N-formimidoyl thienamycin: in vitro comparison with cefoxitin and tobramycin against clinical, bacterial isolates.
The in vitro activity of the novel beta-lactam antibiotic, N-formimidoyl thienamycin (N-f thienamycin) has been compared with those of cefoxitin and tobramycin. An agar dilution method was employed. N-f thienamycin was active against all Enterobacteriaceae isolates (MIC less than or equal to 4 mg/l). All Pseudomonas aeruginosa isolates were inhibited by 2 mg/l. N-f thienamycin was also active against Acinetobacter calcoaceticus (96 per cent inhibited by 0.5 mg/l) and Gram-positive cocci. All enterococci were inhibited by 2 mg/l. The drug was active against Haemophilus influenzae (MIC less than or equal to 1 mg/l) and the Bacteroides fragilis group (MIC less than or equal to 0.5 mg/l). Cefoxitin was inactive against most Enterobacter and A. calcoaceticus isolates and all P. aeruginosa and enterococcal isolates. Tobramycin was virtually inactive against Gram-positive cocci other than Staphylococcus aureus. N-f thienamycin thus has a broad spectrum of in vitro activity, greater than that of cefoxitin and tobramycin, and may therefore be useful in the treatment of serious infection, particularly when the aetiology is unknown.
D000150:Acinetobacter / Q000187:drug effects; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D001441:Bacteroides fragilis / Q000187:drug effects; D002440:Cefoxitin / Q000494:pharmacology*; D004755:Enterobacteriaceae / Q000187:drug effects; D006193:Haemophilus influenzae / Q000187:drug effects; D015378:Imipenem; D008826:Microbial Sensitivity Tests; D013211:Staphylococcus aureus / Q000187:drug effects; D013291:Streptococcus / Q000187:drug effects; D013845:Thienamycins / Q000494:pharmacology*; D014031:Tobramycin / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D013845:Thienamycins; D002440:Cefoxitin; D015378:Imipenem; D014031:Tobramycin