【作者】 程亮；

【导师】 王耀兵；

【作者基本信息】 大连海事大学 ， 海洋化学， 2010， 硕士

【摘要】 抗生素抗性分析法(Antibiotic Resistance Analysis, ARA)作为经济有效的的粪便污染源示踪工具,在欧美等国已开展并得到了应用。本文在研究肠球菌具有ARA方法示踪因子可行性的基础上,检测了来自人、狗、鸡、牛、猪五个物种源粪便中500株肠球菌的抗生素抗性,并对其应用判别分析法构建了抗生素抗性指纹图谱库,得出了指纹图谱库的准确性并对其影响因素展开讨论。目的在于合理有效地构建抗生素抗性指纹图谱库,促进我国利用ARA法在识别粪便源技术中的应用。主要结果如下：(1)不同物种源粪便中的肠球菌与肠球菌标准菌株在模拟的自然海水环境下,存活量随时间逐渐衰减,生存天数为18～20天,但不同物种来源的肠球菌与肠球菌标准菌株的存活规律之间略有差异；肠球菌的抗生素抗性在始终未发生变化,并且与其原始的抗生素抗性保持一致。因此选择肠球菌作为ARA的示踪因子。(2)对500株肠球菌抗生素抗性特征进行耐药率及多重耐药性分析,结果表明五个物种源之间的抗生素抗性具有差异显著性,可以用于抗生素抗性指纹图谱库的构建；对五个物种源具有的耐药表型重叠情况统计分析发现人源与其他物种表型重叠数较多,可能导致指纹图谱库中人源的准确性相对其他物种源低。(3)应用判别分析法构建的抗生素抗性指纹图谱库,在任何一种判别模式下稳定性良好,在金州湾vs星海湾、人源vs非人源判别模式下得到的准确性最高,分别为71.0％与69.0％,应用验证组合得出本数据库最适的判别模式为人源vs非人源。(4)随机抽取的样本量≥80％时指纹图谱库的准确性基本一致,ARCC在57.8％～58.2％之间,样本量不是影响本指纹图谱库的主要影响因素；在日后工作过程中可以考虑增加抗生素种类,并去掉万古霉素,氯霉素与磷霉素可能会提高抗生素抗性指纹图谱库的准确性。更多还原

【Abstract】 As a cost-effective for fecal contamination sources tracking tool, Antibiotic resistance analysis (ARA) has been applied in Europe and the United States successfully. The principle is that using the same tracer with host specificity of antibiotic resistance from the feces of different source to identify fecal contamination sources. Based on the feasibility study of Enterococcus as tracing factor of ARA, it is detected 500 strains of Enterococci antibiotic resistance from five species as people, dogs, chickens, cows, and pigs. Then we used discriminant analysis to construct fingerprint database of antibiotic resistance, and obtained fingerprint database accuracy. Finally it is discussed the factors of the accuracy and promoted the application of ARA in faecel source tracking in our country.The main results as followed:(1)Enterococci of different sources fecal and strains of Enterococci standard in simulated natural water environment survival decreases with time gradually, survival time was from 18 to 20 days, but there was little difference in the survival of law; Enterococci antibiotic resistance had no change and consisted with the original condition. Therefore Enterococcus is chosen as the ARA tracing factor.(2)Analyzing the resistance rate and the multi-resistance characteristics of 500 strains of Enterococci, it is showed that antibiotic resistance had significant differences among the five species, and the antibiotic resistance can be used for constructing the Fingerprint Database. According to the resistance phenotypes of five species source with overlapping statistical, it is found that human have more chance to get overlapped phenotypic than the other species,and this may cause lower accuracy of human sources in fingerprint database.(3)Fingerprint database of antibiotic resistance was stable in any kind of discrimination mode with discriminant analysis. Under discrimination mode of Jinzhou Bay vs Xinghai Bay and human vs nonhuman, we got highest accuracy, respectively the ARCC was 71.0% and 69.0%. Validated-sets came to determine the optimal mode of the database was source vs non-human sources of man.(4)The accuracy of fingerprint database remains the same when the random sampling is large than 80%, with ARCC between 57.8% and 58.2%, sample size will not affect this fingerprint database. In the future, we will consider to use more the types of antibiotics, and remove Vancomycin, Chloramphenicol and Fosfomycin, it will increase the accuracy of the fingerprint database.更多还原