1,720,991 research outputs found
Updating the relationship of Chlamydia pneumoniae with atherosclerotic cardiovascular diseases. A systematic review of reviews
No full textChlamydia pneumoniae is the etiologic agent of respiratory tract infections in humans, including community-acquired pneumonia, and has been associated with atherosclerotic cardiovascular diseases. The present systematic review of reviews aimed at answering important questions on the involvement of C. pneumoniae in the pathogenesis of atherosclerosis, its cellular and molecular mechanisms, and whether there is evidence of a causal relationship. The databases PubMed/Med-line, Scopus, and Web of Science were searched for all review articles published from 2003 to the end of 2023. A total of 27 reviews, systematic reviews, and systematic reviews with metanalysis were included. Overall, current evidence suggests that C. pneumoniae is a biologically plausible candidate for the causation of atherosclerosis, albeit not all the 4 Koch postulates are fulfilled; oxidative stress and inflammation are the most likely pathogenic mechanisms mediated by C. pneumoniae. However, it is still unclear how the persistent form, responsible for chronic inflammation, fits into this etiopathogenetic scenario. In the future, the newly-designed transformation systems for the genomic manipulation of C. pneumoniae will surely help expand our knowledge on the role of this pathogen in atherogenesis
Microbiota and thyroid disease. An updated systematic review
No full textStudies analyzing the relationship between microbiota composition and the thyroid have been increasing rapidly in recent years, and evidence has recently come to light about the involvement of the gut microbiota in various aspects of thyroid pathology. Recently, besides studies analyzing the microbiota composition of different biological niches (salivary microbiota or thyroid tumor microenvironment) in patients with thyroid disorders, some studies have been carried out in peculiar subcategories of patients (pregnant women or obese). Other studies added a metabolomic insight into the characterization of fecal microflora in an attempt to enlighten specific metabolic pathways that could be involved in thyroid disorder pathogenesis. Lastly, some studies described the use of probiotics or symbiotic supplementation aimed at modulating gut microbiota composition for therapeutic purposes. The aim of this systematic review is to analyze the last advancements in the relationship between gut microbiota composition and thyroid autoimmunity, extending the analysis also to nonautoimmune thyroid disorders as well as to the characterization of the microbiota belonging to different biological niches in these patients. The overall results of the present review article strengthen the existence of a bidirectional relationship between the intestine, with its microbial set, and thyroid homeostasis, thus supporting the newly recognized entity known as the gut-thyroid axis
Infectious burden and atherosclerosis. A clinical issue
Full text linkAtherosclerotic cardiovascular diseases, chronic inflammatory diseases of multifactorial etiology, are the leading cause of death worldwide. In the last decade, more infectious agents, labeled as "infectious burden", rather than any single pathogen, have been showed to contribute to the development of atherosclerosis through different mechanisms. Some microorganisms, such as Chlamydia pneumoniae (C. pneumoniae), human cytomegalovirus, etc. may act directly on the arterial wall contributing to endothelial dysfunction, foam cell formation, smooth muscle cell proliferation, platelet aggregation as well as cytokine, reactive oxygen specie, growth factor, and cellular adhesion molecule production. Others, such as Helicobacter pylori (H. pylori), influenza virus, etc. may induce a systemic inflammation which in turn may damage the vascular wall (e.g., by cytokines and proteases). Moreover, another indirect mechanism by which some infectious agents (such as H. pylori, C. pneumoniae, periodontal pathogens, etc.) may play a role in the pathogenesis of atherosclerosis is molecular mimicry. Given the complexity of the mechanisms by which each microorganism may contribute to atherosclerosis, defining the interplay of more infectious agents is far more difficult because the pro-atherogenic effect of each pathogen might be amplified. Clearly, continued research and a greater awareness will be helpful to improve our knowledge on the complex interaction between the infectious burden and atherosclerosis
New insights into Chlamydiae persistence: An energy metabolism strategy?
