-
Hemoglobin May 2021Sickle cell disease is a genetic disease with a predisposition to infections caused by encapsulated organisms, especially Pneumococcal vaccines and prophylactic...
Sickle cell disease is a genetic disease with a predisposition to infections caused by encapsulated organisms, especially Pneumococcal vaccines and prophylactic penicillin have reduced the rate of this infection and mortality in sickle cell disease. However, implementation of these interventions is limited in Africa. The objectives of the study were to assess health care providers' behaviors with the implementation of pneumococcal vaccination and penicillin prophylaxis and to identify barriers to their use. A 25-item online questionnaire was administered through SickleinAfrica: a network of researchers, and healthcare providers, in Ghana, Nigeria, and Tanzania, working to improve health outcomes of sickle cell disease in Africa. Data was collected and managed using the Research Electronic Data Capture (REDCap), tools and data analysis was done using STATA version 13 and R statistical software. Eighty-two medical practitioners responded to the questionnaire. Only 54.0 and 48.7% of respondents indicated the availability of published guidelines on sickle cell disease management and pneumococcal vaccine use, respectively, at their facilities. The majority (54.0%) perceived that the vaccines are effective but over 20.0% were uncertain of their usefulness. All respondents from Ghana and Tanzania affirmed the availability of guidelines for penicillin prophylaxis in contrast to 44.1% in Nigeria. Eighty-five percent of respondents affirmed the need for penicillin prophylaxis but 15.0% had a contrary opinion for reasons including the rarity of isolation of in African studies, and therefore, the uncertainty of its benefit. Lack of published guidelines on the management of sickle cell disease and doubts about the necessity of prophylactic measures are potential barriers to the implementation of effective interventions.
Topics: Anemia, Sickle Cell; Health Personnel; Humans; Nigeria; Penicillins; Pneumococcal Infections; Pneumococcal Vaccines; Streptococcus pneumoniae
PubMed: 34355623
DOI: 10.1080/03630269.2021.1954943 -
Emerging Microbes & Infections Dec 2022Pneumococcal pneumonia is one of the main reasons for child death worldwide. Pneumococcal conjugate vaccines (PCVs) are considered the most effective strategy for...
Pneumococcal pneumonia is one of the main reasons for child death worldwide. Pneumococcal conjugate vaccines (PCVs) are considered the most effective strategy for pneumococcal disease (PD) prevention, but how a pause in PCV vaccination affects the prevalence of PD or the genetic evolution of genetic evolution is unknown. Based on the unique PCV introduction timeline (vaccine unavailable during April 2015-April 2017) in China, we aimed to evaluate the effect of interrupted PCV availability on PD and pneumococcal genome variation. Pneumococcal isolates (n = 386) were collected retrospectively from eight sites in Zhejiang, China from 2009 to 2019 in which 184 pathogenic (isolates from sterile and infection sites) strains were identified. An interrupted time series analysis was conducted to estimate changes in PD and the recombination frequency of whole genome-sequenced strains was estimated via SNP calling. We found that both PD and pneumococcal genome variation were affected by interrupted PCV availability. The proportion (∼70%) of vaccine-type pneumococcal LRTI (VT-LRTI) in all LRTI cases decreased to ∼30% in the later PCV7 period and rebounded to ∼70% in children once PCV7 became unavailable in April 2015 (= 0.0007). The major clone CC271 strains showed slowed (= 0.0293) recombination frequency (decreased from 2.82 ± 1.16-0.72 ± 0.21) upon PCV removal. Our study illustrated for the first time that VT-LRTI fluctuated upon interrupted vaccine availability in China and causing a decreased of recombination frequency of vaccine types. Promoting a nationwide continuous vaccination programme and strengthening molecular epidemiology surveillance are essential for PD prevention.
