Ramphal R, Koo L, Ishimoto K S, Totten P A, Lara J C, Lory S
Department of Medicine, University of Florida, Gainesville 32610.
Infect Immun. 1991 Apr;59(4):1307-11. doi: 10.1128/iai.59.4.1307-1311.1991.
Attachment of Pseudomonas aeruginosa to epithelial cells or tracheobronchial mucin is mediated by surface adhesins. Pili, composed of monomeric pilin subunits, make up one such class of adhesins. The formation of pili and flagella in P. aeruginosa is under the control of the alternative sigma factor rpoN. Isogenic mutant strains with insertionally inactivated rpoN genes were constructed with strains PAK, 1244, and CF613 and were tested for their ability to adhere to respiratory mucin. All rpoN mutants showed significant reduction of adherence to mucin relative to that of their wild-type parents. In contrast, the adherence of pilin structural gene mutants was similar to the adherence of wild types. These results provide suggestive evidence that P. aeruginosa also binds to mucin via adhesins that are distinct from pilin and are still under the genetic control of rpoN. Unlike the laboratory strain PAK, the clinical strains 1244 and CF613 are capable of agglutinating erythrocytes. The rpoN mutation had a minimal effect on the interaction of bacteria with erythrocytes, indicating that the transcription of a gene(s) specifying the agglutination phenomenon does not utilize rpoN. These findings collectively indicate the existence of several classes of adhesins on the surface of P. aeruginosa that may play an important role in colonization of the human respiratory tract.
铜绿假单胞菌与上皮细胞或气管支气管粘蛋白的附着是由表面粘附素介导的。菌毛由单体菌毛蛋白亚基组成，是这类粘附素中的一种。铜绿假单胞菌中菌毛和鞭毛的形成受替代sigma因子rpoN的控制。用PAK、1244和CF613菌株构建了rpoN基因插入失活的同基因突变株，并检测了它们粘附呼吸道粘蛋白的能力。所有rpoN突变株相对于其野生型亲本，对粘蛋白的粘附力均显著降低。相比之下，菌毛蛋白结构基因突变株的粘附力与野生型相似。这些结果提供了提示性证据，表明铜绿假单胞菌也通过不同于菌毛蛋白且仍受rpoN基因控制的粘附素与粘蛋白结合。与实验室菌株PAK不同，临床菌株1244和CF613能够凝集红细胞。rpoN突变对细菌与红细胞的相互作用影响最小，表明指定凝集现象的一个或多个基因的转录不利用rpoN。这些发现共同表明，铜绿假单胞菌表面存在几类粘附素，它们可能在人类呼吸道定植中起重要作用。
