Development and evaluation of a novel vaccine against prevalent invasive multi-drug resistant strains ofStreptococcus pneumoniae

Abstract

Streptococcus pneumoniae is a pathogen that causes serious invasive infections, such as septicemia, meningitis and pneumonia in addition to mild upper respiratory tract infections. Protection from pneumococcal diseases is thought to be mediated mainly by serotype-specific antibodies to capsular antigens. Pneumococcal conjugate vaccine consists of sugars (polysaccharides) from the capsule of the bacterium S. pneumoniae that are conjugated to a carrier protein. Three pneumococcal conjugated vaccines, each directed against a group of serotypes, are registered in Egypt; however, local vaccine production is required to cover the most prevalent serotypes. In this work, capsular polysaccharide from the most current and prevalent serotypes in Egypt were extracted, purified and conjugated to bovine serum albumin (BSA). The polysaccharide protein conjugate was purified through ultrafiltration technique and molecular size distribution was compared to an available vaccine. The immunogenicity of the prepared vaccine was examined via two methods: First, by measuring the levels of the elicited antibodies in the sera of the vaccinated mice; second, by challenging the vaccinated groups of mice with approximately 107 CFU of each specific serotype and determining the degree of protection the developled vaccine offers. Our results show that the developed conjugated capsular polysaccharide vaccine is highly immunogenic and protective in mice. This finding illustrates the importance of tracking the most recent and predominant peneumococcal serotypes to generate effective vaccines, instead of using expensive imported vaccines with large number of serotypes which might not be even present in the community.

Antibiotic susceptibility and capsular genes of Streptococcus pneumoniae colonizing children with chronic respiratory diseases.

“…Our results support previous work results of Badawy and his colleagues who reported that serogroup 6 is considered one of the most common colonizers in asymptomatic children in Africa and the Middle East [28]. Our results also supported the results of some earlier Egyptian studies where they found that types 6A/6B were the most common isolated capsular type in Egyptian children [29,30]. In contrast, another study done in Egypt in 2020, found that serotype 1 predominates in clinical and nasopharyngeal samples of Egyptian children [27].…”

“…The resistance rate to beta-lactam drugs (oxacillin) was 34% as it was detected in 11 out of the 32 isolates. Comparable results to the present study were obtained by previous Egyptian studies where susceptibility to penicillin, macrolides, clindamycin, tetracyclines, chloramphenicol, fluoroquinolones, and linezolid ranged between (15%-85%), (50%-78.9%), (64.5%-94.7%), (16.1%-68.4%), (75%-100%), (85%-100%), and (84%-100%) respectively [27][28][29][30].…”

Preparation and evaluation of a new combined conjugated vaccine against Klebsiella pneumonia and Pseudomonas aeruginosa

“…The first group was received a dose of 1 μg of P. aeruginosa LPS vaccine; the second group was received a 0.1 ml vaccine containing 1 μg of K. pneumonia LPS; the third group was received a combined vaccine that contained 1 μg P. aeruginosa and 1 μg K. pneumonia LPS vaccine through intraperitoneal injection. The lowest safe and effective dose in the induction of immunization was detected at 1 μg of LPS (Bahy et al, 2016). Two control groups, one for each microorganism injected with saline, contain 1 mg alum ml −1 .…”

Inhalable Capsular Polysaccharide‐Camouflaged Gallium‐Polyphenol Nanoparticles Enhance Lung Cancer Chemotherapy by Depleting Local Lung Microbiota

“…By self-assembling Ga 3+ with tannins, we successfully formed GaTa NPs (Figure S8a,b, Supporting Information). To avoid in vivo immune clearance, [21] we extracted CPs from S. pneumoniae, a bacterium known for its ability to colonize the lung, using a thermal enzymatic hydrolysis method. [22] The successful extraction of CPs was confirmed by an obvious absorption peak at 206 nm in the UV-vis spectrum (Figure 3b and Figure S8c, Supporting Information).…”