Airway response to respiratory syncytial virus has incidental antibacterial effects.

RSV infection is typically associated with secondary bacterial infection. We hypothesise that the local airway immune response to RSV has incidental antibacterial effects. Using coordinated proteomics and metagenomics analysis we simultaneously analysed the microbiota and proteomes of the upper airway and determined direct antibacterial activity in airway secretions of RSV-infected children. Here, we report that the airway abundance of Streptococcus was higher in samples collected at the time of RSV infection compared with samples collected one month later. RSV infection is associated with neutrophil influx into the airway and degranulation and is marked by overexpression of proteins with known antibacterial activity including BPI, EPX, MPO and AZU1. Airway secretions of children infected with RSV, have significantly greater antibacterial activity compared to RSV-negative controls. This RSV-associated, neutrophil-mediated antibacterial response in the airway appears to act as a regulatory mechanism that modulates bacterial growth in the airways of RSV-infected children

Epidemiological Data, Serovar Distribution and Antimicrobial Resistance Patterns of Salmonella Species in Children, Greece 2011-2017: A Retrospective Study

OBJECTIVE: This study aimed to describe Salmonella epidemiology and antimicrobial resistance in Greek children over the period of 2011-2017. MATERIALS AND METHODS: A 7-year retrospective study (2011-2017) was performed, based on data recorded by the National Reference Centre for Salmonella, among children aged ≤14 years. Epidemiological data, serovar distribution and antimicrobial resistance patterns were recorded. RESULTS: Overall, 2347 Salmonella isolates were collected (27 typhoid-paratyphoid). Salmonellosis cases increased by almost 2-fold in 2017 compared to 2011. The highest rates were reported in August, with infants being the most vulnerable group (17.9%). The majority of isolates were identified in stool samples (91%). Boys slightly outnumbered girls (˜1.05:1). Salmonella Enteritidis was the most prevalent serovar (28.5%), followed by Salmonella Typhimurium (12.2%) and Salmonella monophasic Typhimurium (10.4%). Non-typhoid isolates displayed low resistance rates to 3rd generation cephalosporins (1%) and ciprofloxacin (0.3%), while the corresponding resistance of typhoid isolates was 10% and 5% respectively. An increasing trend of Salmonella monophasic Typhimurium was recorded, associated with high rates of multidrug resistance, reaching a percentage of 97.8% in 2017. CONCLUSIONS: Salmonellosis epidemiology in Greek children is comparable to previously published European data. Antimicrobial resistance rates to 3rd-generation cephalosporins and ciprofloxacin for non-typhoid and typhoid-paratyphoid remain low. Notably, there is an increasing prevalence of Salmonella monophasic Typhimurium isolates, associated with multiple antimicrobial resistance. Copyright © 2020 by Academy of Sciences and Arts of Bosnia and Herzegovina

Understanding host immune responses to pneumococcal proteins in the upper respiratory tract to develop serotype-independent pneumococcal vaccines

Contains fulltext : 229530.pdf (Publisher’s version ) (Closed access)Introduction: Nasopharyngeal colonization is a precondition for mucosal and invasive pneumococcal disease. Prevention of colonization may reduce pneumococcal transmission and disease incidence. Therefore, several protein-based pneumococcal vaccines are currently under investigation. Areas covered: We aimed to better understand the host immune responses to pneumococcal proteins in the upper respiratory tract (URT) that could facilitate the development of serotype-independent pneumococcal vaccines. English peer-reviewed papers reporting immunological mechanisms involved in host immune response to pneumococcal proteins in the URT were retrieved through a PubMed search using the terms 'pneumococcal proteins,' 'nasopharyngeal colonization' and/or 'cellular/humoral host immune response.' Expert opinion: Although pneumococcal protein antigens induce humoral immune responses, as well as IL-17A-mediated immunity, none of them, when used as single antigen, is sufficient to control and broadly protect against pneumococcal colonization. Novel vaccines should contain multiple conserved protein antigens to activate both arms of the immune system and evoke protection against the whole spectrum of pneumococcal variants by reducing, rather than eradicating, pneumococcal carriage. The highest efficacy would likely be achieved when the vaccine is intranasally applied, inducing mucosal immunity and enhancing the first line of defense by restricting pneumococcal density in the URT, which in turn will lead to reduced transmission and protection against disease

