Widders P R, Thomas L M, Long K A, Tokhi M A, Panaccio M, Apos E
Australian Quarantine and Inspection Service, Mascot, NSW.
Vet Microbiol. 1998 Nov;64(1):39-50. doi: 10.1016/s0378-1135(98)00251-x.
Poultry consumption has been identified as a major risk factor for human infection with Campylobacter jejuni in developed countries. C. jejuni is present in the gastrointestinal tract of broiler chickens at the time of slaughter, and faecal contamination of carcases during processing results in significant campylobacter loads on carcases. One approach to reducing the level of carcase contamination with C. jejuni is to control campylobacter infection in broiler chickens. To this end, the study described here investigated the specificity of antibody in serum and intestinal secretions of chickens that had been immunised with campylobacter antigens and then challenged with viable bacteria. The immunodominant antigens in the serum of birds that showed a 2-log reduction in caecal colonisation with C. jejuni included flagellin protein (61-63 Kd) and three additional antigens of 67, 73.5 and 77.5 Kd. Only flagellin and the 67 Kd antigen were recognised by IgG antibody in gastrointestinal secretions of the same birds. Antibody from chickens immunised with purified native flagellin protein recognised flagellin protein and the 67 Kd antigen in Western blots probed with serum, but only the flagellin proteins (61-63 Kd) in Westerns probed with gastrointestinal secretions. Analysis of the specificity of the response to flagellin protein using recombinant clones that expressed regions of the flagellin gene suggests that epitopes in each region of the flagellin protein were immunogenic. Of the immunodominant antigens, only flagellin appeared to be surface-exposed on viable C. jejuni, although conformational epitopes of flagellin appeared to be sensitive to the method of antigen purification. The results of this study suggest that flagellin and possibly the 67 Kd antigen may be valuable for immunological control of intestinal infection with C. jejuni in chickens, but that further work is required to purify these as vaccine candidates by using methods that preserve conformational epitopes.
在发达国家，食用家禽已被确定为人类感染空肠弯曲菌的主要风险因素。空肠弯曲菌在肉鸡屠宰时存在于其胃肠道中，加工过程中胴体的粪便污染会导致胴体上有大量弯曲杆菌。降低空肠弯曲菌对胴体污染水平的一种方法是控制肉鸡的弯曲杆菌感染。为此，本文所述研究调查了用弯曲杆菌抗原免疫后再用活菌攻击的鸡血清和肠道分泌物中抗体的特异性。空肠弯曲菌盲肠定植数量减少2个对数级的鸡血清中的免疫显性抗原包括鞭毛蛋白（61 - 63 Kd）以及另外三种分子量分别为67、73.5和77.5 Kd的抗原。在同一只鸡的胃肠道分泌物中，只有鞭毛蛋白和67 Kd抗原能被IgG抗体识别。用纯化的天然鞭毛蛋白免疫的鸡产生的抗体，在用血清进行检测的蛋白质印迹中能识别鞭毛蛋白和67 Kd抗原，但在用胃肠道分泌物进行检测的蛋白质印迹中只能识别鞭毛蛋白（61 - 63 Kd）。使用表达鞭毛蛋白基因区域的重组克隆分析对鞭毛蛋白的反应特异性表明，鞭毛蛋白每个区域的表位都具有免疫原性。在这些免疫显性抗原中，只有鞭毛蛋白似乎暴露于活的空肠弯曲菌表面，不过鞭毛蛋白的构象表位似乎对抗原纯化方法敏感。本研究结果表明，鞭毛蛋白以及可能的67 Kd抗原对于鸡空肠弯曲菌肠道感染的免疫控制可能具有重要价值，但需要进一步开展工作，通过保留构象表位的方法将这些抗原纯化作为候选疫苗。
