Mycoplasma hyopneumoniae pathogenicity: the known and the unknown.

2021 ◽  
pp. 73-86
Author(s):  
Peter Kuhnert ◽  
Jörg Jores
Keyword(s):  
Simple Model ◽  
Virulence Factors ◽  
Immune Modulation ◽  
Current Knowledge ◽  
Mycoplasma Hyopneumoniae ◽  
Host Interaction

Abstract This chapter discusses the current knowledge of Mycoplasma hyopneumoniae virulence, sequence of pathogenesis, adhesion, candidate virulence factors, immune modulation and Mycoplasma host interaction. A simple model of M. hyopneumoniae pathogenicity was also presented.

scholarly journals Cutibacterium acnes as an Opportunistic Pathogen: An Update of Its Virulence-Associated Factors

2021 ◽  
Vol 9 (2) ◽  
pp. 303 ◽  
Author(s):  
Constance Mayslich ◽  
Philippe Alain Grange ◽  
Nicolas Dupin
Keyword(s):  
Virulence Factors ◽  
Current Knowledge ◽  
Opportunistic Pathogen ◽  
Bacterial Attachment ◽  
Molecular Structures ◽  
Ecological Niches ◽  
Target Cells ◽  
Skin Microbiota ◽  
Host Immune Responses ◽  
Cutibacterium Acnes

Cutibacterium acnes is a member of the skin microbiota found predominantly in regions rich in sebaceous glands. It is involved in maintaining healthy skin and has long been considered a commensal bacterium. Its involvement in various infections has led to its emergence as an opportunist pathogen. Interactions between C. acnes and the human host, including the human skin microbiota, promote the selection of C. acnes strains capable of producing several virulence factors that increase inflammatory capability. This pathogenic property may be related to many infectious mechanisms, such as an ability to form biofilms and the expression of putative virulence factors capable of triggering host immune responses or enabling C. acnes to adapt to its environment. During the past decade, many studies have identified and characterized several putative virulence factors potentially involved in the pathogenicity of this bacterium. These virulence factors are involved in bacterial attachment to target cells, polysaccharide-based biofilm synthesis, molecular structures mediating inflammation, and the enzymatic degradation of host tissues. C. acnes, like other skin-associated bacteria, can colonize various ecological niches other than skin. It produces several proteins or glycoproteins that could be considered to be active virulence factors, enabling the bacterium to adapt to the lipophilic environment of the pilosebaceous unit of the skin, but also to the various organs it colonizes. In this review, we summarize current knowledge concerning characterized C. acnes virulence factors and their possible implication in the pathogenicity of C. acnes.

Vaccines and vaccination against Mycoplasma hyopneumoniae.

2021 ◽  
pp. 207-228
Author(s):  
Dominiek Maes ◽  
Filip Boyen ◽  
Odir Dellagostin ◽  
Guo-qing Shao ◽  
Freddy Haesebrouck
Keyword(s):  
Current Knowledge ◽  
Mycoplasma Hyopneumoniae ◽  
Vaccination Strategies

Abstract This chapter reviews the current knowledge on vaccination of pigs against Mycoplasma hyopneumoniae, including the currently available vaccines and their effects, the mechanisms of protection, the different vaccination strategies and the different experimental vaccines that have been developed to further improve the efficacy of vaccination.

scholarly journals A Review of Current Knowledge on Staphylococcus agnetis in Poultry

Animals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1421
Author(s):  
Gustaw M. Szafraniec ◽  
Piotr Szeleszczuk ◽  
Beata Dolka
Keyword(s):  
Virulence Factors ◽  
Broiler Chickens ◽  
Current Knowledge ◽  
Gallus Domesticus ◽  
Gallus Gallus Domesticus ◽  
Poultry Industry ◽  
Emerging Pathogen ◽  
Welfare Losses ◽  
Host Jump ◽  
Global Problems

