scholarly journals The eminence status of bacterial pigments under different aspects

2017 ◽  
Vol 32 (4) ◽  
Author(s):  
Parisa Sabbagh ◽  
Amirmorteza Ebrahimzadeh Namvar
Keyword(s):  
Virulence Factors ◽  
Significant Role ◽  
Current Knowledge ◽  
Medical Bacteriology ◽  
Bacterial Pigments

Several bacteria such as Flavobacterium, Serratias, Chromobacterium and Streptomyces that produce different pigments are playing a significant role in various fields of sciences. Alternatively, current knowledge about bacterial pigments is limited to medical bacteriology, for instance their importance in virulence factors and protective features, however recently the investigators have revealed the supplementary consequence of pigments in food, textile and pharmaceutical aspects.

scholarly journals Carta al Editor Es erróneo hacer una asociación directa entre la detección de Helicobacter spp. y gastritis en caninos

2017 ◽  
Vol 35 (2) ◽  
pp. 61
Author(s):  
Marcela Suárez-Esquivel ◽  
Elías Barquero-Calvo
Keyword(s):  
Virulence Factors ◽  
Significant Role ◽  
Current Knowledge ◽  
Multifactorial Disease ◽  
Gastric Lesions ◽  
Positive Correlation ◽  
Clear Association ◽  
Direct Association ◽  
True Ability

It has been proposed that Helicobacter may play a significant role in the generation of gastritis and cancer in dogs.  However, despite several independent efforts, there is still controversy regarding the true ability of Helicobacter to cause gastric lesions in these animals. The foregoing is due in part to the fact that gastritis is a multifactorial disease. Studies focused on naturally acquired infections have been unable to establish a positive correlation between Helicobacter colonization and gastritis.  Establishing a clear association between the presence of Helicobacter and gastritis may be difficult due to the following reasons: (i) taxonomy of the genus Helicobacter remains unclear, (ii) virulence factors of Helicobacter species that colonize dogs are not well known, and (iii) simultaneous infections have been reported with several species of Helicobacter. Current knowledge in taxonomy and pathogenesis of Helicobacter species is insufficient to differentiate between pathogenic and non-pathogenic strains.  Therefore, no direct association should be made between the detection of Helicobacter and gastritis.

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.

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 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.

The Role of Symbioses in the Adaptation and Stress Responses of Marine Organisms

2020 ◽  
Vol 12 (1) ◽  
pp. 291-314 ◽  
Author(s):  
Amy Apprill
Keyword(s):  
Coral Reef ◽  
Significant Role ◽  
Stress Responses ◽  
Current Knowledge ◽  
Technological Development ◽  
Marine Organisms ◽  
Anthropogenic Change ◽  
Subject Knowledge ◽  
Coral Reef Ecosystems

Ocean ecosystems are experiencing unprecedented rates of climate and anthropogenic change, which can often initiate stress in marine organisms. Symbioses, or associations between different organisms, are plentiful in the ocean and could play a significant role in facilitating organismal adaptations to stressful ocean conditions. This article reviews current knowledge about the role of symbiosis in marine organismal acclimation and adaptation. It discusses stress and adaptations in symbioses from coral reef ecosystems, which are among the most affected environments in the ocean, including the relationships between corals and microalgae, corals and bacteria, anemones and clownfish, and cleaner fish and client fish. Despite the importance of this subject, knowledge of how marine organisms adapt to stress is still limited, and there are vast opportunities for research and technological development in this area. Attention to this subject will enhance our understanding of the capacity of symbioses to alleviate organismal stress in the oceans.

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.