Topics: Child; Heptavalent Pneumococcal Conjugate Vaccine; Humans; Infant; Pneumococcal Infections; Recombination, Genetic; Retrospective Studies; Serogroup; Vaccines, Conjugate
PubMed: 35135440
DOI: 10.1080/22221751.2022.2040921 -
EBioMedicine Jul 2022
A particulate matter: How environmental irritants and particulate matter increase sensitivity to bacterial respiratory tract infections. Commentary for "Underground railway particulate matter and susceptibility to pneumococcal infection".
Topics: Air Pollutants; Environmental Exposure; Humans; Irritants; Particulate Matter; Pneumococcal Infections; Respiratory Tract Infections
PubMed: 35728486
DOI: 10.1016/j.ebiom.2022.104116 -
Journal of the Pediatric Infectious... Feb 2023Pneumococcal conjugate vaccines (PCVs) effectively reduce infection and asymptomatic carriage of Streptococcus pneumoniae vaccine serotypes. In 2016, Belgium replaced...
BACKGROUND
Pneumococcal conjugate vaccines (PCVs) effectively reduce infection and asymptomatic carriage of Streptococcus pneumoniae vaccine serotypes. In 2016, Belgium replaced its infant PCV13 program by a 4-year period of PCV10. Concomitantly, S. pneumoniae serotype carriage was monitored together with the carriage of other nasopharyngeal pathogens in children attending day-care centers.
METHODS
From 2016 to 2019, a total of 3459 nasopharyngeal swabs were obtained from children aged 6-30 months. Culture and qPCR were used for the identification of S. pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Staphylococcus aureus and for serotyping and antimicrobial susceptibility assessment of S. pneumoniae strains.
RESULTS
S. pneumoniae colonization was frequent and stable over the study years. H. influenzae and M. catarrhalis were more frequently carried (P < .001) than S. pneumoniae, by, respectively, 92.3% and 91.0% of children. Prevalence of all PCV13 serotypes together increased significantly over time from 5.8% to 19.6% (P < .001) and was attributable to the increasing prevalence of serotype 19A. Coincidently, non-vaccine serotype 6C increased (P < .001) and the overall pneumococcal non-susceptibility to tetracycline and erythromycin. Non-susceptibility to cotrimoxazole decreased (P < .001).
CONCLUSIONS
The switch to a PCV program no longer covering serotypes 19A, 6A, and 3 was associated with a sustained increase of serotypes 19A and 6C in healthy children, similarly as in invasive pneumococcal disease. This resulted in a re-introduction of the 13-valent conjugate vaccine during the summer of 2019.
Topics: Infant; Humans; Child; Streptococcus pneumoniae; Serogroup; Belgium; Carrier State; Pneumococcal Vaccines; Pneumococcal Infections; Haemophilus influenzae; Vaccines, Conjugate
PubMed: 36377804
DOI: 10.1093/jpids/piac117 -
PloS One 2023Two next-generation pneumococcal conjugate vaccines (PCVs), a 15- and a 20-valent PCV (PCV15 and PCV20), have recently been licensed for use in adults, and PCV15 has...
Mathematical modeling of pneumococcal transmission dynamics in response to PCV13 infant vaccination in Germany predicts increasing IPD burden due to serotypes included in next-generation PCVs.
INTRODUCTION
Two next-generation pneumococcal conjugate vaccines (PCVs), a 15- and a 20-valent PCV (PCV15 and PCV20), have recently been licensed for use in adults, and PCV15 has also been licensed in children. We developed a dynamic transmission model specific for Germany, with the aim to predict carriage prevalence and invasive pneumococcal disease (IPD) burden for serotypes included in these vaccines.
METHODS
The model allows to follow serotype distributions longitudinally both in the absence and presence of PCV vaccinations. We considered eight age cohorts and seven serotype groups according to the composition of different pneumococcal vaccines. This comprises the additional serotypes contained in PCV15 and PCV20 but not in PCV13.
