Urinary Bladder Matrix Protects Host in a Murine Model of Bacterial-Induced Lung Infection

The extracellular matrix (ECM) is composed of a complex mixture of structural and functional macromolecules that are important during growth, development, and wound repair. In this study, we seek to determine if an ECM derived from the porcine urinary bladder, specifically urinary bladder matrix (UBM), can act to prevent bacterial infection in the context of lung injury. In this study, we examined a digested form of UBM, which prevented bacterial biofilm formed by both Gram-positive bacteria (GPB) such as methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA) and Gram-negative bacteria (GNB), including Pseudomonas aeruginosa (PA) and Klebsiella pneumoniae (KP) in vitro. Furthermore, exogenously administered UBM digest exhibited host protection from MSSA-, MRSA-, and PA-induced respiratory infection in a murine infection model. The protection against both GPB- and GNB-induced infection demonstrated by UBM suggests the antibacterial function is likely through biofilm prevention. In addition, two potential off the shelf UBM product forms (preformulated digested UBM and intact UBM particulate) showed significant protection from acute severe respiratory infection. Taken together, our results support further study of the use of UBM as an alternative treatment to attenuate bacterial-induced infection.