No full textChlamydiaceae is a family of obligate intracellular bacteria generally considered energy parasites. Several studies have suggested that Chlamydiae are capable of independently producing energy and, more importantly, several genes involved in the energy metabolism are up-regulated during the persistent state. Thus, it has been suggested that chlamydial persistence could be a complex and flexible metabolic strategy designed to favor a lengthy survival in the host cell by evading the immune response. In conclusion, more detailed studies on the shift in the chlamydial energy metabolism, from the active to the persistent form, may be helpful in future to determine whether chlamydial persistence observed in vitro does occur in vivo and whether chronic sequelae of chlamydial diseases may be related to the persistence. Copyright © by BIOLIFE, s.a.s.Chlamydiaceae is a family of obligate intracellular bacteria generally considered energy parasites. Several studies have suggested that Chlamydiae are capable of independently producing energy and, more importantly, several genes involved in the energy metabolism are up-regulated during the persistent state. Thus, it has been suggested that chlamydial persistence could be a complex and flexible metabolic strategy designed to favor a lengthy survival in the host cell by evading the immune response. In conclusion, more detailed studies on the shift in the chlamydial energy metabolism, from the active to the persistent form, may be helpful in future to determine whether chlamydial persistence observed in vitro does occur in vivo and whether chronic sequelae of chlamydial diseases may be related to the persistence
Editorial for the Special Issue "Antibacterial activity of drug-resistant strains"
Full text linkAntimicrobial resistance is an urgent global public health threat, as approximately 700,000 deaths annually can be attributed to antibiotic-resistant bacterial infections, and this figure is expected to reach 10 million deaths/year by 2050, a number that greatly exceeds the number of deaths resulting from cancer [...]
Chlamydia pneumoniae and cardiovascular disease in end-stage renal disease patients: An update
No full textCardiovascular diseases (CVD), due to accelerated atherosclerosis, are responsible for approximately 50% of mortality in End Stage Renal Disease (ESRD) patients undergoing haemodialysis (HD). Over the last decade, Chlamydia pneumoniae, a respiratory pathogen, has been involved in the pathogenesis of atherosclerosis and several reports have suggested the association between C. pneumoniae infection and CVD in HD patients. This report reviews the contribution of C. pneumoniae infection in cardiovascular diseases in ESRD patients, in light of recent studies on cardiovascular risk factors; we hypothesize that C. pneumoniae-infection may contribute to mineral bone disorder and, consequently, vascular calcification. However, further studies are needed to define the relationship between C. pneumoniae and bone and vascular disorders in HD patients. Copyright © by BIOLIFE, s.a.s
Chlamydia pneumoniae infection in atherosclerotic lesion development through oxidative stress: A brief overview
No full textChlamydia pneumoniae, an obligate intracellular pathogen, is known as a leading cause of respiratory tract infections and, in the last two decades, has been widely associated with atherosclerosis by seroepidemiological studies, and direct detection of the microorganism within atheroma. C. pneumoniae is presumed to play a role in atherosclerosis for its ability to disseminate via peripheral blood mononuclear cells, to replicate and persist within vascular cells, and for its pro-inflammatory and angiogenic effects. Once inside the vascular tissue, C. pneumoniae infection has been shown to induce the production of reactive oxygen species in all the cells involved in atherosclerotic process such as macrophages, platelets, endothelial cells, and vascular smooth muscle cells, leading to oxidative stress. The aim of this review is to summarize the data linking C. pneumoniae-induced oxidative stress to atherosclerotic lesion development
RESVERATROL IN CHLAMYDIA PNEUMONIAE-INDUCED FOAM CELL FORMATION AND INTERLEUKIN-17A SYNTHESIS
