In vitro susceptibility of Campylobacter jejuni and Campylobacter coli isolated in Denmark to fourteen antimicrobial agents.

The in vitro susceptibility of 95 recent Danish human clinical isolates of Campylobacter jejuni and Campylobacter coli to 14 antimicrobial agents was determined by an agar dilution technique. C. jejuni and C. coli were considered together. Doxycycline, ciprofloxacin, gentamicin, clindamycin, nitrofurantoin and erythromycin were the most active drugs. 2% of the strains tested were resistant to erythromycin (MIC greater than 3.1 micrograms/ml). Therefore susceptibility testing is suggested if antimicrobial therapy with erythromycin is considered to be indicated. Ciprofloxacin might prove to be an alternative to erythromycin. Susceptibility testing in a CO2 atmosphere affected the determination of MICs of doxycycline, erythromycin, gentamicin and clindamycin, probably reflecting pH-changes in the media during incubation under increased CO2 tension.