Antibacterial properties of carumonam (Ro 17-2301, AMA-1080), a new sulfonated monocyclic beta-lactam antibiotic.

The in vitro and in vivo activity of carumonam was tested in comparison with that of aztreonam and other beta-lactam antibiotics. With the exception of a few isolates that were overproducers of cephalosporinase, Enterobacteriaceae were highly susceptible to carumonam, 90% of the isolates being inhibited at 0.5 micrograms/ml. Aztreonam, ceftriaxone and ceftazidime were overall slightly less active than carumonam against Enterobacteriaceae. Carumonam was intermediate between ceftazidime and aztreonam as to the activity against Pseudomonas aeruginosa. Staphylococci were resistant to the monocyclic beta-lactams. In accordance with the in vitro data, carumonam was effective against experimental septicemias and infections of the thigh and the kidney that were caused by gram-negative pathogens.