title: In vitro activity and beta-lactamase stability of the new oral cephalosporin Bay v 3522.
abstract: The activity of the new oral cephalosporin Bay v 3522 was compared to that of six other beta-lactam agents. Bay v 3522 inhibited methicillin-susceptible Staphylococcus aureus and Staphylococcus epidermidis at less than or equal to 2 micrograms/ml, compared to MICs of greater than or equal to 8 micrograms/ml for the other cephalosporins tested. It was more active against Streptococcus pyogenes (MIC less than or equal to 0.06 microgram/ml) than cefuroxime, cefixime, cephalexin and cefaclor. Groups B, C and G streptococci were inhibited at less than or equal to 0.12 microgram/ml, while the MI"90 for Streptococcus bovis and viridans streptococci was 0.5 and 2 micrograms/ml, respectively. The MIC90 for enterococci and Listeria monocytogenes was 8 micrograms/ml. Clostridium perfringens was inhibited by 0.12 microgram/ml, but most Bacteroides spp. were resistant. The MIC90 for beta-lactamase positive Escherichia coli (producing primarily TEM-1) was greater than 64 micrograms/ml and for beta-lactamase negative strains 16 micrograms/ml. The MIC90 for high-level beta-lactamase producing Klebsiella pneumoniae was greater than 64 micrograms/ml versus 4 micrograms/ml for other isolates. The MIC90 for Moraxella catarrhalis was 2 micrograms/ml, for Haemophilus influenzae 1 micrograms/ml, and for Neisseria gonorrhoeae 4 micrograms/ml. Enterobacter cloacae, Citrobacter freundii, Proteus mirabilis, Providencia spp. and Pseudomonas aeruginosa were resistant. Bay v 3522 was destroyed by TEM-1, SHV-1, TEM-3 and P99 beta-lactamases.
authors.affiliation: Department of Medicine, College of Physicians & Surgeons, Columbia University, New York, New York 10032.
authors.forename: N X
authors.initials: NX
authors.lastname: Chin
authors.forename: J W
authors.initials: JW
authors.lastname: Gu
authors.forename: H C
authors.initials: HC
authors.lastname: Neu
mesh_terms: D000284:Administration, Oral; D000658:Amoxicillin / Q000494:pharmacology; D019980:Amoxicillin-Potassium Clavulanate Combination; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D052160:Benzothiazoles; D002511:Cephalosporins / Q000494:pharmacology*; D002969:Clavulanic Acids / Q000494:pharmacology; D004359:Drug Therapy, Combination / Q000494:pharmacology; D004755:Enterobacteriaceae / Q000187:drug effects* / Q000201:enzymology; D004795:Enzyme Stability / Q000187:drug effects; D008712:Methicillin / Q000494:pharmacology; D013045:Species Specificity; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000201:enzymology; D013212:Staphylococcus epidermidis / Q000187:drug effects* / Q000201:enzymology; D001618:beta-Lactamases / Q000096:biosynthesis*
chemical_list: D000900:Anti-Bacterial Agents; D052160:Benzothiazoles; D002511:Cephalosporins; D002969:Clavulanic Acids; C064738:Bay v 3522; D019980:Amoxicillin-Potassium Clavulanate Combination; D000658:Amoxicillin; D001618:beta-Lactamases; D008712:Methicillin