RESULTS
The model predicted that by continuing the current vaccine policy (standard vaccination with PCV13 in children and with PPSV23 in adults) until 2031, IPD case counts due to any serotype in children <2 years of age will remain unchanged. There will be a continuous decrease of IPD cases in adults aged 16-59y, but a 20% increase in adults ≥60y. Furthermore, there will be a steady decrease of the proportion of carriage and IPD due to serotypes included in PCV7 and PCV13 over the model horizon and a steady rise of non-PCV13 serotypes in carriage and IPD. The highest increase for both pneumococcal carriage and absolute IPD case counts was predicted for serotypes 22F and 33F (included in both PCV15 and PCV20) and serotypes 8, 10A, 11A, 12F, and 15B (included in PCV20 only), particularly in older adults. Between 2022 and 2031, serotypes included in PCV20 only are expected to cause 19.7-25.3% of IPD cases in adults ≥60y.
CONCLUSIONS
We conclude that introduction of next-generation PCVs for adults may prevent a substantial and increasing proportion of adult IPDs, with PCV20 having the potential to provide the broadest protection against pneumococcal disease.
Topics: Child; Humans; Infant; Aged; Child, Preschool; Serogroup; Streptococcus pneumoniae; Pneumococcal Infections; Pneumococcal Vaccines; Vaccines, Conjugate; Vaccination; Germany
PubMed: 36791091
DOI: 10.1371/journal.pone.0281261 -
PloS One 2023This systematic review evaluates pneumolysin (PLY) as a target for new treatments against pneumococcal infections. Pneumolysin is one of the main virulence factors... (Meta-Analysis)
Meta-Analysis
BACKGROUND
This systematic review evaluates pneumolysin (PLY) as a target for new treatments against pneumococcal infections. Pneumolysin is one of the main virulence factors produced by all types of pneumococci. This toxin (53 kDa) is a highly conserved protein that binds to cholesterol in eukaryotic cells, forming pores that lead to cell destruction.
METHODS
The databases consulted were MEDLINE, Web of Science, and Scopus. Articles were independently screened by title, abstract, and full text by two researchers, and using consensus to resolve any disagreements that occurred. Articles in other languages different from English, patents, cases report, notes, chapter books and reviews were excluded. Searches were restricted to the years 2000 to 2021. Methodological quality was evaluated using OHAT framework.
RESULTS
Forty-one articles describing the effects of different molecules that inhibit PLY were reviewed. Briefly, the inhibitory molecules found were classified into three main groups: those exerting a direct effect by binding and/or blocking PLY, those acting indirectly by preventing its effects on host cells, and those whose mechanisms are unknown. Although many molecules are proposed as toxin blockers, only some of them, such as antibiotics, peptides, sterols, and statins, have the probability of being implemented as clinical treatment. In contrast, for other molecules, there are limited studies that demonstrate efficacy in animal models with sufficient reliability.
DISCUSSION
Most of the studies reviewed has a good level of confidence. However, one of the limitations of this systematic review is the lack of homogeneity of the studies, what prevented to carry out a statistical comparison of the results or meta-analysis.
CONCLUSION
A panel of molecules blocking PLY activity are associated with the improvement of the inflammatory process triggered by the pneumococcal infection. Some molecules have already been used in humans for other purposes, so they could be safe for use in patients with pneumococcal infections. These patients might benefit from a second line treatment during the initial stages of the infection preventing acute respiratory distress syndrome and invasive pneumococcal diseases. Additional research using the presented set of compounds might further improve the clinical management of these patients.
Topics: Animals; Humans; Reproducibility of Results; Pneumococcal Infections; Streptococcus pneumoniae; Streptolysins; Bacterial Proteins
PubMed: 36947540
DOI: 10.1371/journal.pone.0282970 -
Frontiers in Cellular and Infection... 2023() is one of the most widespread pathogens in the world and one of the largest infectious causes of infant mortality. Although current vaccines have various benefits,...
INTRODUCTION
() is one of the most widespread pathogens in the world and one of the largest infectious causes of infant mortality. Although current vaccines have various benefits, antibiotic resistance and the inability to vaccinate infants less than one year old demands the development of new protective strategies. One strategy, 'maternal immunization', is to protect infants by passive immunity from an immunized mother, although its mechanism is still not fully understood.
