INCREASED RESISTANCE TO QUINOLONES IN CAMPYLOBACTER-JEJUNI - A GENETIC-ANALYSIS OF GYRA GENE-MUTATIONS IN QUINOLONE-RESISTANT CLINICAL ISOLATES

Campylobacter jejuni is a frequent cause of enteritis and sometimes it requires antimicrobial therapy. We have studied the evolution of resi stance to nine antibiotics from 1990 to 1994 and investigated how freq uently gyrA mutations are involved in the acquisition of quinolone res istance. The percentage of chloramphenicol-, clindamycin-, tertracycli ne- and amoxicillin plus clavulanic acid-resistant strains has remaine d practically unchanged and erythromycin and gentamicin resistance has decreased, whereas the percentage of ampicillin-, nalidixic acid-or c iprofloxacin-resistant strains has almost doubled in the followup peri od, from 56 to 76% for ampicillin-and from 47.5 to 88% for quinolone-r esistant strains. This study clearly shows that a mutation in Thr-86 t o Be or Lys is a frequent mechanism associated with the acquisition of a high level of resistance to quinolones in clinical isolates of C. j ejuni.