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1.
Susceptibility for Some Infectious Diseases in Patients With Diabetes: The Key Role of Glycemia.
Chávez-Reyes, J, Escárcega-González, CE, Chavira-Suárez, E, León-Buitimea, A, Vázquez-León, P, Morones-Ramírez, JR, Villalón, CM, Quintanar-Stephano, A, Marichal-Cancino, BA
Frontiers in public health. 2021;:559595
Abstract
Uncontrolled diabetes results in several metabolic alterations including hyperglycemia. Indeed, several preclinical and clinical studies have suggested that this condition may induce susceptibility and the development of more aggressive infectious diseases, especially those caused by some bacteria (including Chlamydophila pneumoniae, Haemophilus influenzae, and Streptococcus pneumoniae, among others) and viruses [such as coronavirus 2 (CoV2), Influenza A virus, Hepatitis B, etc.]. Although the precise mechanisms that link glycemia to the exacerbated infections remain elusive, hyperglycemia is known to induce a wide array of changes in the immune system activity, including alterations in: (i) the microenvironment of immune cells (e.g., pH, blood viscosity and other biochemical parameters); (ii) the supply of energy to infectious bacteria; (iii) the inflammatory response; and (iv) oxidative stress as a result of bacterial proliferative metabolism. Consistent with this evidence, some bacterial infections are typical (and/or have a worse prognosis) in patients with hypercaloric diets and a stressful lifestyle (conditions that promote hyperglycemic episodes). On this basis, the present review is particularly focused on: (i) the role of diabetes in the development of some bacterial and viral infections by analyzing preclinical and clinical findings; (ii) discussing the possible mechanisms by which hyperglycemia may increase the susceptibility for developing infections; and (iii) further understanding the impact of hyperglycemia on the immune system.
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2.
The intracellular phase of extracellular respiratory tract bacterial pathogens and its role on pathogen-host interactions during infection.
Lamberti, Y, Surmann, K
Current opinion in infectious diseases. 2021;(3):197-205
Abstract
PURPOSE OF REVIEW An initial intracellular phase of usually extracellular bacterial pathogens displays an important strategy to hide from the host's immune system and antibiotics therapy. It helps the bacteria, including bacterial pathogens of airway diseases, to persist and eventually switch to a typical extracellular infection. Several infectious diseases of the lung are life-threatening and their control is impeded by intracellular persistence of pathogens. Thus, molecular adaptations of the pathogens to this niche but also the host's response and potential targets to interfere are of relevance. Here we discuss examples of historically considered extracellular pathogens of the respiratory airway where the intracellular survival and proliferation is well documented, including infections by Staphylococcus aureus, Bordetella pertussis, Haemophilus influenzae, Pseudomonas aeruginosa, and others. RECENT FINDINGS Current studies focus on bacterial factors contributing to adhesion, iron acquisition, and intracellular survival as well as ways to target them for combatting the bacterial infections. SUMMARY The investigation of common and specific mechanisms of pathogenesis and persistence of these bacteria in the host may contribute to future investigations and identifications of relevant factors and/or bacterial mechanisms to be blocked to treat or improve prevention strategies.
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3.
The Role of Proteases in the Virulence of Plant Pathogenic Bacteria.
Figaj, D, Ambroziak, P, Przepiora, T, Skorko-Glonek, J
International journal of molecular sciences. 2019;(3)
Abstract
A pathogenic lifestyle is inextricably linked with the constant necessity of facing various challenges exerted by the external environment (both within and outside the host). To successfully colonize the host and establish infection, pathogens have evolved sophisticated systems to combat the host defense mechanisms and also to be able to withstand adverse environmental conditions. Proteases, as crucial components of these systems, are involved in a variety of processes associated with infection. In phytopathogenic bacteria, they play important regulatory roles and modulate the expression and functioning of various virulence factors. Secretory proteases directly help avoid recognition by the plant immune systems, and contribute to the deactivation of the defense response pathways. Finally, proteases are important components of protein quality control systems, and thus enable maintaining homeostasis in stressed bacterial cells. In this review, we discuss the known protease functions and protease-regulated signaling processes associated with virulence of plant pathogenic bacteria.
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4.
Diet-Microbe-Host Interactions That Affect Gut Mucosal Integrity and Infection Resistance.
