Abstract
The in vitro activity of Ro 23-9424, which is desacetyl-cefotaxime linked to fleroxacin, was compared with the activities of cefotaxime, desacetyl-cefotaxime, fleroxacin, ofloxacin, and ciprofloxacin. It inhibited the majority of members of the family Enterobacteriaceae, except for some Serratia marcescens, Citrobacter freundii, and Enterobacter cloacae strains, at less than or equal to 0.25 microgram/ml and had an MIC for 90% of strains tested (MIC90) of 8 micrograms/ml against Pseudomonas aeruginosa. Most group A, B, C, and G streptococci and Streptococcus pneumoniae were inhibited at less than or equal to 0.25 microgram/ml. Ninety percent of the staphylococci were inhibited at less than or equal to 4 micrograms/ml, except for some methicillin-resistant Staphylococcus aureus isolates. The MIC90S of Ro 23-9424 for Enterococcus faecalis and Listeria monocytogenes were greater than or equal to 16 micrograms/ml. Ninety percent of Clostridium perfringens isolates were inhibited by less than or equal to 2 micrograms/ml, whereas Bacteroides fragilis had an MIC90 of 32 micrograms/ml. There was a minimal inoculum size effect. The MICs and MBCs were either identical or within a twofold dilution. The MICs of Ro 23-9424 for Escherichia coli, Klebsiella pneumoniae, Serratia marcescens, Enterobacter cloacae, Citrobacter freundii, Pseudomonas aeruginosa, and Staphylococcus aureus increased 16- to 128-fold after 2 weeks of transfer in the presence of Ro 23-9424, showing that the presence of two agents does not prevent resistance.
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- Beskid G., Fallat V., Lipschitz E. R., McGarry D. H., Cleeland R., Chan K., Keith D. D., Unowsky J. In vitro activities of a dual-action antibacterial agent, Ro 23-9424, and comparative agents. Antimicrob Agents Chemother. 1989 Jul;33(7):1072–1077. doi: 10.1128/aac.33.7.1072. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chin N. X., Brittain D. C., Neu H. C. In vitro activity of Ro 23-6240, a new fluorinated 4-quinolone. Antimicrob Agents Chemother. 1986 Apr;29(4):675–680. doi: 10.1128/aac.29.4.675. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Georgopapadakou N. H., Bertasso A., Chan K. K., Chapman J. S., Cleeland R., Cummings L. M., Dix B. A., Keith D. D. Mode of action of the dual-action cephalosporin Ro 23-9424. Antimicrob Agents Chemother. 1989 Jul;33(7):1067–1071. doi: 10.1128/aac.33.7.1067. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jones R. N., Barry A. L., Thornsberry C. Antimicrobial activity of Ro 23-9424, a novel ester-linked codrug of fleroxacin and desacetylcefotaxime. Antimicrob Agents Chemother. 1989 Jun;33(6):944–950. doi: 10.1128/aac.33.6.944. [DOI] [PMC free article] [PubMed] [Google Scholar]
- O'Callaghan C. H., Sykes R. B., Staniforth S. E. A new cephalosporin with a dual mode of action. Antimicrob Agents Chemother. 1976 Aug;10(2):245–248. doi: 10.1128/aac.10.2.245. [DOI] [PMC free article] [PubMed] [Google Scholar]