In vitro activity of FCE 22101, imipenem, and ceftazidime against over 6,000 bacterial isolates and MIC quality control limits of FCE 22101.

Six geographically separate laboratories within the USA tested 6,198 bacterial isolates against FCE 22101 (a penem), imipenem (a carbapenem) and ceftazidime (a third-generation cephalosporin). Ninety-three percent of 2,749 Enterobacteriaceae were inhibited by FCE 22101, while 95% were susceptible to ceftazidime and 99% were susceptible to imipenem. FCE 22101 had little activity against Pseudomonas spp. but was active against most gram-positive pathogens, including enterococci. FCE 22101 MICs for standard quality control strains were defined as 0.5-2.0 micrograms/ml for Escherichia coli ATCC 25922, 2-8 micrograms/ml for Enterococcus faecalis ATCC 29212 and 0.06-0.25 microgram/ml for Staphylococcus aureus ATCC 29213.