Forgie, AJ, Fouhse, JM, Willing, BP
Frontiers in immunology. 2019;:1802
Abstract
The gastrointestinal tract microbiome plays a critical role in regulating host innate and adaptive immune responses against pathogenic bacteria. Disease associated dysbiosis and environmental induced insults, such as antibiotic treatments can lead to increased susceptibility to infection, particularly in a hospital setting. Dietary intervention is the greatest tool available to modify the microbiome and support pathogen resistance. Some dietary components can maintain a healthy disease resistant microbiome, whereas others can contribute to an imbalanced microbial population, impairing intestinal barrier function and immunity. Characterizing the effects of dietary components through the host-microbe axis as it relates to gastrointestinal health is vital to provide evidence-based dietary interventions to mitigate infections. This review will cover the effect of dietary components (carbohydrates, fiber, proteins, fats, polyphenolic compounds, vitamins, and minerals) on intestinal integrity and highlight their ability to modulate host-microbe interactions as to improve pathogen resistance.
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5.
[Efficiency of immunomodulatotors for complex therapy of chronic recurrent cystitis in women].
Kuzmenko, AV, Kuzmenko, VV, Gyaurgiev, TA
Urologiia (Moscow, Russia : 1999). 2019;(2):9-14
Abstract
INTRODUCTION Currently, chronic recurrent cystitis is one of the most important problems in urology. Considering the role of immune status disorders in the pathogenesis of inflammatory diseases, the use of immunocorrective drugs as part of the complex therapy is of particular relevance. AIM: to study the efficiency of therapy for chronic recurrent bacterial cystitis in combination with immunomodulators (Galavit). MATERIALS AND METHODS A total of 60 women with acute stage of chronic recurrent bacterial cystitis were examined. The patients were randomized into 2 groups of 30 patients. In the control group, standard antibiotic therapy was administered. In the treatment group, patients received Galavit in combination with standard therapy. All patients were followed-up on the 1st, 5th and 10th day. Voiding diaries, chronobiological status and pain severity using a 5-point scale were evaluated. In addition, complete blood count, urinalysis, urine culture and enzyme immunoassay for determination of serum level of interleukin (IL) 1, IL-6, tumor necrosis factor (TNF-) were analyzed. A number of recurrences after 3 months of therapy was assessed. RESULTS Complex therapy in combination with Galavit in women with acute stage of chronic bacterial cystitis allows to decrease in desynchronosis by 20%, reduce pain by 2.5 times, frequency of urination by 1.7 times, the number of urgent voids and night urination by 2.4 and 5 times, respectively, by the 5th day of therapy. In the group of patients receiving immunomodulators a significantly more pronounced decrease in the level of IL-1, IL-6, TNF- and CRP was noted. During 3 months of follow-up, there were 2 recurrences in the control group and no recurrences in treatment group (10%). CONCLUSION The use of Galavit in the treatment of women with chronic recurrent bacterial cystitis has pathogenetic basis. A clear advantage of the drug is more rapid relief of symptoms, normalization of laboratory parameters, recovery of chronorhythms and the achievement of clinical remission.
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Body mass index and the risk of infection - from underweight to obesity.
Dobner, J, Kaser, S
Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases. 2018;(1):24-28
Abstract
BACKGROUND Nutritional status is a well-known risk factor for metabolic and endocrine disorders. Recent studies suggest that dietary intake also affects immune function and as a consequence infection risk. AIMS This reviews aims to give an overview on the effect of body weight on infection rate at different periods of life. SOURCES Clinically relevant prospective, cross-sectional and case-control community-based studies are summarized. CONTENT In children and adolescents underweight is a significant risk factor for infection especially in developing countries, probably reflecting malnutrition and poor hygienic standards. Data from industrialized countries suggest that infection rate is also increased in obese children and adolescents. Similarly, several studies suggest a U-shaped increased infection rate in both underweight and obese adults. In the latter, infections of the skin and respiratory tract as well as surgical-site infections have consistently been reported to be more common than in normal-weight participants. Paradoxically, mortality of critically ill patients was reduced in obesity in some studies. IMPLICATIONS Several studies in children or adults suggest that both underweight and obesity are associated with increased infection risk. However, confounding factors such as malnutrition, hygienic status and underlying disease or co-morbidities might aggravate accurate assessment of the impact of body weight on infection risk.
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7.
Role of divalent metals in infectious disease susceptibility and outcome.
