Figure 1.

Pairwise competitions between FQ^S and FQ^R strains in chickens using isogenic pairs of 62301R33S/62301R33R (A,B) and 11168(S)/11168(R) (C). (A) The colonization level of total Campylobacter in three groups of chickens that were inoculated with 62301R33S (solid circle), 62301R33R (open circle), or 1:1 mixture of the two stains. (B) Differential enumeration of FQ^S (solid circle) and FQ^R (open circle) Campylobacter in the group inoculated with a mixture of 62301R33S and 62301R33R. (C) A second chicken experiment shows the competition between FQ^S (solid triangle) and FQ^R (open triangle) Campylobacter in a different strain background. The chickens were inoculated with a 1:1 mixture of 11168(S) and 11168(R). In all panels, each symbol represents the colonization level of a single chicken and the median level of each group is indicated by a horizontal bar. The detection limit of the plating method was about 100 CFU/g of feces and a negative sample was arbitrarily assigned a value of zero. DAI, days after inoculation.