-
Nature Reviews. Microbiology Jun 2018Streptococcus pneumoniae has a complex relationship with its obligate human host. On the one hand, the pneumococci are highly adapted commensals, and their main... (Review)
Review
Streptococcus pneumoniae has a complex relationship with its obligate human host. On the one hand, the pneumococci are highly adapted commensals, and their main reservoir on the mucosal surface of the upper airways of carriers enables transmission. On the other hand, they can cause severe disease when bacterial and host factors allow them to invade essentially sterile sites, such as the middle ear spaces, lungs, bloodstream and meninges. Transmission, colonization and invasion depend on the remarkable ability of S. pneumoniae to evade or take advantage of the host inflammatory and immune responses. The different stages of pneumococcal carriage and disease have been investigated in detail in animal models and, more recently, in experimental human infection. Furthermore, widespread vaccination and the resulting immune pressure have shed light on pneumococcal population dynamics and pathogenesis. Here, we review the mechanistic insights provided by these studies on the multiple and varied interactions of the pneumococcus and its host.
Topics: Bacterial Adhesion; Carrier State; Humans; Nasopharynx; Pneumococcal Infections; Streptococcus pneumoniae
PubMed: 29599457
DOI: 10.1038/s41579-018-0001-8 -
Clinical Microbiology and Infection :... May 2014To overview the present global burden of pneumococcal disease is important because new preventive measures such as the pneumococcal conjugate vaccine 13 are currently... (Review)
Review
To overview the present global burden of pneumococcal disease is important because new preventive measures such as the pneumococcal conjugate vaccine 13 are currently being evaluated. Pneumococcal disease is roughly divided into non-invasive and invasive disease. The burden of non-invasive pneumococcal disease in adults is mainly determined by community-acquired pneumonia. Pneumococcal pneumonia has high incidence rates and carries a high mortality risk, especially in the elderly. Within the cluster of invasive pneumococcal diseases, pneumonia also represents the most common infectious source. Incidence and mortality rates of both non-invasive and invasive disease have changed as a result of pneumococcal vaccination in children. However, especially elderly patients with comorbidities remain vulnerable to morbidity and mortality caused by pneumococcal disease. The current review summarizes the current knowledge on the epidemiology including outcome of the main clinical forms of pneumococcal disease, with a special focus on elderly patients. Furthermore, the economic burden and future vaccine strategies are briefly discussed.
Topics: Adult; Community-Acquired Infections; Comorbidity; Humans; Incidence; Pneumococcal Infections; Pneumococcal Vaccines; Streptococcus pneumoniae; Vaccination; Vaccines, Conjugate
PubMed: 24313448
DOI: 10.1111/1469-0691.12461 -
Glycoconjugate Journal Apr 2023Multivalent vaccines addressing an increasing number of Streptococcus pneumoniae types (7-, 10-, 13-, 15-, 20-valent) have been licensed over the last 22 years. The use... (Review)
Review
Multivalent vaccines addressing an increasing number of Streptococcus pneumoniae types (7-, 10-, 13-, 15-, 20-valent) have been licensed over the last 22 years. The use of polysaccharide-protein conjugate vaccines has been pivotal in reducing the incidence of invasive pneumococcal disease despite the emergence of non-vaccine serotypes. Notwithstanding its undoubtable success, some weaknesses have called for continuous improvement of pneumococcal vaccination. For instance, despite their inclusion in pneumococcal conjugate vaccines, there are challenges associated with some serotypes. In particular, Streptococcus pneumoniae type 3 remains a major cause of invasive pneumococcal disease in several countries.Here a deep revision of the strengths and weaknesses of the licensed pneumococcal conjugate vaccines and other vaccine candidates currently in clinical development is reported.