Weiss, G, Carver, PL
Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases. 2018;(1):16-23
Abstract
BACKGROUND Divalent metals play important roles in maintaining metabolism and cellular growth of both eukaryotic hosts and invading microbes. Both metal deficiency and overload can result in abnormal cellular function or damage. Given its central role in host-pathogen interactions, subtle alterations of divalent metal homeostasis can occur in the course of infectious diseases which aim, from the host perspective, either to reduce the availability of respective metals to microbes or to use toxic metal accumulation to eliminate pathogens. AIMS To provide the reader with background information and clinical data on divalent metal homeostasis in host-pathogen interactions, how this affects the course of infectious disease and whether correction of metal disturbances has shown benefit in infections. SOURCES An in-depth analysis of PubMed articles related to the topic of this review published in English between 1970 and 2016 was performed. CONTENT From the microbial perspective, divalent metals are essential for growth and pathogenicity and to mount effective protection against antimicrobial host responses, including toxic radical formation. Microbes have evolved multiple strategies to control their access to divalent metals. From the clinical perspective, alterations of divalent metal levels may result in increased or decreased susceptibility to infection and often occur in response to infections. However, keeping in mind the strategies underlying such alterations, for which the term 'nutritional immunity' was coined, the uncritical correction of such divalent metal imbalances may cause harm to patients. This review addresses the role of the divalent metals iron, selenium, zinc, manganese and copper in infectious diseases from a mechanistic and clinical perspective. IMPLICATIONS We point out areas of research needed to expand our limited knowledge, hoping to improve the clinical management of patients with infections and to identify promising new targets for treatment by modulation of host or microbe divalent metal metabolism.
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8.
Nanocoatings for Chronic Wound Repair-Modulation of Microbial Colonization and Biofilm Formation.
Mihai, MM, Preda, M, Lungu, I, Gestal, MC, Popa, MI, Holban, AM
International journal of molecular sciences. 2018;(4)
Abstract
Wound healing involves a complex interaction between immunity and other natural host processes, and to succeed it requires a well-defined cascade of events. Chronic wound infections can be mono- or polymicrobial but their major characteristic is their ability to develop a biofilm. A biofilm reduces the effectiveness of treatment and increases resistance. A biofilm is an ecosystem on its own, enabling the bacteria and the host to establish different social interactions, such as competition or cooperation. With an increasing incidence of chronic wounds and, implicitly, of chronic biofilm infections, there is a need for alternative therapeutic agents. Nanotechnology shows promising openings, either by the intrinsic antimicrobial properties of nanoparticles or their function as drug carriers. Nanoparticles and nanostructured coatings can be active at low concentrations toward a large variety of infectious agents; thus, they are unlikely to elicit emergence of resistance. Nanoparticles might contribute to the modulation of microbial colonization and biofilm formation in wounds. This comprehensive review comprises the pathogenesis of chronic wounds, the role of chronic wound colonization and infection in the healing process, the conventional and alternative topical therapeutic approaches designed to combat infection and stimulate healing, as well as revolutionizing therapies such as nanotechnology-based wound healing approaches.
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9.
Metal homeostasis in infectious disease: recent advances in bacterial metallophores and the human metal-withholding response.
Neumann, W, Gulati, A, Nolan, EM
Current opinion in chemical biology. 2017;:10-18
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Abstract
A tug-of-war between the mammalian host and bacterial pathogen for nutrients, including first-row transition metals (e.g. Mn, Fe, Zn), occurs during infection. Here we present recent advances about three metal-chelating metabolites that bacterial pathogens deploy when invading the host: staphylopine, staphyloferrin B, and enterobactin. These highlights provide new insights into the mechanisms of bacterial metal acquisition and regulation, as well as the contributions of host-defense proteins during the human innate immune response. The studies also underscore that the chemical composition of the microenvironment at an infection site can influence bacterial pathogenesis and the innate immune system.
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10.
[Non-Antibiotic Strategies to Prevent the Recurrence of Uncomplicated Urinary Tract Infections in Women].
Bauer, HW, Bessler, WG
Aktuelle Urologie. 2016;(3):214-9
Abstract
The aim of all medical treatment is "primum nihil nocere" ("First, do no harm").Restoring the integrity of intestinal microbiota and optimising the immune response in recurrent infections, especially in the urinary tract, are treatment alternatives which are closer to this target than the usual focus on antibiotic prevention of recurrence.In the future, antibiotics will continue to be recommended for the prevention of urinary tract infections on a case-by-case basis. However, the problems of an excessive use of antibiotics, e. g. resistance and long-term interference with intestinal microbiota, are forcing us to search for alternatives. The use of probiotics alone or in combination with immunotherapeutics, or the sole use of immunotherapeutics, are important treatment options, which are already routinely available in clinical practice. These therapies are focused on the pathomechanism of an infection and tackle the root cause of the problem. Phytotherapeutics or small molecules like mannose, which restricts the adherence of bacteria to the urothelium, are complementary approaches.The EAU guidelines recommend the following treatments for the long-term prevention of urinary tract infections:Oral and parenteral immunostimulants (StroVac(®)), local estrogen replacement and administration of Lactobacillus rhamnosus and Lactobacillus reuteri.