Kuehn M, Lent K, Haas J, Hagenzieker J, Cervin M, Smith A L
Division of Infectious Disease, Children's Hospital, Seattle, Washington.
Infect Immun. 1992 May;60(5):2002-7. doi: 10.1128/iai.60.5.2002-2007.1992.
Fimbriae (pili) on the surface of bacteria have been suggested to facilitate adherence to mucosal epithelial surfaces. Three Pseudomonas cepacia cystic fibrosis isolates were screened for their ability to agglutinate erythrocytes (HA), a characteristic of some fimbrial types. One strain, designated PC103, was HA+, while another, PC109, was HA-. A fimbriated (f+) HA+ derivative of PC109 (PC2(13)) was selected by repeated erythrocyte adsorption. The two HA+ strains were shown by transmission electron microscopy to possess fimbriae which averaged 4.8 +/- 1.36 nm in width and 200 to greater than 2,100 nm in length (PCE2(13)) and 3.4 to 11.4 nm in diameter and 280 to 720 nm in length (PC103). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of outer membrane proteins prepared from PC103, PC109, and PCE2(13) indicated that the putative fimbrial subunit had a mass of 16 kDa. Western blot (immunoblot) analysis of sheared cell supernatants indicated that the 16-kDa subunit from PC103 and PCE2(13) reacted with antibody to the P. aeruginosa PAK pilin subunit. Southern blot analysis of a SalI digest of PC103 DNA showed DNA fragments which hybridized to P. aeruginosa PAK probes containing either the pilin structural gene (pilA) or the pilin accessory genes (pilB, -C, and -D) but not the conserved N-terminal region of pilA. A 15-kb band was common to both hybridizations, indicating that this fragment contains the PC103 fimbrial gene cluster. These results indicated the presence of homology between P. aeruginosa PAK and PC103 fimbriae but also suggested that the P. cepacia fimbriae are not type IV-like. The importance of fimbriae in adherence to A549 cells (type II pneumocytes) was assessed with PC109 (f-) and PCE2(13) (f+). PCE2(13) had an approximately 20-fold-higher level of adherence to A549 cells than PC109. This suggested that fimbriation of P. cepacia is associated with increased adherence in vitro.
细菌表面的菌毛（纤毛）被认为有助于黏附到黏膜上皮表面。对三株洋葱伯克霍尔德菌囊性纤维化分离株进行了红细胞凝集能力（血凝，HA）筛选，血凝是某些菌毛类型的一个特征。一株命名为PC103的菌株为血凝阳性（HA+），而另一株PC109为血凝阴性（HA-）。通过反复的红细胞吸附，从PC109中筛选出一株菌毛化（f+）的HA+衍生物（PC2(13)）。透射电子显微镜显示，两株HA+菌株均具有菌毛，PC2(13)菌毛宽度平均为4.8±1.36 nm，长度为200至大于2100 nm，PC103菌毛直径为3.4至11.4 nm，长度为280至720 nm。对PC103、PC109和PC2(13)制备的外膜蛋白进行十二烷基硫酸钠-聚丙烯酰胺凝胶电泳表明，推测的菌毛亚基质量为16 kDa。对剪切后的细胞上清液进行蛋白质免疫印迹（免疫印迹）分析表明，PC103和PC2(13)的16-kDa亚基与抗铜绿假单胞菌PAK菌毛蛋白亚基的抗体发生反应。对PC103 DNA的SalI酶切产物进行Southern印迹分析，结果显示DNA片段与含有菌毛蛋白结构基因（pilA）或菌毛蛋白辅助基因（pilB、-C和-D）的铜绿假单胞菌PAK探针杂交，但不与pilA的保守N端区域杂交。两次杂交均出现一条15-kb的条带，表明该片段包含PC103菌毛基因簇。这些结果表明铜绿假单胞菌PAK菌毛与PC103菌毛之间存在同源性，但也表明洋葱伯克霍尔德菌菌毛不是IV型菌毛。用PC109（f-）和PC2(13)（f+）评估了菌毛在黏附A549细胞（II型肺细胞）中的重要性。PC2(13)对A549细胞的黏附水平比PC109高约20倍。这表明洋葱伯克霍尔德菌的菌毛化与体外黏附增加有关。
