scholarly journals Contribution of vaccines to our understanding of pneumococcal disease

2011 ◽  
Vol 366 (1579) ◽  
pp. 2790-2798 ◽  
Author(s):  
Keith P. Klugman
Keyword(s):  
Cause Of Death ◽  
Pneumococcal Disease ◽  
Disease Burden ◽  
Viral Infections ◽  
Bacterial Pathogen ◽  
Pneumococcal Serotypes ◽  
Pneumococcal Infections ◽  
The Impact ◽  
Recent Demonstration

Pneumonia is the leading cause of mortality in children in developing countries and is also the leading infectious cause of death in adults. The most important cause of pneumonia is the Gram-positive bacterial pathogen, Streptococcus pneumoniae , also known as the pneumococcus. It has thus become the leading vaccine-preventable cause of death and is a successful and diverse human pathogen. The development of conjugate pneumococcal vaccines has made possible the prevention of pneumococcal disease in infants, but has also elucidated aspects of pneumococcal biology in a number of ways. Use of the vaccine as a probe has increased our understanding of the burden of pneumococcal disease in children globally. Vaccination has also elucidated the clinical spectrum of vaccine-preventable pneumococcal infections; the identification of a biological niche for multiple pneumococcal serotypes in carriage and the differential invasiveness of pneumococcal serotypes; the impact of pneumococcal transmission among children on disease burden in adults; the role of carriage as a precursor to pneumonia; the plasticity of a naturally transformable pathogen to respond to selective pressure through capsular switching and the accumulation of antibiotic-resistance determinants; and the role of pneumococcal infections in hospitalization and mortality associated with respiratory viral infections, including both seasonal and pandemic influenza. Finally, there has been a recent demonstration that pneumococcal pneumonia in children may be an important cause of hospitalization for those with underlying tuberculosis.

scholarly journals The Role of Micronutrients in Support of the Immune Response against Viral Infections

Nutrients ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 3198 ◽  
Author(s):  
Francesco Pecora ◽  
Federica Persico ◽  
Alberto Argentiero ◽  
Cosimo Neglia ◽  
Susanna Esposito
Keyword(s):  
Fatty Acids ◽  
Immune Response ◽  
Immune System ◽  
Viral Infections ◽  
Omega 3 Fatty Acids ◽  
Omega 3 ◽  
Optimal Function ◽  
The Impact

Viral infections are a leading cause of morbidity and mortality worldwide, and the importance of public health practices including handwashing and vaccinations in reducing their spread is well established. Furthermore, it is well known that proper nutrition can help support optimal immune function, reducing the impact of infections. Several vitamins and trace elements play an important role in supporting the cells of the immune system, thus increasing the resistance to infections. Other nutrients, such as omega-3 fatty acids, help sustain optimal function of the immune system. The main aim of this manuscript is to discuss of the potential role of micronutrients supplementation in supporting immunity, particularly against respiratory virus infections. Literature analysis showed that in vitro and observational studies, and clinical trials, highlight the important role of vitamins A, C, and D, omega-3 fatty acids, and zinc in modulating the immune response. Supplementation with vitamins, omega 3 fatty acids and zinc appears to be a safe and low-cost way to support optimal function of the immune system, with the potential to reduce the risk and consequences of infection, including viral respiratory infections. Supplementation should be in addition to a healthy diet and fall within recommended upper safety limits set by scientific expert bodies. Therefore, implementing an optimal nutrition, with micronutrients and omega-3 fatty acids supplementation, might be a cost-effective, underestimated strategy to help reduce the burden of infectious diseases worldwide, including coronavirus disease 2019 (COVID-19).

scholarly journals Silver Nanoparticles as Potential Antiviral Agents

Pharmaceutics ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2034
Author(s):  
Zubair Ahmed Ratan ◽  
Fazla Rabbi Mashrur ◽  
Anisha Parsub Chhoan ◽  
Sadi Md. Shahriar ◽  
Mohammad Faisal Haidere ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Potential Role ◽  
Viral Infections ◽  
Antiviral Agents ◽  
Host Cells ◽  
Characterization Methods ◽  
New Horizons ◽  
Bacteria And Fungi ◽  
The Impact

Since the early 1990s, nanotechnology has led to new horizons in nanomedicine, which encompasses all spheres of science including chemistry, material science, biology, and biotechnology. Emerging viral infections are creating severe hazards to public health worldwide, recently, COVID-19 has caused mass human casualties with significant economic impacts. Interestingly, silver nanoparticles (AgNPs) exhibited the potential to destroy viruses, bacteria, and fungi using various methods. However, developing safe and effective antiviral drugs is challenging, as viruses use host cells for replication. Designing drugs that do not harm host cells while targeting viruses is complicated. In recent years, the impact of AgNPs on viruses has been evaluated. Here, we discuss the potential role of silver nanoparticles as antiviral agents. In this review, we focus on the properties of AgNPs such as their characterization methods, antiviral activity, mechanisms, applications, and toxicity.

