de Graaf F K, Wientjes F B, Klaasen-Boor P
Infect Immun. 1980 Jan;27(1):216-21. doi: 10.1128/iai.27.1.216-221.1980.
The production of the K99 antigen by enterotoxigenic Escherichia coli strains with various O antigens was investigated by means of slide agglutination tests, enzyme-linked immunosorbent assays, and hydrophobic interaction chromatography. The extent of K99 production appeared to be dependent on the nutrient medium, as well as on the incubation temperature. Minimal salt medium with glucose and semisynthetic Minca medium were the most suitable for K99 production. In complex media the production of K99 antigen was strongly reduced. Optimal amounts of K99 antigen were produced at 37 degrees C. At 30 degrees C, weak production of K99 antigen was detected by hydrophobic interaction chromatography of enzyme-linked immunosorbent assay. Slide agglutination tests were negative with cultures grown below 32 degrees C. The production of K99 antigen appeared to be related to the O antigen carried by the host strain, but it seemed to be independent of the absence or the presence of various K polysaccharide antigens. Under all conditions used, strains with antigen O101 produced about 10 times more K99 antigen than did strains with antigen O8, O9, or O20. Transfer of the K99 plasmid from wild-type strains of different O antigens to E. coliK-12 C600 confirmed that phenotypic expression of the K99 antigen is most probably related to the cell wall composition of the host.
通过玻片凝集试验、酶联免疫吸附测定和疏水相互作用色谱法，对具有不同O抗原的产肠毒素大肠杆菌菌株产生K99抗原的情况进行了研究。K99的产生程度似乎取决于营养培养基以及培养温度。含葡萄糖的最低盐培养基和半合成明胶培养基最适合K99的产生。在复合培养基中，K99抗原的产生显著减少。在37℃时产生的K99抗原量最佳。在30℃时，通过酶联免疫吸附测定的疏水相互作用色谱法检测到K99抗原产生较弱。对于在32℃以下培养的培养物，玻片凝集试验呈阴性。K99抗原的产生似乎与宿主菌株携带的O抗原有关，但似乎与各种K多糖抗原的有无无关。在所有使用的条件下，具有O101抗原的菌株产生的K99抗原比具有O8、O9或O20抗原的菌株多约10倍。将来自不同O抗原野生型菌株的K99质粒转移至大肠杆菌K-12 C600，证实K99抗原的表型表达很可能与宿主的细胞壁组成有关。
