European journal of microbiology & immunology最新文献

B-cells serve as a niche for Salmonella to establish a chronic infection, enabling bacteria to evade immune responses. One mechanism Salmonella uses to survive inside B-cells involves inhibiting the NLRC4 inflammasome activation, thereby preventing pyroptotic cell death. This study investigates whether Salmonella-infected B-cells can mount bactericidal responses to control intracellular bacteria. Our results show that Salmonella-infected B-cells can produce and release TNFα, IL-6, and IL-10, but not RANTES. Furthermore, priming B-cells with TNFα, IL-1β, or IFNγ enhances their bactericidal activity by promoting the production of reactive oxygen and nitrogen production species, reducing intracellular load. These results suggest that B-cells can clear Salmonella infection within a pro-inflammatory environment. However, the concurrent production of IL-10 may counteract the effects of pro-inflammatory cytokines, potentially modulating the immune response in the microenvironment.

Multi-drug resistant bacterial infections are of global concern, leading to staggering health care costs and loss of lives. Hence, novel therapeutic options are highly required. Garcinia mangostana, a plant known as mangosteen (also termed "queen of the fruits"), is said to possess a multitude of favorable features like anti-microbial capacity. Accordingly, we compiled a literature review addressing the potential of the mangosteen and its compounds for the treatment of bacterial infections. The included 23 publications consistently reported the inhibition or elimination of bacteria following the administration of mangosteen extracts and compounds such as the xanthone α-mangostin, both in vitro and in vivo. Even pathogens like methicillin-resistant Staphylococcus aureus as well as vancomycin-resistant Enterococcus species were tackled. While the effect of mangosteen extracts and compounds appeared to be dose-dependent, they exhibited also anti-biofilm activity and strong stability under varying conditions, suggesting suitability for a versatile approach to combat infectious diseases. Moreover, the combination of α-mangostin with other phytotherapeutic agents and especially antibiotics revealed enhanced anti-bacterial results, at low or no toxicity. In light of this review, we conclude that mangosteen extracts and compounds are promising candidates for the anti-bacterial therapy of human infections, warranting further consideration in clinical trials.

Epigenetic modifications are critical for the regulation of CD4+ T cell differentiation and function. Previously, we identified Acyl-CoA Synthetase Bubble Gum 1 (Acsbg1), a gene involved in fatty acid metabolism, as part of an epigenetic signature that was selectively demethylated in ex vivo isolated T helper 17 (TH17) cells. However, its functional relevance for CD4+ T cells remains incompletely understood. Here, we used in vitro differentiation assays and the adoptive transfer colitis model to investigate the role of Acsbg1 in the differentiation and function of TH1, TH17, and regulatory T (Treg) cells. In vitro, Acsbg1 was expressed in both TH17 and in vitro-induced Treg (iTreg) cells, whereas TH1 cells lacked Acsbg1 expression. Accordingly, Acsbg1 deficiency resulted in impaired TH17 and iTreg differentiation, whereas TH1 differentiation was unaffected. In vivo, upon adoptive transfer of Acsbg1⁻/⁻ Tnaïve cells, immunodeficient recipient mice exhibited an exacerbated colitis, characterized by an altered balance of TH17 and Treg cells, indicating that Acsbg1 expression is essential for optimal TH17 and Treg cell differentiation and function. Our findings highlight the importance of fatty acid (FA) metabolism in maintaining immune homeostasis by regulating T cell differentiation and provide novel insights into the metabolic targeting of inflammatory diseases.

Aronia melanocarpa, a main constituent of black chokeberry, provides a rich source of bioactive molecules including polyphenols, flavonoids, and anthocyanins and has been used for long in traditional medicine due to its various health-promoting and disease-alleviating properties. The aim of our literature survey was to provide an actual update of evidence regarding the antibacterial activities exerted by Aronia melanocarpa and its potential application for the treatment of human bacterial pathogenic including food-borne infections. Our survey revealed that distinct ingredients in Aronia melanocarpa do not only inhibit growth of Gram-positive and to a lesser extent of Gram-negative bacteria, but also biofilm formation that is even more pronounced upon combined application. Furthermore, the anti-microbial effects against food-spoiling bacteria underscores the application of defined Aronia-derived molecules in food preservation decreasing the risk for transmission of food-borne pathogens and thereby, improving food safety. Notably, in vivo studies revealed that prophylactic Aronia juice application alleviated murine Listeria monocytogenes-induced enteritis, dampened growth of streptococci involved in dental caries development, and decreased the incidence of urinary tract infections in nursing home residents. In conclusion, Aronia-derived bioactive molecules exhibit promising anti-bacterial and disease-alleviating effects that should be further elucidated in clinical studies.

Conventional laboratory mice are protected from oral Campylobacter jejuni infection due to colonization resistance (CR) mediated by their host-specific gut microbiota. Here, we used differential effects of distinct antibiotics on gut microbiota composition to identify microbial groups associated with CR against C. jejuni. Therefore, specific pathogen-free (SPF) mice were subjected to ampicillin plus sulbactam (A/S), ciprofloxacin (CIP), or vancomycin (VAN) via the drinking water for 28 days or left untreated before peroral C. jejuni challenge. Cultural analyses revealed that CR displayed by untreated mice was abrogated by A/S treatment, but only reduced in mice treated with CIP or VAN. Notably, differential analysis of antibiotic-induced microbiota changes and C. jejuni colonization dynamics identified lactobacilli and Clostridium leptum as key microbial groups that were associated with CR. Notably, the complete eradication of intestinal bacteria in A/S treated mice supported high intestinal C. jejuni colonization levels which triggered apoptosis and inflammatory responses accompanied by enhanced expression of matrix-degrading gelatinases in the colon. In conclusion, A/S treated mice represent a valuable infection model for the study of campylobacteriosis and the treatment of mice with specific antibiotics support the investigation of molecular mechanisms involved in CR against enteropathogens.

