amebiasis, an enteropathic disease affecting millions of people worldwide. This ancient protozoan is an elementary example of how parasites evolve with humans, e.g. taking advantage of multiple mechanisms to evade immune responses, interacting with microbiota for nutritional and protective needs, utilizing host resources for growth, division, and encystation. These skills of perpetuate the species and incidence of infection. However, in 10% of infected cases, the parasite turns into a pathogen; the host-parasite equilibrium is then disorganized, and the simple lifecycle based on two cell forms, trophozoites and cysts, becomes unbalanced. Trophozoites acquire a virulent phenotype which, when non-controlled, leads to intestinal invasion with the onset of amoebiasis symptoms. Virulent must cross mucus, epithelium, connective tissue and possibly blood. This highly mobile parasite faces various stresses and a powerful host immune response, with oxidative stress being a challenge for its survival. New emerging research avenues and omics technologies target gene regulation to determine human or parasitic factors activated upon infection, their role in virulence activation, and in pathogenesis; this research bears in mind that is a resident of the complex intestinal ecosystem. The goal is to eradicate amoebiasis from the planet, but the parasitic life of is ancient and complex and will likely continue to evolve with humans. Advances in these topics are summarized here.
Topics: Humans; Entamoeba histolytica; Virulence; Ecosystem; Amebiasis; Intestines
PubMed: 36519347
DOI: 10.1080/21505594.2022.2158656 -
Virulence Dec 2023Infections with and cause over 600,000 deaths each year, concentrated in Africa and in young children, but much of the world's population remain at risk of infection.... (Review)
Review
Infections with and cause over 600,000 deaths each year, concentrated in Africa and in young children, but much of the world's population remain at risk of infection. In this article, we review the latest developments in the immunogenicity and pathogenesis of malaria, with a particular focus on , the leading malaria killer. Pathogenic factors include parasite-derived toxins and variant surface antigens on infected erythrocytes that mediate sequestration in the deep vasculature. Host response to parasite toxins and to variant antigens is an important determinant of disease severity. Understanding how parasites sequester, and how antibody to variant antigens could prevent sequestration, may lead to new approaches to treat and prevent disease. Difficulties in malaria diagnosis, drug resistance, and specific challenges of treating pose challenges to malaria elimination, but vaccines and other preventive strategies may offer improved disease control.
Topics: Child; Humans; Child, Preschool; Virulence; Malaria; Malaria, Falciparum; Plasmodium falciparum; Plasmodium vivax; Protozoan Proteins
PubMed: 36419237
DOI: 10.1080/21505594.2022.2150456 -
Virulence Dec 2023Pulmonary infections caused by the mould pathogen are a major cause of morbidity and mortality globally. Compromised lung defences arising from immunosuppression,... (Review)
Review
Pulmonary infections caused by the mould pathogen are a major cause of morbidity and mortality globally. Compromised lung defences arising from immunosuppression, chronic respiratory conditions or more recently, concomitant viral or bacterial pulmonary infections are recognised risks factors for the development of pulmonary aspergillosis. In this review, we will summarise our current knowledge of the mechanistic basis of pulmonary aspergillosis with a focus on emerging at-risk populations.
Topics: Humans; Aspergillus fumigatus; Virulence; Aspergillosis; Virulence Factors; Pulmonary Aspergillosis
PubMed: 36752587
DOI: 10.1080/21505594.2023.2172264 -
Frontiers in Cellular and Infection... 2023The human-bacterial association is long-known and well-established in terms of both augmentations of human health and attenuation. However, the growing incidents of... (Review)
Review
The human-bacterial association is long-known and well-established in terms of both augmentations of human health and attenuation. However, the growing incidents of nosocomial infections caused by the ESKAPE pathogens (, , , , , and sp.) call for a much deeper understanding of these organisms. Adopting a holistic approach that includes the science of infection and the recent advancements in preventing and treating infections is imperative in designing novel intervention strategies against ESKAPE pathogens. In this regard, this review captures the ingenious strategies commissioned by these master players, which are teamed up against the defenses of the human team, that are equally, if not more, versatile and potent through an analogy. We have taken a basketball match as our analogy, dividing the human and bacterial species into two teams playing with the ball of health. Through this analogy, we make the concept of infectious biology more accessible.