Topics: Humans; Pneumococcal Vaccines; Streptococcus pneumoniae; Pneumococcal Infections; Vaccination; Vaccines, Conjugate; Antibodies, Bacterial
PubMed: 36652051
DOI: 10.1007/s10719-023-10100-3 -
F1000Research 2020The introduction of pneumococcal conjugate vaccines (PCVs) 7 and 13 into national childhood immunization programs in the US in 2000 and 2010, respectively, proved to be... (Review)
Review
The introduction of pneumococcal conjugate vaccines (PCVs) 7 and 13 into national childhood immunization programs in the US in 2000 and 2010, respectively, proved to be remarkably successful in reducing infant mortality due to invasive pneumococcal disease (IPD), resulting in widespread uptake of these vaccines. Secondary herd protection of non-vaccinated adults against IPD has proven to be an additional public health benefit of childhood immunization with PCVs, particularly in the case of the vulnerable elderly who are at increased risk due to immunosenescence and underlying comorbidity. Despite these advances in pneumococcal immunization, the global burden of pneumococcal disease, albeit of unequal geographic distribution, remains high. Reasons for this include restricted access of children living in many developing countries to PCVs, the emergence of infection due to non-vaccine serotypes of the pneumococcus, and non-encapsulated strains of the pathogen. Emerging concerns affecting the elderly include the realization that herd protection conferred by the current generation of PCVs (PCV7, PCV10, and PCV13) has reached a ceiling in many countries at a time of global population aging, compounded by uncertainty surrounding those immunization strategies that induce optimum immunogenicity and protection against IPD in the elderly. All of the aforementioned issues, together with a consideration of pipeline and pending strategies to improve access to, and serotype coverage of, PCVs, are the focus areas of this review.
Topics: Humans; Pneumococcal Infections; Pneumococcal Vaccines; Serogroup; Streptococcus pneumoniae; Vaccination; Vaccines, Conjugate
PubMed: 32411353
DOI: 10.12688/f1000research.22341.1 -
Journal of Preventive Medicine and... Dec 2021To assess the prevalence of pneumococcal nasopharyngeal carriage, the role of potential risk factors, and the pneumococcal vaccination coverage among sheltered homeless...
OBJECTIVE
To assess the prevalence of pneumococcal nasopharyngeal carriage, the role of potential risk factors, and the pneumococcal vaccination coverage among sheltered homeless people in Marseille, France.
METHODS
During the winters 2015-2018, we enrolled 571 sheltered homeless males and 54 non-homeless controls. Streptococcus pneumoniae was directly searched from nasal/pharyngeal samples using real-time polymerase chain reaction.
RESULTS
The homeless people were mostly migrants from African countries, with a mean age of 43 years. Pneumococcal vaccination coverage was low (3.1%). The overall pneumococcal carriage rate was 13.0% and was significantly higher in homeless people (15.3% in 2018) than in controls (3.7%), with p = 0.033. Among homeless people, being aged ≥ 65 years (1.97, 95% CI; 1.01-3.87), living in a specific shelter (OR = 1.80, 95% CI: 1.06-3.05), and having respiratory signs and symptoms at the time of enrolment (OR = 2.55, 95% CI: 1.54-4.21) were independently associated with pneumococcal carriage.
CONCLUSION
Pneumococcal nasopharyngeal carriage, which is a precursor for pneumococcal disease in at-risk individuals, is frequent among French homeless people. Studies conducted in other countries have also reported outbreaks of pneumococcal infections in homeless people. Pneumococcal vaccination should be systematically considered for sheltered homeless people in France, as is being done in Canada since 2008.
