Table 2.

Scenarios of antibacterial action based on the size of involved populations, presented as a 2 × 2 matrix. Numbers refer solely to the order of discussion in the main text. Parentheticals refer to the state of target organisms vis-à-vis biofilm status; see Table 1 for review. “Producing” refers to antibacterial production, e.g., such as the production of antibiotics, whereas a “Target” is an antibacterial-sensitive bacterium. Not indicated is Scenario 5, which instead involves antibiotic impact on target bacteria only “After” the biofilm they are associated with has by some alternative mechanism been disrupted. Abbreviations refer to “Defensive” (δ) or “Offensive” (ω) as well as “Before” (B) or “During” (D), i.e., as employed in Table 1.

	One Target Cell	Many Target Cells
One Producing Cell	Not involving biofilm: Scenario 3 (“Before”, δB or ωB)	Effecting biofilm invasion: Scenario 1 (“During”, ωD, but also δD)
Many Producing Cells	Effecting biofilm protection: Scenario 2 (“Before”, δB, but also ωB)	Within-biofilm competition: Scenario 4 (“During”, δD or ωD)