scholarly journals Role of unfolded proteins in lung disease

Thorax ◽  
2020 ◽  
Vol 76 (1) ◽  
pp. 92-99
Author(s):  
Kirsty L Bradley ◽  
Clare A Stokes ◽  
Stefan J Marciniak ◽  
Lisa C Parker ◽  
Alison M Condliffe
Keyword(s):  
Protein Synthesis ◽  
Er Stress ◽  
Respiratory Diseases ◽  
Viral Infections ◽  
Genetic Manipulation ◽  
Experimental Models ◽  
Misfolded Proteins ◽  
Pharmacological Agents ◽  
The Impact

The lungs are exposed to a range of environmental toxins (including cigarette smoke, air pollution, asbestos) and pathogens (bacterial, viral and fungal), and most respiratory diseases are associated with local or systemic hypoxia. All of these adverse factors can trigger endoplasmic reticulum (ER) stress. The ER is a key intracellular site for synthesis of secretory and membrane proteins, regulating their folding, assembly into complexes, transport and degradation. Accumulation of misfolded proteins within the lumen results in ER stress, which activates the unfolded protein response (UPR). Effectors of the UPR temporarily reduce protein synthesis, while enhancing degradation of misfolded proteins and increasing the folding capacity of the ER. If successful, homeostasis is restored and protein synthesis resumes, but if ER stress persists, cell death pathways are activated. ER stress and the resulting UPR occur in a range of pulmonary insults and the outcome plays an important role in many respiratory diseases. The UPR is triggered in the airway of patients with several respiratory diseases and in corresponding experimental models. ER stress has been implicated in the initiation and progression of pulmonary fibrosis, and evidence is accumulating suggesting that ER stress occurs in obstructive lung diseases (particularly in asthma), in pulmonary infections (some viral infections and in the setting of the cystic fibrosis airway) and in lung cancer. While a number of small molecule inhibitors have been used to interrogate the role of the UPR in disease models, many of these tools have complex and off-target effects, hence additional evidence (eg, from genetic manipulation) may be required to support conclusions based on the impact of such pharmacological agents. Aberrant activation of the UPR may be linked to disease pathogenesis and progression, but at present, our understanding of the context-specific and disease-specific mechanisms linking these processes is incomplete. Despite this, the ability of the UPR to defend against ER stress and influence a range of respiratory diseases is becoming increasingly evident, and the UPR is therefore attracting attention as a prospective target for therapeutic intervention strategies.

scholarly journals The Role of Streptococcus pneumoniae in Community-Acquired Pneumonia

2020 ◽  
Vol 41 (04) ◽  
pp. 455-469 ◽  
Author(s):  
Charles Feldman ◽  
Ronald Anderson
Keyword(s):  
Antibiotic Resistance ◽  
Streptococcus Pneumoniae ◽  
Antimicrobial Agents ◽  
Bacterial Pathogen ◽  
Epidemiological Data ◽  
The United States ◽  
Invasive Infection ◽  
Geographic Variations ◽  
The Impact

AbstractWith the notable exceptions of the United States and Canada in particular, the global burden of disease in adults due to invasive infection with the dangerous respiratory, bacterial pathogen, Streptococcus pneumoniae (pneumococcus) remains. This situation prevails despite the major successes of inclusion of polysaccharide conjugate vaccines (PCVs) in many national childhood immunization programs and associated herd protection in adults, as well as the availability of effective antimicrobial agents. Accurate assessment of the geographic variations in the prevalence of invasive pneumococcal disease (IPD) has, however, been somewhat impeded by the limitations imposed on the acquisition of reliable epidemiological data due to reliance on often insensitive, laboratory-based, pathogen identification procedures. This, in turn, may result in underestimation of the true burden of IPD and represents a primary focus of this review. Other priority topics include the role of PCVs in the changing epidemiology of IPD in adults worldwide, smoking as a risk factor not only in respect of increasing susceptibility for development of IPD, but also in promoting pneumococcal antibiotic resistance. The theme of pneumococcal antibiotic resistance has been expanded to include mechanisms of resistance to commonly used classes of antibiotics, specifically β-lactams, macrolides and fluoroquinolones, and, perhaps somewhat contentiously, the impact of resistance on treatment outcome. Finally, but no less importantly, the role of persistent antigenemia as a driver of a chronic, subclinical, systemic proinflammatory/procoagulant phenotype that may underpin the long-term sequelae and premature mortality of those adults who have recovered from an episode of IPD, is considered.

