Non-encapsulated<i>Streptococcus pneumoniae</i>, vaccination as a measure to interfere with horizontal gene transfer

Langereis, Jeroen D.; Jonge, Marien I. de

doi:10.1080/21505594.2017.1309492

Cited by 12 publications

(10 citation statements)

References 14 publications

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“…Increased vaccine pressure caused by PCVs might open an environmental niche that NESp is adept to employ. This could explain the increased prevalence of NESp isolates in the PostVac-II period, or the increase might simply be a natural trend that reflects longer-term variation (42, 43). Our data support the need for continued surveillance of pneumococci in Iceland.…”

Section: Discussionmentioning

confidence: 99%

Vaccination of Icelandic Children with the 10-Valent Pneumococcal Vaccine Leads to a Significant Herd Effect among Adults in Iceland

et al. 2019

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The introduction of pneumococcal conjugate vaccines (PCVs) into childhood vaccination programs has reduced carriage of vaccine serotypes and pneumococcal disease. The 10-valent PCV was introduced in Iceland in 2011. The aim of this study was to determine PCV impact on the prevalence of serotypes, genetic lineages, and antimicrobial-resistant pneumococci isolated from the lower respiratory tract (LRT) of adults. Pneumococci isolated between 2009 and 2017 at the Landspitali University Hospital were included (n = 797). The hospital serves almost three-quarters of the Icelandic population. Isolates were serotyped and tested for antimicrobial susceptibility, and the genome of every other isolate collected between 2009 and 2014 was sequenced (n = 275). Serotypes and multilocus sequence types (STs) were extracted from the genome data. Three study periods were defined, 2009 to 2011 (PreVac), 2012 to 2014 (PostVac-I), and 2015 to 2017 (PostVac-II). The total number of isolates and vaccine-type (VT) pneumococci decreased from PreVac to PostVac-II (n = 314 versusn = 230 [p = 0.002] andn = 170 versusn = 33 [p < 0.001], respectively), but non-vaccine-type (NVT) pneumococci increased among adults 18 to 64 years old (n = 56 versusn = 114 [p = 0.008]). Serotype 19F decreased in the PostVac-II period; these isolates were all multidrug resistant (MDR) and were members of the Taiwan19F-14 PMEN lineage. Serotype 6A decreased among adults ≥65 years old in the PostVac-II period (p = 0.037), while serotype 6C increased (p = 0.021) and most serotype 6C isolates were MDR. NonencapsulatedStreptococcus pneumoniae(NESp) isolates increased among adults 18 to 64 years old in the PostVac-II period, and the majority were MDR (p = 0.028). An overall reduction in the number of LRT samples and pneumococcus-positive cultures and significant changes in the serotype distribution became evident within 4 years, thereby demonstrating a significant herd effect.

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Section: Discussionmentioning

confidence: 99%

Vaccination of Icelandic Children with the 10-Valent Pneumococcal Vaccine Leads to a Significant Herd Effect among Adults in Iceland

et al. 2019

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“…Current pneumococcal polysaccharide vaccines are composed of capsular polysaccharides from the most prevalent serotypes of pneumococcus [3]. The limited vaccine coverage, replacement by non-vaccine serotypes [3] and non-encapsulated S. pneumoniae (NESp) which have been isolated from patients with invasive and non-invasive pneumococcal disease [5,6] and increasing antibiotic resistance [7] are some serious threats in the near future; Therefore, the search for new candidates for a vaccine that elicit protection against a broader range of pneumococcal strains is necessary [[8], [9], [10]]. Pneumococcal surface protein A (PspA) is a very promising candidate for novel vaccine development against pneumococcal infections [11].…”

Section: Introductionmentioning

confidence: 99%

Protective responses of an engineered PspA recombinant antigen against Streptococcus pneumoniae

Akbari

Negahdari

Faraji

et al. 2019

Biotechnology Reports

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“…IgA1 protease, which cleaves human IgA1, is one of the most important virulence factors produced by S. pneumoniae and several other invasive mucosal pathogens (e.g., Neisseria species and Haemophilus influenzae) [17]. Given the importance of streptococcal infections and the lack of an effective vaccine against all strains of S. pneumoniae [9], we here cloned, expressed, and purified a part of the pneumococcal IgA1 protease to assess its immunogenicity. For this purpose, antibody titer against the truncated recombinant IgA1 protease was determined in the serum of healthy individuals from three age groups.…”

Section: Discussionmentioning

confidence: 99%

“…Nowadays, in addition to encapsulated bacteria, nonencapsulated strains of S. pneumoniae are frequently isolated from many patients with pneumococcal infections. Therefore, current vaccines, which are generally based on capsular antigens, are not effective against the newly emerged infections [9]. For this reason, researchers have been investigating other proteins of the bacterium to develop new vaccines with the ability to induce high protection against all pneumococcal serotypes.…”

Section: Introductionmentioning

confidence: 99%

High Titer of Antibody Against Pneumococcal IgA1 Protease in Healthy Individuals

Gholami¹,

Afshar²,

Kheirandish³

et al. 2020

TOMICROJ

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Background and Objectives: Considering rising antibiotic resistance in various strains of Streptococcus pneumoniae, there is a need to find new immunogenic candidates for developing pneumococcal vaccines. Immunoglobulin A1 (IgA1) protease is one of the virulence factors playing an important role in the pathogenesis of S. pneumoniae infections. In the present study, we aimed to evaluate the titer of antibody against pneumococcal recombinant IgA1 protease in the serum of healthy humans. Materials and Methods: A part of the IgA1 protease gene (705 bp) from S. pneumonia ATCC 49619 was amplified by PCR and then digested using restriction enzymes and ligated by the pET28a expression vector. The recombinant protein was expressed in E. coli BL21 strain. Affinity chromatography was used to purify the protein. The titer of antibody against the recombinant protease was determined in healthy individuals in three age groups of <2, 2-40, and > 40 years using indirect Enzyme-Linked Immunosorbent Assay (ELISA). Results: The expression and purification of the IgA1 recombinant protease were successful. The concentration of the purified protein was determined as 1.013 mg/ml using the NanoDrop method. The titer of anti-recombinant IgA1 protease antibody (20, 40, 80 and 160) showed a significant correlation with age (p-value<0.05). According to our results, the antibody titer was desirable, especially in individuals over two years old. Conclusion: In the present study, desirable antibody titers against the pneumococcal recombinant IgA1 protease were seen in the three groups’ serum of healthy individuals. However, a significant correlation was not totally observed among groups.

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Non-encapsulatedStreptococcus pneumoniae, vaccination as a measure to interfere with horizontal gene transfer

Cited by 12 publications

References 14 publications

Vaccination of Icelandic Children with the 10-Valent Pneumococcal Vaccine Leads to a Significant Herd Effect among Adults in Iceland

Vaccination of Icelandic Children with the 10-Valent Pneumococcal Vaccine Leads to a Significant Herd Effect among Adults in Iceland

Protective responses of an engineered PspA recombinant antigen against Streptococcus pneumoniae

High Titer of Antibody Against Pneumococcal IgA1 Protease in Healthy Individuals

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