THE DEVELOPMENT OF AN ATTACHING AND EFFACING LESION BY AN ENTEROHAEMORRHAGIC ECHERICHIA COLI IN VIVO

用附着和消失的E. coli（O 103：H-），并在接种后3小时至3个月内分离接种的微生物。并观察了微生物在鸡肠道的粘附情况和粘附-消退性病变。对100头腹泻犊牛进行了病理学观察，从感染后3 h至感染后第1天，从所有犊牛盲肠内容物中分离到AEEC，平均为8.67 ± 0.41（<10>logCFU/g ± SD）。从接种后3小时到3周，AEEC粘附到肠表面。从接种后9小时至3周识别AE病变。感染早期，AEEC出现在轻微的细胞表面.细胞内微丝和微绒毛扩张，附着在粘膜表面的微生物被微绒毛包围。微绒毛消失，杯状突起和基台突起为细胞膜。AE病灶扩张成网状，包围隐窝。AEEC在感染后期遗留黏膜，黏膜修复。用PCR方法从腹泻犊牛肠道内容物中检出stx 1基因（2 0/83）、stx 1 + 2基因（2/83）和eaeA基因（9/83），且stx 1基因携带率很高。

Young chicken were inoculated orally with an attaching and effacing E. coli (O103 : H-), and an inoculated microorganisms were isolated from 3 hours to 3 months after the inoculation. The adhesion of the microorganisms to the intestines of the chicken and the attaching-effacing lesions were also observed. Furthermore, one hundred of the calves with diarrhea were observed pathologically.AEEC was isolated from the cecal contents of all the chickens from 3 hrs until the first day in the infection experiment with the average 8.67 ± 0.41 (log_<10>CFU/g ± SD). Adhesion to the intestinal surface of AEEC was recognized from 3 hrs until 3 wks after the inoculation. The AE lesion was recognized from 9 hrs until 3 wks after the inoculation. AEEC was found on the surface of slight cellular the early stages of infection. The intracellular-filament and microvilli were expanded, and the microorganisms that attached to the mucosal surface were surrounded in the microvilli. And, its microvilli were disappeared and the Cup-formation and the pedestal protrusion were recognized as a cell membrane. The AE lesions expanded into the net-shaped to surround the crypt. AEEC left mucous membrane at the infection latter term, and the mucous membrane was repaired. The stx 1 gene (20/83), stx 1 + 2 gene (2/83) and an eaeA gene (9/83) were detected by the PCR method in the intestinal contents of calves with diarrhea, and the rate of the stx 1 genetic possession strain was very high.