Abstract
The activity of β-lactamases from Citrobacter diversus ULA-27 on ceftriaxone, a widely recognized third-generation cephalosporin, has been examined and compared to the activity of various other β-lactamases from different sources. Ceftriaxone (Roche S.p.A. Milan) was found to be resistant to hydrolysis by β-lactamases from Enterobacter cloacae and Bacillus cereus, but susceptible to β-lactamases from Mycobacterium fortuitum strain Cow 18 and, mostly, to β-lactamases from various strains of Citrobacter diversus. Derivatives with substituents in the 3-position of ceftriaxone, namely cefotaxime (Roussel Maestretti S.p.A., Milan) and ceftizoxime (Farmitalia Carlo Erba, Milan), were much less susceptible to hydrolysis by C. diversus ULA-27 enzymes (22 and 6% of ceftriaxone hydrolysis, respectively), the hydrolysis rate being paralleled by differences in MIC values. Ceftriaxone inhibited the activity of E. cloacae β-lactamases toward cefazolin as substrate, but the inhibition was totally abolished by preincubation of ceftriaxone with the enzyme before addition of the substrate. Overall, the data point to a relevance of C. diversus ULA-27 β-lactamases in the mechanism of resistance of this strain to the various third-generation cephalosporins.
| Original language | English |
|---|---|
| Pages (from-to) | 25-30 |
| Number of pages | 6 |
| Journal | Drugs under Experimental and Clinical Research |
| Volume | 14 |
| Issue number | 1 |
| Publication status | Published - 1988 |
ASJC Scopus subject areas
- Molecular Medicine
- Pharmacology (medical)
- Drug Discovery
- Pharmacology