Intra-species tranduction with Proteus mirabilis high frequency transducing phages

Area of Science:

• Microbiology
• Bacteriology
• Virology

Background:

• Proteus mirabilis is a Gram-negative bacterium.
• High frequency transducing (HFT) phages are specialized bacteriophages capable of efficient gene transfer.
• Understanding phage-host interactions is crucial for molecular biology and genetic engineering.

Purpose of the Study:

• To describe the properties of novel Proteus mirabilis hosts for HFT phages 5006MHFTkappa and 5006MHFTak.
• To investigate the mechanisms of host-controlled modification and restriction in P. mirabilis.
• To elucidate the role of these systems in phage transduction and host range.

Main Methods:

• Bacterial strain characterization and phage adsorption assays.
• Transduction experiments to assess gene transfer efficiency.
• Lysogenic conversion and segregation analysis.
• Ultraviolet induction of phages and analysis of transductant properties.

Main Results:

• Two new P. mirabilis hosts, PM804 and strain N, exhibited distinct phage adsorption, modification, and restriction capabilities.
• PM804 demonstrated a host-controlled modification system and a restriction system influencing HFT phage transduction.
• Strain N and its restrictionless mutant NHI showed avid phage adsorption and limited modification, with varying transduction frequencies.
• Transductants exhibited heterogenote features, with non-lysogenic transductants adsorbing homologous phage.

Conclusions:

• The HFT phages studied are likely defective for lysogenic conversion, leading to homologous phage non-adsorption.
• Host-controlled modification and restriction systems in P. mirabilis play significant roles in regulating phage-host interactions.
• Further research is needed to characterize the specific restriction enzymes involved.