Related Experiment Videos
Bactericidal activity and postantibiotic effect of cefdinir (Cl 983, FK 482) against selected pathogens
G Blandino1, F Caccamo, R Di Marco
1Institute of Microbiology, University of Catania, Italy.
Abstract:
The bactericidal activity and the postantibiotic effect (PAE) of cefdinir (Cl 983, FK 482) (CDR), were determined against Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, Branhamella catarrhalis and Escherichia coli (5 strains each) in comparison to erythromycin (E), cotrimoxazole (SXT) and amoxicillin-clavulanic acid (AMC). Kinetic studies of kill showed that CDR was rapidly bactericidal at concentrations 2 and 4 times the minimum inhibitory concentration (MIC): a reduction of 99.9% in CFU values was observed after 6-8 h for many of the isolates tested. As expected, a PAE was observed when S. aureus was treated with CDR at MIC (range of individual values for 5 strains 0.8-1.5 h) and 4 x MIC (range 1.1-1.4 h). Moreover, CDR showed a significant PAE at both its MIC and 4 x MIC against S. pneumoniae (range 0.5-1.0 h and 0.9-1.1 h), H. influenzae (range 0.4-0.7 h and 0.4-0.8 h), B. catarrhalis (range 0.5-0.7 h and 0.65-0.95 h) and E. coli (range 0.5-0.6 h and 0.5-0.7 h). The good bactericidal activity and the significant PAE of CDR against Gram-positive and Gram-negative bacteria (including respiratory pathogens) are a promising indication for the clinical efficacy of this cephalosporin in several bacterial infections.
Insights
Cefdinir demonstrates rapid bactericidal activity and a significant postantibiotic effect (PAE) against common Gram-positive and Gram-negative bacteria, including respiratory pathogens.
Area of Science:
- Microbiology
- Pharmacology
- Infectious Diseases
Background:
- Cefdinir (CDR) is a third-generation cephalosporin antibiotic.
- Assessing bactericidal activity and postantibiotic effect (PAE) is crucial for determining clinical efficacy.
Purpose of the Study:
- To evaluate the bactericidal activity and PAE of cefdinir.
- To compare cefdinir's antimicrobial properties with erythromycin, cotrimoxazole, and amoxicillin-clavulanic acid.
Main Methods:
- Kinetic kill studies were performed.
- Postantibiotic effect (PAE) was assessed at various concentrations (MIC and 4x MIC).
- Tested bacterial strains included Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, Branhamella catarrhalis, and Escherichia coli.
Main Results:
- Cefdinir exhibited rapid bactericidal activity, achieving a 99.9% reduction in CFU within 6-8 hours at 2x and 4x MIC.
- Significant PAE was observed for cefdinir against all tested bacterial species, including S. aureus, S. pneumoniae, H. influenzae, B. catarrhalis, and E. coli.
- PAE values ranged from 0.4 to 1.5 hours depending on the bacterium and concentration.
Conclusions:
- Cefdinir possesses strong bactericidal activity and a notable postantibiotic effect.
- These properties suggest promising clinical efficacy for cefdinir in treating various bacterial infections, particularly those caused by respiratory pathogens.