Figure 2

Experimental timeline. At day 14, a total of 24 birds were divided in two groups and kept in two different rooms. All birds prior to the experimental challenge were confirmed Campylobacter-negative via qualitative bacteriological examination of cloacal swabs. At the same day of life, day 17, each of the 12 birds kept in room 2 was experimentally challenged with C. jejuni, while all birds in room 1 received 1 ml of an isotonic 0.9% sodium chloride solution. Three days later, the success of the experimental infection was checked via qualitative detection of C. jejuni in cloacal swabs of all experimentally infected birds, so that at day 21, the experimental phase started and lasted for 21 days. Within these 21 days, a cloacal swab was obtained from each chicken every three days for qualitative detection of C. jejuni. Additionally, a quantitative bacteriological examination of C. jejuni was performed in excreta samples of the two birds in room 2 that subsequently changed rooms. The experiment ended at day 41 of life. Birds were dissected one day later to obtain caecal contents for qualitative detection of C. jejuni. The figure was created with http://biorender.com.