Frenemy: adaptive temperate phage_SAP_1432 supports Staphylococcus aureus survival in changing temperatures

Area of Science:

• Microbiology
• Evolutionary Biology
• Climate Science

Background:

• Pathogen-host interactions are critical for predicting microbial ecosystem responses to climate change.
• Understanding how microbial hosts adapt to rising temperatures is essential.

Purpose of the Study:

• To investigate the influence of a heat-resistant temperate phage (phage_SAP_1432) on the thermal performance and survival of its bacterial host (Staphylococcus aureus Q1432).
• To explore the potential adaptive advantages conferred by phages to their hosts in changing thermal environments.

Main Methods:

• Experimental co-culture of Staphylococcus aureus Q1432 with phage_SAP_1432 at various temperatures.
• Analysis of bacterial growth rates, optimal growth temperatures, and survival at extreme temperatures.
• Assessment of lysogenesis at different temperatures and phage concentrations.

Main Results:

• Phage_SAP_1432 enhanced the maximal growth rate of S. aureus Q1432 by 41.2% and shifted the optimal growth temperature from 41.0°C to 44.1°C at a low multiplicity of infection (MOI).
• Bacterial survival at high temperatures increased significantly, with some bacteria surviving up to 80°C in the presence of the phage, compared to 51°C without the phage.
• Lysogenesis was more frequent at lower temperatures, and increased phage concentration led to decreased host growth rate.

Conclusions:

• Heat-resistant temperate phages can provide significant survival and performance benefits to their bacterial hosts at specific temperatures.
• These phage-host interactions represent a novel mechanism for microbial adaptation to global climate change.
• Phages may act as crucial allies for bacterial survival and evolution in warming environments.