Eshdat Y, Speth V, Jann K
Infect Immun. 1981 Dec;34(3):980-6. doi: 10.1128/iai.34.3.980-986.1981.
Escherichia coli strain 2699 (O6:K13) which had been isolated from a case of urinary tract infection exhibited pili during the stationary phase (24 to 40 h), but not during the exponential phase (4 h), when grown in static broth culture. The bacteria were also piliated when grown for 24 h on agar. They agglutinated Saccharomyces cerevisiae (baker's yeast) in the piliated as well as in the nonpiliated state. The agglutinations were mannose sensitive, i.e., they could be inhibited with 50 mM methyl-alpha-mannoside. The bacteria were first depiliated by shearing and then used for the isolation of outer membrane vesicles with an Omnimixer. Purified pili and outer membranes were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and electron microscopy. The pili could be demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis only after treatment at low pH or in saturated guanidine hydrochloride which is typical of the common type 1 pili. Depiliated bacteria, purified pili, and purified outer membranes gave mannose-sensitive agglutination of S. cerevisiae. The findings are discussed with respect to possible mechanisms of cell agglutination.
从一例尿路感染病例中分离出的大肠杆菌菌株2699（O6:K13），在静置肉汤培养中生长时，在稳定期（24至40小时）会呈现菌毛，但在指数期（4小时）则不会。该细菌在琼脂上生长24小时时也有菌毛。它们在有菌毛和无菌毛状态下均能凝集酿酒酵母（面包酵母）。这些凝集反应对甘露糖敏感，即可以用50 mM的α-甲基甘露糖苷抑制。首先通过剪切使细菌去菌毛，然后用Omnimixer用于分离外膜囊泡。纯化的菌毛和外膜通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳和电子显微镜进行表征。只有在低pH或饱和盐酸胍处理后，菌毛才能通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳显示出来，这是常见的1型菌毛的典型特征。去菌毛细菌、纯化的菌毛和纯化的外膜均能对酿酒酵母产生甘露糖敏感的凝集反应。针对细胞凝集的可能机制对这些发现进行了讨论。
