FIG. 3.

Population dynamics and biological warfare. (A) Relative proportions of two P. aeruginosa clones (G and L) during host colonization calculated previously by quantitative reverse transcription-PCR using genomic DNA extracts of tracheal aspirates (11). (B) Pyocin susceptibilities of the isolate of clone G obtained on day −1 (−1) and of the isolate of clone L obtained on day 7 (7). Four microliters of culture supernatant from nine colonizing isolates was spotted on top agar plates, and the results were determined after incubation for 18 h at 37°C.