A bacterial pathogen that affects the human nervous system is Streptococcus pneumoniae. This bacterium is associated with several diseases, the most frequent being meningitis, otitis media, and pneumonia. The central nervous system becomes affected when the pathogen enters the brain and spinal cord tissue (Prager et al., 2017). Each of the mentioned illnesses is characterized by the bacteria multiplying in the nasopharyngeal regions, from where it spreads to other individuals through drops of mucus during coughing and sneezing. An essential virulence factor of this pathogen is its extracellular polysaccharide capsule, which is critical for connecting to the host’s cells and avoiding damage from the immune system (Prager et al., 2017). M protein and lipoteichoic acid are also vital to ensure the pathogen’s attachment.
Lyssavirus is another pathogen that impacts the nervous system; however, this microorganism has a viral nature. Lyssavirus causes rabies in humans, being transferred through the saliva of an affected animal, typically due to a bite (Mollentze et al., 2020). Virus uptake and cell-to-cell spread are the most prominent virulence factors for this pathogen, as they determine Lyssavirus’ rate of development in the host’s organism (Mollentze et al., 2020). The received dose of the virus and the location of the bite are also significant virulence factors that can promote the virus’ effectiveness in the host.
A eukaryotic pathogen capable of causing disease in the human nervous system is Candida albicans. Having a fungal origin, this organism can cause fungal infection, namely the candidiasis disease, after entering the human body (Staniszewska, 2020). Candida albicans is one of the few neuromycoses transmitted both orally and genitally; however, while pathogen’s spores entering the host’s system can cause infection, the host’s immune system must also be compromised (Staniszewska, 2020). The virulence factors of this fungus are adhesins, necessary for colonizing the host and multiplying. Additionally, calcineurin has also been reported to contribute to the cell membrane’s breakdown to promote the infection rate.
References
Mollentze, N., Streicker, D. G., Murcia, P. R., Hampson, K., & Biek, R. (2020). Virulence mismatches in index hosts shape the outcomes of cross-species transmission. Proceedings of the National Academy of Sciences, 117(46), 28859–28866. Web.
Prager, O., Friedman, A., & Nebenzahl, Y. M. (2017). Role of neural barriers in the pathogenesis and outcome of Streptococcus pneumoniae meningitis. Experimental and Therapeutic Medicine, 13(3). Web.
Staniszewska, M. (2020). Virulence factors in Candida species. Current Protein & Peptide Science, 21(3), 313–323. Web.