NOVIELLO S, ESPOSITO S, IANNIELLO F; Interscience Conference on Antimicrobial Agents and Chemotherapy.
Abstr Intersci Conf Antimicrob Agents Chemother Intersci Conf Antimicrob Agents Chemother. 1999 Sep 26-29; 39: 9 (abstract no. 30).
Dept. Infectious Diseases, University of Naples, ITALY.
BACKGROUND: Older fluoroquinolones (FQ) and macrolides are only moderately in vitro active against pneumococci whereas the newer FQ and newer macrolides are characterized by an expanded antipneumococcal activity. The killing activity of MOX, GRP and CLR were compared, after simulating their human pharmacokinetics, against S. pneumoniae (SP) and S. pyogenes (GABHS).METHODS: Three clinical isolates of SP (penicillin-susceptible, -intermediate and -resistant) and two GABHS strains (erythromycin-susceptible and -resistant) were selected. The in vitro model, according to Grasso, simulating the concentration time curves (400 mg oral dose of MOX and GRP and 250 mg oral dose of CLR) was used to determine the bactericidal activity. All tests were performed in duplicate. Results were achieved by measuring the reduction in viable bacterial count during the 24 h experimental period.RESULTS: All the three antimicrobials led to a continuous reduction in the bacterial counts of penicillin-susceptible SP and erythromycin-susceptible GABHS strains, the maximal reduction observed already after 8-10 hours being 5-6 logs for MOX and 3 logs for GRP; clarithromycin exhibited a similar reduction of 5 logs only after 24 hrs. No regrowth was observed for any strain after 24 hrs with any of the antibiotics. The bactericidal activity of MOX and GRP was not affected by penicillin resistance of SP and erythromycin resistance of GABHS, the killing kinetic being similar to the above described profiles. In contrast, CLR was not able to reduce the bacterial count of penicillin-resistant SP and erythromycin-resistant GABHS strains.CONCLUSIONS: MOX exhibits, within 24 hrs, the higher and faster bactericidal activity against SP, superior to GRP and CLR, not being affected by penicillin-resistance. These results suggest that MOX is a promising new agent for treatment of streptococcal infections.
Publication Types:
Keywords:
- Anti-Bacterial Agents
- Anti-Infective Agents
- Aza Compounds
- Clarithromycin
- Erythromycin
- Fluoroquinolones
- Humans
- In Vitro
- Penicillin Resistance
- Penicillins
- Piperazines
- Quinolines
- Streptococcus pneumoniae
- grepafloxacin
- moxifloxacin
Other ID:
UI: 102244603
From Meeting Abstracts