This review aims to summarize recent discoveries and advancements regarding the characteristics of Staphylococcus agnetis (S. agnetis) and its role in poultry pathology. S. agnetis is an emerging pathogen that was primarily associated with mastitis in dairy cattle. After a presumed host jump from cattle to poultry, it was identified as a pathological agent in broiler chickens (Gallus gallus domesticus), causing lameness induced by bacterial chondronecrosis with osteomyelitis (BCO), septicemia, and valvular endocarditis. Economic and welfare losses caused by lameness are global problems in the poultry industry, and S. agnetis has been shown to have a potential to induce high incidences of lameness in broiler chickens. S. agnetis exhibits a distinct repertoire of virulence factors found in many different staphylococci. It is closely related to S. hyicus and S. chromogenes, hence infections caused by S. agnetis may be misdiagnosed or even undiagnosed. As there are very few reports on S. agnetis in poultry, many facts about its pathogenesis, epidemiology, routes of transmission, and the potential impacts on the poultry industry remain unknown.

scholarly journals Relating GPI-Anchored Ly6 Proteins uPAR and CD59 to Viral Infection

Viruses ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1060 ◽  
Author(s):  
Yu ◽  
Murthy ◽  
Liu
Keyword(s):  
Viral Infection ◽  
Viral Entry ◽  
Current Knowledge ◽  
Cellular Functions ◽  
Lymphocyte Antigen ◽  
Host Interaction ◽  
Type Plasminogen Activator ◽  
Cell Adhesion And Migration ◽  
And Migration

The Ly6 (lymphocyte antigen-6)/uPAR (urokinase-type plasminogen activator receptor) superfamily protein is a group of molecules that share limited sequence homology but conserved three-fingered structures. Despite diverse cellular functions, such as in regulating host immunity, cell adhesion, and migration, the physiological roles of these factors in vivo remain poorly characterized. Notably, increasing research has focused on the interplays between Ly6/uPAR proteins and viral pathogens, the results of which have provided new insight into viral entry and virus–host interactions. While LY6E (lymphocyte antigen 6 family member E), one key member of the Ly6E/uPAR-family proteins, has been extensively studied, other members have not been well characterized. Here, we summarize current knowledge of Ly6/uPAR proteins related to viral infection, with a focus on uPAR and CD59. Our goal is to provide an up-to-date view of the Ly6/uPAR-family proteins and associated virus–host interaction and viral pathogenesis.

scholarly journals Mecanismos Moleculares de Adesão e Colonização da Mucosa Gástrica pela Helicobacter pylori e suas Implicações Clínicas

2016 ◽  
Vol 29 (7-8) ◽  
pp. 476 ◽  
Author(s):  
Elisabete Coelho ◽  
Ana Magalhães ◽  
Mário Dinis-Ribeiro ◽  
Celso A. Reis
Keyword(s):  
Helicobacter Pylori ◽  
Virulence Factors ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Helicobacter Pylori Infection ◽  
Gastric Epithelium ◽  
Antibiotics Resistance ◽  
Gastric Disease ◽  
Preventive Strategy

Introduction: Helicobacter pylori infection is very prevalent worldwide and is associated with the progression of the gastriccarcinogenesis cascade, being one of the main risk factors for the development of gastric carcinoma. Several factors are determinant for the infection and for the development of gastric disease, including environmental factors, host genetic factors and virulence factors of the bacteria.Material and Methods: In this review, we present an overview of the current knowledge on the determinants of the infection and on the recently described molecular mechanisms of Helicobacter pylori adhesion to the gastric mucosa, as well as its possible future therapeutic application.Results: The adhesion of Helicobacter pylori to the gastric epithelium is critical for gastric pathogenesis, allowing bacterial access to nutrients and the action of bacterial virulence factors, promoting recurrence of the infection and the progression of the gastric carcinogenesis pathway.Discussion: Eradication of Helicobacter pylori infection is the best preventive strategy available against gastric cancer, mainly if it is achieved before the development of pre-neoplastic lesions. The increase in antibiotics resistance, together with the eradication failures in some patients, has promoted the development of alternative treatments.Conclusion: The new therapeutic strategies, focused on the molecular mechanism of Helicobacter pylori adhesion, are very promising; however, future studies are needed to evaluate its in vivo efficiency and toxicity.

scholarly journals Bifidobacterial surface-exopolysaccharide facilitates commensal-host interaction through immune modulation and pathogen protection

