In Vitro Studies with Cefaclor, a New Oral Cephalosporin
Open Access
- 1 October 1977
- journal article
- Published by American Society for Microbiology in Antimicrobial Agents and Chemotherapy
- Vol. 12 (4), 490-497
- https://doi.org/10.1128/aac.12.4.490
Abstract
In vitro studies were performed to evaluate the activity of cefaclor in comparison with cephalexin against 180 clinical isolates. Broth dilution susceptibility tests showed cefaclor to be 4- to 16-fold more active than cephalexin against Streptococcus pneumoniae, Haemophilus influenzae , and cephalothin-susceptible Enterobacteriaceae . Neither drug was highly active against cephalothin-resistant Enterobacteriaceae or methicillin-resistant Staphylococcus aureus . Cefaclor zones with 30-μg disks were generally larger than cephalexin zones, 4 mm larger than cephalothin zones against Enterobacteriaceae , and 6 mm smaller than cephalothin zones against S. aureus . Quantitative kill curves indicated that killing by both cefaclor and cephalexin was slow and often incomplete over a 24-h period. Cefaclor-induced filamentation of gram-negative bacilli was not as extensive as that produced by cephalexin, and some spherule formation did occur. However, cefaclor was significantly more unstable in solution than cephalexin, with a half-life of less than 6 h at 37°C. Thus, results obtained in tests after prolonged incubation may not provide an accurate measure of cefaclor's activity.Keywords
This publication has 5 references indexed in Scilit:
- Comparison of In Vitro Activity of Cephalexin, Cephradine, and CefaclorAntimicrobial Agents and Chemotherapy, 1977
- Comparison of the Responses of Escherichia coli and Proteus mirabilis to Seven -Lactam AntibioticsThe Journal of Infectious Diseases, 1973
- The effect of some cephalosporins on Escherichia coli.1970
- Laoratory appraisal of cephalexin.1968
- Antibiotic susceptibility testing by a standardized single disk method.1966