Comparative in vitro study of SQ26,776

A new monocyclic β-lactam antibiotic, SQ26,776, was evaluated in vitro against clinical isolates, and its activity was compared with that of other cephalosporins, penicillins, and aminoglycosides. This compound was very active against the majority of the aerobic gram-negative bacilli tested, including 47 multiresistant strains. It had no activity against the gram-positive cocci. It also showed activity comparable to that of moxalactam, ceftazidime, ceftriaxone, thienamycin, and tobramycin. It was superior to mezlocillin. The in vitro activity suggests that SQ26,776 should prove useful in settings in which the most likely pathogens are gram-negative bacilli.