loading page

No man’s land: Species-specific formation of “exclusion zones” bordering Actinomomyces graevenitzii microcolonies in nanoliter cultures
  • +4
  • Fatemeh Jalali,
  • Felix Ellett,
  • Pooja Balani,
  • Margaret Duncan,
  • Floyd Dewhirst,
  • Gary Borisy,
  • Daniel Irimia
Fatemeh Jalali
Massachusetts General Hospital
Author Profile
Felix Ellett
Massachusetts General Hospital
Author Profile
Pooja Balani
The Forsyth Institute
Author Profile
Margaret Duncan
The Forsyth Institute
Author Profile
Floyd Dewhirst
The Forsyth Institute
Author Profile
Gary Borisy
The Forsyth Institute
Author Profile
Daniel Irimia
Massachusetts General Hospital
Author Profile

Peer review status:IN REVISION

11 Jun 2020Submitted to MicrobiologyOpen
12 Jun 2020Assigned to Editor
12 Jun 2020Submission Checks Completed
16 Jun 2020Reviewer(s) Assigned
10 Jul 2020Review(s) Completed, Editorial Evaluation Pending
11 Jul 2020Editorial Decision: Revise Minor

Abstract

To survive within complex environmental niches, including the human host, bacteria have evolved intricate inter-species communities driven by competition for limited nutrients, cooperation via complementary metabolic proficiencies, and establishment of homeostatic relationships with the host immune system. Such complex, interdependent relationships have hampered attempts to culture many bacterial strains in research settings, where standard readout of co-culture experiments are usually limited to the relative abundance of each species. Here, we utilize a microfluidic-based co-culture system to characterize dynamic interactions between multiple oral bacterial isolates. Using time-lapse imaging, we define species-specific effects on spatial community relationships during co-culture of Streptococcus species and Staphylococcus aureus with Actinomyces species. Co-culture of Streptococcus cristatus or S. salivarius in nanoliter compartments with Actinomyces graevenitzii revealed localized exclusion of Streptococcus and Staphylococcus from media immediately surrounding A. graevenitzii micro colonies. This community structure did not occur with S. mitis or S. oralis strains, or in co-cultures containing other Actinomycetaceae species such as S. odontolyticus or A. naeslundii. Moreover, fewer neutrophils were attracted to compartments containing both A. graevenitzii and Staphylococcus aureus than to equal number of either species alone, suggesting a possible survival benefit from the interaction.