Two flagellotropic phages and one pilus-specific phage active against Asticcacaulis biprosthecum

Area of Science:

• Microbiology
• Virology
• Bacteriology

Background:

• Asticcacaulis biprosthecum is a bacterium with distinct polar appendages including flagella and pili.
• Bacteriophages (phages) are viruses that infect bacteria and can be specific to certain bacterial hosts.
• Understanding phage-host interactions is crucial for microbial ecology and biotechnology.

Purpose of the Study:

• To investigate the attachment mechanisms of three bacteriophages (phiAcS2, phiAcM2, phiAcM4) targeting Asticcacaulis biprosthecum.
• To identify the specific cell surface receptors involved in phage infection.
• To determine the role of flagella and pili in phage entry.

Main Methods:

• Microscopic observation of phage-host cell attachment.
• Experiments involving mechanical removal of flagella and pili.
• Studies using phage-resistant mutants and KCN-treated cells.

Main Results:

• All three phages attach to receptor sites at the pole of Asticcacaacaulis biprosthecum cells.
• Phage phiAcS2 and phiAcM4 attach to flagella (flagellotropic) and also to polar receptor sites.
• Phage phiAcM2 attaches to pili and polar receptor sites, but not flagella.
• Removal of flagella and pili confers protection against all three phages.
• Pili are essential for infection by both flagellotropic and pilus-specific phages.

Conclusions:

• Phage attachment to Asticcacaulis biprosthecum is mediated by polar receptor sites, flagella, and pili.
• Pili play a critical role in the infection process for all studied phages.
• The specific attachment strategy varies among phages, with some exhibiting flagellotropic behavior.