Comparative antibacterial activity of an arylglycyl oral cephalosporin, LY164846

LY164846 is a semisynthetic arylglycyl cephalosporin which can be absorbed orally. It had in vitro activity comparable to that of cefaclor against beta-hemolytic streptococcal species and was two- to fourfold more active than cephalexin. Enterococci and Listeria species were resistant, and its activity against staphylococci was similar to that of other oral cephalosporins. Although some Bacteroides species were inhibited, the MICs for 25% were greater than or equal to 16 micrograms/ml. LY164846 was hydrolyzed by Staphylococcus aureus beta-lactamase and by cephalosporinases, but it was more stable than cefaclor.