Significance of bacterial pili on urinary tract infection and application of anti-pili antibody to the treatment

1.细菌菌毛分布：检测尿路感染(UTI)临床分离株中毛状菌的分布。大肠埃希菌和沙雷氏菌出现的频率较高。铜绿假单胞菌和变形杆菌出现的频率较低。在大肠杆菌和沙雷氏菌中发现了对甘露糖耐药(MR)和甘露糖敏感(MS)菌毛。菌毛基因克隆及菌毛寄主反应：从粘质葡萄球菌临床分离株中克隆出菌毛基因，并通过基因操作技术将菌毛基因转入未去毛的大肠杆菌中。通过使用这些新菌株，MS纤毛细菌而不是MR菌毛刺激了更严重的肾脏疤痕形成。这种疤痕的形成是由超氧化物歧化酶(SOD)预防的。这一发现表明，超氧化物(SO)是由MS菌毛刺激产生的，并破坏了周围的肾组织。UTI的宿主防御机制：多形核白细胞(PMNL)是宿主防御UTI的主要因素。但肾髓质尿中的高渗透压抑制了PMNL的功能。由于高渗透压的主要成分是氯化钠和尿素，因此研究了高浓度的氯化钠和尿素对中性粒细胞功能的影响。它既有能量依赖机制，也有独立机制。

1. Distribution of bacterial pili: Frequency of piliated bacteria in clinical isolates from urinary tract infeciton (UTI) was examined. High frequency was observed in E. coli and Serratia sp. and low frequency was observed in P. aeruginosa and Proteus sp. Mannose resistant (MR) and mannose sensitive (MS) pili was observed in E. coli and Serratia sp.2. Cloning of pili-gene and host response of piliation: Cloned DNA was obtained from clinical isolate of S. marcescens and either MR or MS pili gene was transfered to non-piliated E.coli with gene manipulation technique. By the use of these new strain, MS piliated bacteria rather than MR pili stimulated more severely scar formation of the kidney. This scar formation was prophylacted by superoxide dismutase (SOD). This findings suggested that superoxide (SO) was produced by the stimulation of MS pili, and destructed surrounding renal tissue.3. Host defense mechanism on UTI: Polymorphornuclear leukocytes (PMNL) was main factor of host defense mechanisms against UTI. However, function of PMNL was suppressed by ligh osmolality in the urine of renal medulla. As the main component of high osmolality in them was NaCl and urea, influence of high concentration of NaCl and ures on PMNL function was investigated. Energy dependent and indepent mechanisms were existed in it.