广泛药物耐药铜绿假单胞菌与鲍曼不动杆菌对多粘菌素B的MIC值分布调查

The distribution of MIC value of polymyxin B against extensively drug-resistant Pseudomonas aeruginosa and Acinetobacter baumannii clinical isolates from Zhejiang Provinical People’s Hospitals in China

目的通过检测多粘菌素B体外对广泛药物耐药(extensive drug-resistant,XDR)的铜绿假单胞菌与鲍曼不动杆菌的最低抑菌浓度(MIC)的分布上,来评价其对此类细菌的抗菌活性,为临床治疗、控制感染提供依据。方法用纸片扩散法检测临床分离的288株细菌(铜绿假单胞菌130株,鲍曼不动杆菌158株)对临床常见的25种抗菌药物的敏感性以确定其中广泛药物耐药菌;用E-试验检测多粘菌素B及临床常用11种抗菌药物MIC值,分析菌株的MIC值分布情况。结果 288株细菌经K-B法确认均为XDR菌株,对临床常用的11种抗菌药物的敏感性均低于15%;对多粘菌素B的MIC值均≤2μg/ml;130株铜绿假单胞菌的MIC值分布情况为0.125μg/ml1株、0.19μg/ml2株、0.25μg/ml9株、0.38μg/ml37株、0.5μg/ml48株、0.75μg/ml19株、1.0μg/ml11株、1.5μg/ml4株,MIC50为0.5μg/ml,MIC90为1.0μg/ml;158株鲍曼不动杆菌的MIC值分布情况为0.125μg/ml1株、0.19μg/ml3株、0.25μg/ml12株、0.38μg/ml45株、0.5μg/ml56株、0.75μg/ml21株、1.0μg/ml13株、1.5μg/ml7株、2.0μg/ml1株,MIC50为0.5μg/ml,MIC90为1.0μg/ml。结论多粘菌素B体外对广泛药物耐药铜绿假单胞菌与鲍曼不动杆菌均敏感,本地区临床未发现有多粘菌素B耐药株;但存在敏感区域内的高MIC值菌株,应引起临床重视。

Objective To study in vitro activity of polymyxin B against extensive drug-resistant Pseudomonas aeruginosa and Acinetobacter baumannii clinical isolates by detecting MIC,in order to help carrying on the prevention and therapy of infection.Methods Firstly,the extensive drug-resistant bacteria were confirmed by using K-B method for these isolates on 25 kinds of antibiotics.Secondly,the antimicrobial susceptibility of 11 kinds of clinical routine antimicrobial agents and MIC of polymyxin B for 130 strains of extensive drug-resistant Pseudomonas aeruginosa and 158 strains of extensive drug-resistant Acinetobacter baumannii by E-test mothed.Results 288 strains were confirmed that these isolates were extensive drug-resistant bacteria.For 130 strains of extensive drug-resistant Pseudomonas aeruginosa and 158 strains of extensive drug-resistant Acinetobacter baumannii,the antimicrobial susceptibility of all of the 11 kinds of clinical routine antimicrobial agents were lower 15%.The distrubution of MIC of polymyxin B for 130 strains extensive drug-resistant Pseudomonas aeruginosa was 0.125 μg/ml 1strain,0.19 μg/ml 2 strains,0.25 μg/ml 9 strains,0.38 μg/ml 37 strains,0.5 μg/ml 48 strains,0.75 μg/ml 19 strains,1.0 μg/ml 11 strains,1.5 μg/ml 4 strain,respectively.The MIC50 was 0.5 μg/ml,and the MIC90 was 1.0 μg/ml.For 158 strains of extensive drug-resistant Acinetobacter baumannii,the distrubution of MIC was 0.125 μg/ml 1 strain,0.19 μg/ml 3strains,0.25 μg/ml 12strains,0.38 μg/ml 45strains,0.5 μg/ml 56strains,0.75 μg/ml 21 strains,1.0 μg/ml 13 strains,1.5 μg/ml 7 strain,2.0 μg/ml 1 strain,respectively.Conclusion The activity of polymyxin B aganist extensive drug-resistant Pseudomonas aeruginosa and Acinetobacter baumannii in vitro was significant.The resistant strain was not found in this study.