Topics: Adult; Carrier State; Ill-Housed Persons; Humans; Infant; Male; Nasopharynx; Pneumococcal Infections; Pneumococcal Vaccines; Prevalence; Streptococcus pneumoniae
PubMed: 35603253
DOI: 10.15167/2421-4248/jpmh2021.62.4.1805 -
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 -
Frontiers in Cellular and Infection... 2022The gram-positive bacterium is a leading cause of pneumonia, otitis media, septicemia, and meningitis in children and adults. Current prevention and treatment efforts... (Review)
Review
The gram-positive bacterium is a leading cause of pneumonia, otitis media, septicemia, and meningitis in children and adults. Current prevention and treatment efforts are primarily pneumococcal conjugate vaccines that target the bacterial capsule polysaccharide, as well as antibiotics for pathogen clearance. While these methods have been enormously effective at disease prevention and treatment, there has been an emergence of non-vaccine serotypes, termed serotype replacement, and increasing antibiotic resistance among these serotypes. To combat , the immune system must deploy an arsenal of antimicrobial functions. However, has evolved a repertoire of evasion techniques and is able to modulate the host immune system. Antibodies are a key component of pneumococcal immunity, targeting both the capsule polysaccharide and protein antigens on the surface of the bacterium. These antibodies have been shown to play a variety of roles including increasing opsonophagocytic activity, enzymatic and toxin neutralization, reducing bacterial adherence, and altering bacterial gene expression. In this review, we describe targets of anti-pneumococcal antibodies and describe antibody functions and effectiveness against .
Topics: Adult; Antibodies, Bacterial; Child; Humans; Pneumococcal Infections; Pneumococcal Vaccines; Streptococcus pneumoniae; Vaccines, Conjugate
PubMed: 35155281
DOI: 10.3389/fcimb.2022.824788 -
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 -
ELife May 2023is a major pathogen in children, elderly subjects, and immunodeficient patients. Pentraxin 3 (PTX3) is a fluid-phase pattern recognition molecule (PRM) involved in...
is a major pathogen in children, elderly subjects, and immunodeficient patients. Pentraxin 3 (PTX3) is a fluid-phase pattern recognition molecule (PRM) involved in resistance to selected microbial agents and in regulation of inflammation. The present study was designed to assess the role of PTX3 in invasive pneumococcal infection. In a murine model of invasive pneumococcal infection, PTX3 was strongly induced in non-hematopoietic (particularly, endothelial) cells. The IL-1β/MyD88 axis played a major role in regulation of the gene expression. mice presented more severe invasive pneumococcal infection. Although high concentrations of PTX3 had opsonic activity in vitro, no evidence of PTX3-enhanced phagocytosis was obtained in vivo. In contrast, -deficient mice showed enhanced recruitment of neutrophils and inflammation. Using deficient mice, we found that protection against pneumococcus was dependent upon PTX3-mediated regulation of neutrophil inflammation. In humans, gene polymorphisms were associated with invasive pneumococcal infections. Thus, this fluid-phase PRM plays an important role in tuning inflammation and resistance against invasive pneumococcal infection.
Topics: Animals; Mice; Inflammation; Neutrophils; Phagocytosis; Pneumococcal Infections; Streptococcus pneumoniae
PubMed: 37222419
DOI: 10.7554/eLife.78601 -
Occupational Medicine (Oxford, England) Jul 2012In 2011, the Department of Health in England recommended that welders should each receive a single dose of the 23-valent pneumococcal polysaccharide vaccine (PPV23). (Review)
Review
BACKGROUND
In 2011, the Department of Health in England recommended that welders should each receive a single dose of the 23-valent pneumococcal polysaccharide vaccine (PPV23).
AIMS
To assess the evidence behind the advice and its practical implications.
METHODS
The review was informed by a systematic search in Medline, which related pneumonia to welding and/or exposure to metal fume, and was supplemented using the personal libraries of the authors.
RESULTS
There is consistent evidence that welders die more often of pneumonia, especially lobar pneumonia, are hospitalized more often for lobar and pneumococcal pneumonia, and more often develop invasive pneumococcal disease (IPD). It is estimated that one case of IPD may be prevented over a 10-year period by vaccinating 588 welders against pneumococcal infection.
CONCLUSIONS
A good case exists that employers should offer PPV23 vaccination to welders and other employees exposed to metal fume. Additionally, reasonable measures must be taken to minimize exposure to welding fume, and welders should be encouraged not to smoke.
Topics: Canada; England; Gases; Humans; Metals; Occupational Exposure; Pneumococcal Infections; Pneumococcal Vaccines; Pneumonia; Pneumonia, Pneumococcal; United States; Welding
PubMed: 22764269
DOI: 10.1093/occmed/kqs055