Radiometric susceptibility testing of Mycobacterium xenopi

Mycobacterium xenopi is an opportunistic pathogen, frequently isolated in various areas of Europe from pulmonary specimens, which may also cause infections in AIDS patients. We used the Bactec radiometric system (Becton Dickinson, USA) with a procedure expressly adapted to the particular growth characteristics of M. xenopi to determine the susceptibility patterns of 40 clinical isolates to six antimicrobial drugs. The majority of the strains were resistant to ethambutol and susceptible to amikacin, ciprofloxacin, rifampin, rifabutin and streptomycin.