THE INDUCTION OF QUINOLONE RESISTANCE IN CAMPYLOBACTER BACTERIA IN BROILERS BY QUINOLONE TREATMENT

Induction of quinolone resistance in campylobacters by a quinolone tre atment of Campylobacter-colonized broilers was studied. Six groups of 15 broiler chicks each were administered a quinolone-sensitive Campylo bacter 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 drinkin g water for 4 d. One group was treated with enrofloxacin during the fi rst 4 d of life. Quinolone treatment did not eradicate Campylobacter c olonization in the broilers. On days 29, 33 and 43 (at slaughter) of l ife, chicks in both enrofloxacin-treated groups harboured nalidixic ac id-, flumequine- and enrofloxacin resistant-campylobacters. Campylobac ter isolates from all other groups remained sensitive to these quinolo nes. Two Campylobacter-free control groups were not colonized by campy lobacters during the whole experiment.