MATERIALS AND METHODS
The current study aimed to acquire immunity against in infants by maternal immunization with pneumococcal common antigen, pneumococcal surface protein A (PspA). Four-week-old female mice were immunized with recombinant PspA intranasally twice a week for three weeks. Females were mated with age-matched males after immunization, and delivered offspring.
RESULTS
The week-old offspring derived from and fostered by immunized mothers had more anti-PspA-specific antibody producing cells in the spleen than those derived from sham-immunized mothers. The offspring were raised up to four weeks old and were subcutaneously stimulated with recombinant PspA. The levels of anti-PspA IgG in sera after stimulation were significantly higher in the offspring derived from the immunized mothers and the induced specific antibody to PspA showed protective efficacy against systemic pneumococcal infection.
DISCUSSION
Maternal immunization is suggested to be able to provide a sustained immune memory to offspring. The current study would be a milestone in the field of maternal immunization toward a universal pneumococcal vaccine.
Topics: Male; Female; Animals; Mice; Immunologic Memory; Immunoglobulin G; Pneumococcal Infections; Bacterial Proteins; Immunization; Vaccination; Streptococcus pneumoniae; Antigens, Bacterial; Pneumococcal Vaccines; Antibodies, Bacterial; Mice, Inbred BALB C
PubMed: 37033488
DOI: 10.3389/fcimb.2023.1059603 -
Canadian Family Physician Medecin de... Oct 1999To determine the clinical effectiveness of pneumococcal vaccine. (Meta-Analysis)
Meta-Analysis
OBJECTIVE
To determine the clinical effectiveness of pneumococcal vaccine.
DATA SOURCES
Computerized searches of MEDLINE, EMBASE, and SCISEARCH databases were performed, reference lists of retrieved articles were reviewed, and first authors of published studies were contacted.
STUDY SELECTION
Studies of use of pneumococcal vaccines in adults were included if the study design was a randomized or quasi-randomized controlled trial and at least one of the following clinical outcomes was reported: vaccine-type systemic pneumococcal infection, systemic pneumococcal infection, vaccine-type pneumococcal pneumonia, pneumococcal pneumonia, non-vaccine-type pneumococcal pneumonia.
SYNTHESIS
Study quality was assessed and descriptive information concerning the study populations, interventions, and outcome measurements was extracted for 13 trials involving more than 65,000 patients. Estimates of vaccine efficacy, based on a meta-analysis of randomized and quasi-randomized trials, were determined for clinical outcomes.
CONCLUSIONS
Vaccination with pneumococcal polysaccharide vaccine can be expected to reduce the risk of systemic infection due to pneumococcal types included in the vaccine by 83% and systemic infection due to all pneumococci by 73%. We found no evidence that the vaccine was less efficacious for the elderly, institutionalized people, or those with chronic disease.
Topics: Adolescent; Adult; Age Factors; Bacterial Vaccines; Chronic Disease; Humans; Middle Aged; Pneumococcal Infections; Streptococcus pneumoniae; Vaccination
PubMed: 10540698
DOI: No ID Found -
Journal of Microbiology and... Jan 2024(pneumococcus) is an opportunistic pathogen that can cause severe infectious diseases such as pneumonia, meningitis, and otitis media. Despite the availability of...
