[Antibacterial activity of N-formimidoyl-thienamycin in comparison with other beta-lactam antibiotics against clinical problem strains (author's transl)].

The efficacy of N-formimidoyl-thienamycin (MK 0787) has been tested against 549 cultures of different species, which often cause therapeutic problems. Included were 286 mezlocillin-resistant strains, 100 Serratia marcescens and 66 Pseudomonas aeruginosa. The minimal inhibitory concentration ranged between 0.06 and 4 micrograms/ml by means of the agar-dilution-method. Resistant strains were not observed. Among the 11 beta-lactam- and aminoglycoside-antibiotics tested N-formimidoyl-thienamycin was the most effective with the broadest spectrum.