巴尔通体体外药敏试验方法研究

Comparison of two methods in vitro test of drug susceptibility of Bartonella

目的优化巴尔通体体外药敏试验方法,检测多种抗生素对巴尔通体的最低抑菌浓度(MICs),并分析耐药性。方法优化Etest法试验条件;将该方法与琼脂稀释法进行比较,评价该方法的可靠性。采用Etest法,检测了7株ATCC参考株对22种抗生素的MICs,数据分析使用SPSS 13.0软件。结果确定含5%羊血的胰酶大豆琼脂培养基为最佳培养基、2.0 MCF(麦氏浊度)度为最佳细菌接种浓度,7天为最佳孵育时间。测试的7株巴尔通体在体外对强力霉素等13种抗生素敏感(MIC<0.016),对克林霉素等4种抗生素MIC偏高。结论 Etest法简便易行、定值准确、重复性好、结果可靠,可以用于巴尔通体体外药敏试验,并获得了巴尔通体的一些体外药敏数据,为将来制订巴尔通体药敏标准提供一定的依据。

Objective To establish and optimize the Etest method for the in vitro test of drug susceptibility of Bartonella isolates,detect the minimal inhibitory concentration（ M ICs） of different antibiotics to Bartonella and analyze the drug-resistant spectrum. Methods The optimum experimental conditions of Etest method w ere established before detection of M ICs. This method w as compared w ith the agar dilution method（ the gold standard） to evaluate its reliability. The M ICs of 22 antibiotics to 7 reference strains of Bartonella w ere tested by using the established Etest method,and data w ere analyzed w ith softw are SPSS 13. 0. Results The optimum conditions for Etest method in vitro test of the drug susceptibility of Bartonella strains w ere as follow s： The optimum medium w as soybean trypsin agar medium containing 5% defibrinated sheep blood; the optimal inoculation concentration w as 2. 0 M CF; the optimum incubation time w as 7 days. Bartonella strains w ere sensitive to 13 antibiotics in vitro（ MIC〈0. 016）,such as doxycycline,azithromycin etc. How ever,they w ere non-sensitive to 4 antibiotics in vitro,such as clindamycin. etc.Conclusion Etest method is easy to perform in testing Bartonella strains in vitro,the result is accurate and reliable,and the reproducibility is good,This method can used in in vitro test of drug susceptibility of Bartonella to provide evidence for the development of standards for drug susceptibility of Bartonella.