Bacterial neuraminidase facilitates mucosal infection by participating in biofilm production

Area of Science:

• Microbiology
• Pathogenesis
• Bacterial Virulence

Background:

• Respiratory pathogens like Pseudomonas aeruginosa possess neuraminidases that cleave sialic acids on mucosal surfaces.
• Neuraminidases are hypothesized to expose bacterial receptors, but their role in bacterial pathogenesis is unclear.
• Influenza virus neuraminidase is well-studied, contrasting with the limited understanding of bacterial counterparts.

Purpose of the Study:

• To investigate the role of Pseudomonas aeruginosa neuraminidase in bacterial pathogenesis and virulence.
• To determine the impact of neuraminidase on respiratory tract colonization and biofilm formation.

Main Methods:

• Construction of a Pseudomonas aeruginosa PAO1 mutant lacking the PA2794 neuraminidase locus (Delta2794).
• Assessment of mutant virulence via intraperitoneal (i.p.) and intranasal (i.n.) inoculation in a mouse model.
• Evaluation of biofilm production using scanning electron microscopy and in vitro assays.
• Testing the effect of viral neuraminidase inhibitors on bacterial biofilm formation.

Main Results:

• The Delta2794 mutant retained virulence after i.p. inoculation but failed to establish respiratory infection following i.n. inoculation.
• Respiratory colonization deficiency correlated with significantly diminished biofilm production in the mutant.
• Clinical viral neuraminidase inhibitors effectively blocked Pseudomonas aeruginosa biofilm formation in vitro.

Conclusions:

• Pseudomonas aeruginosa neuraminidase plays a critical role in the early stages of pulmonary infection.
• The enzyme is essential for targeting bacterial glycoconjugates and facilitating biofilm formation.
• Targeting bacterial neuraminidases presents a potential novel strategy for preventing bacterial pneumonia.