Interferon-gamma (IFN-γ) autoantibody syndrome is an emerging clinical entity that has been associated with disseminated non-tuberculous mycobacterial infection (dNTM) particularly in healthy young people, a population not previously thought to be at particular risk. A 29-year-old South-East Asian man presented with several weeks of fever, cough, lymphadenopathy, and constitutional symptoms while working on an international cargo ship, deteriorating rapidly with a sepsis-like syndrome. Eventually lymph node and sputum cultures revealed a diagnosis of dNTM infection with growth of both Mycobacterium persicum and Mycobacterium abscessus. He was commenced on rituximab as well as combination anti-mycobacterial therapy with good clinical response. This case highlights some of the difficulties faced by patients with dNTM in the context of IFN-γ autoantibodies, particularly delayed diagnosis, and lack of evidence base surrounding optimal management. Further research into long-term outcomes and treatment is required as well as increased awareness among clinicians.

This work aimed to investigate interactions between antibody-opsonized SARS-CoV-2 and monocytes enriched from human peripheral blood mononuclear cells (PBMC) to determine whether antibody dependent enhancement might contribute to the pathophysiology of COVID-19. Pre-incubation of SARS-CoV-2 with sera from hospitalized COVID-19 patients led to significantly increased virus uptake and viral replication in monocytes. Remarkably, SARS-CoV-2 pre-incubated with sera from patients with severe COVID-19 but not those with mild disease or post vaccination strongly increased IL-6 secretion by monocytes. Antibody dependent viral uptake was partially inhibited by monoclonal anti-FcγRIIa antibody whereas IL-6 secretion was completely abolished. FcγRIIa preferentially binds IgG2, and sera from patients with severe COVID-19 contained lower IgG2 levels as compared to mild COVID-19 cases whereas IgG1 levels were increased. These data suggests that FcγRIIa-mediated binding of antibody-opsonized SARS-CoV-2 critically impacts monocytic inflammatory cytokine release and COVID-19 pathophysiology.

Introduction: This study was conducted to determine the specific features of the mutual influence of the immune and haemostatic systems in immunohaemostasis, the role of immune reactions in the regulation of blood coagulation, and the efficacy of modern methods of treating thrombosis and bleeding.

Methods: The study analysed relevant scientific sources on immunology and haematology and identified the specific features of the blood clotting process and the role of immune reactions in it.

Results: The study found that the immune system influences the haematological system through the interaction of blood clotting factors, platelets, plasminogen, endothelial cells with immune cells. The haemostatic system influences the immune system through mechanisms to maintain immune tolerance and immune memory and the properties of clotting factors to activate the stimulation and migration of immune cells to the site of infection. Immune reactions regulate blood coagulation by activating platelets, regulating blood coagulation factors, affecting fibrinolysis, and immune tolerance. The process of platelet activation involves immune cells, immune complexes, and microbial components. The regulation of blood coagulation factors is influenced by the ability of immune cells to produce activators and inhibitors of these factors and to stimulate or slow down fibrinolysis. The immune system's maintenance of immune tolerance to blood components is regulated by mechanisms of immune response suppression, partial immune ignoring of certain blood elements, inhibition of activation of certain immune cells, apoptosis, and selection of immature T-lymphocytes. Treatment methods for patients at risk of thrombosis and bleeding include anticoagulation, antiplatelet, dual antiplatelet therapy, thrombectomy, endovascular methods, medical prophylaxis of bleeding, and coagulation monitoring.

Conclusions: The findings of this study suggest the significance of immune responses in the regulation of blood coagulation processes, and therefore they can be used in the development of immunotherapy methods for the treatment of thrombosis and bleeding.

Barbershops are important venues for men to get their hair and beards done and hence, play an important role in men's social life. But barbershops can also be a source of infections. The barber's profession brings the barber into direct contact with customers who may carry pathogens, and contaminated instruments or skin-to-skin contacts might transmit infectious agents. Since barbers work with non-sterile and reusable sharp objects, a simple nick might facilitate blood-borne infections. In our review article we summarize current knowledge regarding barbershop-acquired infections including transmission routes and preventive measures. In fact, shaving in barbershops, particularly when reusing non-disinfected razor blades increases the transmission risk for the human immunodeficiency virus (HIV) and hepatitis B or C viruses. Furthermore, distinct bacteria like Staphylococcus aureus, fungi (in particular dermatophytic Trichophyton species) as well as ectoparasitic lice could be identified upon screening of the barbers' equipment and working places. However, knowledge regarding and compliance in hygiene practices varied considerably among barbers. Notably, since in certain countries barbershops are venues to contact sex workers, sexually transmitted diseases might also be acquired in barbershops. In conclusion, improving hygiene standards including disinfection of reusable equipment, and surveillance of the preventive measures would reduce the risk for barbershop-acquired infections.

Actinomycetoma, a neglected tropical disease affecting the skin and soft tissues, is primarily caused by filamentous bacteria including Nocardia species. Here, we report a healthy 56-year-old man who has a one-year history of nodular lesions with seropurulent discharge on his right knee. Despite negative initial tissue culture, the sulfur granules that were partially acid-fast and Gram-positive branching filamentous rods were revealed in the tissue section. Repeated investigation identified the rare pathogen Nocardia wallacei, using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and 16S ribosomal ribonucleic acid (rRNA) gene sequencing. The patient was successfully treated with a six-month course of trimethoprim-sulfamethoxazole.This report describes a rare case of actinomycetoma due to N. wallacei, highlighting the challenges in diagnosis and the importance of accurate pathogen identification for the successful management of infection. The current literature regarding the causative agent will also be discussed.