【摘要】 目的:通过了解小肠结肠炎耶尔森菌强毒力岛在肠聚集性大肠杆菌中的结构和摄铁功能,从而进一步研究肠聚集性大肠杆菌的毒力进化及其致病机制。方法:实验于2005-08/2006-09在南方医科大学公共卫生与热带医学学院完成。6株肠聚集性大肠杆菌采自某部队腹泻患者粪便,并经血清学鉴定。采用聚合酶链反应方法观察肠聚集性大肠杆菌中强毒力岛irp2和fyua阳性检出率和强毒力岛在阳性菌株中的定位鉴定。原位杂交方法进行肠聚集性大肠杆菌中强毒力岛irp2和fyua基因序列分析。SDS-聚丙烯酰氨凝胶电泳方法观察小肠结肠炎耶尔森菌WA和毒力岛阳性的肠聚集性大肠杆菌HMWP1和HMWP2的表达。结果:6株肠聚集性大肠杆菌有5株检出了强毒力岛,检出率达到83.33%,而且这些阳性菌株中的毒力岛都位于天冬氨酸tRNA位点;在缺铁条件下,肠聚集性大肠杆菌能够表达和小肠结肠炎耶尔森菌相同的摄铁蛋白HMWP1和HMWP2。结论:小肠结肠炎耶尔森菌强毒力岛在肠聚集性大肠杆菌中具有阳性率较高的分布,并具有相同的摄铁功能,很可能肠聚集性大肠杆菌和小肠结肠炎耶尔森菌中的强毒力岛有相同的转移机制。更多还原

【Abstract】 AIM:To detect the structure and iron uptake function of High Pathogenicity Island(HPI) of Yersinia enterocolitica(Yen) in enteroaggregative E.coli(EAggEC),and further investigate the bacterial evolution process and pathogenic mechanism of EAggEC.METHODS:The experiment was carried out at the Department of Public Health and Tropical Medicine in Southern Medical University from August 2005 to September 2006.Six EAggEC strains were selected from the stool of diarrhea patients in the armed forces,and identified serologically.Polymease chain reaction was used to detect the positive rate of irp2 and fyua genes of Yen HPI and identify HPI in positive strains.Nucleic acid hybridization in situ was used for DNA sequencing of HPI among the EAggEC.Sodium dodecyl sulfate polyacrylamide gel electropheresis was used to detect the expressions of Yen WA,HMWP1 and HMWP2.RESULTS:There were 5 strains detected from 6 EAggEC strains,occupying 83.33%.In these isolates,the HPI was bordered by an asparagines tRNA locus.At the condition of iron deficiency,EAggEC expressed two high molecular weight proteins,HMWP1 and HMWP2.CONCLUSION:The HPI of Yen can be detected in EAggEC,and the HPI which harbors the asparagines tRNA locus has full structure and same iron uptake function as Yen,maybe the HPI of EAggEC and Yen are transferred at the same evolution.更多还原