Abstract
An in vitro study was done to evaluate combination use of aspoxicillin (ASPC) with each of β-lactam preparations, ceftazidime (CAZ), cefmetazole (CMZ) and aztreonam (AZT). The results obtained are summarized as follows:
1. ASPC has strong activity against Gram-positive bacteria and anaerobic bacteria, while CMZ and CAZ have strong activity against Gram-negative bacteria.
2. Rates of β-lactamase producing strains among the isolated bacteria (a total of 383 isolates) were 4.4% among Gram-positive bacteria, 71.6% among Gram-negative bacteria and 89.3% among anaerobic bacteria. The overall rate of β-lactamase secreting strains among all isolates was 46.5%.
3. Efficacies of combination uses were studied using the FIC index. Combination of ASPC and CAZ was effective against 95.0% of the isolates, ASPC and AZT against 85.7%, and ASPC and CMZ against 83.5%. Combination of ASPC and CMZ showed antagonism in 12.8% of the isolates.
In conclusion, combination use of ASPC with any one of CMZ, AZT or CAZ proved to be highly effective. In particular, combination of ASPC and CAZ appeared to be the best in view of complementing antibacterial spectra.
