摘要目的 研究肠出血性大肠杆菌O157:H7基因工程疫苗免疫小鼠后对该菌感染的保护能力.方法 将60只BALB/c小鼠平均分为5组,分别为3种抗原单独免疫、三抗原联合免疫和PBS对照组,用注射方式免疫3次,抗原和佐剂均为每次100μg/只.采集免疫前和各次免疫后7d的小鼠血清检测抗体,末次免疫10d后以109CFU的0157全菌液经口感染小鼠.观察小鼠临床症状及死亡情况,检测粪便与肠道带菌情况,并作病理组织学检测.结果 各抗原免疫组小鼠特异抗体明显增加,感染后各组小鼠均有死亡,IntiminC300、Stx2B、HlyAN436和联合免疫组保护率分别为73%、64%、36%和91%.未病死小鼠粪便排菌情况:对照组22d,实验组为5～14d.肠道带菌情况:对照组阳性率为100%,实验组为25%～83%.病死小鼠肺脏、肝脏均有明显组织病理学改变.结论 Intim-inC300、Stx2B和HlyAN436疫苗对于O157感染具有一定的预防作用,而联合免疫效果又大于单独免疫.

abstractsObjective To investigate immunoprophylactic potential of genetic engineering vaccines of enterohaemorrhagie Escherichia coli O157:H7 in BALB/c mice after immunization with these vaccines. Methods Sixty BALB/c mice (3 weeks old) were randomized averagely into 5 groups. Group 1-3 were im-munized respectively with IntiminC300, Stx2B and HIyAN436, group 4 with a combination of these three vaccines, and group 5 with PBS. Each mouse was immunized with vaccine(100 μg)and Al(OH)3 adjuvant (100 μg) for 3 times. After 7 d of the second and third immunization, serum of each mouse was collected and the different antibodies were detected. After 10 d of the last immunization, all mice were given drinking water containing streptomycin for 3 d before and following oral challenge with O157:H7 (109 CFU), and treated with clinical, microbiological and pathological examination. Results The three vaccines elicited high titer antiserum, and some mice were died after infection with O157. The livability of group 1-4 was re-spectively 73%, 64%, 36% and 91%. And these vaccines depressed fecal and colon shedding with O157. Condusion IntiminC300, Stx2B and HIyAN436 have certain protective efficacy for infection of O157, and combined immunization was more effective than single vaccine.