2012 ◽  
Vol 109 (6) ◽  
pp. 2108-2113 ◽  
Author(s):  
S. Fanning ◽  
L. J. Hall ◽  
M. Cronin ◽  
A. Zomer ◽  
J. MacSharry ◽  
...  
Keyword(s):  
Immune Modulation ◽  
Host Interaction

scholarly journals Pathogenic Acinetobacter: from the Cell Surface to Infinity and Beyond

2015 ◽  
Vol 198 (6) ◽  
pp. 880-887 ◽  
Author(s):  
Brent S. Weber ◽  
Christian M. Harding ◽  
Mario F. Feldman
Keyword(s):  
Virulence Factors ◽  
Current Knowledge ◽  
Multidrug Resistant ◽  
Protein Glycosylation ◽  
Opportunistic Pathogens ◽  
Secretion Systems ◽  
Content Type ◽  
Bacterial Surface ◽  
Acinetobacter Pittii ◽  
New Strategies

The genusAcinetobacterencompasses multiple nosocomial opportunistic pathogens that are of increasing worldwide relevance because of their ability to survive exposure to various antimicrobial and sterilization agents. Among these,Acinetobacter baumannii,Acinetobacter nosocomialis, andAcinetobacter pittiiare the most frequently isolated in hospitals around the world. Despite the growing incidence of multidrug-resistantAcinetobacterspp., little is known about the factors that contribute to pathogenesis. New strategies for treating and managing infections caused by multidrug-resistantAcinetobacterstrains are urgently needed, and this requires a detailed understanding of the pathobiology of these organisms. In recent years, some virulence factors important forAcinetobactercolonization have started to emerge. In this review, we focus on several recently described virulence factors that act at the bacterial surface level, such as the capsule,O-linked protein glycosylation, and adhesins. Furthermore, we describe the current knowledge regarding the type II and type VI secretion systems present in these strains.

scholarly journals A Timely Review of Cross-Kingdom Regulation of Plant-Derived MicroRNAs

2021 ◽  
Vol 12 ◽  
Author(s):  
Dan Li ◽  
Jianhui Yang ◽  
Yong Yang ◽  
Jianxin Liu ◽  
Hui Li ◽  
...  
Keyword(s):  
Immune Modulation ◽  
Current Knowledge ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Messenger Rnas ◽  
Plant Mirnas ◽  
Complementary Oligonucleotide ◽  
Density Lipoprotein Receptor ◽  
The Cross ◽  
The Stability

MicroRNAs (miRNAs) belong to a class of non-coding RNAs that suppress gene expression by complementary oligonucleotide binding to the sites in target messenger RNAs. Numerous studies have demonstrated that miRNAs play crucial role in virtually all cellular processes of both plants and animals, such as cell growth, cell division, differentiation, proliferation and apoptosis. The study of rice MIR168a has demonstrated for the first time that exogenous plant MIR168a influences cholesterol transport in mice by inhibiting low-density lipoprotein receptor adapter protein 1 expression. Inspired by this finding, the cross-kingdom regulation of plant-derived miRNAs has drawn a lot of attention because of its capability to provide novel therapeutic agents in the treatment of miRNA deregulation-related diseases. Notably, unlike mRNA, some plant miRNAs are robust because of their 3′ end modification, high G, C content, and the protection by microvesicles, miRNAs protein cofactors or plant ingredients. The stability of these small molecules guarantees the reliability of plant miRNAs in clinical application. Although the function of endogenous miRNAs has been widely investigated, the cross-kingdom regulation of plant-derived miRNAs is still in its infancy. Herein, this review summarizes the current knowledge regarding the anti-virus, anti-tumor, anti-inflammatory, anti-apoptosis, immune modulation, and intestinal function regulation effects of plant-derived miRNAs in mammals. It is expected that exploring the versatile role of plant-derived miRNAs may lay the foundation for further study and application of these newly recognized, non-toxic, and inexpensive plant active ingredients.