Topics: Humans; Quorum Sensing; Anti-Bacterial Agents; Virulence; Staphylococcal Infections; Enterococcus faecium
PubMed: 37457962
DOI: 10.3389/fcimb.2023.1159798 -
Virulence Dec 2024The genus includes human, animal, insect, and plant pathogens as well as many symbionts and harmless bacteria. Within this genus are and the complex, with four human... (Review)
Review
The genus includes human, animal, insect, and plant pathogens as well as many symbionts and harmless bacteria. Within this genus are and the complex, with four human pathogenic species that are highly related at the genomic level including the causative agent of plague, . Extensive laboratory, field work, and clinical research have been conducted to understand the underlying pathogenesis and zoonotic transmission of these pathogens. There are presently more than 500 whole genome sequences from which an evolutionary footprint can be developed that details shared and unique virulence properties. Whereas the virulence of now seems in apparent homoeostasis within its flea transmission cycle, substantial evolutionary changes that affect transmission and disease severity continue to ndergo apparent selective pressure within the other that cause intestinal diseases. In this review, we will summarize the present understanding of the virulence and pathogenesis of , highlighting shared mechanisms of virulence and the differences that determine the infection niche and disease severity.
Topics: Animals; Humans; Yersinia; Virulence; Yersinia pestis; Plague; Yersinia Infections
PubMed: 38389313
DOI: 10.1080/21505594.2024.2316439 -
Virulence Dec 2023Infection with often triggers pathophysiologic perturbations that are further augmented by the inflammatory responses of the host, resulting in the severe clinical... (Review)
Review
Infection with often triggers pathophysiologic perturbations that are further augmented by the inflammatory responses of the host, resulting in the severe clinical conditions of Lyme disease. While our apprehension of the spatial and temporal integration of the virulence determinants during the enzootic cycle of is constantly being improved, there is still much to be discovered. Many of the novel virulence strategies discussed in this review are undetermined. Lyme disease spirochaetes must surmount numerous molecular and mechanical obstacles in order to establish a disseminated infection in a vertebrate host. These barriers include borrelial relocation from the midgut of the feeding tick to its body cavity and further to the salivary glands, deposition to the skin, haematogenous dissemination, extravasation from blood circulation system, evasion of the host immune responses, localization to protective niches, and establishment of local as well as distal infection in multiple tissues and organs. Here, the various well-defined but also possible novel strategies and virulence mechanisms used by to evade obstacles laid out by the tick vector and usually the mammalian host during colonization and infection are reviewed.
Topics: Animals; Humans; Borrelia burgdorferi; Virulence; Lyme Disease; Virulence Factors; Mammals
PubMed: 37814488
DOI: 10.1080/21505594.2023.2265015 -
Plant Biotechnology Journal Jan 2024Colletotrichum fructicola causes a broad range of plant diseases worldwide and secretes many candidate proteinous effectors during infection, but it remains largely...
Colletotrichum fructicola causes a broad range of plant diseases worldwide and secretes many candidate proteinous effectors during infection, but it remains largely unknown regarding their effects in conquering plant immunity. Here, we characterized a novel effector CfEC12 that is required for the virulence of C. fructicola. CfEC12 contains a CFEM domain and is highly expressed during the early stage of host infection. Overexpression of CfEC12 suppressed BAX-triggered cell death, callose deposition and ROS burst in Nicotiana benthamiana. CfEC12 interacted with apple MdNIMIN2, a NIM1-interacting (NIMIN) protein that putatively modulates NPR1 activity in response to SA signal. Transient expression and transgenic analyses showed that MdNIMIN2 was required for apple resistance to C. fructicola infection and rescued the defence reduction in NbNIMIN2-silenced N. benthamiana, supporting a positive role in plant immunity. CfEC12 and MdNPR1 interacted with a common region of MdNIMIN2, indicating that CfEC12 suppresses the interaction between MdNIMIN2 and MdNPR1 by competitive target binding. In sum, we identified a fungal effector that targets the plant salicylic acid defence pathway to promote fungal infection.
Topics: Plant Immunity; Virulence; Virulence Factors; Plant Diseases
PubMed: 37596985
DOI: 10.1111/pbi.14166 -
Virulence Dec 2023Tularaemia is a zoonotic disease caused by the Gram-negative bacterium, . Depending on its entry route into the organism, causes different diseases, ranging from... (Review)
Review
Tularaemia is a zoonotic disease caused by the Gram-negative bacterium, . Depending on its entry route into the organism, causes different diseases, ranging from life-threatening pneumonia to less severe ulceroglandular tularaemia. Various strains with different geographical distributions exhibit different levels of virulence. is an intracellular bacterium that replicates primarily in the cytosol of the phagocytes. The main virulence attribute of is the type 6 secretion system (T6SS) and its effectors that promote escape from the phagosome. In addition, has evolved a peculiar envelope that allows it to escape detection by the immune system. In this review, we cover tularaemia, different strains, and their pathogenicity. We particularly emphasize the intracellular life cycle, associated virulence factors, and metabolic adaptations. Finally, we present how largely escapes immune detection to be one of the most infectious and lethal bacterial pathogens.
Topics: Humans; Francisella tularensis; Virulence; Tularemia; Virulence Factors; Phagosomes
PubMed: 37941380
DOI: 10.1080/21505594.2023.2274638