No full textThe involvement of Chlamydia pneumoniae in the pathogenesis of atherosclerosis has been suggested by numerous seroepidemiological, in vivo and in vitro studies. In particular, it has been shown that C. pneumoniae is able to promote the accumulation of low-density lipoproteins into macrophages, thus facilitating foam cell formation. The aim of our study was to investigate the effects of resveratrol on macrophage-derived foam cell formation induced by C. pneumoniae, examining its underlying biochemical mechanisms. Our results showed a relevant decrease in the number of foam. cells, in the production of thiobarbituric acid reactive substances, superoxide anion and IL-17A while treating C. pneumoniae infected macrophages with resveratrol. Furthermore, the inhibition of Peroxisome Proliferator-Activated Receptors gamma by a specific antagonist (GW 9662), in presence of resveratrol and C. pneumoniae, enhanced intracellular lipid and cholesterol accumulation and the subsequent foam cell formation. In conclusion, the main result of our study is the evidence of an antiatherogenic effect of resveratrol on macrophage-derived foam cell formation and IL-17A production induced by C. pneumoniae.The involvement of Chlamydia pneumoniae in the pathogenesis of atherosclerosis has been suggested by numerous seroepidemiological, in vivo and in vitro studies. In particular, it has been shown that C. pneumoniae is able to promote the accumulation of low-density lipoproteins into macrophages, thus facilitating foam cell formation. The aim of our study was to investigate the effects of resveratrol on macrophage-derived foam cell formation induced by C. pneumoniae, examining its underlying biochemical mechanisms. Our results showed a relevant decrease in the number of foam. cells, in the production of thiobarbituric acid reactive substances, superoxide anion and IL-17A while treating C. pneumoniae infected macrophages with resveratrol. Furthermore, the inhibition of Peroxisome Proliferator-Activated Receptors gamma by a specific antagonist (GW 9662), in presence of resveratrol and C. pneumoniae, enhanced intracellular lipid and cholesterol accumulation and the subsequent foam cell formation. In conclusion, the main result of our study is the evidence of an antiatherogenic effect of resveratrol on macrophage-derived foam cell formation and IL-17A production induced by C. pneumoniae
Effects of Mentha suaveolens essential oil on C. trachomatis
Full text linkChlamydia trachomatis, the most common cause of sexually transmitted bacterial infection worldwide, has a unique biphasic developmental cycle alternating between the infectious elementary body and the replicative reticulate body. C. trachomatis is responsible for severe reproductive complications including pelvic inflammatory disease, ectopic pregnancy, and obstructive infertility. The aim of our study was to evaluate whether Mentha suaveolens essential oil (EOMS) can be considered as a promising candidate for preventing C. trachomatis infection. Specifically, we investigated the in vitro effects of EOMS towards C. trachomatis analysing the different phases of chlamydial developmental cycle. Our results demonstrated that EOMS was effective towards C. trachomatis, whereby it not only inactivated infectious elementary bodies but also inhibited chlamydial replication. Our study also revealed the effectiveness of EOMS, in combination with erythromycin, towards C. trachomatis with a substantial reduction in the minimum effect dose of antibiotic. In conclusion, EOMS treatment may represent a preventative strategy since it may reduce C. trachomatis transmission in the population and, thereby, reduce the number of new chlamydial infections and risk of developing of severe sequelae
Growth kinetics of Chlamydia trachomatis in primary human Sertoli cells
No full textChlamydia trachomatis (Ct) is the leading cause of bacterial sexually transmitted infections worldwide and has been associated with male infertility. Recently, it was hypothesized that Ct may infect the epithelium of the seminiferous tubule, formed by Sertoli cells, thus leading to impaired spermatogenesis. To date, there is a lack of data on Ct infection of the seminiferous epithelium; therefore, we aimed to characterize, for the first time, an in vitro infection model of primary human Sertoli cells. We compared Ct inclusion size, morphology and growth kinetics with those in McCoy cells and we studied F-actin fibres, Vimentin-based intermediate filaments and α-tubulin microtubules in Sertoli and McCoy cells. Our main finding highlighted the ability of Ct to infect Sertoli cells, although with a unique growth profile and the inability to exit host cells. Furthermore, we observed alterations in the cytoskeletal fibres of infected Sertoli cells. Our results suggest that Ct struggles to generate a productive infection in Sertoli cells, limiting its dissemination in the host. Nevertheless, the adverse effect on the cytoskeleton supports the notion that Ct may compromise the blood-testis barrier, impairing spermatogenesis.</p
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