In vitro antimicrobial activity and clinical investigation of T-1982

In vitro antimicrobial activity of T-1982, a new cephamycin, was examined by a broth dilution method with Dynatech MIC 2000 system. Also, therapeutic efficacy of T-1982 in the treatment of patients with respiratory and urinary tract infections was evaluated. The minimum inhibitory concentrations (MICs) of T-1982 were compared with those of cefazolin (CEZ), cefotiam (CTM), cefoxitin (CFX) and cefmetazole (CMZ) against following 20 strains each of clinical isolates; Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae Serratia marcescens, Pseudomonas aeruginosa. It was revealed that T-1982 was more highly active against gram-negative rods, such as Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae and Serratia marcescens except Pseudomonas aeruginosa and more weakly active against Staphylococcus aureus than cefazolin, cefotiam, cefoxitin and cefmetazole. Especially, reductions in the MICs of T-1982 were marked for β-lactamase producing strains of Escherichia coli, Enterobacter cloacae and Serratia marcescens A daily dose of 2 grams of T-1982 was given by an intravenous drip infusion to a total of 4 patients with respiratory tract infections, such as 2 patients with acute pneumonia, 1 patient with infection associated with bronchiectasis and 1 patient with infection associated with lung cancer, and 1 gram of the drug to 1 patient with acute pyelonephritis. Clinical response to the treatment with T-1982 was excellent in 2 patients and good in 3 patients. Each 2 strains of Haemophilus influenzae and Escherichia coli were recovered from the specimen of these patients at the start of the treatment with T-1982. All of them were eradicated during the treatment with the drug. In 1 patient of these 5 patients, transient elevation of slight degree of serum transaminase was observed but returned to normal after cessation of the drug. From the above results, it was concluded that T-1982 is one of the most effective and useful antibiotics against gram-negative bacterial infections in compromised hosts.