Antibody persistence 5 years after a 13-valent pneumococcal conjugate vaccine in asplenic patients with β-thalassemia: assessing the need for booster

Streptococcus pnemoniae is a major cause of morbidity and mortality among splenectomised patients with β-thalassemia major. We have previously shown that a 13-valent pneumococcal conjugate vaccine (PCV13) induces robust early immune responses in such patients, while history of repeated immunisations with the 23-valent polysaccharide pneumococcal vaccine (PPSV23) results in attenuation of the response to PCV13. However, the duration of vaccine-induced protection in splenectomised thalassemic patients and the associated need for booster immunisation remains unclear. In the current study, we enumerate antibody persistence 5 years post-PCV13 and investigate any correlation with early immune response and immunisation history. Pneumococcal serotype (PS)-specific antibodies against 5 vaccine antigens were measured 5 years post-PCV13 in 34 asplenic adults with β-thalassemia. PS-specific antibodies against 5 vaccine serotypes had declined significantly at 5 years post-PCV13 (year 5).Year 5 antibody titres remained above baseline for PS9V, 19A and19F, returned to baseline for PS23F, and dropped below baseline for PS3 (p < 0.001).Year 5 antibodies were positively correlated with day 28 antibody titres, while no correlation was found with early memory B cell response. Previous PPSV23 history was correlated with impaired antibody persistence against serotype 19A. Antibody levels dropped significantly but remained at protective levels 5 years post-PCV13.We propose that asplenic patients with β-thalassemia may benefit from measurement of antipneumococcal antibodies after 5 years post-PCV13 as they may eventually be in need for booster pneumococcal vaccination. Clinical Trials Registration ID: www.clinicaltrials.gov NCT01846923. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature

Pneumococcal immunization strategies for high-risk pediatric populations worldwide: One size does not fit all

Despite the significant reduction in pneumococcal disease due to pneumococcal vaccines, protection of vulnerable high-risk individuals, especially pediatric populations, remains a great challenge. In an effort to maximize the protection of high-risk children against pneumococcal disease, a combined schedule that includes both conjugate and polysaccharide vaccines is recommended by several countries in the developed world. On the other hand, middle-and low-income countries do not have in place established policies for pneumococcal immunization of children at risk. Pneumococcal conjugate vaccines, despite their benefits, have several limitations, mainly associated with serotype replacement and the wide range of serotype coverage worldwide. In addition, PPV23-impaired immunogenicity and the hyporesponsiveness effect among populations at risk have been well-documented. Therefore, the added value of continuing to include PPV23 in vaccination schedules for high-risk individuals in the years to come remains to be determined by monitoring whether the replacing/remaining serotypes causing IPD are covered by PPV23 to determine whether its benefits outweigh its limitations. In this review, we aim to describe serotype distribution and vaccine efficacy data on pneumococcal disease in the pre-and post-PCV implementation era among high-risk children in both developed and developing countries, assessing the optimization of current recommendations for their vaccination against pneumococcal disease. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Epidemiology of community-acquired pneumonia hospitalizations and associated complications before and after the implementation of the heptavalent pneumococcal conjugate vaccine in Athens, Greece

We determined the rates of community-acquired pneumonia (CAP)-associated hospitalizations and complications in Athens, over a period covering 4 years before and 4 years after the implementation of the 7-valent pneumococcal vaccine (PCV7) in Greece. PCV7 had no impact on pediatric CAP rates, whereas there was an increase in CAP-associated complications. © The Author 2014. Published by Oxford University Press on behalf of the Pediatric Infectious Diseases Society