Bacteriophage resistance in Bacillus subtilis 168, W23, and interstrain transformants

Area of Science:

• Microbiology
• Molecular Biology
• Bacteriology

Background:

• Teichoic acids are essential cell wall components in Gram-positive bacteria like Bacillus subtilis.
• Glucosylated teichoic acid has been implicated as a primary attachment site for bacteriophages.
• Variations in cell wall composition can influence bacterial susceptibility to phage infection.

Purpose of the Study:

• To investigate the role of glucosylated teichoic acid in Bacillus subtilis resistance to bacteriophage infection.
• To identify alternative receptor sites for bacteriophage attachment.
• To understand how different teichoic acid types affect bacteriophage susceptibility.

Main Methods:

• Generating and characterizing Bacillus subtilis 168 mutants deficient in glucosylated teichoic acid (gtaA, gtaB, gtaC).
• Assessing the resistance patterns of these mutants against three specific bacteriophages (phi25, phie, SP82).
• Comparing bacteriophage susceptibility between Bacillus subtilis strains 168 and W23, which possess different teichoic acids.
• Transferring bacteriophage resistance from strain W23 to a strain 168 derivative.

Main Results:

• Mutants lacking glucosylated teichoic acid exhibited varied resistance profiles, indicating the presence of alternate bacteriophage receptor sites.
• The specific type of teichoic acid, in addition to glucosylation, was found to be crucial for bacteriophage attachment.
• Bacillus subtilis strains 168 and W23 displayed differential susceptibility to bacteriophage infection due to distinct teichoic acid compositions.
• Transferred resistance in modified strain 168 correlated with impaired bacteriophage adsorption and reduced transfection efficiency.

Conclusions:

• Glucosylated teichoic acid is not the sole determinant of bacteriophage attachment in Bacillus subtilis.
• Bacterial cell wall teichoic acid type plays a significant role in determining susceptibility to bacteriophage infection.
• Understanding these interactions can lead to strategies for controlling bacteriophage activity in bacterial populations.