scholarly journals Modelling the potential role of media campaigns on the control of Listeriosis

2021 ◽  
Vol 18 (6) ◽  
pp. 7580-7601
Author(s):  
C. W. Chukwu ◽  
◽  
F. Nyabadza ◽  
Fatmawati ◽  
◽  
...  
Keyword(s):  
Removal Rate ◽  
Bacterial Pathogen ◽  
Food Contamination ◽  
Food Products ◽  
Model Parameters ◽  
Media Campaigns ◽  
Awareness Campaigns ◽  
Contaminated Food ◽  
The Impact

<abstract><p>Human Listeria infection is a food-borne disease caused by the consumption of contaminated food products by the bacterial pathogen, Listeria. In this paper, we propose a mathematical model to analyze the impact of media campaigns on the spread and control of Listeriosis. The model exhibited three equilibria namely; disease-free, Listeria-free and endemic equilibria. The food contamination threshold is determined and the local stability analyses of the model is discussed. Sensitivity analysis is done to determine the model parameters that most affect the severity of the disease. Numerical simulations were carried out to assess the role of media campaigns on the Listeriosis spread. The results show that; an increase in the intensity of the media awareness campaigns, the removal rate of contaminated food products, a decrease in the contact rate of Listeria by humans results in fewer humans getting infected, thus leading to the disease eradication. An increase in the depletion of media awareness campaigns results in more humans being infected with Listeriosis. These findings may significantly impact policy and decision-making in the control of Listeriosis disease.</p></abstract>

scholarly journals Significantly Low Levels of IgG Antibodies Against Oncogenic Merkel Cell Polyomavirus in Sera From Females Affected by Spontaneous Abortion

2021 ◽  
Vol 12 ◽  
Author(s):  
Chiara Mazziotta ◽  
Giulia Pellielo ◽  
Mauro Tognon ◽  
Fernanda Martini ◽  
John Charles Rotondo
Keyword(s):  
Antibody Response ◽  
Spontaneous Abortion ◽  
Viral Infections ◽  
Merkel Cell Polyomavirus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Merkel Cell ◽  
Igg Antibodies ◽  
Igg Antibody ◽  
The Impact

Merkel cell polyomavirus (MCPyV) is a small DNA tumor virus ubiquitous in humans. MCPyV establishes a clinically asymptomatic lifelong infection in healthy immunocompetent individuals. Viral infections are considered to be risk factors for spontaneous abortion (SA), which is the most common adverse complication of pregnancy. The role of MCPyV in SA remains undetermined. Herein, the impact of MCPyV infection in females affected by SA was investigated. Specifically, an indirect enzyme-linked immunosorbent assay (ELISA) method with two linear synthetic peptides/mimotopes mimicking MCPyV antigens was used to investigate immunoglobulin G (IgG) antibodies against MCPyV in sera from 94 females affected by SA [mean ± standard deviation (SD) age 35 ± (6) years] and from 96 healthy females undergoing voluntary pregnancy interruption [VI, mean (±SD) age 32 ± (7) years]. MCPyV seroprevalence and serological profiles were analyzed. The overall prevalence of serum IgG antibodies against MCPyV was 35.1% (33/94) and 37.5% (36/96) in SA and VI females, respectively (p &gt; 0.05). Notably, serological profile analyses indicated lower optical densities (ODs) in females with SA compared to those undergoing VI (p &lt; 0.05), thus indicating a reduced IgG antibody response in SA females. Circulating IgGs were identified in sera from SA and VI females. Our immunological findings indicate that a relatively reduced fraction of pregnant females carry serum anti-MCPyV IgG antibodies, while SA females presented a more pronounced decrease in IgG antibody response to MCPyV. Although yet to be determined, this immunological decrease might prompt an increase in MCPyV multiplication events in females experiencing abortive events. The role of MCPyV in SA, if present, remains to be determined.

scholarly journals Bacterial Clearance Is Enhanced by α2,3- and α2,6-Sialyllactose via Receptor-Mediated Endocytosis and Phagocytosis

2018 ◽  
Vol 87 (1) ◽  
Author(s):  
Jimin Kim ◽  
Yong-Jae Kim ◽  
Jae Wha Kim
Keyword(s):  
Breast Milk ◽  
Viral Infections ◽  
Human Breast Milk ◽  
Bacterial Clearance ◽  
Content Type ◽  
Receptor Mediated Endocytosis ◽  
Significant Efficacy ◽  
New Perspective ◽  
The Impact

