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Frontiers in Immunology 2022Pneumolysin (PLY) is a pore-forming toxin produced by the human pathobiont , the major cause of pneumonia worldwide. PLY, a key pneumococcal virulence factor, can form... (Review)
Review
Pneumolysin (PLY) is a pore-forming toxin produced by the human pathobiont , the major cause of pneumonia worldwide. PLY, a key pneumococcal virulence factor, can form transmembrane pores in host cells, disrupting plasma membrane integrity and deregulating cellular homeostasis. At lytic concentrations, PLY causes cell death. At sub-lytic concentrations, PLY triggers host cell survival pathways that cooperate to reseal the damaged plasma membrane and restore cell homeostasis. While PLY is generally considered a pivotal factor promoting colonization and survival, it is also a powerful trigger of the innate and adaptive host immune response against bacterial infection. The dichotomy of PLY as both a key bacterial virulence factor and a trigger for host immune modulation allows the toxin to display both "Yin" and "Yang" properties during infection, promoting disease by membrane perforation and activating inflammatory pathways, while also mitigating damage by triggering host cell repair and initiating anti-inflammatory responses. Due to its cytolytic activity and diverse immunomodulatory properties, PLY is integral to every stage of pathogenesis and may tip the balance towards either the pathogen or the host depending on the context of infection.
Topics: Bacterial Proteins; Humans; Pneumococcal Infections; Streptococcus pneumoniae; Streptolysins; Virulence Factors
PubMed: 35529870
DOI: 10.3389/fimmu.2022.878244 -
Expert Review of Vaccines Mar 2020: This review analyzes the efficacy of pneumococcal vaccinations in lung transplant patients before and after transplantation.: This review addresses the risk for... (Review)
Review
: This review analyzes the efficacy of pneumococcal vaccinations in lung transplant patients before and after transplantation.: This review addresses the risk for respiratory infections, in particular pneumococcal infections, in lung transplantation patients in the context of immunodeficiency and immunosuppressive medication. Vaccination is recommended to counteract the increased risk of pneumococcal infection, and the relevant guidelines are discussed in this review. The design of specific vaccination schedules is required because of the impaired antibody response in specific patient categories.: Lung transplantation candidates should be vaccinated with pneumococcal vaccines prior to transplantation. Currently, the 23-valent pneumococcal polysaccharide vaccine offers the broadest coverage, but the antibody response should be monitored. New generation pneumococcal conjugate vaccines with equally broad serotype coverage could be used in the future. During the post-transplantation period, the immune status of the patients should be monitored regularly, and vaccination should be repeated when indicated.
Topics: Antibody Formation; Humans; Immunization Schedule; Lung Transplantation; Pneumococcal Infections; Pneumococcal Vaccines; Practice Guidelines as Topic; Vaccination
PubMed: 32133883
DOI: 10.1080/14760584.2020.1738224 -
Human Vaccines & Immunotherapeutics Dec 2022There is a paucity of evidence linking pneumococcal infection and influenza with SARS-CoV-2 and COVID-19. There is circumstantial evidence of the possibility of an... (Review)
Review
There is a paucity of evidence linking pneumococcal infection and influenza with SARS-CoV-2 and COVID-19. There is circumstantial evidence of the possibility of an association between and SARS-CoV-2 such as the increased binding of to coronavirus-infected human airway epithelium, the frequent use of broad-spectrum antibiotics in the management of COVID-19 which could mask secondary bacterial infection, and the observation that pneumococcal vaccination is associated with decreased SARS-CoV-2 nasopharyngeal swab positivity. We performed a targeted literature review for the year 2020, using search terms , influenza, SARS-CoV-2, and found 25 relevant articles of a total of 291. Pneumococcal and influenza vaccinations have the potential to contribute toward efforts aimed at reducing the health burden of SARS-CoV-2, especially by reducing preventable admissions to hospital for pneumonia and the consequent risk of nosocomial SARS-CoV-2 transmission.
Topics: COVID-19; Humans; Influenza, Human; Pneumococcal Infections; SARS-CoV-2; Streptococcus pneumoniae
PubMed: 34406914
DOI: 10.1080/21645515.2021.1957647 -
Clinical Obstetrics and Gynecology Dec 2019Streptococcus pneumoniae, a gram-positive diplococcus, is the most common cause of bacterial pneumonia. The diagnosis of pneumococcal pneumonia is usually confirmed by...
Streptococcus pneumoniae, a gram-positive diplococcus, is the most common cause of bacterial pneumonia. The diagnosis of pneumococcal pneumonia is usually confirmed by chest x-ray and gram stain. The most appropriate antibiotics for treatment pneumococcal infection are macrolides, beta-lactams, and quinolones. Two vaccines, PPSV23 and PCV13, are highly effective in preventing infection.
Topics: Anti-Bacterial Agents; Female; Humans; Pneumococcal Infections; Pneumococcal Vaccines; Pregnancy; Pregnancy Complications, Infectious; Streptococcus pneumoniae
PubMed: 31008732
DOI: 10.1097/GRF.0000000000000451 -
EBioMedicine Jun 2022Concentrations of particulate matter less than 10 microns (PM) on underground railways are higher than those near urban roads. Traffic-related PM increases pneumococcal...
