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首页> 外文学位 >Characterization of biological contaminants in the Rio Grande from Las Cruces, New Mexico in the United States to Ciudad Juarez, Chihuahua, Mexico using a hollow-fiber ultrafiltration system.
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Characterization of biological contaminants in the Rio Grande from Las Cruces, New Mexico in the United States to Ciudad Juarez, Chihuahua, Mexico using a hollow-fiber ultrafiltration system.

机译：使用中空纤维超滤系统表征了从美国新墨西哥州拉斯克鲁塞斯到墨西哥奇瓦瓦州华雷斯城的里奥格兰德州的生物污染物。

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The contamination of the Rio Grande by pathogenic microorganisms is of public health concern on both sides of the U.S.-Mexico border. The aims of this dissertation were: (i) to optimize an ultrafiltration system to simultaneously concentrate and detect viruses, bacteria and protozoa; (ii) to develop a selective detection method for the human pathogen Helicobacter pylori; and (iii) to survey the Paso del Norte region surface water for the presence of bacterial indicators of pathogenic microorganisms. During ultrafiltration the addition of Tween-80 clearly increased the recovery of seeded microbes from 10 L, which was 50, 60 and 90% for viruses, protozoa and bacteria, respectively.; Helicobacter pylori was enumerated in the Rio Grande at concentrations ranging from 0 to 2.0 x 102 colony forming units per liter (CFU/L) in five of six sites analyzed. Presumptive identification by cell culture was possible in five of twenty four water samples (25%), while PCR confirmation was obtained in 12 (50%) of the twenty four water samples. Levels of heterotrophic bacteria ranged from 3.9 x 10 4 to 1.0 x 1010 CFU/L, total coliforms ranged from 2.0 x 102 to 4.3 x 107 CFU/L, and values of fecal coliforms were between 7.5 x 101 and 1.8 x 108 CFU/L. Numbers of putative Salmonella species grown on selenite cystine ranged from 8.9 x 10 2 to 1.1 x 108 CFU/L. Conventional media was supplemented with a mixture of trimethoprim, sulfamethoxazole, polymyxin B, and vancomycin and these media were compared to tetracycline and ampicillin-amended agars and minus antibiotic agars.; Percentage of total coliforms, fecal coliforms and putative Salmonella species able to grown in the presence of antibiotics of ranged from 0 to 4.5, from 3 to 40, and from 4 to 23%, respectively. There was no apparent seasonal effect observed between samples. These results indicate that both Rio Grande and Agricultural drain samples harbor fecal bacteria that include pathogens like H. pylori and coliforms which can grow in the presence of antibiotics.
机译：病原微生物对里奥格兰德州的污染在美国-墨西哥边境的两侧均引起公共卫生关注。本文的目的是：（i）优化超滤系统，以同时浓缩和检测病毒，细菌和原生动物； （ii）开发针对人类病原体幽门螺杆菌的选择性检测方法； （iii）调查北索（Paso del Norte）地区的地表水中是否存在病原微生物的细菌指示剂。在超滤过程中，添加Tween-80明显提高了10 L种子微生物的回收率，其中病毒，原生动物和细菌的回收率分别为50％，60％和90％。在分析的六个地点中的五个地点，在里奥格兰德州列举了幽门螺杆菌，其浓度范围为每升0至2.0 x 102个菌落形成单位（CFU / L）。在24个水样中的5个（25％）中可以通过细胞培养进行推定鉴定，而在24个水样中的12个（50％）中获得PCR确认。异养细菌的水平范围从3.9 x 10 4到1.0 x 1010 CFU / L，总大肠菌群的范围从2.0 x 102到4.3 x 107 CFU / L，粪便大肠菌群的值介于7.5 x 101和1.8 x 108 CFU / L之间。在亚硒酸盐胱氨酸上生长的推定沙门氏菌的数量范围为8.9 x 10 2至1.1 x 108 CFU / L。常规培养基中添加了甲氧苄啶，磺胺甲恶唑，多粘菌素B和万古霉素的混合物，并与四环素和氨苄青霉素修饰的琼脂和减去抗生素的琼脂进行了比较。在抗生素存在下能够生长的总大肠菌，粪大肠菌和沙门氏菌的百分比分别为0％至4.5％，3％至40％和4％至23％。样品之间没有观察到明显的季节性影响。这些结果表明，里奥格兰德州和农业排水渠样品都含有粪便细菌，其中包括诸如幽门螺杆菌和大肠菌的病原体，它们可以在存在抗生素的情况下生长。

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