(pneumococcus) is an opportunistic pathogen that can cause severe infectious diseases such as pneumonia, meningitis, and otitis media. Despite the availability of antibiotics and pneumococcal vaccines against some invasive serotypes, pneumococcal infection remains a tremendous clinical challenge due to the increasing frequency of infection by antimicrobial resistant, nonencapsulated, and/or non-vaccine serotype strains. Short-chain fatty acids (SCFAs), which are produced at various mucosal sites in the body, have potent antimicrobial activity, including inhibition of pathogen growth and/or bacterial biofilm formation. In this study, we investigated the antimicrobial activity of SCFAs (acetate, propionate, and butyrate) against various serotypes pneumococci. Propionate generally inhibited the growth of serotypes included in the pneumococcal conjugate vaccine (PCV) 13, except for serotypes 3 and 7F, though butyrate and acetate showed no or low inhibition, depending on the serotypes. Of note, butyrate showed strong inhibition against serotype 3, the most prevalent invasive strain since the introduction of the PCV. No SCFAs showed inhibitory effects against serotype 7F. Remarkably, the nonencapsulated pneumococcal strain had more sensitivity to SCFAs than encapsulated parental strains. Taken together, these results suggest that propionate showing the most potent inhibition of pneumococcal growth may be used as an alternative treatment for pneumococcal infection, and that butyrate could be used against serotype 3, which is becoming a serious threat.
Topics: Humans; Infant; Streptococcus pneumoniae; Serogroup; Propionates; Pneumococcal Infections; Anti-Bacterial Agents; Pneumococcal Vaccines; Fatty Acids, Volatile; Butyrates; Vaccines, Conjugate; Acetates; Serotyping
PubMed: 38044707
DOI: 10.4014/jmb.2309.09003 -
Frontiers in Cellular and Infection... 2021is an important pathogen causing high morbidity and high mortality in children and undergoes frequent recombination for capsule switching to neutralize the 13-valent...
BACKGROUND
is an important pathogen causing high morbidity and high mortality in children and undergoes frequent recombination for capsule switching to neutralize the 13-valent pneumococcal conjugate vaccine (PCV13). This study aimed to investigate the prevalence, and molecular characteristics including serotypes and antibiotic susceptibility of isolated from children living in Southwest China from 2017 to 2019 to facilitate the selection of effective vaccine formulations and appropriate antibiotic treatment regimens.
METHODS
This study was conducted at West China Second University Hospital (Chengdu, Sichuan Province, China), Zunyi Medical University Third Affiliated Hospital/First People's Hospital of Zunyi (Zunyi, Guizhou Province, China) and Chengdu Jinjiang District Maternal and Child Healthcare Hospital (Chengdu, Sichuan Province, China). Demographic and clinical characteristics of children infected with were collected and analysed. Next-generation sequencing and sequence analysis were used to determine the serotypes, sequence types, antibiotic resistance and potential protein vaccine target genes of the pneumococcal isolates. The coverage rate provided by PCV13 was estimated by calculating the percentage of the specific serotypes that were specifically the PCV13-included serotypes. Antimicrobial susceptibility was determined by the microdilution broth method.
RESULTS
The most prevalent pneumococcal serotypes were 19F (25.8%), 19A (14.1%), 6B (12.5%), 6A (9.4%) and 14 (7.8%). The predominant STs were ST271 (23.3%), ST320 (15.5%) and ST90 (8.6%), dominated by the clonal complex Taiwan-14 (39.1%). The coverage rate of PCV13 was 77.3% in all the isolates, with relatively higher values in invasive isolates (86.4%). Over the decade, the rates of resistance to penicillin, amoxicillin and cefotaxime were 5.6%, 5.3% and 5.1%, respectively, with significantly higher values in invasive isolates (22.4%, 14.9% and 11.9%). Almost all the isolates were resistant to erythromycin (99.1%) and clindamycin (95.9%). All isolates carried virulence-related genes, including , and . The carriage of virulence and resistance genes varied among serotypes and clades, with serotype 19F/ST271 showing higher resistance to antibiotics and being more likely to carry pilus genes and other virulence genes.
CONCLUSION
These data provide valuable information for the understanding of pneumococcal pathogenesis, antimicrobial resistance and the development of protein-based vaccines against pneumococcal infection.
Topics: Anti-Bacterial Agents; Child; China; Humans; Infant; Microbial Sensitivity Tests; Multilocus Sequence Typing; Pneumococcal Infections; Pneumococcal Vaccines; Serogroup; Streptococcus pneumoniae
PubMed: 34796125
DOI: 10.3389/fcimb.2021.726740