BACKGROUND
Concentrations of particulate matter less than 10 microns (PM) on underground railways are higher than those near urban roads. Traffic-related PM increases pneumococcal infection via increasing the expression of platelet-activating factor receptor (PAFR), a receptor co-opted by pneumococci to adhere to cells. To date, it is unknown whether underground railway PM increases pneumococcal infection. This study sought to determine the effect of London Underground (LU) PM on; i) pneumococcal adhesion to airway cells, and ii) susceptibility to pneumococcal disease.
METHODS
A549 cells and human primary airway epithelial cells were cultured with 20 µg/mL PM from the Bakerloo (B-PM) and Jubilee (J-PM) line platforms of Baker Street station. PAFR expression was assessed by flow cytometry, and pneumococcal adhesion by colony forming unit (CFU) counts. Traffic-related PM was collected next to a main road near the station's entrance. The PAFR blocker CV3988 and the antioxidant N-acetyl cysteine were used to assess the role of PAFR-mediated pneumococcal adhesion and oxidative stress respectively. Pneumococcal infection of mice was done after exposure to 3×80 μg doses of intranasal LU-PM.
FINDINGS
In A549 cells, human primary nasal cells, and human primary bronchial epithelial cells, B-PM and J-PM increased PAFR expression and pneumococcal adhesion. Stimulated adhesion was abrogated by CV3988 and N-acetyl cysteine. Traffic-related PM stimulated increased adhesion compared with B-PM. B-PM and J-PM increased lung and blood CFU and mortality in mice. Treatment of B-PM-exposed mice with CV3988 reduced blood CFU.
INTERPRETATION
LU-PM increases pneumococcal adhesion to airway cells and susceptibility to invasive disease in mice.
FUNDING
The Medical College of Saint Bartholomew's Hospital Trust, and the UK Medical Research Council Programme Grant (MR/P011284/1).
Topics: Animals; Cell Line; Cysteine; Humans; Lung; Mice; Particulate Matter; Pneumococcal Infections; Streptococcus pneumoniae
PubMed: 35598440
DOI: 10.1016/j.ebiom.2022.104063 -
Morphologie : Bulletin de L'Association... Mar 2020Platelets phagocytosed by neutrophils is a rare morphological finding on peripheral blood films. It is rarely an EDTA-dependent artifact but mainly caused by an active...
Platelets phagocytosed by neutrophils is a rare morphological finding on peripheral blood films. It is rarely an EDTA-dependent artifact but mainly caused by an active vascular inflammation process. Here is reported an unexpected observation of neutrophilic thrombophagocytosis, in the context of a disseminated Streptococcus pneumoniae infection.
Topics: Blood Platelets; Humans; Neutrophils; Phagocytosis; Platelet Count; Pneumococcal Infections; Sepsis; Streptococcus pneumoniae
PubMed: 31521508
DOI: 10.1016/j.morpho.2019.08.004 -
Frontiers in Cellular and Infection... 2020Capsular polysaccharide (CPS), which surrounds the bacteria, is one of the most significant and multifaceted contributors to virulence. Capsule prevents entrapment in... (Review)
Review
Capsular polysaccharide (CPS), which surrounds the bacteria, is one of the most significant and multifaceted contributors to virulence. Capsule prevents entrapment in mucus during colonization, traps water to protect against desiccation, can serve as an energy reserve, and protects the bacterium against complement-mediated opsonization and immune cell phagocytosis. To date, 100 biochemically and serologically distinct capsule types have been identified for ; 20 to 30 of which have well-defined propensity to cause opportunistic human infection. Among these, serotype 3 is perhaps the most problematic as serotype 3 infections are characterized as having severe clinical manifestations including empyema, bacteremia, cardiotoxicity, and meningitis; consequently, with a fatality rate of 30%-47%. Moreover, serotype 3 resists antibody-mediated clearance despite its inclusion in the current 13-valent conjugate vaccine formulation. This review covers the role of capsule in pneumococcal pathogenesis and the importance of serotype 3 on human disease. We discuss how serotype 3 capsule synthesis and presentation on the bacterial surface is distinct from other serotypes, the biochemical and physiological properties of this capsule type that facilitate its ability to cause disease, and why existing vaccines are unable to confer protection. We conclude with discussion of the clonal properties of serotype 3 and how these have changed since introduction of the 13-valent vaccine in 2000.
Topics: Humans; Pneumococcal Infections; Pneumococcal Vaccines; Serogroup; Streptococcus pneumoniae; Sugars
PubMed: 33425786
DOI: 10.3389/fcimb.2020.613287 -
ESMO Open Jun 2023Patients with cancer have a well-known and higher risk of vaccine-preventable diseases (VPDs). VPDs may cause severe complications in this setting due to immune system... (Review)
Review
Vaccination for seasonal influenza, pneumococcal infection and SARS-CoV-2 in patients with solid tumors: recommendations of the Associazione Italiana di Oncologia Medica (AIOM).
