Mycoplasma arthritidis bacteriophage MAV1 prophage integration, deletions, and strain-related polymorphisms

Area of Science:

• Microbiology
• Virology
• Genetics

Background:

• Mycoplasma arthritidis is a bacterium that can cause severe infections.
• The temperate bacteriophage MAV1 is found in some virulent M. arthritidis strains.
• Understanding phage-host interactions is crucial for studying bacterial virulence.

Purpose of the Study:

• To characterize the integration sites of the MAV1 bacteriophage in M. arthritidis.
• To investigate potential correlations between MAV1 prophage characteristics and M. arthritidis strain phylogeny.
• To identify genetic variations within MAV1 prophages in different strains.

Main Methods:

• DNA sequencing of prophage ends and flanking regions from eight MAV1 prophages in seven M. arthritidis strains.
• Analysis of att sites and prophage integration site sequences.
• Comparison of MAV1 prophage sequences for structural variations and deletions.

Main Results:

• MAV1 att sites largely matched the consensus sequence TATTTTT, with minor polymorphisms observed.
• Identical integration sites were found in strains with multiple prophage copies, suggesting common ancestry.
• Four MAV1 copies exhibited significant substitutions in genes for structural and repressor proteins, with two also showing a 3-kb deletion.
• Unique integration sites were identified in strains with single prophage copies.

Conclusions:

• MAV1 integration site polymorphisms can be used to trace phylogenetic relationships among virulent M. arthritidis strains.
• Variations within the MAV1 prophage genome, including gene substitutions and deletions, provide further markers for strain differentiation.
• This study highlights the utility of bacteriophage genetics in understanding bacterial evolution and virulence.