FIG. 3.
Development of protective acquired immunity in septic guinea pigs. Animals were grouped based on their pretreatment bacteremia levels as follows: up to 104 (blue), 104 to 105 (green), 105 to 106 (orange), 106 to 107 (red), and above 107 (black) CFU/ml. The treatment regime was doxycycline (A), ciprofloxacin (B), or ciprofloxacin and anti-PA antibodies (C) for 21 days. After cessation of antibiotic administration, the animals were monitored for 30 days, rechallenged s.c. with Vollum spores, and observed for an additional 14 days.