Arshadi Nasim, Mousavi Seyed Latif, Amani Jafar, Nazarian Shahram
Department of Biology, Faculty of Basic Sciences, Shahed University, Tehran, Iran.
Applied Microbiology Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran.
Avicenna J Med Biotechnol. 2020 Jul-Sep;12(3):194-200.
Enterohemorrhagic (EHEC) O157:H7 is a major foodborne pathogen causing severe disease in humans worldwide. Cattle are important reservoirs of O157:H7 and developing a specific immunity in animals would be invaluable. The administration of Whole Cell Vaccines (WCV) is a well-established method of vaccination against bacterial infections. Route of administration, inactivation and using suitable adjuvant have significant effects on the characteristics and efficacy of WCV.
In the present study, an attempt was made to evaluate the immunogenic potency of heat and formalin inactivated cells administered orally and subcutaneously in mouse model by ELISA. Mice pretreated with streptomycin were used as a model to evaluate the efficacy of subcutaneous versus oral administration of the vaccine. Following immunization, mice were infected with O157:H7 and feces were monitored for shedding.
Both forms of inactivated cells induced immune response and hence protection against infectious diseases caused by O157:H7. However, formalin inactivated cells of O157:H7 showed superior antigenicity compared to heat inactivated cells. Subcutaneous immunization of mice with both heat and formalin inactivated O157:H7 induced significant specific levels of IgG antibodies but did not lead to significant antigen-specific IgA rise in feces, whereas oral immunization elicited significant levels of IgG antibodies with some animals developing antigen-specific IgA in feces.
Inactivated O157:H7 is highly immunogenic and can induce protective immune responses via oral immunization.
肠出血性大肠杆菌（EHEC）O157:H7是一种主要的食源性病原体，在全球范围内导致人类严重疾病。牛是O157:H7的重要宿主，在动物中产生特异性免疫将非常有价值。全细胞疫苗（WCV）的接种是一种成熟的预防细菌感染的疫苗接种方法。接种途径、灭活方式和使用合适的佐剂对WCV的特性和效力有显著影响。
在本研究中，试图通过ELISA评估在小鼠模型中口服和皮下接种热灭活和福尔马林灭活细胞的免疫原性效力。用链霉素预处理的小鼠用作评估疫苗皮下接种与口服接种效果的模型。免疫后，小鼠感染O157:H7，并监测粪便中的病菌排出情况。
两种形式的灭活细胞均诱导免疫反应，从而预防由O157:H7引起的传染病。然而，与热灭活细胞相比，O157:H7的福尔马林灭活细胞显示出更高的抗原性。用热灭活和福尔马林灭活的O157:H7对小鼠进行皮下免疫均诱导了显著水平的特异性IgG抗体，但未导致粪便中抗原特异性IgA显著升高，而口服免疫则诱导了显著水平的IgG抗体，一些动物粪便中出现了抗原特异性IgA。
灭活的O157:H7具有高度免疫原性，可通过口服免疫诱导保护性免疫反应。
