Host Serum Amyloid A1 Facilitates <i>Streptococcus pneumoniae</i> Adaptation to Acidic Stress Induced by Pneumococcal Anaerobic Metabolism.

ABSTRACT: Streptococcus pneumoniae (S. pneumoniae) is a leading cause of pneumonia, and its interaction with host acute-phase proteins remains underexplored. Serum amyloid A1 (SAA1), an acute-phase protein, plays a crucial role in immune modulation. This study investigates the role of SAA1 in the early stages of respiratory infection by S. pneumoniae and its potential contribution to bacterial adaptation under acidic stress. We used a murine nasal infection model to simulate the early phase of S. pneumoniae invasion into the lower respiratory tract. Levels of SAA1 and C-reactive protein (CRP) in bronchoalveolar lavage fluid (BALF) and serum were quantified using ELISA. In vitro assays examined the effect of serum and recombinant SAA1 on bacterial survival under acidic con

SUBMITTER: Gong W 

PROVIDER: S-EPMC12195312 | biostudies-literature | 2025 Jun

REPOSITORIES: biostudies-literature