Lin Min, Todoric Dobrila, Mallory Maria, Luo B Steven, Trottier Erin, Dan Hanhong
Animal Diseases Research Institute, Ottawa, Ontario, Canada K2H 8P9.
J Med Microbiol. 2006 Mar;55(Pt 3):291-299. doi: 10.1099/jmm.0.46305-0.
Serotype 4b strains of the food-borne pathogen Listeria monocytogenes are responsible for a large portion of sporadic listeric infections and all major food-borne listeriosis outbreaks in humans. Hybridomas were produced from three fusions with lymphocytes of ND4 mice immunized either with the insoluble antigens of L. monocytogenes serotype 4b or with formalin-killed bacterial cells and screened for monoclonal antibodies (mAbs) reactive to L. monocytogenes serotype 4b. A set of 35 mAbs was identified by ELISA as having reactivity with both the insoluble antigen fraction and the whole-cell antigens. Thirteen of these mAbs belonged to immunoglobulin subclass G1 (IgG1), fifteen were IgG2a and seven mAbs were IgM. Only 20 out of the 35 mAbs were capable of detecting protein bands of various sizes ranging from 20 to 88 kDa in Western blots. Two of these mAbs, M2365 and M2367, were capable of binding to cell-surface antigens of live L. monocytogenes serotype 4b, as demonstrated by immunofluorescence microscopy and immunogold transmission electron microscopy. Immunofluorescence microscopy showed that M2365 and M2367 failed to bind to the cell surfaces of Escherichia coli O157 : H7, Salmonella enterica (serotype Typhimurium DT104) or Campylobacter jejuni. Evaluation of the cross-reactions of all 35 mAbs with whole-cell antigens of E. coli O157 : H7, S. Typhimurium, C. jejuni and Listeria innocua by ELISA indicated that the majority of the mAbs, including M2365 and M2367, did not cross-react with E. coli O157 : H7, S. Typhimurium or C. jejuni and showed no or a very weak reaction with L. innocua. Furthermore, M2365 and M2367 showed no reaction with whole-cell antigens derived from L. monocytogenes serotypes 1/2a, 1/2b and 3a, and from Listeria grayi, Listeria ivanovii and Listeria seeligeri, in an ELISA. Collectively, these data suggest that M2365 and M2367 have potential use in the development of immunological methods of laboratory diagnosis for L. monocytogenes serotype 4b in clinical or food samples.
食源性病原体单核细胞增生李斯特菌的4b血清型菌株是人类散发性李斯特菌感染的一大部分原因，也是所有主要食源性李斯特菌病暴发的罪魁祸首。用单核细胞增生李斯特菌4b血清型的不溶性抗原或福尔马林灭活的细菌细胞免疫ND4小鼠，通过三次淋巴细胞融合产生杂交瘤，并筛选对单核细胞增生李斯特菌4b血清型有反应的单克隆抗体（mAb）。通过酶联免疫吸附测定（ELISA）鉴定出一组35种mAb，它们与不溶性抗原组分和全细胞抗原均有反应。这些mAb中，13种属于免疫球蛋白亚类G1（IgG1），15种是IgG2a，7种mAb是IgM。在蛋白质印迹法中，35种mAb中只有20种能够检测到大小从20到88 kDa不等的各种蛋白条带。其中两种mAb，即M2365和M2367，能够结合活的单核细胞增生李斯特菌4b血清型的细胞表面抗原，免疫荧光显微镜和免疫金透射电子显微镜已证实这一点。免疫荧光显微镜显示，M2365和M2367不能结合大肠杆菌O157 : H7、肠炎沙门氏菌（鼠伤寒血清型DT104）或空肠弯曲菌的细胞表面。通过ELISA评估所有35种mAb与大肠杆菌O157 : H7、鼠伤寒沙门氏菌、空肠弯曲菌和无害李斯特菌全细胞抗原的交叉反应，结果表明，包括M2365和M2367在内的大多数mAb与大肠杆菌O157 : H7、鼠伤寒沙门氏菌或空肠弯曲菌无交叉反应，与无害李斯特菌的反应不明显或非常微弱。此外，在ELISA中，M2365和M2367与源自单核细胞增生李斯特菌1/2a、1/2b和3a血清型，以及格氏李斯特菌、伊氏李斯特菌和斯氏李斯特菌的全细胞抗原无反应。总体而言，这些数据表明，M2365和M2367在开发用于临床或食品样品中单核细胞增生李斯特菌4b血清型实验室诊断的免疫学方法方面具有潜在用途。
