ARISA fingerprint analyses of trials 1 and 2 combined. The Dice similarity index was used to estimate differences between fingerprints from 3-week-old poults. Treatments include the following: d1, poults killed at day 1 posthatch; UC, uninoculated controls; IC, controls inoculated with Campylobacter-free adult intestinal contents; ENR, inoculated and enrofloxacin-treated poults; VIR, inoculated and virginiamycin-treated poults; NEO, inoculated and neomycin-treated poults; and VNC, inoculated and vancomycin-treated poults. “Adult” indicates the Campylobacter-free adult intestinal inoculum. “Negative” indicates a no-template ARISA reaction. Principal component analysis was prepared from Dice similarity indices via the Paleontological Statistics software package. Microbiota from all 28 poults and the adult turkey inoculum are represented. ✳, adult; ○, day 1 posthatch; □, uninoculated control; +, inoculated control; ▴, virginiamycin derived; ▪, enrofloxacin derived; ♦, neomycin derived; and •, vancomycin derived. Alternate views of this graph are available in the Fig. S1 in the supplemental material.