Stickler D J, Lear J C, Morris N S, Macleod S M, Downer A, Cadd D H, Feast W J
Cardiff School of Biosciences, Cardiff University, Cardiff, Wales, UK.
J Appl Microbiol. 2006 May;100(5):1028-33. doi: 10.1111/j.1365-2672.2006.02840.x.
Infection of the catheterized urinary tract with Proteus mirabilis causes blockage of the catheter by crystalline bacterial biofilms. The aim of this work is to identify a surface-coating for catheters that is not vulnerable to colonization by Pr. mirabilis.
A parallel-plate flow-cell and phase contrast microscopy were used to follow bacterial adhesion onto polymer films. Experiments with a urease-negative mutant of Pr. mirabilis suspended in buffer or urine, identified agarose as a polymer on which biofilm did not form. In tests with wild-type urease-producing cells in urine, no adhesion of cells onto agarose was observed for 3 h but then as the pH rose above 8.2, the surface rapidly became colonized by crystalline biofilm.
In urine at pH below 8.0, Pr. mirabilis does not adhere to agarose-coated surfaces. When the pH rises above 8.2, however, aggregates of crystals and bacteria form in the urine and are deposited on such surfaces.
Strategies to prevent the formation of crystalline biofilms on urinary catheters will need to consider both the properties of the surface-coatings and the requirement to prevent the alkaline conditions that induce crystal formation in urine.
奇异变形杆菌感染导尿管尿路会导致结晶性细菌生物膜阻塞导管。本研究的目的是确定一种不易被奇异变形杆菌定植的导管表面涂层。
使用平行平板流动池和相差显微镜观察细菌在聚合物膜上的黏附情况。用悬浮在缓冲液或尿液中的奇异变形杆菌脲酶阴性突变体进行实验，确定琼脂糖是一种不会形成生物膜的聚合物。在用产脲酶野生型细胞进行的尿液测试中，3小时内未观察到细胞黏附在琼脂糖上，但随着pH值升至8.2以上，表面迅速被结晶性生物膜定植。
在pH值低于8.0的尿液中，奇异变形杆菌不会黏附在琼脂糖涂层表面。然而，当pH值升至8.2以上时，尿液中会形成晶体和细菌聚集体，并沉积在这些表面上。
预防导尿管上结晶性生物膜形成的策略需要同时考虑表面涂层的特性以及防止尿液中诱导晶体形成的碱性条件的要求。
