Sustainability of spatially distributed bacteria-phage systems

Area of Science:

• Microbiology
• Theoretical Ecology
• Mathematical Biology

Background:

• Virulent phages can cause severe bacterial epidemics, theoretically leading to host extinction.
• Experimental observations show significant bacterial population reductions but not complete elimination.
• The role of spatial organization in bacterial survival during phage outbreaks remains under-explored.

Purpose of the Study:

• To investigate how spatial organization influences bacterial survival during phage epidemics.
• To model the transient dynamics of bacteria and phages in a resource-limited environment.
• To identify factors contributing to bacterial persistence despite phage predation.

Main Methods:

• Development of a mathematical model simulating bacterial and phage population dynamics.
• Inclusion of parameters such as finite resources, time-delayed lysis, and initial bacterial spatial distribution.
• Analysis of bacterial survival based on colony structure and spatial separation.

Main Results:

• Time-delayed lysis, spatial separation of initial bacterial positions, and self-protection in spherical colonies favor bacterial survival.
• Finite resources and spatial structures on the millimeter and submillimeter scale significantly enhance bacterial persistence.
• Complete extinction of bacterial hosts by virulent phages was not observed in the model.

Conclusions:

• Spatial organization is a critical factor in bacterial resilience against phage predation.
• Microbial communities can maintain diversity through spatial structures that buffer against epidemic collapse.
• The findings highlight the ecological importance of physical structure in microbial population dynamics.