Streptococcus pneumoniae’s Virulence and Host Immunity: Aging, Diagnostics, and Prevention

Abstract

Streptococcus pneumoniae is an infectious pathogen responsible for millions of deaths worldwide. Diseases caused by this bacterium are classified as pneumococcal diseases. This pathogen colonizes the nasopharynx of its host asymptomatically, but overtime can migrate to sterile tissues and organs and cause infections. Pneumonia is currently the most common pneumococcal disease. Pneumococcal pneumonia is a global health concern and vastly affects children under the age of five as well as the elderly and individuals with pre-existing health conditions. S. pneumoniae has a large selection of virulence factors that promote adherence, invasion of host tissues, and allows it to escape host immune defenses. A clear understanding of S. pneumoniae’s virulence factors, host immune responses, and examining the current techniques available for diagnosis, treatment, and disease prevention will allow for better regulation of the pathogen and its diseases. In terms of disease prevention, other considerations must include the effects of age on responses to vaccines and vaccine efficacy. Ongoing work aims to improve on current vaccination paradigms by including the use of serotype-independent vaccines, such as protein and whole cell vaccines. Extending our knowledge of the biology of, and associated host immune response to S. pneumoniae is paramount for our improvement of pneumococcal disease diagnosis, treatment, and improvement of patient outlook.

Microarray Gene Expression Dataset Re-Analysis Reveals Variability in Influenza Infection and Vaccination

“…During the flu season, the majority of hospitalizations and deaths from influenza are within the elderly population (3). Young children are also at high risk for severe infections of influenza due to their underdeveloped immune system (33). Current vaccine development methods, though effective are also flawed.…”

“…This is in part due to immune system development and deterioration. For example, B and T cell function diminishes with age (49, 33). In our analysis, we identified 907 disease-associated genes with a statistically significant interaction with age that were also enriched in immune related KEGG pathways (SDF30 of online supplementary data files).…”

Structural insights into secretory immunoglobulin A and its interaction with a pneumococcal adhesin

“…Due to the critical function of SIgA in immune defenses, various pathogens have developed strategies to disrupt its function. Streptococcus pneumoniae , also known as pneumococcus, is a Gram-positive bacterium that causes millions of deaths worldwide 13,14 . It is an opportunistic pathogen residing in the upper respiratory tract of many people especially young children.…”

CCR5 and CCR5Δ32 in bacterial and parasitic infections: Thinking chemokine receptors outside the HIV box

“…Infection by this bacterium affects mainly children, elderly people, and individuals with a deficient immune function. In some cases, the disease can be fatal (Brooks & Mias, 2018). As expected, different cell receptors, chemokines and host cell pathways are involved in the immune responses against S. pneumoniae .…”

“…As expected, different cell receptors, chemokines and host cell pathways are involved in the immune responses against S. pneumoniae . The inflammatory profile of each individual can significantly influence such responses, affecting bacterial pathogenesis and transmission (Brooks & Mias, 2018). In this context, there is evidence that CCR5 and its ligand CCL5 have some influence on the interactions between S. pneumoniae and the host (Palaniappan et al, 2006).…”