Primary study of antofloxaicn breakpoints with disc-diffusion sensitivity test

Abstract

Abstract: AIM: To determine the breakpoints of Antofloxacin sensitivity with disc-diffusion test for staphylococci, enterobacteriaceae, non-fermenter and hemophili in primary. METHODS: The in vitro antibacterial activity of Antofloxacin and other comparators was detected with standard agar dilution and disc-diffusion (Antofloxacin 5 μg and 10 μg discs) methods. Referring to the association of in vitro antibacterial activity of different fluoroquinolones and pharmacokinetics property of the investigated agent, the breakpoints of Antofloxacin were determined with scat tergram between MIC and bacterial inhibitory zone. RESULTS: The in vitro antibacterial activity of Antofloxacin against clinical isolates shown better association with those of levof loxacin. Referring to the proposed sensitive breakpoints of Antofloxacin with agardilution method (hemophili being recommended as ≤1 mg/L for sensitive the sensitive, intermediate and resistant breakpoint sagainst other pathogens being≤2, 4, ≥8 mg/L, respectively), the bacterial inhibitory zone breakpoints with disc-diffusion method (10μg disc) were setas ≥21 mm against hemophili for sensitive and ≤14 mm, 15-17 mm, ≥18 mm against the other germs for resistant, intermediate and sensitive. The quality control inhibitory zones against referring strains were 24-31mm for Escherichia coli A TCC25922, 22-26 mm for Pseudomonas aeruginosa A TCC27853 and 22-28mm for Staphylococcus aureus ATCC25923, respectively. CONCLUSION: Referring to the in vitro antibacterial activity and making use of the scatter gram between MIC and inhibition zone of Antofloxacin, the breakpoints for in vitro sensitive test with disc-diffusion method were established in primary and recommended for clinical practice and future review.

Key words: Anto flo xacin, Breakpoint, Minimum inhibitory concentration, Disc-diffusiontest, Bacterial inhibi to ryzone

CLC Number:

R965.2

XIAO Yong-hong, LI Yun, LIU Jian, ZHONG Wei, YANG Wei-wei. Primary study of antofloxaicn breakpoints with disc-diffusion sensitivity test[J]. Chinese Journal of Clinical Pharmacology and Therapeutics, 2010, 15(3): 298-304.

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