Patients with cancer have a well-known and higher risk of vaccine-preventable diseases (VPDs). VPDs may cause severe complications in this setting due to immune system impairment, malnutrition and oncological treatments. Despite this evidence, vaccination rates are inadequate. The Italian Association of Medical Oncology [Associazione Italiana di Oncologia Medica (AIOM)] has been involved in vaccination awareness since 2014. Based on a careful review of the available data about the immunogenicity, effectiveness and safety of flu, pneumococcal and anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines, we report the recommendations of the AIOM about these vaccinations in adult patients with solid tumors. The AIOM recommends comprehensive education on the issue of VPDs. We believe that a multidisciplinary care model may improve the vaccination coverage in immunocompromised patients. Continued surveillance, implementation of preventive practices and future well-designed immunological prospective studies are essential for better management of our patients with cancer.
Topics: Adult; Humans; SARS-CoV-2; Influenza, Human; Prospective Studies; Seasons; COVID-19; Neoplasms; Vaccination; Influenza Vaccines; Pneumococcal Infections
PubMed: 37104930
DOI: 10.1016/j.esmoop.2023.101215 -
Trends in Microbiology Jun 2022Streptococcus pneumoniae (the 'pneumococcus') is a significant cause of morbidity and mortality worldwide, causing life-threatening diseases such as pneumonia,... (Review)
Review
Streptococcus pneumoniae (the 'pneumococcus') is a significant cause of morbidity and mortality worldwide, causing life-threatening diseases such as pneumonia, bacteraemia, and meningitis, with an annual death burden of over one million. Discovered over a century ago, pneumococcal serotype 1 (S1) is a significant cause of these life-threatening diseases. Our understanding of the epidemiology and biology of pneumococcal S1 has significantly improved over the past two decades, informing the development of preventative and surveillance strategies. However, many questions remain unanswered. Here, we review the current state of knowledge of pneumococcal S1, with a special emphasis on clinical epidemiology, genomics, and disease mechanisms.
Topics: Genomics; Humans; Pneumococcal Infections; Serogroup; Streptococcus pneumoniae
PubMed: 34949516
DOI: 10.1016/j.tim.2021.11.007 -
BMC Pulmonary Medicine Jun 2023Infection caused by Streptococcus pneumoniae, mainly invasive pneumococcal disease (IPD) and pneumococcal pneumonia (PP), are a major public health problem worldwide....
BACKGROUND
Infection caused by Streptococcus pneumoniae, mainly invasive pneumococcal disease (IPD) and pneumococcal pneumonia (PP), are a major public health problem worldwide. This study investigated population-based incidence and risk of PP among Catalonian persons ≥ 50 years-old with and without specific underlying conditions/comorbidities, examining the influence of single and multi-comorbidities in the risk of suffering PP.
METHODS
Population-based cohort study involving 2,059,645 persons ≥ 50 years-old in Catalonia, Spain, who were retrospectively followed between 01/01/2017-31/12/2018. The Catalonian information system for development of research in primary care (SIDIAP) was used to establish baseline characteristics of the cohort (comorbidities/underlying conditions), and PP cases were collected from discharge codes (ICD-10: J13) of the 68 referral Catalonian hospitals.
RESULTS
Global incidence rate (IR) was 90.7 PP cases per 100,000 person-years, with a 7.6% (272/3592) case-fatality rate (CFR). Maximum IRs emerged among persons with history of previous IPD or all-cause pneumonia, followed by haematological neoplasia (475.0), HIV-infection (423.7), renal disease (384.9), chronic respiratory disease (314.7), liver disease (232.5), heart disease (221.4), alcoholism (204.8), solid cancer (186.2) and diabetes (159.6). IRs were 42.1, 89.9, 201.1, 350.9, 594.3 and 761.2 in persons with 0, 1, 2, 3, 4 and ≥ 5 comorbidities, respectively. In multivariable analyses, HIV-infection (hazard ratio [HR]: 5.16; 95% CI: 3.57-7.46), prior all-cause pneumonia (HR: 3.96; 95% CI: 3.45-4.55), haematological neoplasia (HR: 2.71; 95% CI: 2.06-3.57), chronic respiratory disease (HR: 2.66; 95% CI: 2.47-2.86) and prior IPD (HR: 2.56; 95% CI: 2.03-3.24) were major predictors for PP.
CONCLUSION
Apart of increasing age and immunocompromising conditions (classically recognised as high-risk conditions), history of prior IPD/pneumonia, presence of chronic pulmonary/respiratory disease and/or co-existing multi-comorbidity (i.e., two or more underlying conditions) are major risk factors for PP in adults, with an excess risk near to immunocompromised subjects. Redefining risk categories for PP, including all the above-mentioned conditions into the high-risk category, could be necessary to improve prevention strategies in middle-aged and older adults.
Topics: Middle Aged; Humans; Aged; Pneumonia, Pneumococcal; Incidence; Cohort Studies; Retrospective Studies; Risk Factors; Pneumococcal Infections; Neoplasms; Pneumococcal Vaccines
PubMed: 37291502
DOI: 10.1186/s12890-023-02497-2