Haemophilus parainfluenzae Strain ATCC 33392 Forms Biofilms and during Experimental Otitis Media Infections.

is a nutritionally fastidious, Gram-negative bacterium with an oropharyngeal/nasopharyngeal carriage niche that is associated with a range of opportunistic infections, including infectious endocarditis and otitis media (OM). These infections are often chronic/recurrent in nature and typically involve bacterial persistence within biofilm communities that are highly resistant to host clearance. This study addresses the primary hypothesis that forms biofilm communities that are important determinants of persistence The results from biofilm studies confirmed that formed biofilm communities within which the polymeric matrix was mainly composed of extracellular DNA and proteins. Using a chinchilla OM infection model, we demonstrated that formed surface-associated biofilm communities containing bacterial and host components that included neutrophil extracellular trap (NET) structures and that the bacteria mainly persisted in these biofilm communities. We also used this model to examine the possible interaction between and its close relative , which is also commonly carried within the same host environments and can cause OM. The results showed that coinfection with promoted clearance of from biofilm communities during OM infection. The underlying mechanisms for bacterial persistence and biofilm formation by and knowledge about the survival defects of during coinfection with are topics for future work.