Recombination-deficient mutant of Streptococcus faecalis

Area of Science:

• Microbiology
• Molecular Biology
• Genetics

Background:

• Streptococcus faecalis is a common bacterium with clinical relevance.
• DNA repair mechanisms are crucial for bacterial survival against environmental mutagens.
• The recA gene in Escherichia coli plays a vital role in DNA repair and recombination.

Purpose of the Study:

• To isolate and characterize a novel ultraviolet (UV) radiation-sensitive mutant of Streptococcus faecalis.
• To investigate the recombination proficiency of the isolated mutant.
• To determine the susceptibility of the mutant to DNA-damaging agents and UV irradiation.

Main Methods:

• Isolation of a UV-sensitive derivative of Streptococcus faecalis strain JH2-2.
• Assessment of recombination using a plasmid-plasmid recombination system.
• Evaluation of sensitivity to chemical agents that interact with deoxyribonucleic acid (DNA).
• Analysis of DNA degradation following UV irradiation.

Main Results:

• A UV-sensitive mutant of Streptococcus faecalis JH2-2 was successfully isolated.
• The mutant exhibited deficiency in plasmid-plasmid recombination.
• The strain showed increased sensitivity to DNA-interacting chemical agents.
• UV irradiation induced significant DNA degradation in the mutant strain.

Conclusions:

• The isolated Streptococcus faecalis mutant possesses characteristics analogous to recA strains of Escherichia coli.
• This mutant represents a valuable tool for studying DNA repair and recombination pathways in Gram-positive bacteria.
• The findings contribute to understanding bacterial responses to DNA damage and mutagenic agents.