Anti-Virulence Strategy against the Multidrug-Resistant Bacterial Pathogen Pseudomonas aeruginosa: Pseudolysin (Elastase B) as a Potential Druggable Target

2019 ◽  
Vol 20 (5) ◽  
pp. 471-487 ◽  
Author(s):  
Anna Clara M. Galdino ◽  
Matheus P. de Oliveira ◽  
Teodorico C. Ramalho ◽  
Alexandre A. de Castro ◽  
Marta H. Branquinha ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Virulence Factors ◽  
Bacterial Pathogen ◽  
Intercellular Junctions ◽  
Multidrug Resistant ◽  
Complement Components ◽  
Healthcare Settings ◽  
Host Interaction ◽  
Promising Target ◽  
Hospital Acquired

Pseudomonas aeruginosa is a non-fermentative, gram-negative bacterium that is one of the most common pathogens responsible for hospital-acquired infections worldwide. The management of the infections caused by P. aeruginosa represents a huge challenge in the healthcare settings due to the increased emergence of resistant isolates, some of them resistant to all the currently available antimicrobials, which results in elevated morbimortality rates. Consequently, the development of new therapeutic strategies against multidrug-resistant P. aeruginosa is urgent and needful. P. aeruginosa is wellrecognized for its extreme genetic versatility and its ability to produce a lush variety of virulence factors. In this context, pseudolysin (or elastase B) outstands as a pivotal virulence attribute during the infectious process, playing multifunctional roles in different aspects of the pathogen-host interaction. This protein is a 33-kDa neutral zinc-dependent metallopeptidase that is the most abundant peptidase found in pseudomonal secretions, which contributes to the invasiveness of P. aeruginosa due to its ability to cleave several extracellular matrix proteins and to disrupt the basolateral intercellular junctions present in the host tissues. Moreover, pseudolysin makes P. aeruginosa able to overcome host defenses by the hydrolysis of many immunologically relevant molecules, including antibodies and complement components. The attenuation of this striking peptidase therefore emerges as an alternative and promising antivirulence strategy to combat antibiotic-refractory infections caused by P. aeruginosa. The anti-virulence approach aims to disarm the P. aeruginosa infective arsenal by inhibiting the expression/activity of bacterial virulence factors in order to reduce the invasiveness of P. aeruginosa, avoiding the emergence of resistance since the proliferation is not affected. This review summarizes the most relevant features of pseudolysin and highlights this enzyme as a promising target for the development of new anti-virulence compounds.

Do Periodontal Pathogens or Associated Virulence Factors Have a Deleterious Effect on the Blood-Brain Barrier, Contributing to Alzheimer’s Disease?

2021 ◽  
pp. 1-17
Author(s):  
Mhd Ammar Kouki ◽  
Anna Barlach Pritchard ◽  
Jane Elizabeth Alder ◽  
StJohn Crean
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Blood Brain Barrier ◽  
Virulence Factors ◽  
Current Knowledge ◽  
Brain Barrier ◽  
Periodontal Pathogens ◽  
Blood Brain

The central nervous system (CNS) is protected by a highly selective barrier, the blood-brain barrier (BBB), that regulates the exchange and homeostasis of bloodborne molecules, excluding xenobiotics. This barrier forms the first line of defense by prohibiting pathogens from crossing to the CNS. Aging and chronic exposure of the BBB to pathogens renders it permeable, and this may give rise to pathology in the CNS such as Alzheimer’s disease (AD). Researchers have linked pathogens associated with periodontitis to neuroinflammation and AD-like pathology in vivo and in vitro. Although the presence of periodontitis-associated bacteria has been linked to AD in several clinical studies as DNA and virulence factors were confirmed in brain samples of human AD subjects, the mechanism by which the bacteria traverse to the brain and potentially influences neuropathology is unknown. In this review, we present current knowledge about the association between periodontitis and AD, the mechanism whereby periodontal pathogens might provoke neuroinflammation and how periodontal pathogens could affect the BBB. We suggest future studies, with emphasis on the use of human in vitro models of cells associated with the BBB to unravel the pathway of entry for these bacteria to the CNS and to reveal the molecular and cellular pathways involved in initiating the AD-like pathology. In conclusion, evidence demonstrate that bacteria associated with periodontitis and their virulence factors are capable of inflecting damage to the BBB and have a role in giving rise to pathology similar to that found in AD.

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