Partial characterization of Pseudomonas phage 2 receptor

Area of Science:

• Microbiology
• Virology
• Biochemistry

Background:

• Pseudomonas aeruginosa is an opportunistic pathogen.
• Bacteriophages are viruses that infect bacteria and are potential therapeutic agents.
• Bacterial lipopolysaccharides (LPS) are crucial surface molecules involved in host-pathogen interactions and can act as phage receptors.

Purpose of the Study:

• To investigate the interaction between Pseudomonas aeruginosa LPS and phage 2.
• To identify the specific saccharide components of LPS responsible for phage binding and inactivation.

Main Methods:

• In vitro inactivation assays were performed using purified LPS from Pseudomonas aeruginosa strain BI and phage 2.
• The inhibitory effects of various mono- and di-saccharides on phage inactivation were quantified at different molar concentrations.

Main Results:

• The LPS strongly inactivated phage 2 in vitro (95-98% within 15 min).
• Several saccharides significantly reduced phage inactivation, with D-glucosamine (0.25 M) and maltose (0.3 M) being particularly effective.
• Other tested sugars like D-glucose, L-rhamnose, and D-galactose also showed inhibitory effects at higher concentrations (1.0 M to 1.6 M).

Conclusions:

• The results suggest that L-rhamnose, D-glucosamine, and/or D-glucose, or structurally related molecules, are likely components of the phage 2 receptor within the Pseudomonas aeruginosa LPS.
• These identified saccharides may be located either terminally or internally within the polysaccharide chain, mediating phage binding and subsequent inactivation.