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Adherence of Neisseria meningitidis to human epithelial cells
Abstract:
Carrier strains of Neisseria meningitidis are recovered almost solely from the posterior pharynx and they are often nongroupable or rough. Invasive strains can be serogrouped (encapsulated). We studied adherence of both carrier- and patient-derived serogroupable and nongroupable meningococci to buccal epithelial and posterior pharyngeal cells. Fresh meningococcal isolates attached significantly better to pharyngeal than to buccal cells (P = 0.01). Strains that could be serogrouped adhered less than nongroupable strains (P less than 0.05). Meningococci passed in vitro became hemagglutinin negative and nonpiliated. Hemagglutinin-negative meningococci always adhered less to both epithelial cell types than the hemagglutinin-positive variants of the same strain. These results indicate that meningococcal pili probably mediate attachment to oropharyngeal cells, but encapsulation may reduce adherence. Localization of meningococci in the posterior pharynx is in part explained by the receptivity of the epithelial cells in this area for meningococci.
Insights
Neisseria meningitidis pili likely help bacteria stick to throat cells, while encapsulation may hinder it. This explains why meningococci are found in the posterior pharynx.
Area of Science:
- Microbiology
- Infectious Diseases
- Bacterial Pathogenesis
Background:
- Carrier strains of Neisseria meningitidis inhabit the posterior pharynx and are often nongroupable.
- Invasive strains are typically encapsulated and serogroupable.
Purpose of the Study:
- To investigate the adherence of carrier and patient-derived Neisseria meningitidis strains to epithelial cells.
- To determine the role of pili and encapsulation in meningococcal adherence to oropharyngeal cells.
Main Methods:
- Studied adherence of serogroupable and nongroupable meningococci (carrier and patient-derived) to buccal and posterior pharyngeal epithelial cells.
- Assessed the impact of in vitro passage on meningococcal piliation and hemagglutination.
- Compared adherence of hemagglutinin-positive and negative variants.
Main Results:
- Meningococci adhered significantly better to pharyngeal cells than buccal cells.
- Nongroupable strains showed higher adherence than serogroupable strains.
- Hemagglutinin-negative and nonpiliated meningococci exhibited reduced adherence.
Conclusions:
- Meningococcal pili likely mediate attachment to oropharyngeal epithelial cells.
- Encapsulation may reduce bacterial adherence.
- The receptivity of posterior pharyngeal cells contributes to meningococcal localization in this area.