FIG 4.

A chronically infected strain is antagonistic to an immune strain. Relative abundances in competitions between a CRISPR-immune strain (RJW003, black) and an uninfected strain (Δcas6 strain, gold) (A) or between a CRISPR-immune strain and a chronically infected strain (Δcas6:SSV9.1, blue) (B). Uninfected or chronically infected strains were added to the mid-log phase of an immune culture and monitored by qPCR for 4 days without dilutions with fresh medium. In a representative experiment of three biological replicates, error bars show mean results ± SEM (3 technical replicates). Virus abundance was measured by qPCR (dashed line).