ABSTRACT Sialyllactose (SL) is a representative human milk oligosaccharide (HMO) of human breast milk. The roles of SL in infant brain development and immunity have been reported in previous studies. In this study, we identified the impact of SL on innate immunity. Our results showed that the administration of SL had significant efficacy on bacterial clearance in Pseudomonas aeruginosa K-infected mice. We also examined the role of SL in the human THP-1 macrophage-like cell line. SL effectively promoted receptor-mediated endocytosis and phagocytosis. Furthermore, SL accelerated the recruitment of Rac1 to the cell membrane, leading to the generation of reactive oxygen species for the elimination of phagocytosed bacteria. Our findings provide a new perspective on the role of SL in breast milk and suggest its application as a therapeutic agent to treat bacterial and viral infections.

scholarly journals Exosome Biogenesis and Biological Function in Response to Viral Infections

2018 ◽  
Vol 12 (1) ◽  
pp. 134-148 ◽  
Author(s):  
Brennetta J. Crenshaw ◽  
Linlin Gu ◽  
Brian Sims ◽  
Qiana L. Matthews
Keyword(s):  
Protein Trafficking ◽  
Viral Infections ◽  
Rna Virus ◽  
Cellular Protein ◽  
Molecular Characteristics ◽  
Exosome Biogenesis ◽  
Pathogen Response ◽  
Viral Hijacking ◽  
The Impact

Introduction: Exosomes are extracellular vesicles that originate as intraluminal vesicles during the process of multivescular body formation. Exosomes mediate intercellular transfer of functional proteins, lipids, and RNAs. The investigation into the formation and role of exosomes in viral infections is still being elucidated. Exosomes and several viruses share similar structural and molecular characteristics. Explanation: It has been documented that viral hijacking exploits the exosomal pathway and mimics cellular protein trafficking. Exosomes released from virus-infected cells contain a variety of viral and host cellular factors that are able to modify recipient host cell responses. Recent studies have demonstrated that exosomes are crucial components in the pathogenesis of virus infection. Exosomes also allow the host to produce effective immunity against pathogens by activating antiviral mechanisms and transporting antiviral factors between adjacent cells. Conclusion: Given the ever-growing roles and importance of exosomes in both host and pathogen response, this review will address the impact role of exosome biogenesis and composition after DNA, RNA virus, on Retrovirus infections. This review also will also address how exosomes can be used as therapeutic agents as well as a vaccine vehicles.

scholarly journals Animal Models of Pneumococcal pneumonia

2019 ◽  
Vol 20 (17) ◽  
pp. 4220 ◽  
Author(s):  
Borsa ◽  
Pasquale ◽  
Restrepo
Keyword(s):  
Animal Models ◽  
Pneumococcal Disease ◽  
Pneumococcal Pneumonia ◽  
Respiratory Tract Infections ◽  
Bacterial Pathogen ◽  
The Elderly ◽  
Lower Respiratory Tract Infections ◽  
Bacterial Inoculation ◽  
Pneumococcal Infections ◽  
Tract Infections

Streptococcus pneumoniae remains the most common bacterial pathogen causing lower respiratory tract infections and is a leading cause of morbidity and mortality worldwide, especially in children and the elderly. Another important aspect related to pneumococcal infections is the persistent rate of penicillin and macrolide resistance. Therefore, animal models have been developed to better understand the pathogenesis of pneumococcal disease and test new therapeutic agents and vaccines. This narrative review will focus on the characteristics of the different animal pneumococcal pneumonia models. The assessment of the different animal models will include considerations regarding pneumococcal strains, microbiology properties, procedures used for bacterial inoculation, pathogenesis, clinical characteristics, diagnosis, treatment, and preventive approaches.

scholarly journals Possible role of vitamin D supplementation in coronavirus disease 2019

2020 ◽  
Vol 6 (9) ◽  
pp. 376
Author(s):  
Devi Dayal
Keyword(s):  
Vitamin D ◽  
Viral Infections ◽  
Respiratory Infections ◽  
Winter Season ◽  
Vitamin D Supplementation ◽  
Vitamin D Status ◽  
Vitamin D Levels ◽  
Respiratory Viral Infections ◽  
The Impact

<p>Vitamin D deficiency (VDD) is presumed to play a role in several infective and non-infective conditions such as acute respiratory infections, tuberculosis, diabetes, hypertension, stroke etc. Most of the respiratory viral infections occur during winter season when the vitamin D levels in most individuals are generally low. The current pandemic of coronavirus disease 2019 (COVID-19) which began during winter season similar to the previous epidemics due to coronaviruses, has again stirred a debate on the role of VDD in the initiation and spread of the pandemic. The data on vitamin D status in patients with COVID-19 is however lacking. Different vitamin D supplementation strategies have recently been suggested as part of several countermeasures aimed at reducing the impact of COVID-19 pandemic. This brief narrative review discusses the evidence for the link between VDD and COVID-19 and the approaches suggested for vitamin D supplementation.</p>

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