The induction of quinolone resistance in Campylobacter bacteria in broilers by quinolone treatment

Abstract

Induction of quinolone resistance in campylobacters by a quinolone treatment of Campylobacter-colonized broilers was studied. Six groups of 15 broiler chicks each were administered a quinolone-sensitive Campylobacter jejuni strain at 19 d of age. At the age of 26 d, two dosages (15 or 50 ppm) of flumequine or enrofloxacin were given via the drinking water for 4 d. One group was treated with enrofloxa-cin during the first 4 d of life. Quinolone treatment did not eradicate Campylobacter colonization in the broilers. On days 29, 33 and 43 (at slaughter) of life, chicks in both enrofloxacin-treated groups harboured nalidixic acid-, flumequine- and enrofloxacin resistant-campylobacters. Campylobacter isolates from all other groups remained sensitive to these quinolones. Two Campylobacter-free control groups were not colonized by campylobacters during the whole experiment.