Abstract:[Background] The process of pathogen invasion into host cells is regulated by various factors, among which extracellular matrix stiffness is a key factor that modulates host cell functions. However, the influence of extracellular matrix stiffness on the growth of pathogens after they invade host cells remains unclear. [Objective] To investigate how extracellular matrix stiffness affects colony growth, population structure, and antibiotic sensitivity of bacteria. [Methods] Polyacrylamide gels were used to mimic varying degrees of extracellular matrix stiffness, and bacterial colony formation on substrates of different stiffness was observed and analyzed. Microscopy was used for observation of bacterial colonies, and image processing software was employed for further analysis. [Results] Bacterial colonies grew larger in the case of higher extracellular matrix stiffness. After the application of antibiotics, the density at the edges of bacterial colonies was more likely to decrease on polyacrylamide gels with lower extracellular matrix stiffness, whereas it was less likely to decrease on tissue-like hydrogels with higher extracellular matrix stiffness. [Conclusion] An increase in extracellular matrix stiffness promotes bacterial adhesion and colony formation, which alters antibiotic penetration and bacterial survival. Understanding the role of matrix stiffness in the growth and antibiotic resistance of bacteria is crucial for developing new antimicrobial treatment strategies.
