[Assay of Acinetobacter SPP drug-resistance by Kirby-Bauer and Etest method]
Lu-xia Wang1, Ling-bo Shi, De-xing Xu
1Department of Clinical Laboratory, Guangzhou General Hospital of Guangzhou Command, Guangzhou 510010, China.
Objective:
To study the drug-resistance of Acinetobacter spp and observe whether antibiotic-beta- lactamase inhibitor complexing agent enhances the sensitivity of the drug-resistant bacteria to the antibiotics.
Methods:
Susceptibility tests to the antibiotics were performed for 60 isolated strains of Acinetobacter spp with Kirby-Bauer (K-B) and Etest methods.
Results:
The drug-resistance rate of the strains to cefoperazone, ampicillin, ticarcillin and piperacillin exceeded 55.0%, and antibiotic-beta-lactamase inhibitor complexing agents evinced better antibacterial activity than antibiotics used alone (P < 0.001). The 2 antibiotic complexes incorporating sulbacta had more potent antibacterial activity than the complexes incorporating clavulanate (2 agents) and tazobactam (1 agent), with the mean ranks of 7.38, 6.43, 5.57, 5.47 and 5.50 respectively. Cefoperazone combined with sulbacta produced a reduction in MIC(90) and MIC(50) that were only 4.69% and 0.59% of the MIC(50) of cefoperazone, and in addition, sulbacta caused cefoperazone- and ampicillin-resistant rates to reduce from both 75.0% to 5.0% and 24.0%, respectively.
Conclusion:
Acinetobacter spp is resistant to a wide spectrum of commonly-used antibiotics, but cefoperazone in combination with sulbacta can obviously enhance antibacterial potency, suggesting the primary role of this regimen in fighting Acinetobacter spp infections in hospital.
