Cefotetan: in-vitro antibacterial activity and susceptibility to -lactamases

Abstract

The in-vitro antibacterial activity of cefotetan was assessed against recent clinical isolates of common bacteria and also against reference strains that produced known β -lactamases. The compound was active against most staphylococci (MICs 4 to 8 mg/l) though methicillin-resistant strains were less sensitive. It was also generally active against streptococci (MICs mostly in the range 1 to 16 mg/l). HoweveT, enterococci and penicillin-resistant pneumococd were resistant. Cefotetan was highly active against enterobacteria, with 75% of isolates inhibited by 0-5 mg/l and 90% inhibited by 4 mg/l. It was also highly active against Haemophilus influemae (MICs 0- 5 to 4 mg/l) and Neisseria gonorrhoeae (MICs 0-06 to 2 mg/l) but had relatively poor activity against Acinetobacter spp. (MICs mosdy 4 to 128 mg/l). Cefotetan had little useful activity against Pseudomonas aeruginosa (MICs 16 to 512 mg/l) but was more active against most other pseudomonads. Cefotetan had moderate activity against the Bacteroidesfragilis group (MICs mostly⋜ 32 mg/l), though Bact.fragilis scnsu stricto and Boot, vulgatus were more sensitive (MICs usually ≤; 4 mg/l). It was more active against most other anaerobes, diough its activity was always exceeded by that of ampicillin. Cefotetan possessed a high degree of resistance to both plasmid-mediated and chromosomally-determined β -lactamases.