Abstract: Objective To determine the minimum inhibitory concentration (MIC) of 11 antibiotics against 46 strains of Yersinia pestis from the natural plague foci in Gansu province, China and master the sensitivity of these strains to the 11 antibiotics in this region, and to provide a scientific basis for the effective prevention and control of plague. Methods According to American Association of Clinical and Laboratory Standards (CLSI)(2017-M100), the agar dilution method was used to determine the MICs of ofloxacin, ciprofloxacin, sulfamethoxazole/trimethoprim, kanamycin sulfate, streptomycin sulfate, ceftriaxone sodium, ampicillin, chloramphenicol, spectinomycin hydrochloride, cefuroxime sodium, and tetracycline hydrochloride against 46 strains of Y. pestis. Results None of the 46 strains of Y. pestis tested were found to have resistance to one or more of the 11 antibiotics. Among the 11 antibiotics, ceftriaxone sodium had the highest in vitro antibacterial activity (MIC90, 0.03 μg/ml), followed by ciprofloxacin (MIC90, 0.06 μg/ml), sulfamethoxazole/trimethoprim (MIC90, 0.12 μg/ml), ofloxacin (MIC90, 0.25 μg/ml), ampicillin (MIC90, 0.50 μg/ml), cefuroxime sodium (MIC90, 1.00 μg/ml), kanamycin sulfate, streptomycin sulfate, tetracycline hydrochloride, and chloramphenicol (MIC90, 4.00 μg/ml), and spectinomycin hydrochloride had the lowest antibacterial activity (MIC90, 16.00 μg/ml). Conclusion The 46 strains of Y. pestis from the natural plague foci in Gansu province are all sensitive to the 11 antibiotics. Monitoring of drug-resistant strains should be continued in order to detect drug-resistant Y. pestis in the early stage, choose antibiotics rationally, and develop the individualized treatment regimen.

Key words: Yersinia pestis, Antibiotics, In vitro antibacterial activity, Gansu

摘要： 目的 检测甘肃省鼠疫自然疫源地分离的46株鼠疫耶尔森菌（鼠疫菌）对11种抗菌药物最低抑菌浓度，掌握该地区鼠疫菌株对11种抗菌药物的敏感性，为有效防治鼠疫提供科学依据。方法 参照美国临床和实验室标准协会（CLSI ）2017-M100药敏试验方法中的琼脂稀释法，测定氧氟沙星、环丙沙星、复方新诺明（甲氧苄啶-磺胺甲恶唑）、硫酸卡那霉素、硫酸链霉素、头孢曲松钠、氨苄西林、氯霉素、盐酸壮观霉素、头孢呋辛钠和盐酸四环素共11种抗生素对46株鼠疫菌的最低抑菌浓度（MIC）。结果 所测的46株鼠疫菌中均未发现对上述11种抗生素具有单个或多个抗菌药物抗性的鼠疫菌株；11种抗菌药物对鼠疫菌的体外抑菌活性以头孢曲松钠的最高（MIC90，0.03 μg/ml），其次分别为环丙沙星（MIC90，0.06 μg/ml），甲氧苄啶-磺胺甲恶唑（MIC90，0.12 μg/ml），氧氟沙星（MIC90，0.25 μg/ml），氨苄西林（MIC90，0.50 μg/ml），头孢呋辛钠（MIC90，1.00 μg/ml），硫酸卡那霉素、硫酸链霉素、盐酸四环素和氯霉素的MIC90均为4.00 μg/ml，盐酸壮观霉素的抑菌活性在11种抗菌药物中最低（MIC90，16.00 μg/ml）。结论 甘肃省鼠疫疫源地分离的46株鼠疫菌对上述11种抗菌药物均敏感。应继续进行耐药菌株监测以便早期发现耐药菌，针对致病病原体，合理选择抗菌药物，制定个体化给药方案。

关键词: 鼠疫耶尔森菌, 抗菌药物, 体外抑菌活性, 甘肃