In vitro and in vivo antibacterial activities of mt 141 sodium 7 beta d 2 amino 2 carboxylethylthioacetamido 7 alpha 1 methoxy 3 1 methyl 1h tetrazol 5 yl thiomethylceph 3 em 4 carboxylate a new semisynthetic cephamycin compared with those of 5 cephalosporins
Et Al
Antimicrobial Agents and Chemotherapy 26(5): 722-729
1984
ISSN/ISBN: 0066-4804 Accession: 005645928
The in vitro and in vivo antibacterial activities of MT-141 were compared with those of cefoxitin, cefmetazole, moxalactam, cefotaxime and cefoperazone. The MIC [minimal inhibitory concentration] of MT-141 for 90% of bacterial isolates were lower than the reference drugs against clinical isolates of Campylobacter jejuni, Clostridium difficile and Bacteroides fragilis, whereas against clinical isolates of other gram-positive, gram-negative and anaerobic bacteria, the MIC of MT-141 were similar to or higher than those of the reference drugs. The bactericidal activity of MT-141 after 6- and 24-h exposures was superior to all of the reference drugs against 9 to 10 of the 12 bacterial strains studied, including Escherichia coli, Klebsiella pneumoniae, Salmonella enteritidis, indol-positive Proteus species, Serratia marcescens, Yersinia enterocolitica, Pseudomonas cepacia, and C. perfringens. In the treatment of systemic infections in mice, MT-141 was again superior against 9 of the 12 strains tested, showing a good correlation with the bactericidal activity. The 50% effective doses of the 6 cephalosporins studied correlated better with the MBC [minimal bactercidal concentrations] than with the MIC. As the serum levels of MT-141 in mice after s.c. administration were similar to those of the reference drugs, the bactericidal activity of MT-141 was evidently a dominant factor in its in vivo activity.