Susceptibility of non-fermentative gram-negative organisms to ureidopenicillins and quinolones

The susceptibility of non-fermentative Gram-negative bacteria (excluding Pseudomonas aeruginosa) to ureidopenicillins and new quinolones was investigated. The ureidopenicillins were not active against the strains except against Pseudomonas species, 90% of which were inhibited by 64 mg/l. The new quinolones, particularly ciprofloxacin, had excellent activity (MIC range 0.06-8 mg/l) against these strains which included those resistant to beta-lactams and aminoglycosides. This suggested a promising alternative group of compounds to be used in chemotherapy of infections caused by non-fermenters.