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.

scholarly journals PORPHYROMONAS GINGIVALIS E PERIODONTITE CRÔNICA - AVANÇOS RECENTES

2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Victor Hugo Rocha Leon ◽  
Ellen Karla Nobre dos Santos-Lima ◽  
Ana Carla Montino Pimentel ◽  
Patricia Mares de Miranda ◽  
Paulo Cirino De Carvalho Filho ◽  
...  
Keyword(s):  
Porphyromonas Gingivalis ◽  
Virulence Factors ◽  
Chronic Periodontitis ◽  
Cellular Response ◽  
Current Knowledge ◽  
Periodontal Diseases ◽  
Tissue Destruction ◽  
Inflammatory State ◽  
Cell Death Mechanisms

Periodontal disease is multifactorial and it affects the tissues surrounding the teeth. Its etiology includes microrganisms as Porphyromonas gingivalis, Tannerella forsythia and Aggregatibacter actinomycetemcomitans. This work aimed to discuss the role of Porphyromonas gingivalis in chronic periodontitis. The electronic bases PubMed, BIREME and SciELO were used to search for historical aspects and studies published between 2000 and 2015, using the following descriptors in Portuguese and English: “Chronic periodontitis, Porphyromonas gingivalis” and “Virulence factors”. 205 articles were found and 24 were included. Records on periodontal diseases from the early civilization to the present day were found. Its prevalence in the world’s population remains high and several studies report the pathogenesis of the disease. P. gingivalis is able to induce humoral and cellular response in infected individuals. Studies on its escape mechanisms and virulence factors report tissue breakdown consequent to immuno-inflammatory exacerbated response in the host which may evolve into edentulism. Studies of the immune response to P. gingivalis suggest its role in perpetuation of the inflammatory state by interfering with cytokines production and cell death mechanisms in the host’s cells, resulting in tissue destruction. The current knowledge about mechanisms of infection and virulence factors of P. gingivalis indicate its role as a key component in chronic periodontitis.

scholarly journals Virulence Genes and the Evolution of Host Specificity in Plant-Pathogenic Fungi

2007 ◽  
Vol 20 (10) ◽  
pp. 1175-1182 ◽  
Author(s):  
H. Charlotte van der Does ◽  
Martijn Rep
Keyword(s):  
Virulence Factors ◽  
Sequence Variation ◽  
Virulence Genes ◽  
Current Knowledge ◽  
Pathogenic Fungi ◽  
Fungal Species ◽  
Arms Races ◽  
Genomic Location ◽  
Evolution Of Virulence ◽  
Fungal Kingdom

In the fungal kingdom, the ability to cause disease in plants appears to have arisen multiple times during evolution. In many cases, the ability to infect particular plant species depends on specific genes that distinguish virulent fungi from their sometimes closely related nonvirulent relatives. These genes encode host-determining “virulence factors,” including small, secreted proteins and enzymes involved in the synthesis of toxins. These virulence factors typically are involved in evolutionary arms races between plants and pathogens. We briefly summarize current knowledge of these virulence factors from several fungal species in terms of function, phylogenetic distribution, sequence variation, and genomic location. Second, we address some issues that are relevant to the evolution of virulence in fungi toward plants; in particular, horizontal gene transfer and the genomic organization of virulence genes.

scholarly journals Potential Roles and Functions of Listerial Virulence Factors during Brain Entry

Toxins ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 297
Author(s):  
Franjo Banović ◽  
Horst Schroten ◽  
Christian Schwerk
Keyword(s):  
Virulence Factors ◽  
Current Knowledge ◽  
Cellular Adhesion ◽  
The Body ◽  
Listeriolysin O ◽  
The Brain ◽  
Adhesion And Invasion

Although it rarely induces disease in humans, Listeria monocytogenes (Lm) is important due to the frequency of serious pathological conditions—such as sepsis and meningitis—it causes in those few people that do get infected. Virulence factors (VF) of Lm—especially those involved in the passage through multiple cellular barriers of the body, including internalin (Inl) family members and listeriolysin O (LLO)—have been investigated both in vitro and in vivo, but the majority of work was focused on the mechanisms utilized during penetration of the gut and fetoplacental barriers. The role of listerial VF during entry into other organs remain as only partially solved puzzles. Here, we review the current knowledge on the entry of Lm into one of its more significant destinations, the brain, with a specific focus on the role of various VF in cellular adhesion and invasion.

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